I'm adopting a baby with mother that has HIV she never took care of her health. The baby's Elisa test come back postive but his PCR come back negative, is it posible that he have HIV in the future or do he have it now? He one year old now. I have him since birth and gave him AZT for 6 weeks. That my baby.

The ELISA test detects antibodies and since all HIV positive women pass their antibodies to their babies (whether the babies are infected or not), all babies born to HIV positive women will have a positive antibody test. Uninfected babies can retain the maternal antibodies for up to 12-18 months. For this reason, antibody tests can not be used to diagnose HIV infection in a baby under 18 months of age.

In babies under 18 months, we like to use tests that look for pieces of the virus in the blood (PCR). These tests are very sensitive. You don't mention when the PCR test was done, but a negative PCR test done after 3-4 months of age means that a baby is not infected.