Used acyclovir or valacyclovir during study follow-up.HSV-2 prevalenceOf the 2,499 participants, 1383 (55.3 ) tested negative for HSV-2 at baseline, 892 (35.7 ) tested positive, 223 (8.9 ) had indeterminate tests, and one test was not done. Of the 223 with indeterminate tests at baseline, 114 (51.1 ) tested positive for HSV-2 infection at some point during follow-up. Factors associated with testin

No differences by randomization group in the proportion of participants with 1 STI examination during which a perianal ulcer (FTC/TDF 3.5 vs. placebo 4.7 , P = 0.37) or groin ulcer (FTC/TDF 2.5 vs. placebo 1.9 , P = 0.51) was identified; results were similar after excluding participants with a positive syphilis rapid plasma reagin test at the same visit. However, symptoms that prompted STI exam