Standard HIV antibody tests for toddlers have a 3.3% misdiagnosis rate because maternal antibodies persist six months longer than medical guidelines assume.
March 31, 2026
Original Paper
Rethinking HIV antibody testing in children aged 18-24 months in the OPPTIM study conducted in Johannesburg, South Africa 2018-2021
SSRN · 6386985
The Takeaway
Public health policies generally assume that a mother's antibodies disappear from a child's blood by 18 months, making tests reliable after that age. This study found that many uninfected children still test positive up to 24 months, meaning healthy toddlers are being incorrectly diagnosed and potentially started on lifelong medication for a virus they don't have.
From the abstract
BackgroundHIV polymerase chain reaction (PCR) testing is recommended for children <18 months, and HIV antibody testing ≥18 months, limited by maternal antibody persistence. We describe seroreversion at various time points in HIV-exposed, uninfected children.MethodsMother-child pairs were enrolled in the “OPPTIM” study at the child’s 6, 10, or 14-week clinic visit, with study visits conducted 4 July 2018 to 27 March 2021. At enrolment, 6-, 9-, 12-, 18-, 21- and 24-months, trained study staff test