BACKGROUND: Early and accurate detection of HIV is crucial when using 
pre-exposure prophylaxis (PrEP) for HIV prevention to avoid PrEP initiation in 
acutely infected individuals and to minimize the risk of drug resistance in 
individuals with breakthrough infection.
OBJECTIVE: To determine if fourth-generation antigen/antibody (Ag/Ab) rapid 
diagnostic tests (RDT) would have detected HIV infection earlier than the 
third-generation RDT used in MTN-003 (VOICE).
STUDY DESIGN: 5029 VOICE participants were evaluated with third-generation Alere 
Determine™ HIV-1/2, OraQuick ADVANCE® Rapid HIV-1/2, Uni-Gold™ Recombigen® 
HIV-1/2 and Bio-Rad GS HIV-1/2+O EIA; and fourth-generation Alere Determine™ 
HIV-1/2 Ag/Ab Combo, Conformité Européene (CE)-Marked Alere™ HIV Combo and 
Bio-Rad HIV Combo Ag/Ab EIA. Multispot®, GS HIV-1 Western Blot (WB) and Geenius™ 
(Bio-Rad) were also evaluated.
RESULTS: Of 57 antibody-negative pre-seroconversion plasma samples with HIV RNA 
>20 copies/mL identified, 16 (28%) were reactive by CE-Marked Alere™ HIV Combo 
(1 Ab; 9 Ag; 6 Ag/Ab reactive) and 4 (7%) by Alere Determine™ HIV-1/2 Ag/Ab 
Combo (2 Ab; 2 Ag; 0 Ag/Ab reactive) (p=0.0005). Multispot® confirmed only 1 of 
16 acute infections while WB and Geenius™ confirmed none. GS HIV Combo Ag/Ab EIA 
identified 27 of 57 (47%) pre-seroconversion RNA-positive samples.
CONCLUSION: In VOICE, 28% of infections missed by current third-generation RDT 
would have been identified with the use of CE-Marked Alere™ HIV Combo. Geenius™, 
Multispot® and WB were all insensitive (<10%) in confirming infections detected 
by fourth-generation assays. An improved diagnostic algorithm that includes a 
fourth-generation RDT with HIV RNA testing will be essential for efficiently 
identifying seroconverters on PrEP.