Epidemiology: Open Access
Open Access

Abstract

Objective: This study explores the trends and associated factors of HIV, HCV and syphilis seroconversion among Chinese
methadone maintenance treatment (MMT) clients over a follow-up period of up to seven years.
Design: Drug users from fourteen MMT clinics in Guangdong province were recruited during 2006-2014. Participants were
seronegative with at least one of HIV, HCV and syphilis infections at baseline and had completed at least one follow-up test
during the study period. We estimated HIV, HCV and syphilis seroconversion rates in follow-up years and identified the
underlying predictors using a multivariate Cox regression model.
Results: Among 9, 240 participants, the overall HIV seroconversion rate was 0.20 (0.13-0.28)/100 person-years (pys), 20.54
(18.62-22.46)/100 pys for HCV, and 0.77 (0.62-0.93)/100 pys for syphilis over the study period. HIV seroconversion rate
showed a moderate but non-significant annual decline of 13.34% (-42.48-30.56%) (Chi-2 trend test: p=0.369), whereas the
decline of HCV seroconversion was 16.12% (5.53-25.52%) per annum (p<0.001). Syphilis seroconversion rate remained stable
(p=0.540). Urine results positive for opioid predicted HIV seroconversion (≥60% versus <60%: HR=3.40, 1.07-10.85), being
unmarried (HR=1.59, 1.15-2.20), injection drug use in the past 30 days (HR=2.17, 1.42-3.32), having sexual intercourse in
the past 3 months (HR=1.74, 1.22-2.47) and higher daily dosage of methadone (≥60 ml versus <60 ml: HR=1.40, 1.01-1.94)
predicted HCV seroconversion. Being female (HR=3.56, 2.25-5.64) and infected with HCV at baseline (HR=2.40, 1.38-8.36)
were associated with subsequent syphilis seroconversion.
Conclusion: MMT in China has demonstrated moderate to good effectiveness in reducing HIV and HCV incidence but not
syphilis infection among participating drug users.

Biography

Xia Zou is a student in Sun Yat-sen University, P.R. China.