The incidence of syphilis, HIV and HCV and associated factors in a cohort of men who have sex with men in Nanjing, China.
OBJECTIVE
This study investigated the incidence of syphilis, HIV and hepatitis C virus (HCV), as well as factors associated with syphilis seroconversion among men who have sex with men (MSM) in Nanjing, China.


METHODS
A cohort of MSM was recruited by respondent-driven sampling methods. Those who were syphilis-, HIV- and HCV-seronegative at the baseline were invited to be retested at month 6. A Poisson regression analysis was performed.


RESULTS
Of the 416 participants in the study, 348 participants were HIV-, syphilis- and HCV-negative at the baseline, 250 (71.84%) of whom returned for retesting at month 6. Nine of these 250 participants had seroconverted to syphilis-positive (incidence=7.58 per 100 person-years (PY); 95% CI 2.63 to 12.53 per 100 PY), and five had seroconverted to HIV-positive (incidence=4.17 per 100 PY; 95% CI=0.52 to 7.83 per 100 PY). No HIV and syphilis coinfection and no HCV seroconversion were found. Multivariate analysis identified four statistically significant factors predicting syphilis seroconversion, including currently single marital status (RR=0.32, 95% CI 0.16 to 0.65, p<0.01), monthly income >US$300 (RR=2.68, 95% CI 1.28 to 5.61, p<0.01), self-reported homosexual orientation (RR=0.48, 95% CI 0.24 to 0.96, p<0.05) and recruitment of male sex partners mostly from gay saunas (RR=6.72, 95% CI 2.88 to 15.68, p<0.01).


CONCLUSIONS
The high incidence of syphilis and HIV reflects the seriousness and urgency of the HIV and sexually transmitted diseases (STD) epidemics among MSM in China. Effective interventions of syphilis treatment and prevention should target MSM with characteristics reflecting the aforementioned risk factors.
Centre for Health Behaviors Research, School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, PR China.
Chun
C
Hao
Hongjing
H
Yan
Haitao
H
Yang
Xiping
X
Huan
Wenhui
W
Guan
Xiaoqin
X
Xu
Min
M
Zhang
Weiming
W
Tang
Na
N
Wang
Jing
J
Gu
Joseph T F
JT
Lau
D000328:Adult; D000368:Aged; D002681:China / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology*; D019698:Hepatitis C, Chronic / Q000453:epidemiology*; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D017533:Marital Status / Q000706:statistics & numerical data; D008875:Middle Aged; D013587:Syphilis / Q000453:epidemiology*; D055815:Young Adult