The World Health Organization (WHO) Regional Office for the Western Pacific in Manila, Philippines, graciously hosted the first Monitoring the AIDS Pandemic (MAP) Network symposium, The Status and Trends of the HIV/AIDS/STD Epidemics in Asia and the Pacific, on 21-23 October 1997, which was an official satellite symposium of the 4th International Congress on AIDS in Asia and the Pacific.
The three-day MAP Network symposium held in Manila was the first symposium formally organized by this new global network formed in December 1996 by the AIDS Control and Prevention (AIDSCAP) Project of Family Health International, the François-Xavier Bagnoud Center for Health and Human Rights of the Harvard School of Public Health and the Joint United Nations Programme on HIV/AIDS (UNAIDS). It was the third in a continuing series of regional and global symposia that have been organized to understand the trajectory of the HIV/AIDS pandemic. Starting with the Status and Trends of the HIV/AIDS Epidemics in Africa Symposium that was held in Kampala, Uganda, in December 1995, a team of internationally recognized technical specialists in epidemiology, modeling, economics, demography, public health and international development was formed to monitor the dynamics of the HIV/AIDS pandemic and various regional epidemics. By collecting, analyzing and disseminating information on HIV/AIDS, this team of experts, which has grown rapidly over the course of two years into a global network, seeks to assist governments, organizations and the world at large to respond more actively and effectively to the challenges posed by the HIV/AIDS pandemic.
The MAP symposium in Manila brought together 40 global and regional experts, including MAP members and some specially invited participants, to achieve the following objectives:
To present and share information on the status and trends of the HIV/AIDS/STD epidemics in Asia and the Pacific and analyze this information in a global context;
To review the epidemiological and behavioral patterns among the HIV/AIDS/STD epidemics affecting the different populations in the region;
To identify specific data needs for monitoring and forecasting the HIV/AIDS/STD epidemics in the region; and
To produce and disseminate a consensus report on the current status of the HIV/AIDS/STD epidemics in Asia and on the current and projected trends for these epidemics in the region.
Because a large percentage of the world's population resides in the Asia-Pacific region, the symposium held in Manila was important in enabling MAP to focus strategically on the evolving HIV/AIDS and sexually transmitted disease (STD) epidemics in the Asian and Pacific countries, fuse current knowledge, identify gaps therein and determine topical and geographical areas for action.
The symposium began by first reviewing the global HIV/AIDS/STD situation to position the various Asia-Pacific epidemics within the worldwide context. From then on, the team concentrated on the situation in the overall region and the Western Pacific and Southeast Asian subregions, presented country-specific epidemic profiles on Australia, China, India, Japan, Malaysia, Myanmar, Philippines, and Vietnam and discussed past, present and potential future issues of relevance.
This provisional report, coauthored by the MAP Manila Symposium participants and produced in some 24 hours, reflects a consensus of the analysis, determinations, projections and recommendations brought forward during the symposium. Its aim is to provide information that can be used by international as well as local bodies to briefly review the most important aspects of the history of the HIV/AIDS epidemics in the Asia-Pacific region to date, recognize the current status of and trends within these epidemics, and take immediate action to affect the course of these epidemics in the future.
With a population in excess of 2.5 billion -- representing more than sixty percent of the world's population -- the Asia-Pacific region has the potential to influence greatly the course and overall impact of the global HIV/AIDS pandemic. This report examines the status and trends of HIV infection and AIDS in countries of Asia and the Pacific, a region which, for the purpose of this analysis, stretches from and includes India on the west, to Japan and island nations in the Pacific, and from China in the north, to countries forming Oceania in the south.
Epidemic patterns
The spread of HIV in this region began in the early to mid-1980s. Early infections could be traced to sexual contacts with infected persons residing outside the region, as well as some apparent further spread within the region itself. By the late 1980s, however, it had become evident that the transmission of HIV was increasing among several populations, in some cases with great velocity, and that two sets of factors strongly influenced the course of the emerging epidemics: participation in sex work and patterns of injecting drug use (IDU).
By early 1997, South and South East Asia accounted for an estimated 5.2 million (23 percent) of the 22.6 million adults and children living with HIV in the world. About one-third of adults living with HIV in the region are female. As the HIV epidemic is still relatively recent, HIV disease, including AIDS, is only beginning to emerge and the associated needs for care are rising steeply. The estimated HIV prevalence in 15 to 49 year-old populations varies from zero (DPR Korea) to one per several thousand in most countries in the region, up to 2 to 3 percent in Cambodia, Myanmar and Thailand.
Figure 3. HIV Trends in Asia and the Pacific - 1997
HIV epidemics in Asia and the Pacific are diverse, localized and have different trends over time (see Figure 1). Against this backdrop, however, it is becoming increasingly clear that the intensity of HIV epidemics associated with sex work, affecting both female sex workers and their clients, is primarily determined by the daily or weekly number of sex partners (clients) per sex worker, the frequency of use of commercial sex by men, and such other factors as the rate of regular condom use in commercial sex and the magnitude and quality of the response to the epidemics. Epidemics associated with injecting drug use have, in many situations, led to explosive outbreaks in the IDU population and then to their sexual partners (e.g., in the late 1980s in Thailand; Myanmar; the Yunnan province of China; and the Manipur state of India, Vietnam and Malaysia). The prevalence of HIV infection in IDUs in these areas reached staggering levels with prevalence reaching 50 to 90 percent within a few months.
Although HIV can spread rapidly among IDUs who share contaminated injection equipment, and then from them to their sexual partners, these epidemics have so far resulted only in limited spread of HIV to the heterosexual population at large. It may be assumed that for a variety of reasons including social isolation of some IDU populations and their sexual partners from other communities, and/or stigmatization to which they are subjected, there are only tenuous bridges between them and other sexually active adults. Strikingly, in Asia and the Pacific, HIV epidemics associated with commercial sex and those involving IDUs do not appear to fuel each other significantly. These epidemics appear to emerge and evolve almost independently from each other, as exemplified by the two concurrent HIV epidemics in Thailand, which were caused by two different subtypes of HIV, with minimum cross-over.
From a regional perspective, the magnitude and short-term trends of HIV epidemics are largely dependent on the extent of ongoing epidemics in a few countries: Cambodia, India, Thailand, Myanmar and, because of their population size, Indonesia and China. With a population close to 1 billion and multiple epidemic foci, India projects the image of a complex epidemic, involving focal outbreaks among injecting drug users and extensive HIV spread among female sex workers and their clients in several regions.
Of increasing concern in the region is the issue of blood safety and HIV transmission. In 1995, WHO/GPA estimated that less than 50 percent of blood transfusions in the region were being routinely screened for HIV. Currently in Bangladesh, virtually no screening for HIV antibodies is performed in the nearly 200,000 units of blood transfused annually. In India and Myanmar, screening of donor blood for HIV remains far from complete and measures are being taken through improved donor selection to address this issue.
Mapping the epidemics
If the HIV epidemics were analyzed on a country-by-country basis, as if HIV epidemics respected national geopolitical boundaries, most countries in the Asian-Pacific region project the reassuring image of low prevalence (proportion of adults living with HIV/AIDS) and low incidence (proportion of adults newly infected each year). Such is the case of Australia and New Zealand which, early in the epidemic, experienced sudden epidemics in men having sex with men (MSM) with a peak of incidence in the mid-1980s, followed by a rapid decline. The spread among IDUs in these two countries has been and remains limited (less than 2 percent), and heterosexual transmission remains at low levels (the prevalence of HIV among pregnant women is lower than 1 per 10,000).
Such is the case as well for Japan, where an initial dramatic outbreak of HIV infection among people with haemophilia was brought under control in the mid-1980s (see Box 1), and where other modes of transmission are only contributing minimally to a limited HIV burden in the country (less than 1 HIV-infected person per 10,000 adults in 1997). Also reassuring would be the situation in China where, in spite of increasing trends in HIV incidence in IDUs in selected southern provinces (Yunnan, Guanxi), the overall national rate of HIV prevalence in adults in this large country remains below 4/10,000 -- one tenth to one-fifth the prevalence found in Western Europe and in North America, and the spread of HIV from IDUs to their sexual partners accounts for most of the heterosexually acquired HIV infections.
Box 1 The Lingering Effect of a Controlled HIV Epidemic: HIV infection from blood coagulation products in Japan
As of the end of August 1997, the cumulative reported number of AIDS cases in Japan was 1,657, which was still very low in Asia comparatively, even among developed countries. A little less than half of the cases (41.6 percent) are, however, those infected through blood coagulation factor products. This high percentage of hemophilia cases is still the distinctive characteristic of HIV infection in Japan and not seen in other countries in the world.
These infections resulted from transfusion of infected blood products in the early 1980s. In July 1985, the Japanese Ministry of Health and Welfare approved the usage of heat-treated blood coagulation factor products. Since the introduction of these heat-treated products, virtually no HIV infection has occurred through infected blood products. The epidemic of HIV in this population is now reflected in an increasing number of people developing AIDS and dying from the disease each year.
Almost all those infected from blood products are hemophiliacs type A or B, and the rest are related coagulopathy, such as von Willebrand disease and few cases of administrated coagulation factor for the prevention of excessive bleeding. An estimated 35 to 40 percent of hemophiliacs in Japan are infected with HIV.
Cases from blood products show a tendency to have a longer incubation period than the cases via other routes of infection. Most of these cases, however, will have the onset of AIDS in the near future. Consequently, every prefectural government in Japan is now preparing base hospitals for the treatment of AIDS. As of the end of May 1997, almost 1,300 people infected through blood products were living in Japan, accounting for 32.4 percent of the total population living with HIV in the country.
Less reassuring would be the estimated and projected trends in India. There, a sharp increase in the estimated number of HIV infections from a few thousand in the early 1990s to a cumulative minimum of 2.5 million in 1997, in a context of a severe gap of knowledge about prevailing risk-taking sexual behaviors, creates great uncertainty about the future course and impact of the epidemics. Yet, the 1997 national prevalence of HIV infection in adults may be between 0.2 to 0.5 percent which, on first analysis, would not place India high on the world list of "hardest hit" countries where prevalence rates may range from 10 to 25 percent.
HIV prevalence among sex workers in India varies widely from state to state, with high HIV prevalence in western and southern India to low levels of HIV in eastern and northern India. HIV prevalence among sex workers tested in Mumbai (formerly Bombay) rose from 1 to 51 percent between 1987 and 1993. Prevalence among sex workers in Calcutta was consistently low at about one percent until 1994, but there are indications that it might be rising. In Mumbai, HIV prevalence increased from two to three percent in STD clinic attendees before 1990 to 36 percent in 1994. Among antenatal clinic attendees tested in Mumbai, two percent tested positive for HIV in 1995 and around 5 percent in 1996. In Manipur, rates of HIV infection among the antenatal clinic attendees are rising.
In some countries, HIV prevalence has remained very low (less than 0.1 percent in the 15- to 49-year-old population. In the Philippines, AIDS case reporting has slowly increased to a total of 958 reported as of September 1997. HIV surveillance has found only a few cases of HIV infection among female sex workers, male STD clinic patients and men who have sex with men. Similarly, a small number of AIDS cases and low levels of HIV infection have been reported from Indonesia.
When examined through the lens of current national HIV prevalence and incidence rates, most other countries in Asia and the Pacific would conform to a pattern of low prevalence and slow HIV spread (see Figure 2).
Large-scale epidemics ahead?
