|Sexually Transmitted Diseases (STD) Prevention: New Challenges, New Approaches (AIDSCAP/FHI - USAID, 1996, 47 p.)|
by Margaret J. Dadian
An STD laboratory in Singapore. Syndromic management of STDs greatly curtails the need for expensive testing. (T. Farkas/WHO)
Since the early 1980s, strong evidence has been building that infection with sexually transmitted diseases (STDs) significantly increases vulnerability to HIV. Health organizations worldwide have reacted with an upsurge of interest in STD prevention and treatment as critically important to curbing the spread of the HIV/AIDS epidemic.
Yet within developing countries, where STDs are a major health problem, this discovery has been overshadowed by some tough economic facts of life. Many poor nations lack the funds, trained medical personnel and laboratory resources to test their citizens for STDs. For example, in sub-Saharan Africa, where STD prevalence rates are among the highest in the world, average per capita income is about U.S.$450. STD lab tests, which can run as high as U.S.$40, may be prohibitively expensive for both individuals and national health care systems.
Throughout the world, though, etiologic diagnosis, which depends on lab results to identify disease and determine treatment, has been the standard diagnostic method for formal health care providers. In settings where lab tests are unavailable or unaffordable, practitioners rely on their own experience with STD-infected patients to determine through patient history and examination which STD is causing the symptoms. This is called clinical diagnosis, and research has shown it to be of limited value in diagnosing STDs.1
1. In a study of 100 men and 100 women with genital ulcers, South African practitioners using clinical diagnosis correctly identified only 42 percent of chancroid cases, 32 percent of syphilis cases, and 8 percent of mixed infections in the men (rates of correct diagnosis were higher for women). See O'Farrell et al. Genital ulcer disease: Accuracy of clinical diagnosis and strategies to improve control in Durban, South Africa. Genitourinary Medicine 70:7-11. 1994.
But with HIV spreading quickly, another approach was clearly needed. In 1988 the World Health Organization (WHO) began promoting an alternative to both etiologic and clinical diagnosis, one more appropriate for conditions in resource-poor settings. Called syndromic management, it offers immediate diagnosis and treatment without requiring expensive and time-consuming lab tests or advanced medical skills on the part of the practitioner. Combined with patient risk assessment, it may prove to be the most effective way to diagnose and treat STD infection in resource-poor settings.
Syndromic algorithms for diagnosing genital ulcer diseases, adapted from WHO's flow chart.
In syndromic management, the clinician bases diagnosis and treatment not on specific diseases identified through testing but rather on syndromes, which are groups of clinical findings and patient symptoms. Treatment is then offered for all diseases that could cause that syndrome. For example, a patient presenting with urethral discharge is treated for all diseases prevalent in the region that could cause such discharge-usually gonorrhea and chlamydial infection. Since all possible treatments are offered, the likelihood of a cure for the STD causing the discharge is greatly enhanced.
What helps the provider make the diagnosis and choose the correct treatment are simple flow charts that clearly map out the steps needed to determine symptoms and treatment (see example). Developed initially by WHO, the algorithms - specific diagnostic pathways - displayed on the flow charts ideally reflect STD prevalence and drug availability in the immediate region. These flow charts may be displayed as posters on the wall of an examination room or on cards or in small pamphlets for easy reference by the provider.
Following the flow chart for genital ulcers helps explain how the algorithms work. When a patient complains of a genital sore, the provider consults the flow chart for genital ulcers - a syndrome usually caused by syphilis, chancroid or herpes. Since an examination alone is not a reliable way to differentiate the cause of such sores, the algorithm on the flow chart helps providers decide whether to treat presumptively for syphilis and chancroid or simply help patients relieve their discomfort.
The first step is to examine the external genitals in men and the outer and inner surfaces of the labia in women. If the sore is in fact an ulcer (a discolored break in the skin or mucous membrane with a central depression), the provider is advised to treat for both syphilis and chancroid. The chart also reminds providers to educate patients about the treatment and how to prevent further transmission, including condom use and referring partners for treatment, and to explain how patients will know whether a follow-up visit is necessary. If the provider instead observes small, fluid-filled (vesicular) lesions, the next step is to treat to relieve the symptoms of herpes, provide education and counseling about the disease and its prevention, and encourage the patient to use condoms.
