• Virologic assays (i.e., HIV RNA and HIV DNA nucleic acid tests [NATs]) that directly detect HIV must be used to diagnose HIV in infants and children aged <18 months with perinatal and postnatal HIV exposure; HIV antibody tests should not be used (AII).
• HIV RNA or HIV DNA NATs are generally equally recommended (AII).
• An assay that detects HIV non-B subtype viruses or Group O infections (e.g., an HIV RNA NAT or a dual-target total DNA/RNA test) is recommended for use in infants and children who were born to mothers with known or suspected non-B subtype virus or Group O infections (AII).
• Virologic diagnostic testing is recommended for all infants with perinatal HIV exposure at the following ages:
  • 14 to 21 days (AII)
  • 1 to 2 months (AII)
  • 4 to 6 months (AII)
• For infants at higher risk of perinatal HIV transmission, additional virologic diagnostic testing is recommended at birth (AII) and at 2 to 4 weeks after cessation of antiretroviral prophylaxis (BII).
• A positive virologic test should be confirmed as soon as possible by a repeat virologic test on a second specimen (AII).
• Definitive exclusion of HIV infection in nonbreastfed infants is based on two or more negative virologic tests, with one obtained at age ≥1 month and one at age ≥4 months, or two negative HIV antibody tests from separate specimens obtained at age ≥6 months (AII).
• Some experts confirm the absence of HIV at 12 to 18 months of age in children with prior negative virologic tests by performing an HIV antibody test to document loss of maternal HIV antibodies (BIII).
• Since children aged 18 to 24 months with perinatal HIV exposure occasionally have residual maternal HIV antibodies, definitive exclusion or confirmation of HIV infection in children in this age group who are HIV antibody -positive should be based on an HIV NAT (AII).
• Diagnostic testing in children with nonperinatal exposure only or children with perinatal exposure aged >24 months relies primarily on the use of HIV antibody (or antigen/antibody) tests; when acute HIV infection is suspected, additional testing with an HIV NAT may be necessary to diagnose HIV (AII).

Note: The National Clinician Consultation Center provides consultations on issues related to the management of perinatal HIV infection (1-888-448-8765; 24 hours a day, 7 days a week).