Are HIV epidemics likely to expand abruptly in India, or in other countries in Asia and the Pacific? To answer this question, possible clues can be drawn from past history in several countries, including Thailand, Myanmar and Cambodia. In Thailand, information was available on IDU needle sharing practices and sex work in the country when, in the mid-1980s, HIV had not begun to spread in epidemic form. The epidemics that were predicted but insufficiently prevented did occur later in this decade, infecting an estimated 800,000 women, men and newborns by 1997. Prevalence rates in pregnant women reached 2 to 3 percent in 1995 nationwide, while rates in army recruits rose to around 4 percent in 1993, then levelled off and began to decline. In Myanmar, rates of HIV infection in IDUs, sex workers and pregnant women are similar to those found in Thailand. Consistent with an East-West gradient of HIV prevalence in Myanmar, the epicenter of the epidemics appears to lie east of the country. The analysis of geographical differentials in HIV infection rates and trends over time underscores both the deepening severity of the epidemics and the potential for national, aggregate data to mask important sub-national epidemic trends. In Cambodia, HIV spread rapidly in the early 1990s, reaching high levels in sex workers (about 40 percent HIV prevalence) and from 2 to 3 percent of the 15- to 49-year-old population (see Box 2). The evolution of the epidemic in Cambodia country illustrates the potential for HIV to spread rapidly and widely when patterns of commercial sex involve high mobility, a high sexual partner exchange rate and low condom use.
The Kingdom of Cambodia has seen a rapid increase in HIV infection over the past few years, giving it the likely dubious distinction of the most widespread and serious HIV epidemic in Asia. Although only about 600 AIDS cases had been reported by mid-1997, the epidemic has progressed so quickly that it is now estimated that approximately 100,000 individuals are infected with HIV. Although substantial variations exist regionally, national rates derived from 1997 serologic surveillance results indicate that approximately 40 percent of sex workers, 6 percent of police/military, and 3 percent of antenatal women are HIV-infected.
Other sexually transmitted diseases are likewise high in Cambodia, contributing to HIV spread in the country. A 1996 survey in selected cities indicated prevalence rates of gonorrhoea of 12 to 31 percent among sex workers and 2 to 6 percent among antenatal women. Similarly, syphilis rates were 4 to 24 percent in sex workers, 0 to 12 percent among police and the military, and 2 to 8 percent among antenatal women.
Despite the widespread HIV epidemic in Cambodia, there are some recent HIV prevention sucesses which may promote a slowdown. A condom social marketing program by Population Services International reports condom sales increasing from about 5 million in 1995 to 9.5 million in 1996. Behavioral surveys confirm that many of these condoms are being used for commercial sex. Men frequent sex workers in high proportions in Cambodia (about 75 percent of military/police and 37 percent of students report visiting a sex worker in the past year), but condom use has substantially increased over the past few years. However, given the state of the Cambodia's political and economic situation, these successes are fragile and continued concentration and strengthening to maintain and increase behavioral changes will be required.
Empirical evidence thus exists showing that sudden and sharp increases in HIV incidence can and have occurred in Asia. However, the lack of quantitative and qualitative epidemiological, behavioral and social information on the nature of and linkages between sexual networks in any of these countries rules out any reliable prediction of the future course of HIV epidemics in countries that would intuitively appear vulnerable to rapid spread. These countries include, in particular, Malaysia, Nepal and Vietnam, where rapid increases of HIV incidence in various vulnerable populations are being noted. There is an urgent need to collect and analyze systematically the information needed for the dual purpose of projecting epidemic trends and targeting prevention toward factors that seem to influence the vulnerability of the population to the further -- and possibly rapid -- spread of HIV.
Populations of affinity
The analysis of HIV epidemic trends in the region becomes more meaningful when a focus is placed on populations whose cultural and social affinity and networks transcend geopolitical borders. A new geography of HIV/AIDS in the region then emerges that helps recognize the foci of intense HIV spread. (See the map, Figure 3.) These include large metropolitan areas in western and southern India (Mumbai, Tamilnadu) (see Box 3); the India/Nepal border area; the larger "Golden Triangle," which reaches out to Northern Thailand, eastern Myanmar, but also encompasses the areas of Manipur in India and Yunnan in China; and the Mekong delta area, which includes Cambodia and southern Vietnam. To gain better understanding of the dynamics of HIV epidemics, factors of affinity between populations as well as mobility patterns must be explored and mapped.
With more HIV infections than any other country in the world, India gives the impression that HIV infection is common and that there is a severe epidemic in the country. However, the estimated 2.5 million HIV infections should be considered in the context of the close to 970 million population of India. The prevalence of HIV is about 0.3 percent, a rate much lower than many other countries in the Asia-Pacific region.
In India, HIV infection is not evenly distributed throughout the country. While it is true that HIV has now been reported from all except one of the 32 states and Union Territories, the infection is actually highly localized.
As the pie chart shows, almost half the total 4,828 cases of AIDS reported so far are from the state of Maharashtra, and of these 80 percent are from Mumbai city. The state of Tamilnadu contributes another 22 percent. It is worth noting that 21 of the 32 states add only 4 percent of the total AIDS cases reported. The state of Manipur, which contributes 6 percent to the total, reports that all the cases of AIDS recorded so far are in IDUs. There are an estimated 25,000 IDUs in the state, which borders on the "Golden Triangle," and at last estimate the HIV prevalence in this group varied from about 50 to a staggering 80 percent.
Another group showing high HIV prevalence is that of long-distance truck drivers and their helpers. It has been shown that this group has a steadily increasing prevalence. In Chennai (Madras) a seroprevalence of close to 10 percent has been reported.
These data bring out the fact that it is often misleading to consider a country as a homogenous entity as far as HIV/AIDS is concerned. Many countries have more than one epidemic, often at different stages of development and in different communities and regions. An appreciation of this fact is important in planning suitable interventions.
The potential for continued spread of HIV/AIDS in Asia and the Pacific is real and requires determined and sustained prevention efforts. Several countries have already experienced intense HIV epidemics in certain population groups or, in some cases, in the population at large. In these countries, including India, Thailand, Myanmar and Cambodia, the individual impact of HIV has begun to be felt as AIDS has imposed new demands on the health care systems. It is essential that countries reinforce their prevention and care efforts in order to enhance their response to the existing HIV/AIDS challenge. In addition, countries should make every effort to collect and analyze the information needed to assess and monitor the evolving potential for large-scale HIV epidemics.
Recognizing the threat of emerging or fast-growing epidemics in certain populations is essential to an early and effective response. Acknowledging the possibility that, in other populations, rapid and extensive spread of HIV may not occur is equally crucial as policy and decision makers may, on the basis of this information, orient efforts and resources towards people who are most at risk.
Figure 1. HIV Penetration into Asian and the Pacific Countries
Countries with epidemic spread
Current HIV Epidemic Trends
Main Populations Affected
Projected HIV Epidemic Trends
.
HIV incidence
HIV prevalence
.
(3-5 Years)
Australia
Low and decreasing
Low and stable
MSM
Decline
Cambodia
High and increasing rapidly
High and increasing
Individuals with high and moderate risk heterosexual behavior
Sustained upward trend
China
Low except in Yunnan
Low and increasing
IDU
Increasing
India
Moderate and increasing(significant regional variation)
Still low but increasing(significant regional variation)
Individuals with high-risk heterosexual behavior and IDUs
Increasing
Malaysia
Moderate and increasing
Low and increasing
Principally IDUs but increasing among individuals with high risk sexual behavior
Increasing
Myanmar
High and increasing
High and increasing
Individuals with high-risk heterosexual behavior, IDUs and their spouses
Increasing
New Zealand
Low and decreasing
Low and stable
MSM and IDU
Decline
Papua New Guinea
Moderate and increasing
Low but increasing
Individuals with high-risk heterosexual behavior
Slowly increasing
Thailand
Moderate and stabilising in specific groups
High but stabilizing
IDUs and individuals with high and moderate risk heterosexual behavior
Tending to stabilize
Vietnam
Moderate and increasing
Still low but increazing
Principally IDUs but increasing among individuals with high risk sexual behavior
Increasing
Countries with low transmission
Current HIV Epidemic Trends
Main Populations Affected
Projected HIV Epidemic Trends
.
HIV incidence
HIV prevalence
.
(3-5 Years)
Bangladesh
Low
Low
Individuals with high-risk heterosexual behavior
Slowly increasing
Indonesia
Low
Low
MSM, Bisexual and high-risk heterosexual behaviour
Slowly increasing
Japan
Low
Low
Previously blood product related, currently sexual
Slowly increasing
Hong Kong
Low
Low
MSM
Slowly increasing
Nepal
Low except in IDUs
Low except in IDUs
Individuals with high-risk heterosexual behavior and IDUs
Slowly increasing
Philippines
Low
Low
Individuals with high-risk heterosexual behavior
Slowly increasing
Singapore
Low
Low
MSM, IDUs
Slowly increasing
Sri Lanka
Low
Low
Individuals with high-risk heterosexual behavior and MSM
Slowly increasing
Figure 2. HIV Distribution Among Selected Asian And Pacific Populations
The following countries in the region have minimal spread of HIV infection: Bhutan, Brunei, DPR Korea, Macao, Mongolia, Pacific Island countries and areas, Republic of Korea.
There are three factors that appear to play a crucial role in HIV transmission in the Asia and Pacific region: female sex work, substance use and mobility. Female sex workers and their clients have been a major factor in the heterosexual transmission of HIV in Thailand, Cambodia and parts of India and Myanmar. Separate but explosive epidemics have been seen in some IDU populations in Thailand, Myanmar, Manipur (India), and Malaysia. And mobile populations, particularly at national borders, are at higher risk of HIV acquisition due to the fact of being away from home and community, and the anonymity and loneliness of traveling. The following three sections focus on monitoring the HIV epidemics in these vulnerable populations.
Female sex workers operate in all countries in the region, but it is important to know how large the sex-worker population may be to adequately interpret surveillance results. It is believed that in some countries, rapid increases in the number of sex workers have resulted from significant political, social or economic changes.
The number of female sex workers in countries can range from a few thousand to a few hundred thousand. Thailand, for example, has approximately 80,000 to 100,000 female sex workers -- an estimate that only recently has gained consensus. In most countries, however, validated estimates of the numbers of sex workers are almost non-existent. Without such numbers, interpretation of surveillance results, policy commitment, planning, intervention designing, and resource allocation are extremely difficult (see Box 4).
Most estimates of the numbers of female sex workers are either restricted to a subset of licensed commercial sex establishments or ad hoc unvalidated "guesstimates." In Dhaka, Bangladesh, estimates of the number of sex workers frequently quoted range from 3,000 to 100,000. It is impossible to anticipate the scale of services and funds and nature of interventions needed without more meaningful numbers.
One promising direct estimation method being used in Thailand, Laos, Nepal and Taiwan developed by the Thai Red Cross and the East-West Center is the method of comprehensive geographic mapping of sex work sites and types. In Thailand, this method has now been adopted by the Ministry of Public Health for their annual survey of sex work. In several areas, the method has detected up to 50 percent more sites than estimates by using the conventional method of referral by STD patients. In other countries, population estimates have been generated through innovative applications of capture-recapture techniques. In Dhaka, CARE/Bangladesh recruited and trained sex workers to assist in "capturing" street sex workers throughout the city by handing out different colored cards for 24 hours on two different days within a fortnight.