Syndromic management flow charts are designed to follow a diagnostic logic close to the provider's own thought processes. This is, in fact, the approach that many doctors follow naturally and subconsciously, said Dr. Johannes van Dam of the joint United Nations Programme on AIDS (UNAIDS). It simply provides a rational basis for a diagnosis or for a therapeutic decision by offering correct information based on the latest possible data.
One of the most frequently mentioned benefits of syndromic management is the lessening of provider dependence on laboratory tests. In resource-limited settings, lab testing may be too expensive to order consistently, or may be unavailable altogether. Even where there are labs, they may take weeks to provide results, which may not in fact be reliable. Adopting syndromic diagnosis allows managers to reallocate precious clinic funds once diverted to testing for other critical needs, such as drugs for STD treatment.
A second advantage of using syndromic algorithms is that they greatly simplify a complex diagnostic process for health workers without advanced medical skills or experience. In developing countries with few doctors and nurses per capita, this significantly expands the pool of providers and range of facilities that can treat STDs, and thus can lower STD prevalence on a much wider scale, at a much faster rate. Even for more highly skilled health providers, who may otherwise be forced to depend on clinical diagnosis or unreliable laboratories, using algorithms can raise the likelihood of effective treatment and complete cure.
A customer buys condoms in a small shop in Vietnam. As part of syndromic treatment, patients receive individual, on-the-spot counseling about STD prevention, including advice about condom use. (Richard Lord)
Perhaps the most important benefit of syndromic management is that treatment begins immediately. In etiologic diagnosis, clinicians usually wait for lab results to begin treatment. At the heart of syndromic management is recognition of the need to diagnose and treat an STD at the first point of contact with patients, who may live far away from the clinic and are often too poor, too busy or too intimidated to return for test results and medication.
Patients like the idea of being treated at first visit, and because syndromic management is more efficient, the waiting time for clinic visits is much shorter, said Dr. Alfred Brathwaite of the Jamaican Ministry of Health, which has implemented syndromic management in many of the country's STD clinics.
Immediate treatment also dramatically increases the odds of a successful cure and reduces the length of time during which the infection can be spread. And because prevention education is an important part of syndromic treatment, patients receive on-the-spot counseling for behavior change, including advice on condom use and other important prevention recommendations.
To be effective, syndromic algorithms must incorporate local data on STD prevalence, antibiotic resistance and drug availability. STDs that are very rare in a certain region, for example, might be dropped from the boilerplate WHO algorithm model, and specific antibiotics to which a significant portion of the STD organisms in the region have developed resistance might be replaced by more effective ones. Where certain drugs are not available or affordable-a problem throughout the developing world- the best possible alternatives are included on the flow chart.
At the heart of syndromic management is recognition of the need to diagnose and treat an STD at the first point of patient contact.
Algorithms may also need modification as health systems develop new treatment strategies, as happened recently in Jamaica.
Findings from a study on vaginal discharge prompted the Ministry of Health to adopt speculum examination for all female STD patients, said Dr. Brathwaite. We then altered the algorithms, adding clinical evidence of infection of the cervix.
Clearly, algorithm development is hard work, requiring serious commitment and input from all key players in national health care networks: ministries of health, the private medical establishment, nongovernmental organizations and public clinic systems. The data needed to determine prevalence and medication needs are often not available and can take much time and considerable research funds to generate. Perhaps the most difficult task is building agreement among all sectors of the health community on which algorithms to adopt for national and local STD guidelines- often a contentious political as well as medical task.
The process can be tough, but it's definitely worth it, said Dr. Ward Gates of Family Health International. Ultimately, what is accomplished is that the whole community comes to understand the value of recognizing and treating symptoms of STD-and that's essential to making syndromic management work.
Another challenge to adoption of syndromic management guidelines often comes from the medical establishment itself. Medical schools invariably train their students in etiologic and clinical diagnosis, and their graduates may resist a methodology they perceive as either inferior to what they've been taught or a diminution of their control.
Physician resistance can come from different sources, said Dr. Frans Crabbe of the Institute of Tropical Medicine, which works with the AIDS Control and Prevention (AIDSCAP) Project in developing syndromic management efforts. Ordering lab tests is often a matter of prestige to physicians, and in many countries, the medical establishment simply won't give up the belief that lab tests are necessary for good medicine.
