Rapidly increasing prevalence of HIV and syphilis and HIV-1 subtype characterization among men who have sex with men in Jiangsu, China.

Objective: To investigate the prevalence of HIV, hepatitis B (HBV), hepatitis C (HCV), and syphilis among men who have sex with men (MSM) in 2 cities of Jiangsu, China, and to characterize the HIV-1 subtypes prevalent among this population.

Methods: During September 2006 and July 2007, 296 and 173 MSM were recruited from Nanjing and Yangzhou, respectively. Sera samples were collected and tested for HIV, HBV, HCV, and syphilis infections. The nucleotide sequences of p17 and C2V3 regions were determined by RT-nested-PCR and sequencing. HIV-1 subtypes were characterized by phylogenetic analysis.

Results: The prevalence of HIV, HBV, HCV, and syphilis infections among MSM was 5.8%, 11.1%, 0.7%, and 27.7%, respectively. The prevalence of HIV and syphilis was significantly higher in 2006-2007 than in 2003 (P 0.05). The phylogenetic tree of p17 showed that HIV-1 subtypes B, CRF01_AE, and CRF07_BC accounted for 35.7%, 35.7%, and 28.6%, respectively. The result of C2V3 showed that 45.5%, 36.4%, and 18.2% sequences belonged to HIV-1 subtype B, CRF01_AE, and BC recombinants, respectively. The subtype characterization in Jiangsu was significantly different from those in Beijing (P <0.05). Furthermore, Jiangsu HIV-1 B strains were different from majority of China B' strains and originated from Beijing.

Conclusions: The rapidly increasing prevalence and complex subtypes of HIV-1 suggest that effective prevention and intervention strategies are urgently needed for MSM in Jiangsu.