All estimates need regular updating and validation but these two approaches are worthy of replication in other settings. Neither method can work without the trust and involvement of sex workers themselves.
Diversity
The nature of sex work and the profile of sex workers vary enormously within and between countries. There are female and male sex workers, and those that work full-time, part-time or seasonally. Sex workers may operate in a variety of settings such as brothels, bars, massage parlors, street corners, restaurants, etc. Sex workers operating in government-registered establishments exist in a few countries such as the Philippines, in contrast to the freelance sex workers in most countries of this region. There are also commercial sex areas that are highly organized, such as in Indonesia, as opposed to those with bonded or sex workers imprisoned in underground settings. There are women in brothels who cannot refuse sex with customers and those in massage parlours or bars who have more freedom of decision.
For surveillance purposes, sex work can be characterized by work conditions, methods of recruitment, number of clients per week, price, how clients are contacted, where sex takes place, types of clients, existence of employers or agents. Despite these diversities, some types of sex workers are more visible and/or more easily brought to the attention of government or public health officials. These are usually the sex workers who are the subjects of epidemiological studies presented without acknowledging the fact that they represent only a subset of all sex workers. Without a clear understanding of these diversities, effective surveillance cannot be designed or implemented.
Sex workers and HIV
Frequency of exposure to HIV infection through sexual intercourse is the key factor for transmission of HIV among sex workers. In many countries, a significant proportion of sex workers is infected with HIV. The rates might vary from less than 1 percent to 40 percent or higher in some settings (see Table 1).
Even where HIV infection has not yet spread extensively, STD infection is often very high among sex workers. For example, in one brothel area in Bangladesh, 95 percent of 466 sex workers tested positive to antibodies for genital herpes virus and 60 percent for syphilis, although HIV was not detected among any of them. With the progression of the epidemic, HIV tends to increase where other STDs are present.
HIV, STD, and behavioral surveillance
Systematic, continuous and quality sentinel surveillance of HIV and STD will provide not only the indications of an emerging epidemic but its progress over time as well. This will benefit policy formulation, planning and resource allocation. For sex workers, confidentiality, community participation and protection against stigmatization should be integral components of surveillance activities. STD services should also be provided as part of the surveillance package. However, if serosurveillance is to be used for monitoring success of intervention programs, it must be accompanied with behavioral surveillance (see Section 4.2) because HIV prevalence may not decline for several years despite successful interventions. Behavioral surveillance results can also be used to direct the detailed design of prevention activities with special emphasis on specific sub-groups within sex worker populations.
Table 1. HIV prevalence among various sex worker populations in Asia
Study group
HIV prevalence
Thailand, sentinel sites in all provinces, brothel-based and "indirect" female sex workers, 1996
18.8 %
Cambodia, 2,906 female sex workers, various sites throughout the country, 1996
40%
Myanmar, NAP sentinel survey of 2 sites, sample (n=200), 1996
25%
Philippines, 6,084 registered female sex workers, 10 cities, 2 rounds of testing, 1996
0.13%
Vietnam, 8,178 female sex workers in 20 provinces, 1996 (median rate)
0.5%
Laos, 216 male and female bar workers in one town, 1995
0%
Indonesia, national seroprevalence study of high-risk groups, 12, 418 registered prostitutes, 1991-2
0.02%
Singapore, 738 brothel-based female sex workers, 1992
0%
Improving surveillance of HIV/AIDS among sex workers
There is no doubt that commercial sex played or is playing a crucial role in the heterosexual transmission dynamic in Thailand, Cambodia, Myanmar and large parts of India. It remains to be seen whether similar experiences will be repeated in countries which at present have little evidence of extensive HIV infection among sex workers. The following are issues and suggested recommendations based on these observations in the region:
Surveillance of sex workers can place an emphasis on sex workers as the "cause" of an HIV epidemic and can, therefore, result in a backlash producing greater discrimination and more support for prohibitive policies leading to an increase in the vulnerability of this population to HIV. Thus, surveillance should be accompanied by clear policies on non-discrimination and supportive prevention interventions.
In many areas of Asia, the high prevalence of HIV detected from surveillance activities has not been translated into resources for programs targeting this group. Even when resources are allocated, funding is often not utilized or restricted to awareness programs that do not necessarily change behavior.
Future efforts in surveillance should attempt to document the distribution and characteristics of female and male sex workers. Such information would lead to a recognition of the biases inherent in the continued use of "captured" groups of sex workers for epidemiological and behavioral surveillance. It would also permit a more meaningful measurement of the variations of condom use and the rates of partner exchange between and within types of sex work.
Better estimates of the numbers of sex workers are also needed. These should also take into account the types of sex work and the diverse settings that influence the negotiating power of sex workers for condom use. Current estimates using geographic, capture-recapture or ad hoc approaches need to be validated.
Focalized surveillance, if possible, is likely to be more useful for intervention design and to permit a more careful analysis of the behaviors and sexual networks of sex workers so that more informed decision-making regarding interventions can occur.
More attention is also needed on the types of indicators to be measured in the behavioral surveillance of sex workers and potential male clients as well as other methodological issues such as reducing selection bias and increasing the truthfulness of responses.
3.2 Substance Use: Patterns and Impact on HIV Transmission
There are many aspects to the nexus of drug use and HIV infection, but globally and in Asia, the direct contribution of HIV transmission by the reuse of contaminated injecting equipment among people injecting illicit drugs, and the indirect contribution of sexual and vertical transmission from this core group far outweigh other aspects. In most of Asia, people who choose to use drugs that are not socially sanctioned are treated as entirely outside society, enemies even of the social structure. What does this mean for HIV/AIDS and drug use? For the majority of injecting drug users (IDUs), it means that lip-service is paid to the principles supposedly learned through the course of the epidemic: in relation to IDUs and the risks of HIV transmission, issues such as human rights, peer education, community participation, and legal and social change are unachievable fictions.
Patterns
Patterns of use of illicit drugs are becoming globalized and "standardized". What were fairly simple equations have largely gone, to be replaced by complex global production and distribution networks, diversified marketing, new and emerging markets - a highly dynamic and thriving scene. Drug control efforts are almost always not one pace, but two, three or even more behind the market. Racism and colonialism continue to be fundamental determing aspects of the global drug trade, both licit and illicit, as they have been for centuries.
Amphetamines are flooding into Thailand and beyond from China and Myanmar. Developing countries are all becoming major illicit drug consumers. New producers are springing up -- Opium production has started again within the borders of China and in Afghanistan opium production has risen rapidly to hold second rank globally among illicit opium producers. The transition from little use of a certain drug in a particular community, to its widespread availability and use orally or nasally, and then to its injection -- followed by epidemics of HIV -- can be extremely rapid, as is exemplified by recent history. This pattern has been so common and so predictable that we must recognize it as the norm, even if we do not fully understand the dynamics of the process. Shifts from smoking or inhaling opium to injecting heroin as a result of "crackdowns", increasing price or decreasing purity of available drug have been seen in many countries. Furthermore, cocaine injecting, if it becomes prevalent in the region, is problematic because of the greater frequency of injecting and the increased social and personal disorganization of the user. This places a further barrier in the way of achieving safer injecting behavior.
We must also recognize the role misguided attempts to control drug use have played in accelerating these processes. The rise in heroin use in India, Thailand, Hong Kong and Laos all date from the institution of anti-opium laws. Prisons in some ways are exemplars of the impact of current policies at national levels: even where there has been successful behavior change in the community, this has not happened in prisons.
Impact on HIV transmitted through injections
The diffusion of HIV among IDUs in South East Asia has been well described. Epidemics that can literally be called explosive have been documented among IDUs in Thailand, Myanmar, Malaysia, Vietnam and China, with prevalences reaching 60 to 90 percent within a few months of the appearance of the first case, and often forming epicenters for wider diffusion of the HIV epidemic. Prevalences of 60 percent or more have been described among young IDUs within their first two years of injecting. Several communities in Asia have now had HIV among IDUs for so long that they are now in the grip of multiple ongoing epidemics: of drug use and its consequences, injecting drug use, resulting HIV infection among IDUs, their sexual partners and their children, AIDS and tuberculosis. The tragedy is that these epidemics are totally predictable and preventable, and we know exactly how to prevent them. The scientific evidence on this point is unassailable (see Box 5).
There are certain places in Asia that now have uncontrolled epidemics of HIV infection that began as explosive epidemics among IDUs, taking the community from one with no HIV infection to one with a large pool of sexually active infected people in a matter of months. These include epidemics that could have been prevented by timely and relatively inexpensive interventions at an early stage, if, and only if, the conceptual leap had been taken that people who inject drugs are human and worth caring about.
Education and advocacy is needed on a much larger scale to influence those authorities concerned nationally and internationally with drug control and drug demand reduction. Efforts should be made to involve them more as partners in prevention of HIV among IDUs, building on the memorandum of understanding between UNAIDS and the United Nations Drug Control Program (UNDCP), for instance, at program level, and empowering and assisting NGOs and communities to advocate and influence national policy and the practices of public security and police.
Globally, there are relatively few programs and very few countries that have as a prime concern the prevention of HIV infection among IDUs. There are far more programs and policies that are oriented toward drug demand reduction, with the prevention of HIV among drug users or in association with drug use tacked on as a subsidiary aim.
Direction for Enhanced Surveillance and Monitoring in IDUs
Most of the information about HIV risk among IDUs comes from captive treatment or incarcerated populations, which are often not representative of the wider community of drug users. Increased investigation of risks and HIV dynamics in these so-called -- hidden populations -- is necessary. A detailed understanding of transmission from core groups of IDUs to their sexual partners and children is urgently needed in Asia to demonstrate the central role IDUs can play in national epidemics and to increase the justification for early and intense action.
In addition, better enumeration or estimation of populations at risk (i.e., those currently injecting drugs, or sex partners of IDUs) and populations coming to be at risk, and a better understanding of the dynamics of drug consumption and social organization of drug use are all necessary for targeting interventions effectively.
Incidence data, in particular, are also necessary from a range of sources to counter the potential for misunderstandings about the interpretation of available prevalence data. Potential sources for incidence data may include drug rehabilitation centers and prisons where recidivism is high and testing is mandatory (as in many Asian countries). While simple conceptually, obtaining these data may be difficult since it may require substantial negotiations with the appropriate authorities.
Finally, a process for categorization and analysis of laws relating to drug use, country by country, and their impact (potential or real) on both drug use and HIV transmission among IDUs is necessary to develop appropriate interventions. Prevention programs should be specifically aimed at reducing transmission of HIV among IDUs based on comprehensive HIV prevention and care programs for injection drug users principles. Evidence-based interventions should be the focal point to prevent HIV transmission among IDUs in Asia. In evaluating programs for their effect in decreasing HIV transmission, there is an absolute need for epidemiologically sound outcomes, especially incidence data, and a need for appropriate analysis of the factors underlying trends in risks or transmission.
Box 5 The Need for Comprehensive HIV Prevention and Care Programs for Injection Drug Users
The principles of comprehensive HIV prevention and care programs for injection drug users are increasingly being applied to stem the emerging epidemic of HIV among injecting drug users in Asia and the Pacific, through a range of different programs including:
needle and syringe exchange programs (NSEPs)
methadone maintenance therapy
sale of clean injecting equipment through pharmacies and other outlets
peer support and outreach programs.
