PREVALENCE OF MATERNAL HIV-INFECTION BASED ON ANONYMOUS TESTING OF NEONATES, SYDNEY 1989

The presence of antibody to human immunodeficiency virus (HIV) in postpartum women may be inferred by screening the blood of their newborn babies, since maternal IgG antibodies freely cross the placenta. We tested a sample of 10 217 newborns from 10 hospitals covering three areas in Sydney and other metropolitan centres in New South Wales from April to July, 1989. None of the specimens gave a positive test for antibody to HIV. Thus, the prevalence of HIV positive serology in this sample of newborns was found to be zero. It was estimated that the seroprevalence of antibody to HIV among all neonates in the study area was between zero and 0.045% (99% confidence interval). Because newborns are an accessible group for the study of HIV, and can act as surrogates for their mothers, anonymous testing of this sentinel group will remove some of the limitations on generalising the information in the present database of HIV infection in Australia. This study provides baseline data and suggests that there is not a widespread epidemic of HIV infection among heterosexual persons in Australia at the present time and that routine antenatal testing of women for antibody to HIV may not be cost-effective. However, it will be important to repeat this study at regular intervals to detect any increase in HIV seroprevalence.