The primary aim of this study is to compare the performance of the three NAATs that are available commercially to test pharyngeal and rectal specimens for C. trachomatis and N. gonorrhoeae infections with culture, the current method of choice, and with each other. In order to enroll adequate numbers of individuals with such infections, the study will be conducted during a 3-year period in a STD clinic and two HIV care clinics located in Birmingham, AL. Enrollment will be confined to individuals who are at high risk for genital C. trachomatis or N. gonorrhoeae infection, or who give a history of orogenital or rectal sexual exposures. An effort will be made to balance enrollment of heterosexual individuals and MSM, but resource limitations require that sample sizes be based on combining these subgroups.