Of these, NSEPs are becoming accepted as an important, relatively inexpensive tool to prevent the spread of HIV among injecting drug users, and there is a growing body of evidence to support their effectiveness. For example, a 1993 review by the Institute for Health Policy Studies in the U.S. showed NSEPs were associated with decreases in sharing of injecting equipment. Recently, an ecological association was demonstrated between the presence of NSEPs in a city and a flat or declining trend in HIV seroprevalence among IDUs as compared with increasing trends for cities without NSEPs.
Although NSEPs have been available since the late 1980s in countries such as Australia and Canada, their introduction to users in Asia has occurred more recently. Asian examples include, among others, the programs run by the Lifesaving and Lifegiving Society in Khatmandu, Nepal, and the Shalom Project in Manipur in northern India. NSEPs in and of themselves do not guarantee reduced incidence, since for this to happen, the need for sharing injecting equipment must be eliminated or substantially reduced.
In some cities in Canada, for example, the prevalence of HIV remained stable in IDUs following the introduction of NSEPs in the late 1980s, but prevalence rates recently have risen dramatically. Reasons for this are unclear, but probably include a shift in the pattern of drug use from heroin injection to cocaine-injecting together with limitations ofof service provision at NSEP sites. This shows that NSEPs must do more than just provide clean injecting equipment; they must provide IDUs with access to the other elements of comprehensive HIV prevention and care programs for injection drug users such as peer counseling and education, provision of condoms and safe sex information, social support, and referral to medical care and/or drug treatment services (i.e., methadone maintenance). Indeed, it is not so much the NSEP itself that can prevent HIV infection amongst IDUs, but the supportive legal and social environment in which NSEPs can exist and flourish. The creation of this environment is an integral part of the development of a comprehensive HIV prevention and care programs for injection drug users approach and it requires one major conceptual step -- admission of IDUs to the human race.
3.3 Mobility, HIV and the Clustering of the HIV Epidemic in Asia
Population Mobility in Asia
Populations in Asia are moving across land and sea borders in increasing numbers. International trade and commerce supports this growth in population mobility, which is also facilitated by the growing number of international highways and construction of new bridges. As in Africa, truckers on international land routes move vast quantities of goods between mainland countries. For example, at one international border between India and Nepal, more than 3,000 trucks cross daily. Also occurring in Asia are high levels of maritime trade, and seamen on fishing vessels travel widely in the region, enabling the transmission of HIV to populations in areas where the virus was formerly unknown.
State of Knowledge
In Africa, mobility has been demonstrated to be an independent risk factor for the spread of HIV. Therefore, extremely mobile population groups such as travelers, fishermen, traders and migrant workers tend to have high HIV prevalence. In Asia, evidence exists showing a similar association between population mobility and vulnerability to HIV. Prevalence of HIV among travelers and fishermen in Thailand and India is higher than in the general population, approximating rates found in male STD patients.
The fact of being away from home, family and community, and the anonymity and loneliness of traveling are factors that increase vulnerability to HIV acquisition. Since opportunities for casual sex may occur frequently en route, itinerant people may adopt high-risk behavior that otherwise might not occur. Current evidence indicates that the environment in well-traveled border crossing areas and international fishing ports in several Asian countries fosters more risk-taking behavior than in other trade towns.
Crossing land or sea borders often requires overnight stays, leaving the individual with idle time and opportunities to visit drinking and gambling establishments and brothels. HIV surveillance data for female sex workers, male STD clinic patients and young males in four countries in the region -- Thailand, Myanmar, Cambodia and Vietnam -- show a clustering of high prevalence sites around international borders and ports (see Figure 4). The map included in the accompanying box shows the distribution of higher and lower HIV prevalence by sentinel site, with clustering of HIV infection along the Thai-Myanmar, Thai-Cambodia, Cambodia-Vietnam and Vietnam-China borders.
Opportunities for Prevention
HIV prevention interventions targeted to border crossing areas could take advantage of the idle time of travelers waiting for border clearance. Such interventions could include those focused on behavior change, provision of sexually transmitted infection (STI) services and access to affordable condoms. Structural interventions, including advocating for policy change to improve the process of border crossing and shorten the waiting time, might help reduce opportunities for high risk-behavior.
Recent cross-border interventions have documented that their effectiveness relies on their service provision on both sides of the border. Those that involve communities passing through and residing at border sites as well as NGOs/PVOs with the ability to work transnationally supported by local governments offer more opportunities for success. Private sector businesses and institutions, such as transport and shipping companies as well as corporations, have a vested interest in ensuring safer environments for their labor force passing through or residing in cross-border areas and offer the potential for collaboration and resource support.
The behavioral and epidemiological patterns found among mobile populations in cross-border areas are poorly known. Investigative study, including ethnographic research, is needed to provide better understanding of the risk environments populations encounter as they pass through or reside in these areas. Border crossings in Indochina and South Asia require urgent prevention and care interventions.
Interventions to reduce the vulnerability of populations traversing cross-border areas are urgently needed because mobile groups can serve as "bridges" between high-risk and low-risk populations, thereby creating the potential for a widespread diffusion of HIV. Well-traveled border towns and ports are also gateways and catchment areas for many different types of travelers passing through them and are, therefore, appropriate and convenient sites for intervention.
Methods for the monitoring of the HIV/AIDS pandemic in the Asia-Pacific region are, in general, no different from methods used in other regions. However, a diversity of HIV epidemics in this region requires adapting HIV/AIDS surveillance methods to measure Asian Pacific HIV/AIDS/STD patterns and prevalence levels. The following sections describe HIV sentinel, behavioral and STD surveillance in the Asia-Pacific region. In addition, the uses and limitations of HIV/AIDS modeling for forecasting and scenario development in this region are described.
4.1 Epidemiological Surveillance for HIV/AIDS and STDs
The evolution of surveillance methods
The HIV epidemic first appeared as a range of opportunistic infections and other diseases defining AIDS, and the counting of new AIDS diagnoses became a central component of HIV/AIDS surveillance systems. However, there were several important limitations. First, AIDS counts provided little information about current patterns of HIV transmission because they represented infections acquired years in the past. Second, AIDS diagnosis required clinical and laboratory expertise that was absent in many countries, particularly those of the developing world. Third, AIDS counting suffered from the limitation that health care workers did not accord a high priority to the passive reporting of cases. On the other hand, AIDS reporting did have the potential to graphically demonstrate the impact of HIV infection in terms of advanced illness, even if it was restricted in most countries to the first episode of illness that satisfied the AIDS case definition.
The advent of the HIV antibody test in 1985 opened up the possibility of directly measuring the prevalence or incidence of infection in populations. Countries of the Asia-Pacific region came up with a variety of approaches to monitoring HIV prevalence. Some countries relied on routine voluntary HIV testing as a means of monitoring prevalence while other countries established comprehensive systems that involved sampling a wide range of population groups at regular intervals. In a third group of countries, prevalence was measured through occasional surveys that were implemented as resources and necessity dictatated. The World Health Organization recommended that measurement of HIV prevalence be done using the anonymous unlinked approach which was designed to minimize the selection bias associated with voluntary testing and to protect the confidentiality of participants. Methods for serological surveillance were greatly refined in the era of HIV infection with the conduct of large-scale regular surveys in a wide variety of populations (see Box 6).
Meanwhile, there was a growing realization of the crucial link between control programs for HIV infection and those for other STDs. Monitoring of the other STDs was generally not well done since the diagnosis usually required a genital examination making special surveys expensive and logistically difficult. Furthermore, STD reporting was even more prone to underdiagnosis and underreporting than AIDS reporting since many people with STDs are asymptomatic or obtain treatment through pharmacies or other venues that do not report cases. Therefore, most countries have relied on some form of passive surveillance system for STDs.
Box 6 Requirements for Serological Surveillance for HIV Infection
Absolute protection of privacy and confidentiality should be maintained, whether the surveillance is on an anonymous unlinked basis, or through voluntary testing.
Repeatability of the sampling frame: In order to track trends over time, the survey should be based on sampling procedures that are likely to recruit the same type of population.
Sustainability of the procedures will only be assured if a clear, simple protocol is devised, pilot-tested and reassessed at regular intervals after implementation.
Coverage of the population: No survey system will produce a truly representative sample, but it should aim to broadly cover population segments, including rural as well as urban.
Appropriate choice of populations will differ from country to country and should be guided by an assessment of scientific needs as well as available resources and cultural and political factors.
Regular analysis and dissemination of results, focusing on prevalence in young age groups as a surrogate measure of HIV incidence and producing data specific for each sex should take place.
Analysis of data by site, age and if applicable by sex should be performed, in an attempt to detect differentials.
Development of surveillance protocols for consistency of survey methods and comparability of results over time and between countries/areas should occur.
Despite these major challenges, most countries now accept the need to monitor HIV and AIDS in a manner that is epidemiologically valid and respects confidentiality. In virtually every country, systems have been established for AIDS case reporting and in most countries the prevalence of HIV has been reasonably well characterized among the higher risk populations.
There nonetheless remains a number of issues surrounding the surveilance of HIV, AIDS and STDs that have not been well addressed. These are discussed below.
Continuing confusion in some countries about the role of surveillance
The role of surveillance is to provide information to support the development and assessment of health programs. In some countries of the Asia-Pacific region, there is confusion about the role of surveillance. In particular, there remains a view in some sectors that one of the roles of surveillance is to detect people with HIV infection for the purpose of subjecting them to direct intervention of some kind, sometimes even involving law enforcement activities.
Implementation of HIV sentinel surveillance in the Asia-Pacific region
HIV sentinel surveillance in the Asia-Pacific region does not require special procedures or methodologies. However, there are some specific issues that should be taken into consideration in implementing HIV sentinel surveillance in the region.
Implementation of HIV sentinel surveillance in the Asia-Pacific region will require a careful selection of sentinel groups, based on their relevance to the epidemic, their accessibility and the feasibility of the study.
Traditionally, the recommended groups for HIV sentinel surveillance were STD patients (high-risk behaviors) and antenatal clinic attenders (low risk or as a proxy of the general population). In addition, data could be available from blood donors and limited serosurveys in sex workers. This methodology was developed looking primarily at the African epidemic and the reality of the African countries, where STD patients are readily available in most health facilities and antenatal screening for syphilis is the most common test for pregnant women.
In several Asian countries, STD patients are rarely seen in the public health facilities. For confidentiality or other reasons, they seek treatment at private practices or prefer to try self-medication. The small numbers and the implicit selection bias make them a difficult group to monitor for HIV surveillance. In addition, antenatal clinic care does not usually include a syphilis test at the first visit (probably due to the low prevalence of syphilis). When blood is collected from pregnant women, it is usually only a small drop for hemoglobin evaluation. This makes unlinked anonymous testing in this group extremely difficult.
On the other hand, sex workers, who are mostly floating and difficult to access in Africa, are often organized in well established brothels or massage parlors in Asia and the Pacific. In this setting, HIV sentinel surveillance can be easily implemented if blood is regularly taken for screening of other diseases, e.g., syphilis. Military recruits have also been used successfully in Thailand to monitor the HIV epidemic. Migrant workers, sailors and fishermen can also be considered for HIV surveillance in specific situations. Blood donors remain a useful sentinel group in most populations that have universal HIV screening programs.
Appropriate analysis of HIV sentinel surveillance data requires the calculation of confidence intervals (90 percent or 95 percent) around the prevalence estimate. Confidence intervals are essential statistical measures of error and should be included in the analysis and reports of HIV sentinel surveillance. Finding them in surveillance reports is, however, the exception rather than the rule. Attempts should be made to be more scientific and in presenting results of HIV sentinel surveillance indicate both the relevance and the limitations of the data.
