Partner notification useful in identifying undiagnosed HIV infections

The use of partner notification services led to the diagnosis of 44 cases of HIV in San Francisco between 2004 and 2008, investigators report in the May edition of AIDS. The researchers found that partner notification was most useful if an individual recently diagnosed with HIV was asked to participate in a partner notification interview within two weeks of their diagnosis.

Partner notification has a valuable role in the control of sexually transmitted infections. However, in comparison to other sexually transmitted infections, partner notification is little used in HIV.

In late 2008, the US Centers for Disease Control and Prevention issued updated guidance for the use of partner notification for the control of HIV and other sexually transmitted infections.

The San Francisco Department of Health offers partner notification for residents with newly diagnosed HIV infection. Investigators undertook a study to evaluate the effectiveness of partner notification in identifying new HIV cases.

Between January 2004 and June 2008, a total of 615 individuals with newly diagnosed HIV were referred for partner notification. A total of 481 of these individuals, 46 (10%) of whom had been recently infected with HIV, had partner notification interviews. Nearly all the individuals having a partner notification interview (89%) were gay men, the median age was 34 years, and 46% had their interview within two weeks of their HIV diagnosis.

Over half (55%) of patients did not name any sexual partners. The remaining individuals provided contact details for 419 sexual partners. It was not possible to locate 56 (13%) of these, and of the remaining 363 individuals, a total of 313 were interviewed.

Of these individuals, 30% reported that they already knew that they were HIV-positive. However, 91% (200) of those who did not know their HIV status agreed to an HIV test and 44 (22%) tested HIV-positive.

The investigators calculated that it was necessary to interview eleven individuals with newly diagnosed HIV to identify one HIV-infected partner through contact tracing. Significantly more partners or individuals who had partner notification interviews within two weeks of their HIV diagnosis tested HIV-positive than the partners of patients who had their partner notification interviews after two weeks (13% vs 5%, p = 0.008).

“Partner notification successfully identified 44 new cases of HIV in San Francisco, with 22% of tested partners newly identified as HIV-infected”, write the investigators. They add, “our findings suggest that earlier interviews should be prioritized and health departments should consider focusing efforts on reducing the time between diagnosis and interview.”