Asking people recently diagnosed with HIV or a sexually transmitted infection (STI) to recruit members of their social network for testing can help root out other undiagnosed cases, aidsmap reports. Publishing their findings in the Journal of Acquired Immune Deficiency Syndromes, investigators drew two cohorts of 45 people apiece from those accessing care at the STI clinic at Kamuzu Central Hospital in Lilongwe, Malawi, between 2010 and 2012. One group was newly diagnosed with HIV, and the other with an STI but not HIV. A third group of 45 people, recruited from the local population, served as a control.

Malawi has an HIV prevalence rate of 11 percent.

The researchers asked the participants to recruit up to five people from their social or sexual network for HIV and STI testing. This yielded a total of 244 contacts, 62 percent of whom were friends or neighbors, 18 percent family members, 11 percent sexual contacts (mostly significant others) and 8 percent some other connection. Sixty-nine percent of the control group recruited at least one person, compared with 53 percent of the STI group and 47 percent of the HIV-positive cohort.

The study identified 20 new cases of HIV. Seven were among recruits from the HIV-positive cohort, another seven from the STI group and six from the control group.

The HIV prevalence among those recruited by the HIV-positive participants was 31 percent, compared with 11 percent for the control group's recruits. The STI prevalence among the contacts of the HIV-positive participants was 29 percent, compared with 19 percent among the contacts of those recently diagnosed with an STI and 9 percent of the contacts of the control group.

Diagnosing one new HIV case required screening eight contacts provided by the HIV-positive participants, compared with 10 from the STI participants and 18 from the control group. Diagnosing one new STI case required screening six contacts provided by the HIV-positive participants, compared with four from the STI participants and 11 from the control group.

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