Can HIV sentinel surveillance monitor trends in a "slow epidemic"?
Data available from several Asian countries, including the Philippines, Indonesia, Bangladesh and China, show HIV prevalence rates increasing very slowly, even in high-risk behavior groups such as sex workers. This contrasts with the exponential increase seen in other populations. Several reasons have been proposed for this pattern, including the relatively low intensity of risk behaviors, particularly commercial sex.
Under these circumstances, analyzing these trends poses a special challenge to the surveillance system because HIV sentinel surveillance can only detect relatively marked increases in prevalence in a short period of time. If the curve is flat, the confidence intervals will overlap for several years and it will be almost impossible to tell whether HIV prevalence is actually progressing, stabilizing or even decreasing.
More samples do not always mean better surveillance
It is commonly accepted that, for meaningful interpretation, results of sentinel surveillance cannot be aggregated between different sites, except under the very unusual circumstance where it can be assumed with confidence that the sites draw from populations uniformly affected. Since this is rare, it is not recommended that data from separate sentinel sites be aggregated. Prevalence rates should be calculated separately per site and sentinel group. If a summary statistic is required, the most appropriate would be a median value with range of rates, or a confidence interval, for any given type of sentinel site.
Incidence monitoring
Of central importance in targetting or assessing prevention activity is the rate at which new HIV infection is occurring, or the incidence. Apart from direct measurement through longitudinal surveys, which are expensive and difficult to sustain, HIV incidence can be estimated from back-projection of AIDS cases, or from repeat cross-sectional surveys. At present, few countries are attempting to regularly and systematically estimate HIV incidence using one or more of the available methods. Although some expertise in modeling and statisics is available in many countries, it is often underutilized in the estimation of HIV incidence. Another measure of HIV incidence can be obtained through the monitoring of HIV prevalence in young age groups.
Monitoring of advanced manifestations of HIV infection
A good understanding of the spectrum of advanced HIV disease is essential for the planning of support and care services, and for assessing the benefit over time of new therapeutic and prophylactic agents. Monitoring of disease spectrum need not take place on any wide scale; it is more practical to select a small number of experienced clinical sites, to regularly report on advanced treatment manifestations, and patterns or therapy.
AIDS case definition
Countries in the Asian Region have so far used the WHO case definitons or modifications of the CDC case definitions. The situation in Asia is complicated by the presence, among countries and within countries, of facilities and groups that can access highly sophisticated diagnostic tools with facilities and groups that can only use basic laboratory or health facilities. In addition, clinical manifestation of HIV opportunistic infections in Asia may be different from the clinical pictures found both in Western and in African countries. As described above, specific AIDS case definitions have been developed for use in Africa, Europe, Latin America and the U.S. By now, we have accumulated sufficient experience and expertise in this region to be able to look critically at the existing definitions and begin to develop AIDS case definition that may be more appropriate for the Asia-Pacific region.
Monitoring of the prevalence and incidence of other STDs
Considerable thought and effort must continue to go into the design of surveillance systems for STDs other than HIV. For too long, methods that were clearly developed for other infectious diseases have been uncritically used for STD surveillance, with the consequence that there is little in the way of reliable estimates of the incidence and prevalence of most STDs, and the extent of morbidity that they actually cause. In addition, innovative ways must be developed to include cases that are treated in venues that often do not report to public health authorities, such as private physicians and pharmacies.
Surveillance of HIV in children
Given the number of women affected by HIV in the Asia and Pacific region, the potential for vertical transmission to newborn children is significant. Although the number of children in the region infected by this route is unknown, the numbers are likely small at present compared to adult infections. However, HIV infections in newborns have an importance that far outweighs their numerical value because they are potentially preventable.
Programs that offer voluntary HIV counseling and testing to pregnant women and appropriate therapy to those infected are needed to prevent vertical transmission of HIV to newborns. In this regard, the surveillance of HIV in children is important since it can help to define the need for such programs, guide their implementation, and evaluate their effectiveness.
Surveillance of HIV infection in early childhood and adolescence in the region is also deficient. The first opportunity surveillance systems have to observe the emergence of HIV infection in this population is when girls become pregnant and attend antenatal clinics, or when boys are enrolled in the military. By the age of 15 -- the earliest age included in routine surveillance in most countries -- some boys and girls may have already become infected with HIV, as found in Manipur state in India, Cambodia and Thailand. Surveillance systems should become more sensitive to age and sex differentials in young people.
4.2 Understanding HIV Spread: the Role of Behavioral Surveillance
Perhaps more so than any other continent, Asian countries are experiencing highly varied HIV epidemics, which are due to a number of factors including differential levels of risk behaviors such as multiple sexual partnerships and injecting drug use. Additionally, because Asia consists of both developing and developed countries with a variety of religious and cultural backgrounds, these risk behaviors are situated in highly varied socioeconomic and cultural environments that can either help or hinder the spread of HIV.
For example, the widespread epidemics in Thailand and Cambodia are based on the high patronage of commercial sex workers in those countries by males. Vietnam, on the other hand, has to date experienced a predominantly IDU-associated HIV epidemic, with concern growing that significant heterosexual spread will occur as well. Although HIV and AIDS case reports are still moderate for Papua New Guinea, that country is expected to face the prospect of a rapidly expanding HIV epidemic because of high rates of multiple sexual partnerships that are not commercially based. One hypothesis of differential rates of HIV spread in Asia appears in Box 7.
Box 7 Why are Epidemics so Different Among Some Countries in Asia?
Data from countries in the region support the consistent finding that the spread of HIV is proceeding very slowly in some parts of Asia and very rapidly in others. The available data suggest that these differences are not the result of early or late introduction of HIV into those areas. For example, HIV has been present in the commercial sex networks of the Philippines and Indonesia as long as it has been in Thailand and Cambodia. Yet rapid and extensive HIV epidemics have occurred in the latter two countries and not yet in the Philippines and Indonesia. What might account for these marked differentials?
Among the behavioral factors that determine the different pattern of these epidemics in heterosexual populations, the following two are believed to be of paramount importance:
the level of sex partner turnover among female sex workers (i.e., the average number of paying customers a sex worker has in a typical work week);
the percentage of the male population who frequent female sex workers in a year.
The first variable (the intensity of risk) will determine whether the initial burst of new infections will occur among sex workers and their male clients. The second variable (the prevalence of risk) will determine how widely HIV will spread in the general population. In Thailand and Cambodia -- prior to their HIV epidemics -- the average number of customers per sex worker was several times higher than comparable figures for sex workers in Indonesia and the Philippines. Similarly, the percentage of the male population who visit commercial sex workers in a given year was considerably higher in the former two countries as well.
The explanatory power of these variables is strongest in situations where there is low or no condom use in commercial sex and where "sex" is primarily penetrative vaginal or anal sex.
The implication for Asia is that, in areas where there is little or no HIV and STD data, program managers can identify regions or communities of greatest vulnerability by conducting behavioral surveys that measure these two variables.
A growing number of Asian countries such as Thailand, the Philippines, Indonesia, India, and Cambodia have initiated behavioral surveillance surveys (BSS) to understand the role of and track behavioral risks for HIV. BSS has its roots in HIV and STD surveillance and uses these methodologic concepts for monitoring HIV risk behaviors. HIV prevalence taken from HIV surveillance is indicative of sexual behaviors from several years back and is slow to change even when risk behaviors may be changing rapidly. BSS thus bring surveillance data closer to what prevention programs require by providing systematic measurements of risk behaviors over time (see Box 8).
Box 8 HIV risk behavioral surveillance: An example from Bangkok, Thailand
Eight population groups in Bangkok, Thailand, were surveyed from 1993 to 1996 as part of a large-scale monitoring of risk behaviors in that city. The figure shows that direct (brothel-based) and indirect (non-brothel-based) sex workers increased their condom use at different levels, depending on the type of sex partner.
Direct sex workers reported high consistent condom use beginning in 1993 and this has increased over time. Their indirect counterparts initially reported far less condom use but this also increased with more intervention focus over time. However, condom use in both sex worker groups with their non-paying clients remained low and unchanged over the three-year time period, signaling that intervention programs need to target these sexual partners as well.
Reported consistent condom use in the past year among direct and indirect sex workers with clients and non-clients in Bangkok, Thailand, 1993-96
Given the emerging epidemics in the region, other countries should be seriously considering adding behavioral surveillance to their epidemic monitoring efforts. Specifically, while existing BSS projects have concentrated on sex workers and various occupational sub-groups of males that tend to visit sex workers, efforts are needed to conduct behavioral surveillance in areas where injecting drug users and men who have sex with men are located in sizable numbers.
Researchers have struggled with determining the important risk behaviors to track and how to best measure them. Consensus is beginning to form around six types of behaviors and characteristics that help to predict the course of the epidemic:
Age at first intercourse
Type of sex partners (e.g., casual, commercial)
Number of sex partners by type
Condom use
Needle-sharing (for injection drug user surveys)
Other factors affecting risk taking, such as alcohol and substance use
Such behaviors are sensitive and respondents may be reluctant to discuss them openly. Surveys thus require well-trained interviewers and appropriate interview settings. Behavioral surveillance, like other surveys reliant on self-reports, must be carefully implemented and validated through other data since self-reported behavioral data can be biased.
Behavioral surveillance is not a panacea for understanding all facets of HIV risk behaviors. In fact, it should be limited to only a few key target groups with a survey instrument containing rapport-building questions and a small but carefully chosen set of risk behavioral questions. In-depth information about target groups, the evaluation of specific interventions, and relationships between several behavioral variables are better obtained through quantitative and qualitative behavioral research specifically designed to answer these questions. They are necessary adjuncts to behavioral surveillance that together form a comprehensive package of monitoring and evaluation.
For example, sexual networking patterns play an important role in the rapidity with which HIV is spread within special populations (e.g., sex workers, clients of sex workers or highly mobile populations, etc.) and within broader segments of the society (e.g., women without sexual risk behavior). These patterns can be monitored to some extent through the application of behavioral surveillance, but also require other types of socio-behavioral investigations (e.g., qualitative/ ethnographic studies).
There is a need to develop minimum common approaches and methodologies for STD surveillance as well. Given the well-documented link between STD and HIV transmission, it is critical to assess how STD rates are affecting the course of AIDS epidemics in the region. With a few notable exceptions, there is a poor understanding of STD prevalence in countries of the region. Analyzed together, HIV, STD, and behavioral surveillance can provide complementary data to understand and track different facets of sexually transmitted diseases and their risk behaviors.
HIV testing may serve any of the following objectives:
Screening: To ensure safe blood transfusion and organ transplant through the screening of blood and blood products, and of tissues, sperm or ova from donors.
Surveillance: Unlinked and/or anonymous testing of serum (or other body fluids) for the purpose of monitoring HIV prevalence over time in a given population.
Diagnosis of HIV infection: Voluntary testing in order to inform individuals about their serostatus.
HIV testing policies and programs are relevant to the monitoring of HIV/AIDS epidemics regardless of the original objective for testing, and the test results unlinked from identifying information may be used additionally for surveillance. For example, test results from blood donors and those seeking diagnosis are often used in surveillance reports.
Testing strategies vary widely and the appropriate test or combination of tests depend on three criteria:
the objective of the test (for screening, surveillance, or diagnosis);
the sensitivity and specificity of the test(s) being used; and
the prevalence of HIV infection in the population being tested.
