Improving Diagnosis of Trichomonas Vaginalis Infection in Resource Limited Health Care Settings in Sri Lanka

OBJECTIVE: This study was designed to compare diagnosis of trichomoniasis by culture, wet smear examination, and Giemsa stain. A modified technique was used to transport and prepare the specimen to ensure parasite viability prior to Giemsa staining. MATERIALS AND METHODS: A clinic-based prospective study was carried out in association with the National STD/AIDS Control Programme over a period of 18 months. Three swabs were collected from the posterior fornix of 346 newly registered female patients for diagnosis of trichomoniasis. A wet smear was prepared using the first swab. The second swab was placed in 5 mL of 0.9% saline with three drops of 5% glucose at room temperature and centrifuged twice at a low speed prior to preparation of a Giemsa stained smear. The third swab was for culture. The three tests were performed independently. The specificity and sensitivity of the wet smear and Giemsa stain were compared to culture. RESULTS: With culture, the prevalence of trichomoniasis was 6.9% (95% CI: 4.1–9.3%). The Giemsa-stained smear was found to be highly sensitive (100%, 95% CI: 86.2–100%) and specific (99.69%, 95% CI: 98.26–99.95%) compared to culture. The wet smear was less sensitive (95.83%, 95% CI: 79.76–99.26%) but equally specific (100%, 95% CI: 98.82–100%). CONCLUSION: In developing countries, facilities for using culture are limited and wet smear examination in the field is also difficult due to the immediate need for laboratory facilities. Our study demonstrated that, in this setting, using a transport medium prior to Giemsa staining is a feasible alternative, with a high-diagnostic yield.