Tuberculosis (TB) is one of the leading causes of death and illness among people living with AIDS in developing countries. More than one-third of people living with HIV/AIDS worldwide are also infected with Mycobacterium tuberculosis (the TB bacillus), and 40 percent to 60 percent of them will develop tuberculosis.¹

The two infections have been closely linked since the beginning of the HIV/AIDS pandemic in the early 1980s, when AIDS patients living in TB endemic areas began to present with disseminated tuberculosis, along with other opportunistic infections. Today we know that this relationship is mutually advantageous. HIV contributes to the reactivation of latent TB infection and makes individuals with recent TB infections more susceptible to rapid progression to active disease. Active TB, in turn, may accelerate the course of HIV infection.

Targeting TB in areas with high HIV infection rates is critical because tuberculosis is one of the few infectious diseases fueled by the HIV epidemic that does not remain confined to people infected with HIV. It is also one of the first opportunistic infections to appear in those who are infected with HIV, providing a warning sign that offers opportunities for early intervention. Yet while HIV and TB work together in deadly partnership, most countries continue to address the two epidemics through separate -- and therefore less effective -- programs.

A Fragmented Approach

The priority of TB control programs remains implementing the strategy called DOTS (directly observed treatment, short course), which has been promoted since the World Health Organization (WHO) declared tuberculosis infection a global emergency in 1993. The goal of DOTS is to detect 70 percent of all sputum-smear-positive TB cases and to cure 80 percent of them through passive detection and directly observed treatment. This means using sputum smear microscopy to identify infectious TB cases among patients seeking treatment, providing a standardized treatment regimen of six to eight months, and ensuring that someone observes the patient taking the drug, at least during the initial two months. Successful implementation of DOTS requires an efficient system for monitoring and evaluation, regular and uninterrupted supply of all essential anti-TB drugs, and a strong government commitment to sustained TB control activities.

Many TB program managers have assumed that DOTS alone would control TB, regardless of the HIV epidemic. This has not proved to be the case. In fact, since their HIV epidemics began, many countries that had successfully implemented DOTS have been struggling to control TB. In one such country -- Tanzania -- a DOTS program that is considered a model reported a 160 percent increase in the number of TB cases between 1984 and 1993, despite reported cure rates of 80 percent. During that period, an estimated 24 percent of all new smear-positive TB cases were attributable to HIV.²

Botswana is another example. After introducing the DOTS strategy in 1986, the country's TB control program recorded a decrease in the incidence of TB cases throughout the 1980s. However, this trend was reversed in the early 1990s. Today Botswana has one of the highest TB incidence rates in the world.³ Similar trends in the number of TB cases have been reported in other countries in sub-Saharan Africa and in selected areas in Southeast Asia, such as the province of Chiang Rai in northern Thailand.⁴

In addition to increasing the number of TB cases, HIV epidemics have also had an impact on the performance of TB control programs. Countries with high HIV rates, where more than half of TB patients are infected with HIV, are reporting increasing mortality among TB patients. Malawi, for example, reported that in 1996, 21 percent of smear-positive TB patients died during the course of their treatment. With such high case fatality rates, these countries cannot reach the DOTS goal of curing 80 percent of TB cases. High mortality rates among tuberculosis patients also threaten the reputations of TB programs, the morale of TB healthcare workers and the popular perception that TB is a curable disease.

While TB programs focus on implementing DOTS, the priority of HIV/AIDS programs is to prevent HIV transmission and mitigate the health, social and economic impact of the HIV epidemic. Most HIV/AIDS programs have left TB control to the their countries' TB programs.

Many people living with HIV, however, do not have access to TB services. This may be because they do not want to reveal their HIV status outside the settings where they usually receive care and support services or because they do not have financial means to gain access to TB services.

The poor management of TB by HIV/AIDS services and increasing transmission of TB (including multi-drug-resistant TB) reflect the consequences of this fragmented approach to the dual epidemic. In countries with high HIV prevalence, HIV/AIDS and TB programs should be working together to support and strengthen the DOTS strategy and to address the needs of people living with HIV.

