Diagnostic accuracy of the syndromic management of four STIs among individuals seeking treatment at a health centre in Nairobi, Kenya: a cross-sectional study

Introduction: the syndromic approach to the management of sexually transmitted diseases (STIs) is recommended in areas without adequate laboratory support. We assessed the diagnostic accuracy of this approach in diagnosing Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) among 18 to 49 year-old individuals seeking treatment for STIs in a health centre in Nairobi, Kenya.

Methods: participants were recruited between April and June 2019. After providing written informed consent, an interviewer-administered questionnaire was completed. Endocervical swabs from women and urethral swabs from men were collected for STI testing using polymerase chain reaction (PCR). Diagnostic accuracy of reported symptoms was calculated using PCR as the gold standard.

Results: a total of 297 individuals (148 men and 149 women) were recruited. Majority of the participants had at least one reported symptom (130/148; 87.8% men and 145/148; 97.3% women). The most commonly diagnosed STI was NG (85/297; 28.6% 95%CI 23.5%-34.1%). Vaginal discharge syndrome had moderate (44.4%) to high (92.9%) sensitivity, low specificity, low positive predictive value (PPV) (2.4 % to 31.5%) and high negative predictive value (NPV) (68.2% to 95.2%). The lower abdominal pain syndrome had moderate to high sensitivity (40% to 71.4%), low specificity (30.9% to 35.6%), low PPV (9.9% to 15.8%) and high NPV (79.2% to 93.8%). The urethral discharge syndrome had high sensitivity (71.4% to 84.8%); moderate specificity (37.6% to 51.7%); low to moderate PPV (5.4% to 53.8%) and high NPV (83.6% to 96.4%). The kappa scores for the three syndromes were generally poor.

Conclusion: these findings support the need for the review of the syndromic management of STIs.