Most HIV tests detect HIV antibody in serum/plasma or other body fluids. Although HIV antibody testing has been available in the region since 1985, tests have recently become available to detect viral antigen. These are much more expensive than HIV antibody tests and are used by only a few Asian and Pacific countries, generally only in specialized medical settings. Tests that detect antibody in fluids such as saliva or urine, although available, are currently used only for research purposes. These collection methods and tests have great potential for use in surveillance testing as they will help reduce some logistical difficulties and costs. Tests commonly used in developing countries are based on the presence of HIV antibody in serum/ plasma, i.e., ELISA, Western Blot, rapid tests. In most countries in the region, testing strategies consist of an initial screening test, usually an ELISA-based test, followed (for reactive specimens only) with a second (supplemented) test, generally either a second ELISA and/or Western Blot test.
Key issues
Testing strategies vary tremendously across the region and within each broad objective (screening, surveillance, and diagnosis). Complex technical, programmatic and ethical/human rights issues abound. The issues presented below are crosscutting and are encountered in most countries in the region:
Financial and qualified human resources are insufficient in most countries to provide adequate coverage for quality blood screening, surveillance, and diagnostic testing. Policymakers must carefully evaluate and provide guidelines for HIV testing options that are appropriate to the country, the purpose of testing and are affordable. Resources must be allocated for surveillance, blood screening and diagnosis, while carefully balancing these needs within the larger public health needs. Innovative approaches must be considered for tapping additional resources, such as referring testing clients to the community for counseling services; also, there is a need to increase and improve training at all levels.
There is an urgent need to assure quality throughout the testing process to ensure accurate results and confidence in data and results. This can be achieved by developing standard procedures, increasing and improving training for field workers (data collectors) and lab technicians, and monitoring the entire process (see Box 9).
An HIV test result not only has important implications for an individual and his/her future decisions, but its accuracy is critical to ensure a safe blood supply and accurate monitoring of the epidemic through surveillance.
The availability of high quality HIV tests does not guarantee that reliable results are reported to the patient or the health system. Quality assurance is the total process that guarantees that the final results reported are accurate and the client is counseled, unless anonymous unlinked testing is performed. This comprehensive attention to quality begins with specimen collection with informed consent and continues through the reporting and interpretation of results. It includes specimen collection and handling, the laboratory procedure itself, documentation, reporting and interpretation of results as well as the counseling process. Quality assurance includes laboratory quality control and external quality assessment programs.
A comprehensive quality assurance program requires the support of policymakers to provide the required infrastructure. Standard policies and procedures appropriate to the country must be developed and disseminated.
Quality test results require commitment of financial and human resources. Training for all those involved in the testing and reporting process is a key component of a quality assurance Program.
HIV testing has the potential for human rights abuses, including marginalization, coercion, discrimination and violence. Policymakers should develop and enforce clear policies on confidentiality and the use of test results and include persons living with HIV/AIDS in policy formulation. Legal provisions must be established to protect testing clients from abuse. Once these policies are developed, they must be disseminated and included in training for all people involved in the testing process from the point of first contact in health care settings, to the lab technicians to the counselors.
There is an increasing demand for early diagnosis of HIV infection, both for personal knowledge and decision making and for medical management. Testing should always be accompanied by counseling, support services and treatment when available. Before aggressive case finding for medical management can be recommended, policymakers must consider the availability of treatment options and balance resource allocations of the overall public health program. Clear policies regarding use of test results and confidentiality must be established and enforced.
A number of countries in the region are considering the use of HIV Rapid Tests for home-based testing. Policymakers should carefully consider the complexity of the administration and interpretation of the tests and the wide ranging implications and effects home testing can have, including the psychosocial support requirements and opportunities for human rights abuses. These must be weighed against the potential benefits and be guided by clear regulation of the use of HIV tests outside the laboratory setting.
4.4 Modeling HIV/AIDS/STDs in the Asia-Pacific Region: Approaches and Limitations
Models for the spread of HIV vary in sophistication from straightforward curve fits to extremely complex process models reproducing the dynamics of multiple modes of transmission, requiring extensive behavioral, epidemiological, and demographic inputs. Both types of models have been applied in the Asia-Pacific region by a number of different groups (see below). A strong demand has been seen for the output of these modeling efforts. This demand is driven by national AIDS programs and AIDS organizations, which wish to use them to advocate for expanded responses and to anticipate the magnitude of the tasks ahead of them, and by policymakers who want to understand the longer term implications of the epidemic for their own work. The value of models comes not only from providing people with concrete estimates of HIV infections and deaths for advocacy and planning purposes, but because they force people to closely examine and try to coherently interpret available epidemiological and behavioral data (see Box 10).
STD modeling approaches have rarely been applied in the Asia-Pacific region, except in the context of models such as iwgAIDS, which simultaneously tracks STDs and HIV. To a great extent, this is the result of the lack of quality STD trend data from any of the countries in the region. Thus, STD models will not be discussed further except as a key issue.
A Brief History of Past HIV/AIDS Efforts in the Asia-Pacific Region
While Epimodel, a simple curve fitting model, has been applied extensively throughout the region (in just about every country), for the most part modeling efforts using process models have been concentrated in Thailand, with some additional work done in Indonesia and Papua New Guinea. All of this work currently exists as "gray literature," and not in published journals.
The earliest and most extensive modeling efforts in the Asian region have looked at Thailand, perhaps encouraged by the ready availability of both epidemiological and behavioral data since 1990. Thailand also offers the best opportunity to check the validity of models, since eight years of epidemiological trend data along with numerous behavioral studies are available. A number of groups have examined the Thai epidemic (see Box 11).
Models can provide a better understanding of the epidemiology and natural history of HIV infection and AIDS.
Models can provide plausible HIV/AIDS estimation and projections (scenarios) to evaluate the morbidity, mortality, economic and demographic impact of HIV/AIDS.
Models cannot and should not be used to provide estimates of the past or current prevalence of HIV infections and AIDS cases. Such estimates must be extrapolated from the available HIV/AIDS data.
Simple models such as the back-calculation method can provide estimates of the past patterns and incidence of HIV infections, if reliable estimates of the annual incidence of AIDS cases are available. Epimodel can provide estimates of the annual incidence of AIDS cases, if reliable estimates of HIV prevalence are available.
More complex models incorporate biological and behavioral variables that describe the transmission and natural history of HIV infection to simulate the entire disease process.
Models that use epidemic curves, such as Epimodel, should not be used in situations where extensive spread of HIV has not been documented.
Estimation and projection of HIV infections and AIDS cases using any HIV/AIDS model cannot be considered precisely accurate. All model outputs have to be constantly reviewed, and revised, as additional data become available.
The methods and models used for estimation and projection of HIV/AIDS need to be examined critically and understood before their outputs are accepted and used for public health program or policy decisions.
The Thai experience is one of relatively abundant data, and an epidemiologically interesting and relatively complex (and in some respects an atypical) epidemic. Consequently, considerable modeling attention has been paid to the Thai case over the past decade (see Box 11).
iwgAIDS: Organized in 1991, the Thai Working Group on HIV/AIDS Projections, a collaboration of various Thai institutions and the U.S. Bureau of the Census, applied the iwgAIDS model to the Thai situation. The results, a cumulative 2 to 4 million HIV infections by 2000, were adopted by the Thai Ministry of Public Health for planning purposes. Subsequent efforts to apply this model had difficulty reproducing certain aspects of the Thai epidemic used for this projection.
The NESDB Model: Faced with the need to update the above projections, the National Economic and Social Development Board (NESDB) Working Group on HIV/AIDS Projection in 1994 followed a similar collaborative approach to develop a model that combined a relatively simple incidence model incorporating commercial sex behavior, condom use, and STD levels, with an HIV-to-AIDS-to-Death progression model. Observed epidemic trends through 1993 were well reproduced by the model, and different scenarios explored the impact of behavior change on the future Thai epidemic. These projections are currently the official population projections used for government planning purposes in Thailand, but have not yet been adjusted to fully reflect the behavioral and epidemiological changes of the past few years.
GPA Age-Cohort Model: Stoneburner et al. prepared a model for incidence and prevalence that fits observed trends in conscripts in the northern Thailand over the first few years of the epidemic. This model showed substantial incidence declines beginning in 1990.
SimulAIDS: Robinson et al. applied SimulAIDS to produce an estimated of 2 million averted infections through 1995. This model produced 600,000 cumulative infections through 1995, and found infections in pregnant women continuing to increase through the year 2000.
Anderson Four-Compartment Model: In work done as a MOPH/Chulalongkorn/ Oxford University collaboration, Anderson's four-compartment model tracked early trends in the Thai epidemic but did not reproduce recent declines in seroprevalence in conscripts while underestimating current infection levels in ANC women.
GPA/WHO Epimodel: This model was used in 1990 in Thailand and projected a cumulative total from 1.5 to 2 million HIV infections by the year 2000.
These efforts, briefly described in the box, lead to a number of observations:
Strong collaboration can help to ensure maximum use of available empirical data, while enhancing the chances for the results of modeling to be adopted by consensus and used in policy decisions and program planning.
But even in the same country using the same sources, considerable variation exists in the translation of epidemiological data into estimated current or cumulative prevalence figures. Further study is needed of how best to convert sentinel data sets to estimates of general population prevalence.
Trends in behavioral data are not easy to incorporate into existing models. The Thai situation in the 1990s has been a very dynamic one, which requires the ability to input behavioral parameters such as condom use and risk behavior over time if the epidemiological trends are to be reproduced.
Despite the complexity of some of the models, they have had limited success in fitting actual trends in the data, raising concerns about whether assumptions in the models correctly describe the complexity of the Thai situation.
Perhaps due to strong collaboration, examined even in hindsight, none of the above efforts produced results that were truly outlandish, although a number of such projections were to be found in the popular press. The higher results of the earliest efforts in part show the fact that much of the Thai behavior change had not yet been reflected in the data available.
Thailand has benefited substantially from these modeling efforts. Programs and policies have been justified by the results of these models, and the Thai AIDS prevention effort has become stronger as a consequence. But the Thai experience also highlights the complexities of modeling AIDS epidemics and the potential pitfalls along the way. Other countries, perhaps with less empirical data and fewer resources devoted to modeling, have had differential success both in developing plausible models of the local epidemic as well as in incorporating these results into their prevention efforts (see Box 12).
With international technical assistance, the Ministry of Health in Indonesia produced projections for the country using a complex deterministic model (iwgAIDS). Multiple projections were prepared, with projected total infections ranging from several hundred thousand to 2.5 million by the year 2000. However, the most publicized projections have been the high end estimates, which have frequently been mentioned in press statements from Ministry officials. These estimates were used to mobilize a national and international response to the impending epidemic.
Recently, a review of the current epidemiological situation produced very low estimates for HIV prevalence in 1997, and considerable confusion has been developing in the country over the discrepancy between these estimates and the earlier projections. Even in a pessimistic scenario with extremely rapid HIV spread, the high estimates are extremely unlikely to be reached by the year 2000 - now less than three years away. This situation highlights the difficulty in modeling epidemics in a country with little empirical data and with an epidemic in a very early phase.
There is a need to improve policymakers' understanding of uses and limitations of HIV/AIDS models. However, before that can be done, modelers themselves need to reach a consensus on the uses and limitations of the models that are in use in the Asia-Pacific region.
