In this study, stored plasma samples from children born to mothers
infected with HIV-1 and adults who attended the Argentinean
National Reference Center for AIDS were examined. For the purpose
of this study, an infant younger than 18 months of age born
to a mother infected with HIV is considered infected if he/she has
positive results by two separate direct tests for HIV (i.e., HIV culture,
PCR or detection of p24 antigen) and infection can be excluded by
the presence of at least two negative HIV PCR tests, both of which
are performed at or after 1 month of age, and one of which is performed
at or after 4 months of age.