Researchers from the University of California, San Francisco (UCSF) and Makerere University in Uganda have used hair and blood samples from three-month old infants born to HIV-positive mothers to measure the uninfected babies’ exposure — both in the womb and from breast-feeding — to antiretroviral medications their mothers were taking. The results, they said, are surprising.

A perspective published in the New England Journal of Medicine this week by professors at UCSF and the Johns Hopkins University asserts that it is now possible to begin to end the AIDS epidemic by widely and strategically applying existing tools.

The AIDS drug Truvada, approved this week for prevention of HIV infection in uninfected people at high risk, may benefit many uninfected women whose male partners have HIV, including pregnant women, who may be at higher risk.