Prevalence and incidence of HIV infection among drug users in Zhongshan, Guangdong, 2010-2014

Objective To understand the prevalence and incidence of HIV infection among drug users in Zhongshan, Guangdong province, from 2010 to 2014, and provide evidence for the evaluation of HIV epidemic in this population.Methods The analysis was conducted by using the HIV test data in drug rehabilitation center in Zhongshan and HIV sentinel surveillance data in Zhongshan during this period. By Spectrum/EPP model estimation, first CD4+ T-cell count detection and open cohort study, the HIV incidence among the drug users was determined.Results From 2010 to 2014, the prevalence of HIV infection among the drug users in drug rehabilitation center were 2.88%(52/1804), 3.33%(64/1920), 3.51%(62/1764), 3.40%(94/2765) and 3.94%(86/2183) respectively, the differences were not statistical significant(2=3.44, P=0.49). According to the sentinel surveillance, the prevalence of HIV infection among injection drug users were 5.13%(12/234), 6.36%(18/283), 4.26%(12/282), 4.94%(12/243) and 4.93%(10/203) respectively, the differences were not statistical significant(2=1.36, P=0.85); while the prevalence of HIV infection among other drug users were 1.81%(3/166), 1.13%(2/177), 0.78%(1/129), 0.60%(1/166) and 0.00%(0/197) respectively, the differences were not statistical significant(2=4.35, P=0.36). According to the estimation of Spectrum/EPP model, the incidence of HIV infection among the drug users remained to be 0.23% approximately and based on the first CD4+ T-cell count detection, the incidence of HIV infection among the drug users were 0.28%, 0.16%, 0.29%, 0.11% and 0.10% respectively during this period,the differences were not statistical significant(2=3.83, P=0.43). Among 1971 drug users receiving repeat HIV test in the open cohort, 4473 person-years were followed with 4 drug users became HIV sero-conversion, the incidence of HIV infection was 0.09 per 100 person-years(95% CI: 0.01-0.18).Conclusion From 2010 to 2014, the prevalence of HIV infection among drug users remained to be less than 0.5% and the incidence of HIV infection among the drug users remained to be less than 0.3% in Zhongshan.