Sexually transmitted Chlamydia trachomatis and Trichomonas vaginalis infections in North Trinidad – prevalence, risk factors and laboratory diagnosis

Background: Annually, there is an estimation of 64 million new cases of curable STIs among people ages 15 to 49 in Latin American and Caribbean countries. Several risk factors such as age, multiple sexual partners, poor socio-economic conditions among others have been associated with STIs. However, there is paucity of data with prevalence, risk factors and effective laboratory detection methods in Trinidad and Tobago. Therefore, this study aims to determine the prevalence, associated risk factors, and the most effective laboratory method for diagnosing Chlamydia and Trichomoniasis. Methods: Urine samples (n=201- both males and females) and endocervical swabs (n=112 only females) from a cross-section of adults attending a STI clinic in the country were processed using standard laboratory methods including the wet mount microscopy, immunochromatographic assay (OSOM Rapid Test), Quickvue C. trachomatis Rapid Test Kit and Polymerase Chain Reaction (PCR). The demographic data, clinical presentations and associated risk factors were analysed using IBM Statistical SPSS v25. The data was descriptive and reported as comparisons of frequency distributions. A P value <0.05 was considered significant. Results: Majority of the participants 85% (171/201) were between the ages 20 and 40, and the rest 14.9% (30/201), were 41 and above. C. trachomatis was seen in 10.9% (22/201) of all participants with 15.7% (14/89 males) and 7.1% (8/112 females). T. vaginalis was detected in 9.0% (18/201) of all participants; 6.7% (6/89, in males), and 10.7% (12/112, in females). Married participants 14.8% (8/54) had Trichomoniasis and 6.8% (6/147) unmarried (p=0.07). When compared with PCR as the gold standard test, the sensitivity and specificity results using the rapid test kit for C. trachomatis was 37.5% and 99.1% respectively; and the sensitivity and specificity of the OSOM Rapid Test for T. vaginalis was 90% and 100% respectively. Wet mount microscopy demonstrated low sensitivity 30%, and high specificity (100%) in the detection of T. vaginalis, while OSOM Rapid Test for T. vaginalis detection displayed high sensitivity 90% and specificity 100%. Discussion: The results are comparable with the global trend. Barbados had an 11% prevalence of Chlamydia infection, while in 2016, Thailand ranged between 5.7-16.2% and China between 4.9 - 14%. Suriname recorded a 15% prevalence. Whereas trichomoniasis prevalence of 9.0% was recorded in this current study, while Tanzania ranged from 10.4% to 13.4%. Chile and Argentina showed lower rates at 2.4% to 3.0% and 1.4% to 5.2%, respectively. However, Brazil had rates ranging from 3.7% to 30%, Haiti from 20.5% to 27.7%, and Mexico at 19.0%. Conclusions: The high prevalence of Chlamydia infection highlights the need for rapid testing kits in the country's STI cases. The efficient performance of the OSOM rapid test suggests its suitability for routine diagnosis of trichomoniasis infections in the country.