Three Approaches to STI/RTI Diagnosis

The management of sexually transmitted infections (STIs) and reproductive tract infections (RTIs) can be difficult:

• Testing is often not available in low-resource settings, so diagnosis must be made based on symptoms and signs.
• Some infections are impossible to differentiate, even by highly trained providers, based solely on their signs and symptoms.
• Clients who seek treatment from multiple providers may present with symptoms altered by previous treatments.

The clinical approach

Clinical management is the least reliable of the three approaches. Using the clinical approach, a health care provider relies on his or her own experiences to arrive at a specific diagnosis based on the symptoms reported by the client and the clinical signs observed during physical examination. Clinical diagnosis can be problematic because:

• STIs often vary in the way they appear upon examination (i.e., they often do not appear as a “textbook” case).
• A person may have more than one infection at a time, making clinical diagnosis even more difficult.
• Previous self-treatment or previous treatment by another provider (or a traditional healer) may alter the signs and symptoms by the time the person comes to the clinic.

Studies have shown that even highly experienced STI specialists using clinical diagnosis will fail to make the correct diagnosis and will miss concurrent infections in a significant number of cases.

Even though the clinical approach is the least reliable of the three approaches and often results in misdiagnosis, it is the most common in many low-resource settings where laboratory services are not available or where providers are not trained in or do not recognize the effectiveness of the syndromic approach.

The etiological approach

The etiological approach, the most traditional and accurate of the three, is based on the results of laboratory tests. These tests identify the specific infectious agent, which then determines the treatment to be administered. Although this approach is the most reliable and desirable for management of STIs/RTIs, it is often not available to health providers in the developing world because it depends on trained laboratory technicians, availability of lab supplies, and in some cases expensive, specialized equipment. Additionally, this method may require the client to return for a second visit in order to collect laboratory results and receive treatment.

The syndromic approach

Because of the unavailability of laboratory tests in many low-resource settings and the potential for inaccuracy when providers rely on the clinical approach alone, syndromic management is often the best approach in low-resource settings.

In this approach, diagnosis is based on the identification of syndromes, which are combinations of the symptoms the client reports and the signs the health care provider observes. The recommended treatments are effective for all the diseases that could cause the identified syndrome. However, syndromic management cannot address the widespread problem of asymptomatic infections, in which clients do not experience any symptoms at all.

The syndromic approach, which has been recommended since 1990 by the World Health Organization (WHO) for use with clients who present with symptoms of STIs, consists of four elements:

1. Classification by syndrome: Classifying the main causal pathogens by the syndromes they produce
2. Use of algorithms: Using flowcharts to guide the management of a given syndrome
3. Treatment and counseling: Using often more than one treatment that addresses all the pathogens with potential to cause a given syndrome
4. Treatment of partners: Promoting treatment of sex partners

To be most effective, the syndromic approach should be backed by scientific data on the local prevalence of STIs and drug susceptibility of the infectious agents and must be supported by appropriate health education. Although syndromic management may be more appropriate than laboratory-based approaches in many settings, this approach is of limited usefulness when applied to vaginal discharge, which is more often related to non-sexually transmitted RTIs than STIs. (We will discuss this topic in more detail later in this module.)

Some STIs, such as chlamydia, gonorrhea, human papillomavirus (HPV), hepatitis B, and genital herpes, often cause infections that are asymptomatic. This means that the STIs might never produce signs and symptoms, or that they might not appear for a long time. For example, the majority of HPV infections in women and men cannot be recognized clinically, and up to 75% of primary episodes of herpes are asymptomatic or produce only mild or unrecognized symptoms. More than 75% of women with chlamydia are symptom-free, yet this STI can lead to pelvic inflammatory disease (PID), which, in turn, can lead to infertility and ectopic pregnancy (pregnancy outside the uterus).

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