Prevalence of Syphilis and Human Immunodeficiency Virus Infections among Men Who Have Sex with Men in Shenzhen, China: 2005 to 2007

IN CHINA, THERE HAS BEEN an emerging epidemic of HIV and syphilis infections among men who have sex with men (MSM). Multiple surveys conducted in recent years have shown a high prevalence of syphilis infections among MSM in China.(1,2) A rapid increase of HIV prevalence has been demonstrated among MSM in some areas, including in China. For example, the prevalence of HIV had increased from 0.4% in 2004 to 5.8% in 2006 in Beijing, China.(3) A high HIV prevalence has also been found among MSM in other Asian countries including Phnom Penn, Cambodia (8.9%), Chiang Mai, Thailand (15.3%), and Andhra Pradesh, India (18.2%).(4) In 2007, homosexual transmission has accounted for 12.2% of the 50,000 estimated new HIV infections in China.(5) Risk of HIV transmission is a particular concern in the context of current syphilis epidemic because infection with ulcerative STDs, including syphilis, has been shown to increase the risk of HIV transmission 3- to 5-fold.(6) HIV may also increase the acquisition of other STDs and alter the natural history and response to standard therapy of ulcerative STDs, resulting in an "epidemiologic synergy" between HIV and STDs.(7) For these reasons there is particular concern about the potentially increasing transmission of HIV and syphilis among MSM.(8) Because of overlaps in sexual networks between the MSM and non-MSM population, it is also predicted that the transmission of HIV and syphilis among MSM may play an important role on driving the epidemic of HIV and syphilis in China in the future.