[A large scale cohort study on AIDS in communities in Dali, Yunnan province, 2014-2015]

Objective: To understand HIV incidence in community residents and epidemiological characteristics of newly detected HIV infection cases in Dali, Yunnan province. Methods: A cohort study was conducted among 146 720 community residents who were tested to be HIV negative during 2010-2011, they were followed-up from June 1, 2014 to May 31, 2015. Results: A total of 136 356 community residents received follow up (92.9%). The follow-up time was 0.23-5.40 years (medium: 3.43 years), cumulatively 459 675 person years, and 78 people were found to be HIV positive. The incidence rate of HIV infection was 0.170/1 000 person years. The incidence rate was 0.037/1 000 person years in age group 15-29 years, 0.288/1 000 person years in age group 30-44 years, 0.210/1 000 person years in age group 45-59 years, 0.204/1 000 person years in age ≥60 years; 0.213/1 000 person years in males, 0.130/1 000 person years in females; 0.248/1 000 person years in Han ethnic group, 0.149/1 000 person years in Minorities; 0.194/1 000 in people with education level ≤ junior middle school, 0.046/1 000 person years in people with education level > junior middle school; 0.070/1 000 person years in the unmarried, 0.194/1 000 person years in the married and 0.425/1 000 person years in the divorced/widowed. Cox proportional hazards regression analysis showed that being male (HR=1.731), aged 30-44 years (HR=13.158), aged 45-59 years (HR=10.329), aged ≥60 years (HR=8.291), unmarried (HR=3.162) and divorced/widowed (HR=2.689) were the risk factors for HIV infection, while the education level > junior middle school (HR=0.132) was the protective factor for HIV infection. Conclusions: By medium 3.43 years follow up, the cohort study showed that incidence rate HIV infection was 0.170/1 000 person years in the community residents in Dali. Male, middle aged and old people, people with low education level, the unmarried and the divorced/widowed had relatively higher risk to be infected with HIV, Close attention should be paid to the prevention and control of AIDS in these populations.