Cepheid Rectal Sample Validation Study

The purpose of this study is to validate Xpert CT/NG for the detection of CT and GC in rectal samples as part of the PA DOH and CLIA requirements. The evaluation of samples obtained from the pharynx is exploratory and will provide new information on the frequency of pharyngeal infection due to CT and GC. A secondary objective will be to evaluate the prevalence of Trichomonas vaginalis in vaginal and rectal samples using both the Xpert system and AC2 to assess whether women positive for this pathogen rectally usually or always have vaginal infection due to this pathogen. The investigators hypothesis is that real-time PCR (polymerase chain reaction) amplification testing with the Cepheid Xpert CT/NG will have greater sensitivity than culture in detecting Neisseria gonorrhoeae in rectal samples. The investigators also hypothesize that Xpert CT/NG will be equivalent to the Gen-Probe APTIMA Combo2 (AC2) in detecting Chlamydia trachomatis and Neisseria gonorrhoeae in rectal samples.