One approach to capacity building for modeling is to establish national technical working groups to assemble the relevant data and supervise the HIV estimation and projection process. These working groups can be linked through the Internet and convened through sub-regional meetings. Current modeling approaches perform best when an epidemic is in progress; tools for estimating levels and trends of HIV in the absence of an epidemic are not yet well-developed. Alternative models need to be developed that include a few key variables and can describe the potential for an epidemic where HIV is still low.
There is still a need in Asia for more capacity building in HIV and behavioral surveillance in order to collect the data that would be required by these models. Multi-country studies, with standardized methodology for collecting HIV/STD and behavioral data, should be applied along the lines of the current UNAIDS project in several countries in Africa. Application of complex process models to produce projections should be limited to countries in which at least three or four years of reliable epidemiological and behavioral trend data are available.
Models that estimate and project levels of STDs have not been widely used in the Asia-Pacific region. There is a need for translating data on STD incidence and prevalence (by type of STD) in the region into measures of HIV epidemic potential. Countries need to be encouraged to conduct estimates and very short-term projections of HIV, revise these estimates on an annual basis, use the lower of multiple scenarios for planning and public dissemination, use these data to project the impact of HIV and of the interventions undertaken to bring the HIV epidemics under control.
5. Use and Non-use of HIV/STD and Behavioral Surveillance: Opportunities for Improvement
HIV, STD, and risk behavioral surveillance are important tools in understanding the dynamics of transmission, the impact of the epidemic, and the effects of interventions designed to reduce disease incidence. But their use in Asia for policy and program development has been varied. In fact, in many countries in Asia, surveillance data has not been collected or, if so, has been presented in a manner not conducive to its use and understanding by decision makers. This impedes the development of regional strategies to respond to the different epidemics more effectively. Three examples from Asia illustrate various of uses of HIV, STD, and behavioral surveillance data:
India has clearly used existing sentinel surveillance data, but the lack of it in many states has hampered the forecasting of the HIV epidemic in these areas. Behavioral surveillance has helped to clarify and bring to consensus the risks of several population segments in the state of Tamilnadu. Future waves should indicate how much these groups are changing their behaviors in the face of interventions.
In Indonesia, continuing serosurveys have helped to clarify the HIV epidemic, with initial estimates suggestive of a widespread epidemic and more recent estimates leaning toward a much more limited and concentrated spread. Behavioral surveillance has quantified the sexual behaviors of several Indonesian population groups -- a relatively new and sensitive topic for many policymakers. Interpreting and disseminating these findings has therefore been done with caution.
Cambodia's HIV epidemic has been well characterized recently, albeit late, by sentinel surveillance. Nevertheless, some gaps remain in understanding the epidemic in rural areas and among pregnant women. Both serologic and behavioral surveillance have been used to stress the dissemination of the epidemic throughout the Cambodian population.
Part of the problem in trying to compare data across Asia is that surveillance data have been collected in a variety of ways. Standardization of basic surveillance data collection among countries in the region would enable better information to gauge the status and trends of the different HIV/STD epidemics and provide opportunities for planning regional intervention strategies at multiple sites. However, while collection of similar data will ensure consistency and the opportunity for transnational comparison, epidemics in different countries are at different stages of development. Therefore, the respective epidemics in each country need to be carefully examined to determine the need for additional data.
Data Gathering for Public Health Action
The overall purpose of data gathering is public health action. This need should guide the types of data that are collected. Surveillance plans also need periodic review to keep pace with changing epidemics and population characteristics to determine the trends of the HIV/STD epidemics in countries.
Involving community members and policymakers in the planning of surveillance will better ensure that the information resulting from it will be used to develop beneficial and equitable policies as well as effective intervention programs. The way surveillance data has been presented in many countries has been a major deterrent to its best use. Surveillance data ideally should be used by policymakers, community groups, and the media for planning intervention and public health programs and for disseminating information to the public. If data are to be used by all of these groups, it needs to be packaged and presented in a targeted manner for ease of comprehension and use.
A surveillance system can become a meaningless exercise in data collection unless the findings motivate action to reduce HIV transmission by key stakeholders, including policymakers, program managers, and the surveyed communities. This can be accomplished in several ways:
Consensus needs to be built among various stakeholders in the communities to be surveyed about the data to be collected and disseminated, and the forms dissemination will take. This helps to build a sense of "ownership" of the findings and ensures that their presentation is appropriate for and relevant to the various target audiences.
A comprehensive dissemination strategy needs to be developed at the same time surveillance is planned. This strategy should include dissemination of some key findings as soon as possible after data collection is completed to sustain stakeholder interest and speed the implementation of prevention activities.
Target audiences should be prepared to understand the meaning, limitations, and interpretation of the surveillance results well in advance of their actual release.
Specific dissemination materials should be developed for each target audience to explain the findings in clear and simple language they can understand.
Target audiences need follow-up to enable questions to be answered, meanings clarified and interpretations developed as well as to empower them to make informed recommendations on the appropriate policies, programs, or actions suggested by the data.
Each of the potential target audiences listed above has a role in reducing HIV transmission and can take action based on the findings. However, it must also be remembered that there are often local concerns and sensitivities about the open discussion of the behaviors that transmit HIV. These sensitivities are often strongest among key government officials or high-ranking religious leaders whose alienation might seriously impede prevention efforts. In designing dissemination activities and materials, careful attention should be paid to these concerns, especially those of key policy, community and media gatekeepers. Whenever possible, data should be disseminated in forms that respect the concerns of the target audience, involve them in the dissemination process, and present the results in language that will not be found objectionable. Indirect avenues for dissemination also should be explored. For instance, the significance of the findings should be explained to those representing influential policymakers and religious leaders with the intention of having them pass on the key information to their colleagues.
Because members of the communities under surveillance are actively involved in the planning of surveillance and have the ability to respond to the findings by changing behavior, surveillance implementers have a special obligation to ensure that community leaders and other community members are informed of the findings. Their active participation throughout the entire process of design, implementation, and dissemination of surveillance will strengthen the system and help to ensure its reliability and validity.
Making Surveillance Count
Those implementing surveillance cannot assume that they have finished their work when they produce a final report with detailed statistical analysis. Most people do not know the meaning of "p-value" or "confidence interval," and such language is likely to confuse the issues in their minds rather than clarify them. In order to reach all potential target audiences with the appropriate messages, a number of forms of dissemination will usually be required including:
A detailed report with complete statistical analysis. This report serves as the technical foundation for preparing other dissemination materials and may be appropriate for distribution to program managers and staff of organizations actively working with the communities surveyed. Even within such a report, significant results should be highlighted and summarized in clear, non-technical language.
Briefing materials for the media. Technical language should be avoided in materials prepared for the media. Press releases or briefing papers should focus on only a few key findings and their implications so as not to confuse the reader. Whenever possible, a written summary of remarks should be provided when discussing surveillance findings with media, which will help to reduce misquoting and misinterpretation. In preparing these materials, it is important to remember that reaching the media can be an indirect way of reaching policymakers and the public if the information is disseminated.
Short policy briefs and personalized briefing sessions. Because policymakers and leaders of the surveyed communities are positioned to have a major impact on prevention measures, materials specifically targeted to them are essential. Each policy brief should focus on a few key aspects of the findings, discuss the most important implications for their own activities, and make specific recommendations for actions they might take to exert positive influence on prevention activities. Separate policy briefs and briefing sessions will often be advisable and perhaps necessary for different policymakers or community leaders so the materials can be made directly relevant to their needs, which can include satisfying their constituents.
Group dissemination meetings or presentations. Meetings or presentations with large groups can offer an opportunity to present the findings to members of the surveyed communities, policymakers or program managers, and the general public. The full process of dissemination may involve such meetings before, during, and after the release of data. Meetings before and after data collection can be used to explain the data that is being collected, discuss issues of its interpretation and prepare people to readily accept it and use it strategically.
Recommendations for action in spheres of influence. Materials for the Ministry of Education might emphasize the need for school-based sexual health education at the late primary or early secondary level, based on the number of young people reporting an age at first intercourse. However, to maintain maximum credibility, any recommendations given in surveillance policy briefs should result from surveillance findings.
Presentation of sensitive information. Data regarding marginalized communities, for instance, sex workers or men having sex with men, need to be carefully presented, with sensitivity to the concerns of these communities. The data should be presented in a way that does not increase stigmatization or discrimination.
The importance of dissemination should not be underestimated. With effective dissemination, surveillance can become an important component of advocating for expanded action and motivating a broader societal response to HIV prevention.
Key recommendations to improve the monitoring of the HIV/AIDS epidemics, enhance the use of surveillance data and better understand the risk and vulnerability for HIV infection in the Asia-Pacific region are summarized below.
Protection of confidentiality and privacy must be absolutely respected in all public health surveillance activities.
Future efforts in surveillance should attempt to document the extent, distribution and characteristics of sex workers. This would lead to a recognition of the biases inherent in the continued use of the same groups of sex workers for epidemiological and behavioral surveillance.
Surveillance of HIV in sex workers may lead to the public perception that sex workers are the "cause" of an HIV epidemic. This can result in greater discrimination and more support for prohibitive policies, which may further aggravate vulnerability to HIV and fuel the epidemic. Thus, surveillance should be accompanied by clear policies on non-discrimination and supportive prevention interventions.
Where possible, localized surveillance is likely to be more useful for intervention design and to permit a more careful analysis of the behaviors and sexual networks of sex workers so that more informed decisions can be made regarding interventions.
The monitoring of HIV trends in injecting drug users has revealed both their high vulnerability to HIV and the positive impact that prevention programs can have in minimizing this vulnerability. Based on this evidence, prevention programs should be specifically aimed at reducing the transmission of HIV among IDUs by using comprehensive HIV prevention and care program principles.
The behavioral and epidemiological patterns found among mobile populations in cross-border areas are poorly known. Investigative studies, including ethnographic research, are needed to provide a better understanding of the increased vulnerability of these populations to HIV and other sexually transmitted diseases while they are in these areas.
Border crossings in Indochina and South Asia require urgent prevention and care interventions. Interventions to reduce the vulnerability of populations traversing cross-border areas are needed because mobile groups can serve as "bridges" between high-risk and low-risk populations, thereby creating the potential for a widespread diffusion of HIV. Well-traveled border towns and ports are also gateways and catchment areas for many different types of travelers and are, therefore, appropriate and convenient sites for intervention.
The surveillance of sexually transmitted diseases in the region remains largely inadequate. Reliable survey methods for STDs other than HIV should be developed for routine surveillance application.
Broad-based behavioral surveillance is not a panacea for understanding all facets of HIV risk behaviors. In-depth information about target behaviors, the effectiveness of interventions and the relationships between several behavioral variables are better obtained through quantitative and qualitative behavioral research designed to answer specific questions.
Lack of confidentiality in HIV testing fosters human rights abuses, including marginalization, coercion, discrimination and violence. Clear policies on confidentiality and the use of test results should be developed with the participation of persons living with HIV/AIDS. Legal provisions must be established to protect testing clients from abuse. Once these policies are developed, they must be disseminated widely and emphasized in the training of all people involved in the testing process.
There is an increasing demand for early diagnosis of HIV infection, both for personal knowledge and decision making and for medical management. Testing should always be accompanied by counseling and care and support services. Before voluntary HIV testing is advocated on a large scale, policymakers must consider availability of treatment options and the allocation of resources to and within the public health sector.
