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Wednesday, May 10, 2006

HIV incidence among men diagnosed with primary or secondary syphilis -- San Francisco and Los Angeles, 2004 2005

Kate Buchacz1, Jeff D. Klausner2, Joe Schwendemann3, Charlotte K. Kent2, Getahun Aynalem4, Kellie Hawkins4, Peter McElroy1, Monique Anthony1, Leah Rauch5, Melanie Taylor4, John T. Brooks1, and Peter R. Kerndt4. (1) Divisions of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS E-45, Atlanta, GA, USA, (2) STD Prevention and Control Services, San Francisco Department of Public Health, San Francisco, CA, USA, (3) The New York State Diagnostic HIV Laboratory, Albany, NY, USA, (4) Sexually Transmitted Disease Program, Los Angeles County Department of Health Services, Los Angeles, CA, USA, (5) Public Health Laboratory, San Francisco Department of Public Health, San Francisco, CA, USA

Syphilis outbreaks among men who have sex with men (MSM) in the U.S. have prompted concerns that HIV transmission may accompany the outbreaks.

To estimate HIV incidence among men diagnosed with primary or secondary (P&S) syphilis in STD clinics in Los Angeles (LA) and San Francisco (SF) served by two public health laboratories.

We abstracted sociodemographic information from routine syphilis surveillance databases and reserved remnant sera for P&S syphilis cases diagnosed during January 2004 May 2005. Anonymous unlinked Treponema pallidum particle agglutination-positive sera were screened for HIV-1 antibodies by enzyme immunoassay (EIA). Specimens that were confirmed HIV-positive by Western Blot were then tested for recent HIV infection using the less sensitive (LS) HIV-1 Vironostika EIA and BED HIV-specific IgG:Total IgG assay. We estimated HIV incidence using the serologic testing algorithm for recent HIV serocoversion (STARHS).

Of 259 men (151 in SF, 108 in LA), 37% had primary syphilis, and 85% were MSM (11% no MSM risk, 4% no information). Median age was 35 years; 49% were white, 14% black, 27% Hispanic, and 10% other. Of the total, 100 (39%) men were HIV-positive; of those, 6 men tested as recently HIV-infected by LS EIA (all 6 confirmed by BED) and had no antiretroviral use history or HIV-positive results ≥ 6 months earlier. The 6 men with recent HIV infection (3 per jurisdiction) were MSM, and 1 had primary syphilis. The estimated HIV incidence was 7.8% per year (95% confidence interval [CI]: 1.6 - 14.1%) among all men and 9.6% per year (95% CI: 1.9 17.3%) among MSM.

We found elevated HIV incidence rates among men diagnosed with P&S syphilis in STD clinics in SF and LA.

Intensive, integrated HIV/STD prevention programs are needed for this population.