Strengthening DOTS

Five years after the introduction of DOTS, 119 of the 189 countries reporting to WHO were implementing this strategy. In 1998, only 17 percent of all estimated cases and 21 percent of estimated smear-positive TB cases were detected under the DOTS strategy. According to WHO's 2000 global TB report, TB treatment success with DOTS varies from 62 percent to 93 percent.⁵ In countries with an HIV prevalence of at least 10 percent in the general population, however, TB treatment success ranges from 58 percent to 73 percent and, on average, 19 percent of the patients die before completing treatment or are lost to follow-up.

In countries with low HIV prevalence, the DOTS strategy, when applied properly, has helped achieve high cure rates and limit the emergence of TB strains resistant to multiple drugs. In countries with high HIV prevalence, this strategy should be reinforced with innovative approaches to detecting TB cases and improving compliance with treatment.

Improving case detection

Detecting infectious TB cases is critical in TB control. Early detection of infectious TB cases reduces the pool of infectious individuals in the community and therefore limits transmission.

Under DOTS, TB programs rely on patients to present themselves to TB clinics for evaluation of their symptoms. This approach assumes that patients are knowledgeable of TB symptoms and that structural and cultural barriers to TB services do not exist. Unfortunately, that is not always the situation. WHO's 2000 global TB report clearly shows that 60 percent of the estimated 3.57 million cases of infectious TB in 1998 were not detected.⁵

The current strategy of TB control programs is to concentrate on increasing case detection only after a program has raised its cure or treatment success rate to around 80 percent. When programs do try to improve case detection, their impact is generally limited at best. This is because these efforts usually overlook the impact of cultural beliefs on healthcare-seeking behavior and do not always target (in their language or approaches) hard-to-reach populations, such as prisoners, ethnic minorities and people living in slums.

Many studies are revealing the impact of cultural beliefs on healthcare-seeking behaviors. In Cambodia, for example, FHI's investigation of perceptions of cough found that people categorize coughs as different types and have a different approach to seeking a diagnosis for each type.⁶ A recently published study shows that in Thailand, many people with TB symptoms were reluctant to seek medical care because they feared being identified as AIDS patients.⁷

Efforts to improve TB case detection offer an opportunity to draw on experience in changing behavior for HIV prevention. TB control programs can work with HIV/AIDS programs to develop interventions and communication strategies to change healthcare-seeking behavior and ensure prompt and effective treatment of new cases.

TB case detection can also be improved by introducing active case-finding interventions. Such interventions can initially target selected groups, such as family members of HIV-positive TB patients, confined populations and people living in overcrowded settlements.

Encouraging treatment compliance

TB treatment is a key element in tuberculosis control. Adequate treatment not only cures the patient, but also reduces transmission, and thereby the number of new infections. But treatment of TB requires at least three different drugs, which should be taken for at least six months. Patients may, for many reasons and particularly when their TB symptoms disappear, opt to interrupt their treatment. Poor compliance with TB treatment is even more dangerous than no treatment because it may increase the risk of developing multi-drug-resistant TB.

TB programs must develop strategies and interventions to ensure that patients who start treatment will complete it. Programs can use formative research among healthcare workers, community members, patients who default on treatment and those who comply with treatment to identify reasons for poor compliance. Then, based on data from this research, they can develop interventions, such as staff training and patient education and support, to encourage patients to complete treatment. This is another area where TB control program might seek assistance from HIV/AIDS programs, which have been studying and applying principles of behavior change for many years.

Another strategy for addressing compliance is to involve others in monitoring TB treatment. The involvement of communities in TB care has contributed to increased treatment success rates in Peru, Haiti and Bangladesh. WHO has just completed eight pilot studies in six sub-Saharan African countries (Botswana, Kenya, Malawi, South Africa, Uganda and Zambia) in which community members were trained to supervise treatment and support TB patients throughout their treatment. Data from these projects indicate that involving community members in TB care is cost-effective and helps achieve higher cure rates.

Beyond DOTS

Most TB control programs in high HIV-prevalence countries do not address HIV, even though many of their patients may be infected with the virus. Services such as HIV/AIDS education and counseling and testing are not always available at TB service points.

