HIV/AIDS: New Findings On Mother-To-Infant Transmission
Antiviral drug therapy "can sharply reduce mother-to-infant transmission of the AIDS virus even when treatment is delayed" for 48 hours after birth, according to a new study published in today's issue of the New England Journal of Medicine. The Boston Globe reports that the findings are "good news for developing countries hard hit by the AIDS epidemic," where women often avoid seeking prenatal care and learn their HIV status only after beginning labor. Prior to the most recent study, scientists were unsure of the drug's effects if therapy was delayed until labor or delivery (Saltus, Boston Globe, 11/12). Researchers from the New York State Department of Health in Albany determined the outcomes of treatment initiated before birth, during labor, within 48 hours of birth and after 48 hours. Led by Dr. Nancy Wade, researchers compiled data from 939 HIV-exposed babies born between Aug. 1995 and Jan. 1997. They found transmission rates of 6.1% among infants treated prenatally; 10% among infants treated during delivery; 9.3% among infants treated within the first 48 hours after birth; and 18.4% among those treated after 48 hours. In contrast, the vertical transmission rate for those infants not receiving therapy was 26.6%.
Wade highlights the public health implications of the study's results, saying, "If perinatal HIV transmission can be reduced, even if zidovudine prophylaxis is begun in the intrapartum period or immediately after birth, there would be greater impetus to initiate zidovudine therapy in newborns whose mothers did not take zidovudine during pregnancy." While the results do not "diminish the importance" of a longterm drug regimen for HIV- positive women to most effectively reduce transmission, they offer a last resort for women without prenatal care (Wade et al., New England Journal of Medicine, 11/12 issue).
In an accompanying editorial in the New England Journal of Medicine, Dr. Kenneth McIntosh of Children's Hospital in Boston notes that the efficacy of late treatment "could have important public health implications in parts of the world where the high cost of antiretroviral agents remains an obstacle to their use." The value of the study, he says, is that it indicates the efficacy of treatment for infants at "a fraction (less than 1/10) of that for even a short course of maternal treatment." He adds, "It also increases the number of questions that can and should be asked about inexpensive preventive regimens that may be suitable for use in many parts of the world where the prevalence of HIV infection is high and resources are severely limited" (McIntosh, New England Journal of Medicine, 11/12 issue). Dr. Deborah Cotton, a national expert on HIV infection in women at Boston University Hospital, applauded the research, saying, "This study adds to our growing awareness that we could end this epidemic ... virtually overnight with the use of routine HIV testing and antiviral therapy" (Boston Globe, 11/12). Click here for past Kaiser Daily HIV/AIDS Report coverage of vertical transmission (the free online report is available at www.kff.org).