Trends of HIV, hepatitis C virus and syphilis seroprevalence among injection and non-injection drug users in southwestern China, 2010-2017.

The primary risk of HIV transmission in China has shifted from injecting drug use (IDU) to sexual contact since 2006. We evaluated the prevalence trends of HIV, hepatitis C virus (HCV), syphilis, and sexual and drug use behaviors among drug users. Methods: People who use drugs participated in any of four rounds of cross-sectional surveys during 2010-2017 in Chongqing. Participants were tested for HIV, HCV, and syphilis. Questionnaire interviewing was conducted to collect behavioral information. Chi-square and trend tests were employed to assess the changes in diseases and behaviors over time. Results: A total of 8,171 people who inject drugs (PWID) and 5,495 non-injection drug users (NIDU) were included in the analyses. HIV prevalence among PWID in four rounds of the survey in 2010-11, 2012-13, 2014-15, and 2016-17 was 11.5%, 9.7%, 6.5%, and 6.9%, and among NIDU, 2.4%, 1.4%, 2.1% and 2.6%, respectively. HCV prevalence among PWID was 83.5%, 85.2%, 67.1% and 79.7% (P < 0.001), and among NIDU, 22.2%, 10.8%, 13.4% and 14.8%, (P < 0.001). Conclusions: The declining HIV and HCV prevalence among PWID is coincident with declining risky drug use behaviors. Tailored disease prevention and interventions targeting PWID and NIDU are needed.