Background Miami, Florida, has the highest rate of HIV diagnoses in the USA (70.3 per 100 000 people), accounting for 1218 of the 41 269 incident HIV cases nationwide (2008). Although Trichomonas vaginalis (TV) infection has been associated with an increased risk of HIV acquisition in women, the prevalence of TV in Miami is unknown due to lack of routine screening and low sensitivity testing methods. The purpose of this study is to establish a prevalence of TV in women seeking services at the Miami-Dade County Health Department Downtown STD Clinic compared to the prevalence of routinely screened STDs, gonorrhoea (GC) and Chlamydia (CT).

Methods This study analyses baseline data from the Miami site of Project AWARE which is a multi-centre randomised clinical trial that seeks to test the effectiveness of risk reduction counselling in preventing sexually transmitted infections including HIV among HIV-negative persons. Eligibility criteria for Project Aware included negative or unknown HIV status, age of 18, and ability to provide informed consent. We recruited 251 women aged 18–64 for STD screening. The screen included FDA-approved Aptima GC/CT NAAT (nucleic acid amplification test) and a newly validated Aptima TV NAAT. Specimens were collected by vaginal swab performed either by a clinician or the patient. Additionally, we report the TV diagnoses given the current clinic protocol in which only symptomatic women received a wet mount analysed by light microscopy. We use descriptive statistics to report the prevalence of GC, CT and TV (as diagnosed by NAAT and wet mount) in our clinic.

Results Of the 251 women in our study, 163 high-risk populations. Received a wet mount. By wet mount, we found a 9% prevalence of TV in our patients. Comparatively, when all 251 patients were screened using NAAT, the TV prevalence was 20%. The prevalence of CT was 14% and GC was 6%.

Conclusions TV is the most prevalent STD in patients in our clinic which draws upon high-risk individuals in urban Miami. TV infections were greater than CT, often believed to be the most prevalent STD in our population. Further, the routine screening using the TV NAAT detected 27 cases of TV that would have been undiagnosed given current clinic protocol. Since Miami, FL has the highest prevalence of HIV in the country and TV infection has been linked to new HIV infection, we believe that routine TV screening by NAAT should be instituted in high-risk populations.