Macro vue rpr

The venipuncture blood specimens were transported to the reference laboratory for serum separation and comparison testing. The reference test for comparison to the HIV component of the dual rapid test was the 4th-generation enzyme immunoassay (Genscreen™ ULTRA HIV Ag-Ab, Bio-Rad, France) for the simultaneous qualitative detection of HIV p24 antigen and antibodies to gp41 and gp36 of HIV Type 1 (HIV-1 groups M and O) and HIV Type 2 (HIV-2) in human serum or plasma. A confirmation Western Blot test was conducted (NEW LAV BLOT I, Bio-Rad, France) for all specimens that were positive on the enzyme immunoassay, as is done routinely in this setting, and those that were positive on both the enzyme immunoassay and the Western Blot were considered HIV infected. For the Treponema pallidum antibody comparison, Treponema Pallidum Particle Agglutination (SERODIA-TPPA, Fujirebio Diagnostics, Inc., Japan) was used qualitatively. Rapid plasma reagin (RPR) (BD Macro-Vue™ RPR, Becton, Dickinson and Co., Franklin Lakes, NJ) results were also available for all participants to assist with clinical diagnosis. RPR titer levels were determined using serial dilutions.

The biologic outcome of interest was a recent diagnosis of either HIV or an STI at baseline using a composite HIV/STI outcome (Hartwell et al., 2013 (link)). New HIV infection was defined as a participant reporting a negative HIV test result within 6 months of their baseline study visit. Positive HIV rapid tests (Determine HIV-1/2, Alere Medical Co, Japan) were followed with confirmatory testing by a 4^th generation Ag/Ab HIV EIA serum test (Genscreen ULTRA HIV Ag-Ab, Bio-Rad, Redmond, WA) and Western Blot confirmation (Genetic Systems HIV-1 New Lav Blot I, Bio-Rad, Marnes-La-Coquette, France). Only participants diagnosed with HIV within 6 months of their study visit were then coded as positive. Participants who were known to be HIV positive for >6 months were not included in the outcome unless they were found to have acquired a new STI. Recent syphilis diagnosis was defined by an RPR (BD Macro-Vue RPR, Beckton-Dickinson, NJ) titer of ≥1:16 and confirmed with TPPA (Serodia TP-PA, Fujirebio Inc, Japan). Rectal Neisseria gonorrhea and Chlamydia trachomatis infections were diagnosed by nucleic acid amplification tests of self-collected rectal swabs (Aptima Combo2 CT/NG, Hologic, San Diego, CA).