We evaluated the Determine庐 HIV1/2 Ag/Ab Combo Rapid Test (Combo RT), a 4th generation test against two 3rd generation tests (SENSA-HIV1/2/0 Tri-line, SD-Bioline) for early detection of HIV-infection in pregnancy.
In a cohort study, plasma samples from 32 pregnant women who seroconverted at a subsequent antenatal visit (incident-infection), samples from 189 women who tested HIV positive at baseline (established-infections) and samples from 32 women remaining HIV-seronegative at a subsequent antenatal visit were tested with 3rd generation (antibody detection only) and 4th generation (antibody/antigen detection) rapid HIV tests. The HIV-1 NucliSENSEasyQ庐 v2.0 PCR test was used to quantify HIV-viral copies in women with incident HIV-infections.
Eighteen of 32 (56.3%) women (incident-infections) had detectable viral copies (baseline); 16 (88.9%) were antibody reactive with the Combo RT. None of the 32 specimens were reactive on the antigen component of the Combo RT. The sensitivity and specificity of the Combo RT in detecting HIV infections prior to seroconversion is 59.4%(95%CI 40.6-76.3) and 96.9%(95%CI 83.8-99.9) respectively. The Combo RT detected 94.0%of all HIV-infections if used as a screening test (baseline) compared to 85.5%detected by 3rd generation tests.
The Combo RT does not identify AHI but is superior to 3rd generation tests in detecting HIV antibody responses.