HIV-1 and CD4 Diagnostic Assays Used for Study Eligibility.

*All assays were required to pass external quality assessment prior to implementation for study-related testing and were required to undergo ongoing external quality assessment for the duration of the study. †Paired HIV-1 rapid tests run in parallel. ‡Confirmation of rapid test positive results performed with 2 wells on primary EIA kit. If initial EIA results were discrepant, the assay was repeated with one well each using the primary and secondary EIA kits.