In many countries, HIV information and education is provided in TB clinics as part of the general health education given to TB patients. But TB and HIV are usually presented separately, and the interaction between them is often ignored. In some areas, HIV is not mentioned at all because healthcare workers believe that providing HIV education at TB clinics would scare away patients. Sometimes healthcare workers are so poorly informed about HIV that they are uncomfortable talking about it with their patients. Such attitudes obviously contribute to fears about AIDS and to the existing stigma associated with HIV.

Providing HIV education to healthcare workers in TB clinics can build their confidence in their ability to discuss HIV with their patients. Regular HIV education can also empower patients and provide them with the skills they need to reduce the risk of acquiring or transmitting HIV. And, by filling gaps in HIV knowledge and dispelling misunderstandings about the disease, HIV education can help reduce the related stigma and discrimination. TB control programs can seek the assistance of HIV/AIDS programs in training TB clinics' healthcare staff and developing educational materials addressing TB and HIV.

Access to counseling and testing

Given the strong relationship between TB and HIV, TB patients should be given the opportunity to know their HIV status. Most of them are aware of the strong correlation between TB and HIV, and once the diagnosis of TB is made, many live with the anxiety of believing that they might be infected with HIV.

Knowledge of serostatus will alleviate anxiety for those who test negative for HIV and motivate them to adopt lifesaving skills. But even for a person who is infected with HIV, knowledge of his or her status is valuable. Such knowledge makes it possible to plan for the future and change one's behavior to protect others. It also makes HIV more visible in communities, contributing to the reduction of stigma. And even though antiretroviral therapy is not widely available in most countries, people living with HIV can benefit from basic healthcare services and early preventive treatment or diagnosis and treatment of opportunistic infections.

TB patients' access to voluntary HIV counseling and testing can be improved by introducing such services into TB clinics or by building strong referral mechanisms between TB clinics and existing HIV voluntary counseling and testing services. In both cases, TB clinics need to train healthcare workers in educating TB patients about HIV, inform TB patients about the availability of the service, and establish linkages between medical services and support groups within the community. If voluntary HIV counseling and testing services are being introduced into a TB clinic, clinic managers need to arrange for the training of counselors, nursing staff and laboratory technicians. They also need to develop mechanisms for a regular supply of HIV testing kits and the referral of blood specimens and results between a laboratory and the clinic.

Managing HIV-related diseases

Health care workers in TB clinics generally know how to manage common, uncomplicated HIV-related illnesses. However, most non-industrialized countries do not have guidelines that would facilitate the management of HIV-infected TB patients and help healthcare workers decide when and where to refer patients. TB programs' proven experience in developing and disseminating TB control guidelines can be exploited by both TB and HIV/AIDS programs to establish guidelines on managing common, uncomplicated HIV-related illnesses. National tuberculosis control programs could build on existing TB training mechanisms to provide regular refresher training that keeps healthcare workers informed about new developments in the management of HIV-related disease.

Providing appropriate care to HIV-infected patients will boost the credibility of healthcare workers in TB programs. Moreover, involving TB healthcare workers in the management of HIV-related disease offers another advantage: if highly active antiretroviral therapy (HAART) for HIV infection becomes more widely available, TB clinics could be used to offer directly observed HAART to TB patients who are also infected with HIV as well as others living with HIV/AIDS.

TB in HIV/AIDS Programs

In countries with high rates of HIV infection where TB is prevalent, HIV/AIDS programs can contribute to TB control programs in various ways. For example, most of the community-based organizations that provide care and support to people living with HIV/AIDS must care for people who are also infected with TB. However, an evaluation by the WHO of the management of TB in HIV/AIDS community care schemes revealed that the quality of such care was generally poor.⁸

The WHO review clearly recognized that HIV/AIDS community care schemes could help improve TB care. HIV/AIDS community-based organizations can educate people living with HIV about TB, prompt early TB case detection, and facilitate access to appropriate TB diagnosis and treatment. The staff and volunteers of these organizations can be trained to conduct active case finding of TB, particularly among partners of TB patients infected with HIV. They can also assist in providing and monitoring TB treatment.

The only potential pitfall in enlisting HIV/AIDS community-based organizations as partners in TB control is the stigma associated with HIV. In areas where such stigma is particularly strong, for example, TB patients may decline to be supervised by a member of an HIV/AIDS organization.

