Tracking HIV infection and networks of drugs users in China: a national series, cross-sectional study

Abstract

BackgroundWHO reported that HIV infection transmitted through injection drug use has declined; however, some studies have indicated that HIV infection is still high in this population in many countries and these changes are uncertain. We therefore aimed to evaluate the prevalence and trend of HIV infection in opioid and synthetic users in China. MethodsWe analysed the Drug User Surveillance Database of 3·3 million drug users reported nationwide in China between Jan 1, 2008, and Aug 1, 2016. We included 368 354 individuals who tested for HIV infection for the first time and persistently used opioid or synthetic drugs in our analysis of prevalence and trend of HIV infection. We grouped all participants into three groups according to their HIV status and positions in social networks: individual users (2·6 million users), HIV clustered network (8175 users), and non-HIV network (0·6 million users). The networks were tied by peer relationships, which was defined as both drug users who were reported at the same time, same location, and one of them nominated another user. Relationship of information was extracted from users' text document record, using breadth first search algorithm and the keywords matching method. The study was approved by Peking University Institutional Review Board. FindingsThe prevalence of HIV infection was estimated at 3·1% (7236 of 232 415) in opioid users, which was about six times more than in synthetic users (598 [0·4%] of 135 939; adjusted odds ratio [ORadj] 5·90, 95% CI 5·37–6·47), but reduced to 2·5 times in injection drug users (2·49, 1·28–4·85). From 2008 to 2015, the prevalence in opioid users presented a U-shaped trend, declining from 3·8% (691 of 18 336) in 2008 to 2·3% (745 of 31 980) in 2010 (ORadj 0·59, 95% CI 0·53–0·65) and increasing by 4·2% (1074 of 25 622) in 2015 (1·47, 1·33–1·62), while it maintained a stable increase in synthetic users from 0·2% (12 of 5047) in 2009 to 0·6% (234 of 40 336) in 2015 (ORadj 3·27, 95% CI 1·72–6·21). A total of 226 357 networks were mapped and 1401 networks were identified as HIV clustered networks, which covered 1962 HIV infections. The prevalence of HIV infection in HIV clustered network was 53·4% (1962 of 3675), which was about 25 times (ORadj 25·69, 95% CI 24·75–26·66) more than 2·1% (7990 of 384 430) in individual users. 75·8% (4324 of 5708) of users in the HIV clustered network were exposed to injection drug use compared with 15·2% (39 158 of 257 126) in the non-HIV cluster network and 26·9% (271 241 of 1 008 561) in individual users. InterpretationHIV infection in opioid users decreased from 2008–10 but subsequently increased from 2010–15, whereas HIV infection keeps increasing stably in synthetic users. Injection drug use in the HIV cluster network is still a high-risk factor and the effect of current strategies on HIV control in drug users, such as the needle and syringe programmes, need to be further estimated. FundingThis study was supported by the National Natural Science Foundation of China (grant number 91546203) and the Chinese Ministry of Public Security (0716-1541GA590508).