To establish HIV infection status in neonates of HIV-positive mothers, the most definitive test is detection of which marker?

To establish HIV infection status in neonates of HIV-positive mothers, the most definitive test is detection of which marker?

• A. HIV-specific RNA
• B. HIV antibodies
• C. HIV p24 antigen
• D. HIV DNA

Answer: (A)

Neonatal HIV status can’t be reliably determined with antibody tests because maternal antibodies cross the placenta and can persist in the infant for many months, making it impossible to tell who is actually infected. The definitive approach is to directly detect the virus itself. HIV-specific RNA in the infant’s blood is the best marker because it shows active viremia, confirming infection when present. Detecting viral RNA reflects ongoing replication and can reveal infection even before the infant’s immune system has mounted a response. P24 antigen testing can miss infections in early infancy due to low circulating levels and assay limitations, so it’s not as reliable on its own. HIV DNA testing (provincial DNA via PCR) is useful and can indicate infection, but RNA detection directly demonstrates active virus in the plasma and is the most straightforward indicator of infection status in neonates.

Neonatal HIV status can’t be reliably determined with antibody tests because maternal antibodies cross the placenta and can persist in the infant for many months, making it impossible to tell who is actually infected. The definitive approach is to directly detect the virus itself.

HIV-specific RNA in the infant’s blood is the best marker because it shows active viremia, confirming infection when present. Detecting viral RNA reflects ongoing replication and can reveal infection even before the infant’s immune system has mounted a response.

P24 antigen testing can miss infections in early infancy due to low circulating levels and assay limitations, so it’s not as reliable on its own. HIV DNA testing (provincial DNA via PCR) is useful and can indicate infection, but RNA detection directly demonstrates active virus in the plasma and is the most straightforward indicator of infection status in neonates.