Routine surveillance for the detection of acute and recent HIV infections and transmission of antiretroviral resistance.

Objective: To estimate the rate of acute and recent HIV infections and the prevalence of primary antiretroviral resistance.
Design, Setting, and Subjects: A consecutive sample of individuals presenting for HIV testing at the San Francisco municipal sexually transmitted diseased (STD) clinic in 2004 (n = 3789).
Main Outcome Measures: HIV antibody-positive specimens were screened by BED IgG capture enzyme immunoassay to identify recent infections. HIV antibody-negative specimens were screened by nucleic acid amplification testing (NAAT) to detect acute infections. Newly detected infections were genotyped to detect primary antiretroviral resistance.
Results: There were 11 acute and 44 recent HIV infections among the total 136 newly detected cases. NAAT increased case identification by 8.08% over standard antibody testing. Acute HIV infections were associated with having a known HIV-positive partner, and a history of hepatitis B, syphilis, and chlamydia. The prevalence of primary antiretroviral resistance was 13.2%, with drug-resistant mutations detected in 17 of 129 cases genotyped. Mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors (NNRTI) were present in 11 of 17 cases.
Conclusion: The integration of HIV nucleic acid amplification, recent infection, and antiretroviral resistance testing enhanced HIV/STD surveillance. The high proportion of NNRTI mutations detected suggests they may be more common in source partners or more fit for transmission than other forms of drug-resistant HIV-1. Primary antiretroviral resistance monitoring in STD clinic patients may guide the selection of treatment and post-exposure prophylaxis regimens active against viruses being transmitted in the community, and provide health departments with surveillance data in a sentinel population at risk of HIV transmission.