The only way to be certain someone has a sexually transmitted disease (STD) is to identify the disease-causing microbe with laboratory tests, which are usually expensive and often require a client to return for results and treatment.
Consequently, the World Health Organization (WHO) has developed an approach for diagnosing and treating STDs without the use of laboratory tests. Called syndromic management, this approach is based only on a person's clinical signs and symptoms. More recently, WHO and other organizations have begun developing a tool called "risk assessment," which seeks to improve the accuracy of syndromic screening by including an evaluation of the client's behavior and other social circumstances that are correlated with STD risks. Having multiple partners, for example, suggests a greater STD risk than being in a monogamous relationship.
"STD risk assessments hold promise, but the research is mixed on their usefulness at this point," says Dr. Willard Cates Jr., FHI senior vice president of biomedical affairs and an expert on STDs. "What is clear is that any STD risk assessment has to be modified to individual countries and regions within countries, according to cultural issues, prevalence of various STDs and other factors."
Identifying infected clients by signs and symptoms alone (syndromic management) works well in some situations. For example, treating men with urethral discharge for gonorrhea and chlamydial infection is effective. However, identifying women with cervical infections, such as gonorrhea and chlamydial infection, has been less successful.1 For many women infected with gonorrhea or chlamydia, there are no symptoms.
While risk assessment models are being studied as ways to improve the accuracy of diagnosis for treatment, they can also play a role in STD prevention strategies. For example, risk assessments can be used effectively by nearly any family planning program for counseling on contraceptive choices to improve STD prevention, says Laurie Fox of FHI, who studies STD services and family planning programs. However, she cautions, "Program managers should not add STD risk assessment to their routine services without understanding its limitations as a diagnostic tool."
Checklist of questions
An STD risk assessment is simply a checklist of questions on demographic, behavioral and related factors. Questions cover such issues as the number of sexual partners a person has, the client's age, whether he or she has had a new partner in recent months, has had a previous STD infection, has symptoms such as a discharge or abdominal pain, whether his or her partner has symptoms or other sexual partners, and whether the partner travels frequently.
In 1993, WHO developed a risk assessment tool to be used in conjunction with its syndromic management approach (also known as syndromic algorithms) for vaginal discharge.2 "We suggested that certain variables would show an increased risk, such as being under age 21, having a symptomatic partner or having a new partner in the last three months," says Dr. Monir Islam, chief of the WHO's Family Planning and Population unit.
"But we should not have been so specific, because the risks will be different in different countries. A lot of countries took this new list as definitive," he says. For example, in some settings, women may not know if their husbands have symptoms. Couples may always have sex in the dark, which may mean that a woman would not observe her husband's genital ulcers or urethral discharge.
Among women with vaginal discharge, STD risk assessments based on local factors seem to improve the identification of those who have gonorrhea or chlamydial infection. Unfortunately, they also incorrectly identify many women as having an STD when they do not, thus leading to unnecessary treatments.
Treating uninfected people who are led to believe they have an STD can be emotionally traumatic, especially when they inform their partners. Hence, an uninfected wife asking her uninfected husband to be treated can imply that he or she has been unfaithful. Excessive treatment with antibiotics can also result in STD organisms that are resistant to the antibiotic.
A study among 996 women attending an antenatal clinic in Haiti found that a risk assessment model based on local risk factors correctly identified almost nine of every 10 infected women. However, the model also concluded incorrectly that many uninfected women were also in need of treatment. For every five women designated by the model for treatment, only one was actually infected.
Among symptomatic women, risk assessment can increase the sensitivity of clinical diagnosis among infected women, concludes Frieda Behets of the University of North Carolina (UNC) Medical School, USA, who led the Haiti study.3 (To evaluate such models, researchers compare the results of a risk assessment with laboratory testing.)
A study among 964 women attending a rural antenatal clinic in Tanzania compared nine risk assessment models. As in Haiti, risk assessments using local sociodemographic factors improved the performance of correctly diagnosing women with gonorrhea and chlamydial infections. One local risk assessment correctly discovered 69 percent of the women who had the diseases, but incorrectly identified about seven uninfected women for treatment for every one true infection it found.
