Finding people who have HIV but don't know it is one of the biggest challenges in stopping the virus. A report from 20 countries suggests a straightforward idea might help: when health workers test the partners and other contacts of someone newly diagnosed, more people end up getting tested. And importantly, more people who have HIV learn their status and can start treatment.
The report looked at a strategy called 'index testing' over about 18 months. It found that when this approach was scaled up, both the total number of people tested and the number of people diagnosed with HIV went up. This is a promising sign that focusing efforts on the people closest to someone with HIV can be an effective way to reach them.
However, this is an observational report, not a controlled study. It doesn't give us specific numbers—we don't know exactly how many more people were tested or diagnosed. It also didn't compare this approach to other ways of finding people with HIV. The work happened in 20 countries supported by the U.S. CDC, so we don't know if the results would look the same elsewhere. The takeaway is that the strategy shows potential, but we need more detailed research to understand its full impact.