High acceptability of rapid HIV test in Argentina. Experience during a seroprevalence study in vulnerable groups

DURAN A, ,, , , , , . ; ROSSI D; MARONE R; ORELLANO G; ROMERO M; PETRACCA C; BENEDETTI E; AVILA MM,; SALOMÓN H,; PANDO MA

Vancouver

Congreso; 8th IAS Conference on HIV Pathogenesis, Treatment and Prevention; 2015

IAS

Background: The Ministry of Health in Argentina recently updated the HIV diagnosis algorithm, incorporating the rapid HIV test (RHT) and the confirmation of reactive cases with HIV viral load instead of Western blot. This new algorithm was implemented for the first time in Argentina to evaluate acceptability and accuracy of the RHT in a seroprevalence HIV study among vulnerable groups from Buenos Aires Metropolitan Area. Methods: From September 2013 to May 2014, a cross-sectional HIV seroprevalence survey was conducted at different settings (non-governmental organizations, hospitals and field visits). Men who have sex with men (MSM), female transgender/travesties, drug users (DU) and female sex workers (FSW) were included in the study. HIV diagnosis was performed with Allere Determine HIV-1/2. All samples were also tested with Genscreen Ultra HIV Ag&Ab. Reactive cases were confirmed with viral load (bDNA Versant HIV RNA). CD4 cell count was also performed. Results: Between September 2013 and May 2014, 1517 individuals were tested. Regarding RHT acceptability, 99.5% of participants reported that proceedings had been "good" or "very good" and 91.2% preferred to know results in the same day. For 19% of the participants this was the first time they tested for HIV. Prevalence of HIV infection was 11.5% (116/1015, 95% CI 9.5-13.5) for MSM, 31.5% (52/165, 95% CI 24.1-38.9) for female transgender/travesties, 3.5% (9/259, 95% CI 1.1-5.9) for DU and 5.1% (4/78, 95% CI 1.4-12.6) for FSW. Comparison of RHT with standard laboratory diagnosis showed 10 discordant results (0.66%). RHT sensitivity and specificity was 97.3% and 99.6%, respectively (PPV: 96.7%, NPV: 99.7%). Acute HIV infection was detected in the laboratory in four MSM with a negative RHT. Fifty eight percent of HIV positive individuals had less than 500 CD4/µl at diagnosis. Conclusions: Implementation of RHT was successful, revealing that its implementation could be a useful tool to facilitate access to diagnosis in vulnerable groups, where prevalence of HIV remains extremely high. RHT expansion, improving early diagnosis, would diminish the frequency of individuals that are diagnosed at advanced stages of the infection.