The local assessments asked each woman (all were pregnant) if she was younger than 25, her marital status, number of sexual partners over the last year, whether she had any symptom related to genital infection, had previously given birth (indicating that sexual activity had not begun recently) and, if so, whether her most recent birth had been more than five years ago (indicating possible low fertility due to STD infection). Answers had weighted scores, with a certain total score or higher indicating treatment for gonorrhea and chlamydia.4
A study in Zaire among urban pregnant women used the results of a leukocyte esterase dipstick (LED) test on urine in addition to other factors, including age, marital status, number of sexual partners and symptoms. The LED, a simple test that does not require laboratory facilities, predicts possible infection using a color chart to show an elevated white blood cell count. This approach identified nearly three of every four infected women.5
Partner's behavior
In a review of STD risk assessment studies conducted in Africa, Susan Chen and her colleagues at FHI concluded that among married, monogamous women, the husband's behavior may be a better indicator of the woman's risk than is the woman's behavior. A husband may bring an infection to his wife from extramarital sex. For the husband's behavior to be useful in the risk assessment, a woman must be able to report her partner's behavior accurately.6
Research in Kenya among pregnant women at an urban clinic found risk assessment generally performed poorly in detecting gonorrhea and chlamydial cervicitis.7 "The women were at risk primarily because of their partners' behavior, and it was very difficult to get accurate information about the partners," explains Dr. Stephen Moses of the collaborative research program of the University of Nairobi Medical School and the University of Manitoba, Canada, which conducted the study.
A recent study at a Jamaican family planning clinic also found that a risk assessment approach did not detect STDs accurately. The most predictive measure of STD infection was the LED test.8 Many of the infected women in Jamaica had no symptoms. "Identifying cervical infection is very difficult among asymptomatic women," says Behets of UNC, who worked on the study. "At this point, we have a very limited array of tools. It's frustrating." FHI coordinated the study, working with the Jamaica Ministry of Health.
The USAID Technical Guidance/Competence Working Group is currently developing guidelines for adapting an STD risk assessment tool to local situations, using many of the variables evaluated in these studies.
Contraceptive choice
With the sharp increase of HIV and other STDs in developing countries, evaluating the risk of STD infection among family planning clients is becoming more common. "It's a subtle but important shift for a provider to make," says Dr. Cates of FHI. "Instead of thinking of themselves as family planning providers, it may be time to think of themselves as reproductive health providers. Using a risk assessment approach can help incorporate STD thinking into contraceptive choice."
In recent years, basic STD/HIV prevention messages have become common at a growing number of family planning clinics. Some programs have taken this a step further, using risk assessments as a part of the contraceptive counseling process.
In Brazil, a 1994 study showed that many clients perceived themselves at possible risk for STD infection.9 The Sociedade Civil Bem-estar Familiar no Brasil (BEMFAM), the International Planned Parenthood Federation (IPPF) affiliate in Brazil, then trained its staff in STD prevention.
"All women who come to the clinic are now invited to participate in a group discussion, where we talk about STD prevention," says Rita Badiani, BEMFAM's planning coordinator. "The group leader explains some of the symptoms of STDs, encouraging those with symptoms to seek services. The goal is to increase awareness of STD risk and to empower women to discuss sexual matters with partners and negotiate safer sexual practice." After this counseling session, women may consider themselves in the "at-risk" group. This group receives a clinical exam, which includes a risk assessment questionnaire.
In Kenya, following a training program for providers from about 200 private sector family planning clinics, many of these clinics now use a one-page behavior risk assessment form in counseling clients about contraception and HIV/AIDS. They ask if a client has had an STD in the last three months, engaged in unprotected sex with more than one partner in the last three months, and other questions.
"The providers classify the clients as high risk or low risk depending on their answers," explains Charles Omondi, who manages this project at the Family Planning Private Sector (FPPS) Programme, which works with the clinics. The classification helps guide the provider and the client with method choice.
While helpful, the risk assessment system also has a potential weakness, cautions Omondi, in that contraceptive decisions might be viewed more as something to be prescribed by providers, rather than chosen by clients. "It could give too much power to the service provider and less autonomy to the woman" as it may discourage choice, Omondi says.
Contraceptive choice is complicated by the dual needs of protecting against both unwanted pregnancy and STDs. Providers must explain that only barrier contraceptive methods can prevent STD transmission, and that latex condoms are the most effective method of protection. If a couple uses condoms consistently and correctly, they are highly effective for both purposes.
Many family planning programs now recommend that a woman concerned about STD infection should use latex condoms in addition to a modern contraceptive method. However, a recent review of research has found that condoms may be used less consistently when recommended for STD prevention, together with a very effective contraceptive.10 Hence, this approach to "dual-method" use may not be effective at preventing disease among some clients.
