Drug-Resistant Virus Can Be Passed in Breast Milk

A small clinical trial conducted by Stanford University researchers shows that HIV-positive women given a single dose of Viramune during labor to prevent them from transmitting the virus to their infants can harbor drug-resistant virus in their breast milk and pass it to their babies through breast-feeding. Twenty HIV-positive women in Zimbabwe were studied and evaluated for 20 weeks after delivery, according to study data presented at the 10th annual Conference on Retroviruses and Opportunistic Infections. At eight weeks following childbirth, virus with mutations conveying resistance to Viramune was still detected in the breast milk of 13 of the women. The concentration of drug-resistant virus in breast milk also was shown to be considerably higher than levels in the blood. During the course of the study, four of the 20 infants born to the women became infected with HIV.