Rapid Serological Tests Ineffectively Screen for HIV Exposure in HIV-Positive Infants.

Background: Data on the performance and utility of rapid serological tests in infants to determine HIV exposure are unclear and in some instances contradictory. This study sought to understand the performance of rapid serological tests in high HIV burden, high Option B+ coverage settings to be used as an HIV exposure screening tool.

Methods: A total of 3600 infants up to 24 months of age at 4 regional hospitals in Uganda were systematically enrolled and tested simultaneously using both HIV rapid serological and nucleic acid-based tests.

Results: Only 58 of the 94 HIV-positive infants who received both rapid serological and nucleic acid-based tests were positive with the rapid serological test (sensitivity: 61.7%; 95% confidence interval: 51.1 to 71.5). Using rapid serological tests to screen infants for exposure to HIV and follow-up nucleic acid-based testing would have missed 38.3% (36 of 94) of HIV-positive infants. Finally, several HIV-positive infants who were negative by rapid serological test presented to well-child entry points and were considered healthy. All 3 HIV-positive infants presenting to outreach and immunization were negative by rapid serological testing and 73% (8 of 11) presenting to outpatient.

Conclusions: These data suggest that the use of rapid serological tests may have inadequate performance as an indicator of exposure and potential HIV infection among infants presenting at both well-child (immunization and community outreach) and sick-infant (nutrition and inpatient) entry points. To improve the identification of HIV-positive infants, nucleic acid-based testing should instead be considered in infants aged younger than 18 months.