Background Chlamydia trachomatis (CT) and Neisseria gonorrhoea (GC) are the two most common bacterial STIs. Screening for CT and/or GC, is recommended in many countries. The prevalence of Trichomonas vaginalis (TV) is also high and negative consequences of untreated infection may be serious. Inclusion of TV as part of a combination assay would facilitate screening of these STI. Here we evaluated the performance of the BD MAX CT/GC/TV assay compared to currently available assays for these STI.

Methods Eight STD and Family Planning clinics enrolled participants for this study. Vaginal and endocervical swabs, and female and male urine specimens were obtained from 1854 women and 843 men. Female samples were used for evaluation of the BD MAX CT/GC/TV assays while male urine was used only for CT/GC evaluation. BD MAX CT/GC/TV results were compared to the Aptima Combo 2 ® CT/GC; BD ProbeTec^TM CT/GC; BD Viper^TM CT Q^x/GC Q^x; TV microscopy and culture. Participants were classified as infected if at least one positive result from each of 2 comparator assays were obtained. Positive wet mount and/or culture results were used as evidence of TV infection for women only.

Results Among women, 7.3%, 2.4% and 14.7% were infected with CT, GC and TV, respectively. Among men the rates were 22.0% and 14.6% for CT and GC. The BD MAX CT/GC/TV assay detected 92.2–99.2%, 94.9–95.1% and 92.9–96.1% of CT, GC and TV infections among women, depending on specimen type, and 96.6% and 99.1% among men. The specificity for all organisms and sample types was >98.5%.

Discussion In this US multi-site study, the prevalence of TV infection was high, demonstrating the benefit of screening women for TV as well as GC and CT. The BD MAX CT/GC/TV assay performance allows combined testing for all 3 STI among women and CT/GC from male urine.­­

Financial disclosure This study was funded by BD Diagnostics.