Thai Study Shows That Inexpensive Treatment Reduces Risk Of Mother To Child HIV Transmission
Second Study Shows Treatment May Increase Drug Resistance
A single dose of the drug nevirapine given at the beginning of labor, when combined with a short course of the anti-HIV drug AZT (zidovudine), dramatically reduces a woman's chances of passing HIV on to her child, according to a study of Thai women funded in part by the National Institute of Child Health and Human Development of the National Institutes of Health.
The study authors, publishing in the July 15 New England Journal of Medicine , found that the two drug combination reduces transmission of the virus to below 2 percent, similar to what is achieved with more expensive three-drug regimens routinely prescribed in developed countries.
However, in a second NIH-funded study in the same issue of the journal, the same researchers followed the progress of women from the first study who developed low levels of CD4+ cells after they had given birth. CD4+ cells are a type of immune cell and low CD4+ levels indicate that the HIV infection is growing worse and advancing toward AIDS. The researchers found that some women who, after they had given birth, developed low CD4 levels and who had received single-dose nevirapine, harbored a strain of the virus that had grown resistant to nevirapine. Women with resistant virus were less likely to show a decrease in HIV levels when receiving anti-HIV therapy that contained the drug nevirapine than women without such resistance. This second study also received funding from NICHD, as well as from NIH's National Institute of Allergy and Infectious Diseases.
In Thailand at the time of the study, the standard treatment to reduce the risk of pregnant women passing HIV on to their infants was a regimen of AZT, given during labor and delivery, and to newborns for 1 week. The standard treatment also called for infants to formula feed, rather than breast feed, to reduce the risk of transmitting the virus through breast milk.
The lead author of the first study was Marc Lallemant, M.D., Institut de Recherche pour le D