Julius Schachter, PhD, from the Department of Laboratory Medicine at UCSF, and Jeffrey Klausner, MD, from the Department of Public Health, are conducting a study to evaluate a type of test (nucleic acid amplification test) for the detection of two sexually transmitted diseases, Chlamydia trachomatis and Neisseria gonorrhoeae, in men who have sex with men (MSM), using urine samples and swabs taken from the throat (pharynx), tip of penis (glans), and rectum. The use of nucleic acid amplification tests on these swabs is experimental, which means that the use of the tests for this purpose have not been approved by the Food & Drug Administration.

For all subjects enrolled in the study, the following clinical data information will be obtained: 1) reason for exam, 2) subject's signs and symptoms and 3) clinical assessment.

For each subject enrolled in the study, three clinician-collected pharyngeal, four rectal swabs (three clinician-collected, 1 self-collected) specimens, one glans swab (self-collected) and a first catch urine specimen (approximately 25 ml) will be obtained. The collection order of the clinician collected swabs will be randomized.

Three pharyngeal swabs will be tested for: 1) CT/NG NAAT (TMA) at DPH, 2) NG culture at DPH and 3) NAATs for CT/NG (TMA, SDA) and CT culture at UCSF. Four rectal swabs will be tested for: 1) CT/NG NAAT (TMA) at DPH, 2) NG culture at DPH and 3) NAATs for CT/NG on Clinician- and self-collected rectal swab (TMA, SDA) and CT culture at UCSF. Self-collected glans swab and the FCU will be tested by NAATs for CT/NG (TMA, SDA) at UCSF. All NAAT specimens collected in a universal NAAT transport medium. After specimen processing, samples will be frozen at -70 C for discrepant analysis.

Inclusion Criteria:

• A subject must be a man who has sex with men (MSM). Subjects must provide verbal consent, must be able to submit all required specimens and must not have urinated within 1 hr prior to providing a study urine specimen.

Exclusion Criteria:

• Subjects are excluded if they do not have sex with men, refuse to give verbal consent, are unable to provide all required specimens and minimum specimen volume, have been on antibiotic therapy within the last 21 days, have urinated within 1 hr prior to submitting study specimens, and have already been evaluated as part of this trial. Subjects will be excluded if specimens are mishandled or inappropriately stored.

Men who have sex with men (MSM) voluntarily presenting at the City STD clinic.