Behavioral characteristics and prevalence of HIV, Treponema pallidum and HCV infections in drug users in Ningbo, Zhejiang, 2009–2018

ObjectiveTo understand the change of behavioral characteristics and the prevalence rates of human immunodeficiency virus (HIV), Treponema pallidum, and hepatitis C virus (HCV) infections in drug users in Ningbo of Zhejiang province.

MethodsFrom 2009 to 2018, annual cross-sectional survey was conducted between April and June among drug users in drug rehabilitation center and blood samples were taken from them for the detections of HIV, Treponema pallidum and HCV antibodies. Trend χ² test and multivariate logistic regression analysis was used to analyze the relationship between Treponema pallidum infection and drug use or sexual behavior.

ResultsThe average age of the 4 000 drug users was 33.48±8.25 years. Among them, 82.98% were males, and 86.15% had the education level of junior high school or below. Novel type drug users accounted for 66.03%, and the trend increased year by year ( χ²＝9.230, P＝0.002). The overall positive rates of HIV, Treponema pallidum and HCV were 0.48%, 13.80% and 21.06%, respectively. The positive rate of Treponema pallidum showed an increase trend year by year ( χ²＝5.355, P＝0.021), and the HCV positive rate showed a decrease trend year by year ( χ²＝37.921, P＜0.001). Multivariate analysis showed that female (aOR＝3.512, P＜0.001), older age (aOR＝2.163, P＝0.014) and commercial sex in the past year (aOR＝1.536, P＜0.001) were risk factors for Treponema pallidum infection (P＜0.05).

ConclusionThe HIV and HCV infection rates in drug users in Ningbo were low, but the infection rate of Treponema pallidum was on rise. The use of novel type drugs was in increase. Targeted effective interventions should be conducted in female and older drug users as well as drug users having commercial sex.