A recent study shows that two-thirds of breastfeeding infants infected with HIV and born to mothers on antiretroviral therapy (ART) have developed resistance to one or more antiretroviral drugs.

The research, which was published in PLos Medicine journal this month, was conducted by Clement Zeh of the Kisumu Breastfeeding Study. It shows that drug resistance does not appear to have developed from transmission of drug-resistant virus from the mother, but rather as a result of exposure to antiretrovirals in breast milk.

Drug resistance mutations among HIV-infected babies developed between two weeks and six months after birth increasing over time: from 30% by week six to 67% by six months. Also, no resistance was found among infants who were infected before two weeks of age or after six months when the mothers stopped both ART and breastfeeding.

This finding brings to conclusion that resistance was transmitted through exposure to ART through breast milk and not to drug-resistant virus.

Source: AIDS Map