HIV diagnosis in neonates born to HIV seropositive mothers

To identify a possible HIV infection in the neonates born to HIV seropositive mother (mother-to-child transmission), in order to timely take corrective measures when needed.

Because maternal antibodies are passively transferred to the infant, HIV antibody testing cannot be used to diagnose infection until the age of 18 months. To overcome this problem a nucleic acid testing (PCR or other) strategy that directly detects the presence of free virus in plasma (HIV RNA) and virus infected cells (HIV proviral DNA) is used. HIV RNA and HIV proviral DNA can be detected in two separated assays or can be detected in one single total nucleic acid test.

HIV diagnosis in children <18 months can be requested by gynaecologists at birth or by the paediatrician in charge of the follow-up of the infant. It is imperative to provide the ARL with the identity and HIV-1 or HIV-2 status of the mother.

Children born to mothers with known HIV infection:

• HIV RNA and DNA testing should be performed at birth and at least two different time points after completion of the neonatal antiretroviral prophylaxis regimen. In case of tri-therapy as the neonatal prophylaxis regimen, then an additional HIV RNA and DNA test should be performed at the age of 6 months. This is necessary due to the drug half-life as any remaining drug can still mask a possible infection remaining undetected by nucleic acid testing.
• Exceptional circumstances: In case the HIV-1 or HIV-2 status of the mother is unknown and she cannot be tested, the HIV serological antibody status of the child needs to be determined before applying this scheme.

Recommendation for testing children born to mothers with known HIV infection:

Children breastfed by a mother with diagnosed HIV infection:

• In Belgium, breastfeeding is not recommended for infants born to HIV positive mothers.
• HIV RNA and DNA testing should be performed at time of presentation, at 4-6 weeks, 3 months and 6 months after stop breastfeeding. At the age of 18 months or later, serological HIV antigen/antibody testing should be performed at first presentation and at 6 weeks (or later) after stop breastfeeding. 

Recommendation for testing children breastfed by mothers with known HIV infection:

Blood sampling in a neonate can be challenging. If insufficient volume is received by the ARL, the blood sample might be diluted for testing, lowering the sensitivity of the test for this sample.

Cordal blood sampling at birth has to be avoided, as contamination with maternal blood cannot be excluded.

In case of HIV-1 group O or HIV-2 infection of the mother, the neonate needs to be tested for this specific virus. These RNA and DNA tests are available but require dedicated assays. Please contact your ARL for further information.

To perform a test for HIV diagnosis in neonates born to HIV seropositive mothers:

1. Collect blood in a in an EDTA-tube by venipuncture (5 to 10 ml).
2. Request an HIV DNA and RNA PCR.
3. Store mother-tube at room temperature and send as soon as possible to any clinical laboratory. Store at 2-8°C if transport cannot be arranged within one day.

When HIV RNA and/or DNA is not detected, infection is not suspected. However only after completion of the full schemes mentioned above  and without any clinical symptoms infection is ruled out.

When HIV RNA and/or DNA is detected, infection is suspected.The ARL will contact the prescriber for clinical confirmation before releasing the test results. 

• Send a new sample as soon as possible to your clinical laboratory, to rule out sampling/labelling errors and contaminations.
• Please refer the patient to a pediatrician specialized in HIV infection after confirmation of the HIV infection.

When an indeterminate result is obtained, HIV infection is neither ruled out nor suspected. Indeterminate test results indicate a possible detection of HIV RNA/DNA but outside the criteria of positivity.
The ARL will contact the prescriber for clinical confirmation before releasing the test results. 

• Send a new sample as soon as possible to your clinical laboratory, to rule out sampling/labelling errors and contaminations.