“The amount of HIV in an infected mother’s breast milk spikes when weaning begins, according to a study published [Wednesday] in Science Translational Medicine,” Nature reports. “The findings are likely to add urgency to efforts to ensure that infected mothers without access to formula take antiretroviral drugs throughout and beyond the time that they wean their infants,” the journal writes (Wadman, 4/17). “To test whether breastfeeding routines affect the levels of HIV in breast milk, the researchers tested nearly 1,000 women and their infants in Lusaka, Zambia, over 24 months,” the Los Angeles Times’ “Science Now” blog writes, adding, “The women were divided into two groups — one that weaned their babies abruptly after four months, and one in which the women continued to breastfeed as long as they chose.” According to the blog, “HIV-infected mothers who breastfed exclusively longer than the first four months after birth had less risk of transmitting the virus to their babies through their milk, researchers said” (MacVean, 4/17).

“The milk from women who … stopped breastfeeding abruptly contained markedly higher levels of HIV than did milk from the women who continued to breastfeed exclusively,” Nature notes. “The current practice of giving mothers one to two weeks of antiretroviral therapy after weaning may not be enough, the authors say, given that weaning is a stop-and-start, often protracted, process in real life,” according to the magazine (4/17). “Our results have profound implications for prevention of mother-to child HIV transmission programs in settings where breastfeeding is necessary to protect infant and maternal health,” the researchers wrote, GlobalPostnotes (Peterson, 4/17). “WHO guidelines suggest that where HIV treatments are used, mothers should breastfeed their infants to at least 12 months,” Bloomberg Businessweek writes, adding, “And if antiretroviral drugs are unavailable, women can still breastfeed for at least the first six months” (Ostrow, 4/17).