Sentinel surveillance for HIV-2 infection in high-risk US populations

Objectives. We conducted sentinel surveillance in persons practicing behaviors known to transmit retroviruses to determine the US presence and extent of human immunodeficiency virus type 2 (HIV-2). Methods. Sentinel surveillance for HIV-2 was conducted by testing 31 533 anonymous blood specimens from patients at sexually transmitted disease clinics, injecting drug users at treatment centers, and clients at HIV counseling and testing sites in 14 US cities where West African immigrants often settle. Specimens were tested by HIV-1 and HIV-2 whole virus and synthetic peptide enzyme immunoassay and confirmed by HIV-1 and HIV-2 Western blots. Results. Nearly 10% of 31 533 sera were positive for HIV-1. Two heterosexual Black male sexually transmitted disease patients were infected with HIV-2. One of the HIV-2 positive specimens did not cross-react on HIV-1 enzyme immunoassay screening. One client had antibodies consistent with malarial infection in West Africa; the other, who had syphilis, did not have antibodies to malaria or to any of 20 arboviruses present in Africa. Conclusions. Clinics serving clients from HIV-2 endemic areas should test persons practicing risk behaviors for both HIV-1 and HIV-2. Sentinel surveillance for HIV-2 serves as an early warning system for the possible spread of this virus in the United States.