STD risk assessment affects other contraceptive choices. "Many providers are not screening women properly for possible STD infection before inserting an IUD," says Dr. Mark Barone, medical associate at AVSC International. AVSC is participating in a project funded by the Mellon Foundation to analyze how STD issues affect IUD use. "The IUD is a very good method that is very popular in developing countries. It is inexpensive, very effective, has few side effects, and the woman does not have to remember anything to use it properly."
If a woman has a reproductive tract infection when she gets an IUD, however, the insertion process could cause the infection to ascend into the cervical canal, possibly leading to pelvic inflammatory disease. When considering an IUD insertion, a provider should examine the client for lower abdominal or cervical motion tenderness, and look at the cervix for inflammation or mucopus. If such signs are present, "then do not insert an IUD," says Dr. Islam of WHO. "Treat for gonorrhea and chlamydia, or make sure the client is treated."
Practical considerations
A consideration for any clinic integrating STD services with other health care is cost. Compared with other options for STD treatment services, the cost of risk assessment appears to be favorable. The Tanzania study among rural antenatal clinics reported that combining the WHO syndromic approach for vaginal discharge with a risk assessment approach among those attending antenatal and maternal and child health clinics "may currently represent the most cost-effective approach" to diagnosing and treating gonorrhea and chlamydial infection.11
While such cost estimates are promising, providers are not used to treating an infection based on signs and symptoms, much less on a risk assessment score. "In our experience, it is not enough to train providers just once on using a syndrome approach," says Behets. "It goes against all of their training, which is to use a microscope to find the cause of the infection. You have to follow up with repeated messages. Changing behaviors of providers is as difficult, if not more so, than changing the behavior patterns of patients."
The Kenya training project among the private sector clinics did not initially include supervisors, which reduced the ability of the clinic staff trainees to introduce syndromic management. "Their supervisors were not convinced of the need for this approach," says Janet Hayman of FHI's AIDSCAP Project, which funded the training. The project added supervisors to the training and has now trained more than 60 supervisors.
Providers can also be trained to determine if a woman is asymptomatic whether or not she has signs of infection. If she does have signs, a risk assessment is more useful. Women often do not realize that a symptom of a reproductive tract infection is something out of the ordinary, explains Dr. Islam. "For all women coming for family planning services, providers could look at the vulva for ulcers, discharge, or bubo, and determine quickly if they are really asymptomatic or not, and act accordingly."
--William R. Finger
References
- Cates W. STD risk assessment: A tool for integrated reproductive health services. Int Fam Plann Perspect. In press.
- World Health Organization. Informal technical working group meeting on STD activities in GPA. The evaluation of algorithms for the diagnosis and treatment of vaginal discharge; agenda item No. IV. Background paper No. 5. Unpublished. 1993.
- Behets FM-T, Desormeaux J, Joseph D, et al. Control of sexually transmitted diseases in Haiti: Results and implications of a baseline study among pregnant women living in Cite Soleil shantytowns. J Infect Dis 1995;172:764-71.
- Mayaud P, Grosskurth H, Changalucha J, et al. Risk assessment and other screening options for gonorrhea and chlamydial infections in women attending rural Tanzanian antenatal clinics. Bull WHO 1995;73(5):621-30.
- Vuylsteke B, Laga M, Alary M, et al. Clinical algorithms for the screening of women for gonococcal and chlamydial infection: Evaluation of pregnant women and prostitutes in Zaire. Clin Infect Dis 1993;17:82-8.
- Chen S, Feldblum P, Welsh M. A survey of STD risk assessment used among low-risk populations in East/Central Africa. Family Health International, Unpublished. November 1996.
- Thomas T, Choudhri S, Kariuki C, et al. Identifying cervical infection among pregnant women in Nairobi, Kenya: limitations of risk assessment and symptom-based approaches. Genitourin Med 1997; in press.
- Behets FM-T, Ward E, Fox L, et al. Sexually transmitted diseases in women attending Jamaican family planning clinics and the lack of appropriate detection tools. Unpublished. 1996.
- Costa N, Bailey P, Fox L, et al. HIV risk assessment in family planning clinics in Brazil. Unpublished. BEMFAM and FHI, 1993.
- Cates W. Contraceptive choice, sexually transmitted diseases, HIV infection and future fecundity. Br Fertil Soc 1996;1(1):18-22.
- Mayaud, 628.
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