| Background Current prevention and intervention measures of HIV/AIDS include condom promotion, needle exchange, methadone maintenance treatment, testing and treatment in China. Prior models in China had analyzed the effects of testing and treatment on HIV/AIDS epidemic, but drug resistance was not included in the above models. Conflicting results appeared between the effects of unsafe sex and testing-and-treatment on the HIV/AIDS epidemic from different international models. Therefore, it is necessary to construct a dynamic model that includes all current prevention and intervention information in China to study how the above measures affect the epidemic.Objective The purpose of this study is to analyze dynamic characteristics and long-term HIV epidemic trends under current intervention strategies and measures in China and to evaluate the effects of different intervention strategies on the HIV epidemic.Methods We developed a deterministic epidemiologic model to simulate the HIV/AIDS epidemic in China. The parameters were obtained mainly from the published literature. The subjects of this study include men who have sex with men (MSM), male intravenous drug users (MIDU), clients of female sex workers (FSW), men in the general population, female intravenous drug users (FIDU), FSW, and women in the general population. We calibrated the model to match the estimates for the HIV/AIDS epidemic once every two years from2005-2011. Main outcome measures included people living with HIV/AIDS (PLHIV), incident cases.Results Under current intervention measures, the total numbers of PLHIV was expected to rise from2005to2020, and the total numbers of incident cases was expected to rise from2006to2020. The total numbers of PLHIV and incident cases in2020were estimated to approximate1.07million,104000, respectively. The number of PLHIV was estimated to be on rising trends among MSM, clients of FSW, low-risk men, FSW, and low-risk women from2005to2020; the number of incident cases was estimated to rise among the above populations from2006to2020; and the numbers were expected to decline year by year among IDU. The proportions of people with HIV infections transmitted by sexual contact were reported to rise during the forecast period among both PLHIV and new infections. Homosexual transmission showed a dramatic increase, and the proportions of homosexual transmission among PLHIV and new infections in2020were22%and28%, respectively. Consistent condom use among MSM, FSW and clients was projected to have a strong influence on the HIV/AIDS epidemic both in these subpopulations and in the total population. Needle exchange and methadone maintenance treatment programs were projected to have a strong influence on the HIV/AIDS epidemic only among IDU. Testing and treatment can reduce the number of incident cases among the total population. We could control the HIV/AIDS epidemic in China in five years if the proportions of consistent condom use among MSM, FSW and clients were all higher than75%. The outcomes of sensitivity analysis showed that the prevalence of unprotected anal intercourse among MSM, the proportion rate of consistent condom use among FSW, the proportion rate of consistent condom use among clients of FSW, the percentage of clean syringes obtained among IDU, the coverage rate of methadone maintenance treatment, testing rate, treatment coverage rate and the rate of drug resistance were all the sensitive parameters of the number of incident cases.Conclusions The total numbers of PLHIV and incident cases are both still expected to rise. We should put more efforts into interventions among high-risk populations who may be transmitted by sexual contact. Unsafe sex is currently the main route of transmission for the HIV/AIDS epidemic in China, the comprehensive prevention on the basis of condom use promotion can control the HIV/AIDS epidemic in China. |
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