Objective: To establish a prediction model for infectious disease index（IDI）by autoregressive integrated moving average（ARIMA）,and to provide forcast of infectious diseases to the public. Methods: The data of the percentage of influenza-like illness（ILI）,the incidence rates of hand-foot-mouth disease（HFMD）and other infectious diarrhea（OID）from the 1st week of 2014 to the 14th week of 2018,and Breteau index（BI）from the 1st week of 2016 to the 14th week of 2018 were collected. ARIMA models were built to predict the risk indicators of ILI,HFMD,OID and BI. The weights of the four indicators were evaluated seasonally by the entropy weight method. Then the IDI was calculated and the data of ILI,HFMD, OID and BI from 15th to 19th week in 2018 was used for verification. Results: The forecast was in summer,so IDI=ROUND（0.33×risk index of ILI percentage +0.47×risk index of HFMD incidence +0.10×risk index of OID incidence+0.10×risk index of BI）. The predicted IDI would be 2（less safe）in the whole city and Xiangzhou District,and 1（safe）in Doumen District and Jinwan District. The consistency rates of IDI prediction was 97.50%,95.00%,97.50%,85.00% and 77.50% from 15th to 19th week in 2018,respectively. Conclusion It was feasible to use IDI for short-term risk prediction of infectious diseases.

Objective: To understand the prevalence of HIV (human immunodeficiency virus) testing and associated factors among sexual active college students in Zhuhai City. Methods: From November to December, 2019, an anonymous electronic questionnaire was administered among 12 235 students in six colleges and universities in Zhuhai City by multistage sampling. A total of 1 789 college students ever had sex were selected. Pearsons Chisquare test and nonconditional Logistic regression model were applied to analyze the factors associated with uptake of HIV testing. Results: Among these students ever had sex, 7.55% (135/1 789) had been tested for HIV mainly through hospitals (71.85%). The main reasons for testing were regular testing (50.37%) and intending to know their infection status (23.70%). Multivariable Logistic regression showed that homosexual individuals (OR=4.62, 95%CI=1.07-19.95) and those who had heterosexual commercial sex in the past year (OR=3.77, 95%CI=1.96-7.26) were more likely to test for HIV, while female (OR=0.41, 95%CI=0.24-0.69) were less likely to test for HIV. Conclusion The proportion of HIV testing was low among sexual active college students in Zhuhai City. Interventions should be tailored including strengthening the HIV testing propaganda education and enhancing students awareness of HIV testing, and the influencing factors such as gender, sexual orientation and commercial sexual behavior should be taken into consideration, so as to improve the HIV testing coverage of this population.

Objective:To analyze the cost-effectiveness and willingness-to-pay of HIV self-testing (HIVST) strategy and facility-based HIV rapid testing (HIV-RDT) strategy in men who have sex with men (MSM) in Zhuhai, and provide scientific evidence for making health policy.Methods:From the perspective of health service providers, the data of the costs and effectiveness of two HIV testing strategies in MSM in Zhuhai during January-September 2019 were collected, and a decision-tree model of cohort of 10 000 MSM was constructed by using software TreeAge Pro 2019 to measure the cost-effectiveness ratio (CER) and the incremental cost-effectiveness ratio (ICER). One-way and probability sensitivity analysis was performed for the uncertainty of the parameters in the model, and the cost-effectiveness and affordability curve was introduced to estimate the affordability of two strategies.Results:After the mobilization of MSM community-based organization through Internet and social media, 2 303 MSM had HIVST, in whom 33 were HIV positive (1.7%), and 816 MSM received HIV-RDT, in whom 35 were HIV positive (4.3%). The cost for per screening was 60.45 yuan and 240.43 yuan (RMB) respectively, and the cost for per positive screening was 4 218 yuan and 5 606 yuan (RMB) rerspectively. The results of the decision-tree model showed that the mean cost for a MSM using HIVST and using HIV-RDT was 44.67 yuan and 148.42 yuan (RMB) respectively, and the ICER was negative. HIVST strategy was a more cost-effective option when the willing-to-pay was below 6 528 yuan (RMB) for per positive screening, and HIV-RDT strategy was a more cost-effective option when the investment was higher than 6 528 yuan (RMB).Conclusion:HIVST strategy in Zhuhai is a public health project with economic value, and policy makers should strengthen the support to MSM community-based organization to promote the application of HIVST among MSM.

