Objective: To evaluate the performance of a quantitative plasma HIV-1 RNA assay for HIV infection diagnosis among African breast-fed children.
Methods: Serial plasma specimens collected in the first week, at day 45-90, 6 months and 9-12 months of age from HIV-exposed children born to HIV-1-infected women enrolled in the DITRAME ANRS 049a perinatal intervention trial (Abidjan, Côte d'Ivoire) were tested for HIV-1 plasma RNA using a branched DNA (bDNA) assay. Sensitivity and specificity of this RNA test were assessed in comparison with a qualitative DNA polymerase chain reaction (PCR) performed on the same blood samples and allowing a reliable detection of the predominant subtype A.
Results: Among 91 samples from 53 infected children which tested positive by DNA PCR, the sensitivity of the bDNA test was 100% [95% confidence interval (CI), 96.0-100.0] at < or = 8 days (n = 19), 6-12 weeks (n = 43), 6 months (n = 26), and 9-12 months (n = 3). The median plasma HIV-1 RNA viral load ranged from 242 000 copies/ml at < or = 8 days to more than 500 000 copies/ml at day 45-90 and at 6 months. Of 106 specimens from 106 uninfected children who were DNA PCR- negative at month 3 or 6 of age, HIV-1 RNA was undetectable in 103, yielding an overall specificity for the bDNA test of 97.2% (95% CI, 92.0-99.4). The viral load in the three remaining samples with false-positive results was low (410, 937 and 3752 copies/ml, respectively).
Conclusions: The quantitative bDNA assay appears a suitable tool for early, reliable and easy diagnosis of paediatric HIV-1 infection among a population of African breast-fed children.