They Thought This HIV Strategy Couldn't Work. But It Did

In high-income countries like the U.S., the standard of care for people infected with HIV is to provide antiretroviral pills when the virus is found, even when there are no symptoms of AIDS. The strategy staves off the disease and has a second — big — benefit. It has been shown to prevent the spread of HIV in sexual encounters. It's called "treatment as prevention" (TasP in medical jargon), or "test and treat."

But in low-income countries, "test and treat" is not the typical approach to prevention. There has been no research to support it.

So 10 years ago, researchers began planning a massive study of treatment as prevention in South Africa and Zambia. The team came from the London School of Hygiene and Tropical Medicine, Imperial College and