The diagnostic challenges to syndromic management are even more significant. Built into the structure of syndromic diagnosis is the presence of patient symptoms- yet many suffering from STDs can be completely asymptomatic, particularly women. In fact, it's estimated that up to 30 percent of women infected with gonorrhea are symptomless; for chlamydial infection, the percentage soars to 70 percent of women (and 30 percent of men). These patients are not helped by syndromic diagnosis-unless their symptomatic sex partners notify them after being diagnosed with an STD.
One way to increase the efficacy of syndromic diagnosis in treatment of asymptomatic patients is to train providers of other health services for women to recognize clinical evidence of STDs where there are no symptoms. For example, providers at family planning clinics, whose main objective is not STD diagnosis, may discover indications of otherwise undetectable STDs while doing speculum examinations on women clients. Such providers can be trained to begin syndromic diagnosis when they find such signs.
Even where algorithms are not very specific, they can help narrow down options for STD treatment. Algorithms that are not specific enough to guide treatment in women may nonetheless help guide more cost-efficient use of single diagnostic tests where testing is possible, said Dr. King Holmes of the Center for AIDS and STDs at the University of Washington.
Another tool that can increase the effectiveness of syndromic diagnosis is risk assessment, which is particularly helpful in determining whether a woman with vaginal discharge should be treated for cervical infection (cervicitis) as well as vaginal infection. By asking a woman who has vaginal discharge focused questions about age, marital status, partner behavior, number of partners and frequency of partner change, a practitioner may be able to determine whether she is likely to have cervicitis, which can lead to serious health complications. Studies in several countries have identified being single, younger than 21, and involved with more than one partner or with a new partner for less than three months as risk factors for cervicitis.
To increase the diagnostic value of risk assessment, local research is necessary to identify which risk factors are effective in predicting which infections. The questions asked of patients must also be culturally sensitive, community-specific and grounded in epidemiological reality.
Risk factors that are useful in managing patients with severe STD symptoms in primary care clinics serving indigent patients in a large port city may not be useful in a rural family planning clinic serving married women with mild symptoms, said Dr. Holmes.
Building agreement on which algorithms to adopt for STD diagnosis guidelines is often contentious, a political as well as a medical task.
Another challenge for the syndromic approach is reducing the effects of overtreatment. Because providers are directed to treat for all possible STD causes of certain symptoms, patients may receive antibiotics and other medications they do not need. The expense and inconvenience to patients of these unnecessary antibiotics can be considerable, but not unreasonable compared to the common alternative in poor communities: self-medication with ineffective drugs.
An Ongoing Effort
The AIDSCAP Project and the organizations with which it works in STD prevention are involved in syndromic management projects in more than 22 countries. Among AIDSCAP's activities in these countries are baseline assessments of prevalence and antibiotic susceptibility needed to create appropriate algorithms, field testing of diagnostic pathways, convening of health providers and leaders from the public and private sectors to build consensus on STD management guidelines, ethnographic assessments of STD health-seeking behaviors, and development of training modules and training of health care providers and national and regional public health officials. AIDSCAP also works closely with such international bodies as WHO and UNAIDS, as well as with nongovernmental organizations and local health networks, to contribute to the worldwide effort to gather, analyze and disseminate data on STDs.
Each of these endeavors can generate immediate and ongoing benefits. For example, one AIDSCAP evaluation in Jamaica confirmed the diagnostic validity of flow charts for vaginal discharge in women and the efficacy of risk assessment in women for diagnosing STDs. The conclusions were shared with providers in the clinic where the evaluation was performed as well as with health policy makers throughout the country. The result has been the creation of new national protocols for all public health clinics in Jamaica that focus more accurately on diagnosing and treating the most prevalent STDs, reduce clinic waiting times by more than half, and save money and resources by eliminating unnecessary tests and procedures.
In the face of HIV/AIDS, AIDSCAP and other international health organizations continue to expand the search for more effective and affordable methods of preventing STD transmission, especially in developing countries. With undeniable evidence that preventing STDs also means preventing HIV, these efforts will remain at the forefront of the international campaign to control the AIDS epidemic.