ELISA+ve PCR -ve


We have a biological son and we had applied for a girl baby. We have been given a reference of a one year old girl by our adoption agency. She is healthy and sound. Both her parents were HIV +ve. However the child is ELISA +ve but three results of PCR test have been -ve.

Is there any chance that our son gets HIV infection from her if we decide to bring her home? Is there any precaution that we should take in case she comes home till the ELISA test shows a -ve result?

Please help us to take the right decision.

  • Arunima


Hello Arunima,

The one-year-old infant girl you are considering adopting has an over 98% chance of being HIV negative. (See similar situation from the archives posted below.)

Is there any chance your son could contract HIV from an ELISA-positive, PCR-negative infant? No, absolutely not. First and foremost an ELISA-positive, PCR-negative individual is not infectious and cannot transmit the virus. Plus the infant girl has an over-98% chance of being HIV negative (probably close to 100% by now). Also it is important to point out that even if she was HIV positive, HIV/AIDS is not transmitted by casual contact, such as living in the same household.

To "help you make the right decision," I can advise you with great certainty that there would be absolutely no HIV-transmission risk to you or your family if you choose to bring this youngster home and make her part of your family. I encourage you to do exactly that without delay and without even the slightest concern or worry. Congratulations on your new addition! Give your new daughter a hug and kiss from me. OK?

Dr. Bob

newborn testing for hiv May 28, 2005

My husband and I are in the process of adopting internationally. A waiting child has become available. She is approx 4 months at this time. Mother is hiv positive but the baby tested negative. They tested her x2 with dna pcr. How accurate is this testing with newborns and what, if any, are the long term concerns. Thanks

Response from Dr. Frascino


HIV DNA PCR is the preferred virologic method for diagnosing HIV during infancy. Clinical studies have shown that by age 28 days, HIV DNA PCR is 96% sensitive and 99% specific for identifying HIV proviral DNA. When two HIV DNA PCR assays are performed one month apart with one assay after four months of age, the sensitivity and specificity are both greater than 98%.

HIV DNA PCR is used rather than ELISA (antibody tests) because maternal anti-HIV antibodies can cross the placenta and consequently, infants born to HIV-positive moms can have positive ELISA and Western Blot tests even though these infants are themselves HIV-negative. Maternally derived antibodies can persist for up to 18 months.

At this point, the child you are considering adopting has an over 98% chance of being HIV negative. Should you adopt him or her, your pediatrician will probably run one more HIV test at the 18-month mark.

Good luck and congratulations!

Dr. Bob