Epidemiological models have been used frequently in the Asia-Pacific region to support the development of national policies on HIV/AIDS. There is a need to improve the understanding by health professionals and policymakers of the appropriate uses and limitations of HIV/AIDS models. Modelers need to reach a consensus on the appropriate uses and limitations of the models that are being applied in the region.
Current modeling approaches perform best when there is a well established HIV epidemic. The application of complex models to produce projections should be limited to countries in which at least three or four years of reliable epidemiological and behavioral trend data are available. Alternative models need to be developed that include a few key behavioral variables and can describe the potential for a more extensive epidemic where HIV is still low.
Martha ANKER Statistician World Health Organization Division of Emerging and other Communicable Diseases Surveillance & Control 20, Avenue Appia 1211 Geneva 27 Switzerland Tel: 41 22 791 2380/4551 Fax: 41 22 791 4198 E-Mail: ankerm@who.ch
Chris ARCHIBALD Chief, Division of HIV Epidemiology Laboratory Centre for Disease Control Health Canada Tunney's Pasture, Postal Locator 0900 B1 Ottawa, Ontario K1A 0K9 Canada Tel: 613 941 3155 Fax: 613 954 5414 E-Mai: carchiba@hpb.hwc.ca
Anthony BENNETT Senior Program Officer Family Health International/AIDSCAP Asia Regional Office Arwan Building, 8th Floor 1339 Pracharaj 1 Road Bangsue, Bangkok 10800 Thailand Tel: 662 587 4750 Fax: 662 587 4758 E-Mail: tbennett@fhi.org
Richard BURZYNSKI Director International Council of AIDS Service Organizations (ICASO) 400 - 100 Sparks Street Ottawa, Ontario KIP 5B7 Canada Tel: 613 230 3580 Fax: 613 563 4998 E-Mail: icaso@web.net
Hehe CHENG Chief of AIDS Prevention Division Yunnan Provincial Health & Anti-Epidemic Center #158 Dongsi Street Kunming 650022 People's Republic of China Tel: 86 871 315 0294 Fax: 86 871 361 3063
James CHIN Clinical Professor of Epidemiology School of Public Health, UC Berkeley 456 Kentucky Avenue Berkeley, California 94707-1735 USA Tel: 510 527 6252 Fax: 510 527 7640 E-Mail: jchin@cdpc.com jchin@socrates.berkeley.edu
Donald James GOODWIN Technical Officer AIDS/STD WHO Representative's Office P.O. Box No. 14 Yangon Myanmar Tel: 95 1 511 076 Fax: 95 1 511 078 E-Mail: dgoodwin%who01.who- mya@nylan1.undp.org
Nguyen Tran HIEN Department of Epidemiology Hanoi Medical College 1 Ton that Tung Street Khuong thuong, Dong da Ha Noi Vietnam Tel: 84 4 852 4141 Fax: 84 4 852 3032 E-Mail: vnholand@netnam.org.vn
Le Dien HONG Former Vice Chairman National AIDS Committee of Vietnam 138 Giang Vo Street Hanoi Vietnam Tel: 844 846 1563 or 844 4914 Fax: 844 846 0134 E-Mail: nac@netnam.org.vn
Dr. IRWANTO Director Centre for Societal Development Studies Atma Jaya University Jalan Jenderal Sudirman 51 Jakarta 10001 Indonesia Tel: 6221 5734355 Fax: 6221 5734355 E-Mail: ppauaj@rad.net.id
Rokiah ISMAIL Associate Professor Department of Medicine University of Malaysia 50603 Kuala Lumpur Malaysia Tel: 603 750 2867 Fax: 603 755 7740 E-Mail: rokiahi@unimed.po.my
John KALDOR Deputy Director and Professor of Epidemiology National Center in HIV Epidemiology and Clinical Research University of New South Wales 376 Victoria Street Darlinghurst, NSW 2010 Australia Tel: 61 29 332 4648 Fax: 61 29 332 1837 E-Mail: jkaldor@nchecr.unsw.edu.au
Mitsuhiro KAMAKURA Assistant Professor Department of Preventive Medicine and Public Health School of Medicine Keio University 35 Shinanomachi, Shinjuku Ward Tokyo 160 Japan Tel: 81 3 3358 1955 (work); or 81 3 3777 6411 (home) Fax: 81 3 3359 3686 (work); or 81 3 3777 6412 (home) E-Mail: kamakura@mc.med.keio.ac.jp (work) mkamakur@po.iijnet.or.jp (home)
Ryuichi KOMATSU Program on Population East-West Center 1601 East-West Road Honolulu, Hawaii 96848 USA Tel: 808 944 7413 Fax: 808 944 7490 E-Mail: ryuichi@hawaii.edu
Peter LAMPTEY Senior Vice President, AIDS Programs Director, AIDS Control and Prevention (AIDSCAP) Project Family Health International 2101 Wilson Boulevard, Suite 700 Arlington, Virginia 22201 USA Tel: 703 516 9779 Fax: 703 516 9781 E-Mail: plamptey@fhi.or
Ann LARSON Senior Lecturer in Population Health ACITHN University of Queensland Medical School Herston Road Herston, QLD 4006 Australia Tel: 61 7 3365 5411 Fax: 61 7 3365 5500 E-Mail: A.Larson@mailbox.uq.edu.au
Stefano LAZZARI Medical Officer STD/AIDS c/o WHO Jl. M.H. Thamrin, 14 10350 Jakarta Indonesia Tel: 62 21 6255334 (Office) 811 18 5478 (Mobile) Fax: 62 21 323827 E-Mail: STEFANOLAZZARI@BIGFOOT.COM
Sophie LE COEUR Institut National d'Etudes Démographiques Establissement Public Scientifique et Technologique 27 Rue du Commandeur Paris 75014 France Tel: 33 1 42 18 21 15 Fax: 33 1 42 18 21 94 E-Mail: lecoeur@ined.fr lecoeur@loxinfo.co.th
Su-su LIAO Associate Professor Department of Epidemiology Peking Union Medical College 5 Dong Dan San Tiao Beijing 100005 People's Republic of China Tel: 86 10 65296971 Fax: 86 10 65240529 E-Mail: susuliao@mx.cei.go.cn
Maria Consorcia LIM-QUIZON National HIV Sentinel Surveillance Field Epidemiology Training Program Department of Health San Lazaro Compound Sta. Cruz Manila Philippines Tel: 632 743 6076 632 741 7048 Fax: 632 743 6076 632 741 7048 E-Mail: hsssfetp@portalinc.com
Stephen MILLS Evaluation Officer, Epidemiologist Family Health International Asia Regional Office Arwan Building 1339 Pracharat 1 Road Bangsue, Bangkok 10800 Thailand Tel: 66 2 587 4750 Fax: 66 2 587 4758 E-Mail: smills@fhibkk.org
Sheila MITCHELL Director, Program Management Family Health International/AIDSCAP 2101 Wilson Boulevard, Suite 700 Arlington, Virginia 22201 USA Tel: 703 516 9779 Fax: 703 516 9781 E-Mail: smitchell@fhi.org
Lalit M. NATH Association for Health, Environment & Development E-21 Defence Colony New Delhi 110024 India Tel: 91 11 460 3282 Fax: 91 11 685 2785 or 686 3522 E-Mail: lmnath@del2.vsnl.net.in nath@doe.ernet.in
Dede OETOMO Member, Central Management Committee, Asia/Pacific International Council of AIDS Service Organizations c/o YCUI, Jalan Belimbing Gay No. 4 Denpasar, Bali 80231 Indonesia Tel: 62 81 131 1743 Fax: 62 36 122 9487 E-Mail: doetomo@indo.net.id
Mary O'GRADY Associate Director, Information Programs Family Health International/AIDSCAP 2101 Wilson Boulevard, Suite 700 Arlington, Virginia 22201 USA Tel: 703 516 9779 Fax: 703 516 9781 E-Mail: mogrady@fhi.org
Michael O'LEARY Medical Officer WHO, P.O. Box 113 Suva Fiji Tel: 679 304600 Fax: 679 300462 E-Mail: whosp@is.com.fj
Wiput PHOOLCHAROEN Director AIDS Division Ministry of Public Health Nondaburi 11000 Thailand Tel: 662 5918411/2 Fax: 662 5918413 E-Mail: WIPUT@health.moph.go.th
Gilles POUMEROL Regional Adviser for STD and AIDS WHO-Western Pacific Regional Office United Nations Avenue, P.O. Box 2932 Manila 1000 Philippines Tel: 632 528 8001 Fax: 632 521 1036 E-Mail: poumerolg@who.org.ph std@who.org.ph
Swarup SARKAR Coordinator, Health and Population Sector CARE-Bangladesh House #60, Road #7/A Dhanmondi R/A Dhaka, Bangladesh Tel: 880 2 814195 (6,7,8) Fax: 880 2 814183 E-Mail: carebang@bangla.net sarkars@bangla.net
Werasit SITTITRAI Coordinator, Department of Policy, Strategy and Research UNAIDS 20, Avenue Appia CH-1211 Geneva 27 Switzerland Tel: 41 22 791 4457 Fax: 41 22 791 4165 E-Mail: werasits@unaids.org
Karen STANECKI DELAY Chief, Health Studies Branch U.S. Bureau of the Census International Programs Center Washington, DC 20233-8860 USA Tel: 301 457 1406 Fax: 301 457 3034 E-Mail: kstaneck@census.gov
Elaine M. STEVENSON HIV/AIDS Epidemiologist MacFarlane Burnet Centre for Medical Research P.O. Box 254 Fairfield, Victoria 3078 Australia Tel: 61 3 9282 2290 Fax: 61 3 9482 3123 E-Mail: stevenso@mbcmr.unimelb.edu.au
Daniel TARANTOLA Director, International AIDS Program François-Xavier Bagnoud Center for Health and Human Rights Harvard School of Public Health 651 Huntington Avenue François-Xavier Bagnoud Building, 7th Floor Boston, Massachusetts 02115 USA Tel: 617 432 4313 Fax: 617 432 4310 E-Mail: danielt@hsph.harvard.edu
Kumnuan UNGCHUSAK Director, Field Epidemiology Training Program (FETP) Division of Epidemiology Ministry of Public Health Soi Bamrasnaradura, Tivanoud Road Nonthaburi 11000 Thailand Tel: 662 590 1734-5 Fax: 662 591 8581 E-Mail: kum@health.moph.go.th
Budi UTOMO Center for Health Research University of Indonesia LPUI Building, Campus UI Depok, West Java 16424 Indonesia Tel: 62 21 727 0154 Fax: 62 21 727 0153 E-Mail: usr20122@indosat.net.id
Peter O. WAY Senior Research Analyst International Programs Center U.S. Bureau of the Census Washington, DC 20233 USA Tel: 301 457 1406 Fax: 301 457 3034 E-Mail: pway@census.gov
Taro YAMAMOTO Department of Health Policy and Planning Faculty of Medicine University of Tokyo 7-3-1 Hongo, Bunkyou-ku Tokyo 113 Japan Tel: 813 3812 2111, ext. 3675 Fax: 813 3813 1314 E-Mail: cyp04070@niftyserve.or.jp
The World Health Organization, Regional Office for the Western Pacific hosted this symposium of the MAP Network. It extended its conference facilities and provided staff support for this event and production of this provisional report. It also contributed extensively to the substance of the symposium by making available to participants information that it had collected, analyzed and published in various documents and reports. MAP wishes to express its warmest thanks to the World Health Organization, Regional Office for the Western Pacific for its enthusiastic and effective support of the Network's activities.
