To estimate the rate of acute and recent HIV infections and the prevalence of primary antiretroviral resistance.
A consecutive sample of individuals presenting for HIV testing at the San Francisco municipal sexually transmitted diseased (STD) clinic in 2004 (n = 3789).
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.
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.
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.
From the aUniversity of California San Francisco, San Francisco, California, USA
bGladstone Institute of Virology and Immunology, San Francisco, California, USA
cSan Francisco Department of Public Health, San Francisco, California, USA.
Received 7 March, 2006
Revised 3 August, 2006
Accepted 8 August, 2006
Correspondence to Hong-Ha M. Truong, Center for AIDS Prevention Studies, University of California San Francisco, 50 Beale Street, Suite 1300, San Francisco, CA 94105, USA. E-mail: Hong-Ha.Truong@ucsf.edu