Bloodborne Viruses Laboratory

Pediatric HIV Testing Service:

The Pediatric HIV Testing Service was implemented by the Department of Health to assist in the diagnosis of perinatal HIV transmission. This service is not intended as a screening test for HIV, but rather to definitively diagnose HIV infection in infants who are known to be HIV antibody positive or whose mothers are known to be positive. Detection of HIV infection in infants less than 18 months of age requires a nucleic acid test (NAT) that directly detects HIV DNA or RNA to diagnose infection. Antibody based tests cannot be used due to the persistence of maternal HIV antibody in this age group.

HIV infection can reasonably be excluded among HIV-exposed children with two or more negative NATs performed at greater than one month of age, with one of those being performed at or greater than four months of age. HIV infection is confirmed in an infant by two positive NATs performed on separate specimens collected at any age. The Pediatric HIV Testing Service currently uses a FDA-approved qualitative RNA detection test for infant diagnosis.

Recommendations on Timing of Testing:

Depending upon the age of the infant when the first specimen is submitted to the laboratory, two to four specimens per infant may be necessary to definitively diagnose the infant's HIV infection status. Any infant, regardless of age, with a positive NAT result should have another blood specimen collected for testing as soon as possible to confirm the positive result. No further testing is needed for diagnosis after the second positive result.

Recommendations for specimen collection for pediatric HIV testing are as follows:

• Initial specimen collected by 48 hours after birth

Follow-up specimens collected at:

• two weeks of age

• four to six weeks of age

• at or greater than 16 weeks of age

Note: Negative NAT results when the infant is less than 28 days
do not exclude HIV infection, particularly if the infant has been exposed to antiretroviral medication in utero or after birth.