Preventing TB

TB preventive therapy -- which is the use of a simple regimen (usually isoniazid for at least six months) to prevent the development of active TB disease in a person known or likely to be infected with TB bacilli -- is an effective means of preventing TB in people living with HIV/AIDS and therefore may reduce the TB burden in a community. The WHO and the Joint United Nations Programme on HIVAIDS (UNAIDS) recommend that TB preventive therapy be given as part of a package of care for people living with HIV/AIDS.⁹ However, care must be taken not to drain limited resources from TB control program activities, where diagnosis, treatment and cure of smear-positive cases must remain the priority. In addition, this TB preventive strategy requires identification of people who are infected with HIV. For both reasons, HIV voluntary counseling and testing centers may be an ideal site for such programs.

Implementation of a TB prevention intervention requires strong commitment from and collaboration between both the TB and HIV programs. Before implementation, TB programs should provide training in TB symptom recognition, diagnosis and treatment, exclusion of active TB, drug supply, treatment monitoring and diagnosis of active TB. Each HIV voluntary counseling and testing center participating in the program should have a clear plan for excluding active TB (systematic symptom evaluation for all HIV-infected patients or a clear referral mechanism to TB diagnostic services), and TB and HIV/AIDS programs should design a plan for monitoring and evaluating treatment. Such interventions could be coupled with other preventive therapies, such as cotrimoxazole (Bactrim) to prevent opportunistic infections.

Conclusion

TB program managers need to understand that there are more benefits than disadvantages to introducing HIV/AIDS services in TB clinics and responding to the needs of TB patients who are living with HIV. In fact, TB programs in countries with high HIV prevalence will not succeed without addressing HIV/AIDS. HIV/AIDS programs, in turn, can only benefit from collaborative efforts to treat and prevent the leading killer of people living with HIV. In countries with high rates of HIV infection, HIV and TB control programs need each other, and they must work together to reduce transmission of both infections and to improve care and support for all their clients.

-- Mukadi Ya Diul

Mukadi Ya Diul, MD, MPH, is a senior technical officer in the Technical Support/Care Group of FHI's HIV/AIDS Prevention and Care Department. As a medical officer with the World Health Organization, he served as the main project coordinator for the ProTest Project, a tuberculosis/HIV integration project, and the Community Tuberculosis Care Project.

References

1. C Dye, S Scheele, P Dolin, V Pathania, M Raviglione. Global burden of tuberculosis: Estimated incidence, prevalence, and mortality by country. JAMA 1999, 282:677-686.
2. HJ Chum, RJ O'Brien, TM Chonde, P Graf, HL Rieder. An epidemiological study of tuberculosis and HIV infection in Tanzania, 1991-1993. AIDS 1996, 10:299, 309.
3. Botswana National Tuberculosis Program. National Tuberculosis Report. Gaborone: Republic of Botswana Ministry of Health, 1997.
4. H Yanai, W Uthaivoravit, V Panich, et al. Rapid increase in HIV-related tuberculosis, Chiang Rai, Thailand, 1990-1994. AIDS 1996, 10:527-31.
5. World Health Organization. Communicable Diseases Cluster. Global Tuberculosis Control Report. WHO Report 2000. WHO/CDS/TB/2000.275. Geneva: World Health Organization, 2000.
6. A Guillou, F Stuer, M Kimmerlin. Perception of TB and cough among squatters in Phnom Penh, Cambodia. XIII International Conference on HIV/AIDS. Durban, South Africa, July 9-14, 2000. Abstract ThPeB5254.
7. J Ngamvithayapong, A Winkvist, V Diwan. High AIDS awareness may cause tuberculosis patient delay: Results from an HIV epidemic area, Thailand. AIDS 2000, 14:1413-1419.
8. D Maher, HP Hausler, MC Raviglione, et al. Tuberculosis care in community care organizations in sub-Saharan Africa: Practice and potential. Int J Tuberc Lung Dis 1997, 1:276-283.
9. Policy Statement on Preventive Therapy against Tuberculosis in People Living with HIV. WHO/TB/98.255. Geneva: World Health Organization, 1998.