Performance of serological and molecular tests within acute HIV infection

BACKGROUND: Early diagnosis of acute HIV infection can be challenging and is critical in regards to early therapeutic decision making.

OBJECTIVES: To evaluate the performance of different HIV tests in detecting early infections.

STUDY DESIGN: A total of 83 leftover specimens of 61 study participants who seroconverted were used in this sub-study. 35 HIV RNA positive but still seronegative specimens (acute infections) were used for analysis of the sensitivity of the different assays in detecting early infections and 42 HIV RNA and antibody negative specimens were used for specificity analysis.

RESULTS: Four (11%) specimens out of 35 acute infections were reactive with the Enzygnost(®) Anti-HIV 1/2 Plus and 12/35 (34%) with the Vironostika(®) HIV Ag/Ab. 16 (46%) specimens were confirmed as acute by the INNOTEST(®) HIV antigen mAb Antigen test. Only three (9%), 10 (29%) and 9 (27%) specimens were reactive with the Determine HIV-1/2 Ag/Ab Combo, SD Bioline HIV Ag/Ab Combo test and the HIV Combo test, respectively. The specificity of the different tests were 100%, 95%, 100%, 93%, 100% and 93% for Enzygnost(®) Anti-HIV 1/2 Plus, Vironostika(®) HIV Ag/Ab, INNO-Test HIV antigen mAb, Determine HIV-1/2 Ag/Ab Combo, SD Bioline HIV Ag/Ab Combo test and HIV Combo test respectively.

CONCLUSION: RNA test, 4th generation ELISA and Single Ag test are the most sensitive tests for detection of an acute infection. As an alternative, the HIV Combo test is generally slightly more sensitive compared to its previous version, but the SD Bioline HIV Ag/Ab Combo tests has the best performance compared to the other simple rapid tests (SRTs) but none of them are precise in detecting Ag in the determination of acute infections.