From Boston, at a conference on Retroviruses and Opportunistic Infections
A drug called nevirapine, sold as Viramune, can reduce the risk of mother-to-newborn transmission of HIV when taken by a woman at the onset of labor. Scientists now report that after taking nevirapine, the women often harbor a form of HIV with genetic mutations that make it resistant to the drug. Moreover, the mutant virus is more prevalent in the breast milk of infected women than in their blood.
The finding suggests that these women could be passing along resistant forms of the virus to their children during breast-feeding, says Esther Lee of Stanford University. HIV-infected mothers who choose to breastfeed have about a one-in-six chance of transmitting the virus to their babies via breast milk.