PERINATAL INFECTIONS
The primary route of human immunodeficiency virus (HIV) infection in infants is vertical transmission from HIV-infected mothers. This is of particular concern as the number of infected women and the number of children infected by perinatal transmission continue to increase rapidly. The number of perinatally acquired acquired immunodeficiency syndrome (AIDS) cases increased 17% in 1989 and 21% in 1990. Similarly, the number of heterosexually acquired AIDS cases increased 27% in 1989 and 40% in 1990. There is evidence that vertical transmission of HIV can occur in utero (congenital/transplacental, similar to rubella),1,2 in the postpartum period (breast-feeding), and perhaps in the intrapartum period (similar to hepatitis B).3 The relative frequency and efficiency of transmission during each of these periods remains uncertain. The best estimates of vertical transmission from an HIV-seropositive mother to the fetus range from 12.9% to 39%4-6 Although the risk of transmission appears to be increased in women who are symptomatic, this point is still unclear.5 Preliminary information suggests that the presence of high levels of high-affinity/avidity antibodies to specific epitopes of the gp 120 of HIV may be protective and may decrease or prevent vertical transmission,7-10 although others have not been able to confirm this finding.11 More detailed information on perinatal HIV infection,12 and infection control13 in pediatric HIV infection is available in previously published statements from the AAP Task Force on Pediatric AIDS.
SEROPREVALENCE
Anonymous seroprevalence data from newborn specimens are being collected in 44 states, Puerto Rico, and the District of Columbia. In some states, seroprevalence data are available by metropolitan area and/or by hospital of birth.