Objective:To evaluate the roles between two different HIV self-testing models in promoting HIV-testing among men who have sex with men (MSM).Methods:This paper focuses on two HIV self-testing service models. The first; is the online self-testing model (HIV self-testing conventional model) with the sexual health promotion network platform. The other one is an innovative HIV self-testing model (secondary distribution model), based on the previous program. The two different self-testing models, including the number of indexes and alters, the positive rate, and the demographics of indexes and alters, are compared. The influence of volunteers with or without leadership on the number of HIV self-test kits distributed or self-use is analyzed through the leadership survey scale.Results:The return rates of HIV self-testing results in the two models are 94.7%(323/341) and 99.2%(1 141/1 150), respectively, within 30 days. The proportion of alters in the secondary distribution is significantly higher (45.9%,281/612) than the conventional HIV self-testing (6.3%,20/318). In the secondary distribution model, the difference between the number of indexes and alters indicators including age, marital status, residence, sex orientation, anal sex with men in the past six months, and HIV test are statistically significant ( χ 2 test, all P<0.05). The opinion leader of MSM has significantly impacted the promotion of HIV self-testing ( P<0.05). Conclusions:Both models can promote HIV self-testing, result return, and HIV positive detection among MSM. In terms of expanding the testing and detection of HIV positive, the secondary distribution mode shows more obvious advantages, which significantly promotes a large number of MSM who have never been tested for HIV to undergo HIV testing. Influential indexes have a significant effect on increasing the HIV testing rate and promoting HIV testing among MSM.

Objective: To examine the prevalence and factors influencing the inconsistency for knowledge and behavior in condom use among college students, so as to provide suggestions for AIDS prevention and education in universities. Methods: From October to December 2019, a multistage cluster sampling method was employed to collect data relating to inconsistency for knowledge and behavior in condom use and other related factors among 1 303 students from six colleges in Zhuhai, China. Chi square test and Logistic regression were performed to analyze the influencing factors and moderating effect. Results: The reporting rate of in consistency of knowledge and behavior in condom use among college students was 41.1%. Multivariate Logistic regression analysis showed that seeking sexual partners offline was negatively correlated with inconsistency for knowledge and behavior in condom use ( OR=0.70, 95%CI =0.51-0.95). However, condom nonuse during the first sexual experience (OR=7.11, 95%CI=5.23-9.67), smoking before sex ( OR=1.47, 95%CI =1.07-2.02), drinking before sex ( OR=1.44, 95%CI =1.09-1.91), history of intimate partner violence ( OR=1.53, 95%CI =1.13-2.07), and having multiple sexual partners ( OR=1.69, 95%CI =1.25-2.29) were positively correlated with inconsistency for knowledge and behavior in condom use ( P <0.05). The moderating effect analysis showed that condom use during the first sexual experience had a moderating effect on smoking before sex and inconsistency for knowledge and behavior in condom use ( β=0.92, P <0.05). Among students who did not use condoms during the first sexual experience, a positive correlation was observed between smoking before sex and inconsistency for knowledge and behavior in condom use ( OR= 2.76 , 95%CI=1.09-6.99, P <0.05). However, no correlation was found between smoking before sex and inconsistency for knowledge and behavior in condom use ( OR=1.32, 95%CI=0.92-1.88, P >0.05) among students who used condoms during the first sexual experience. Conclusion High levels of inconsistency for knowledge and behavior in condom use are found among college students in Zhuhai City. Colleges should carry out sex education activities as soon as possible, and explore new health education models to promote the transformation of their knowledge into behavior.