Objective To describe and analyze the spatial and temporal?spatial epidemiological characteristics of human infection with avian influenza A（H7N9） virus in Foshan City from 2013 to 2017. Method Software Geoda v1.12 was used to analyze the global and local auto?correlation （GISA and LISA） of human infection with H7N9 avian influenza from December 2013 to September 2017 in Foshan City. SaTScan v9.4.3 was used for spatial?temporal scanning analysis. Results Before the restricted sale policy for live poultry was implemented， the GISA Moran’s I showed that the cases of human infection with avian influenza A（H7N9） occurred randomly during the 2013-2015 epidemic period. LISA Moran’s I showed that Dali Town in Nanhai District was a “High?high” clustering area （LISA Moran’s I ＝1.24， P＜0.05）. Spatial?temporal scanning statistics further showed that the epidemic peak of human infection with H7N9 avian influenza was observed in January 2014 in Dali Town， Nanhai District and Zumiao Street， Chancheng District， presenting a cluster occurrence （RR＝50.35， P＜0.01）. After implementing the restricted sale policy for live poultry， the GISA Moran’s I showed that the temporal epidemic characteristics of human infection with H7N9 avian influenza had been changed. The GISA Moran’s I showed that the H7N9 avian influenza epidemic in Foshan City was clustered from winter 2016 to spring 2017. LISA showed that Jiujiang Town in Naihai District was a “High?high” clustring area （LISA Moran’s I＝5.58， P＜0.01）. Spatial?temporal scanning showed that the epidemic in twons of Jiujiang and Xiqiao was serious from December 2016 to January 2017 （RR＝25.10，P＜0.05）. Conclusion The spatial clustering and spatio?temporal clustering of human infection with H7N9 avian influenza in Foshan City were obvious. The epidemic characteristics were different before and after the implementations of the restricted sale policy for live poultry. Before implementing the policy， cases were occurred randomly， but there was a clusterring tendency in densely populated area. After implementing the policy， case cluster area was mainly in the place where the restricted sale policy for live poultry was not implemented.

Objective To understand the status of the coverage of HIV/AIDS prevention services in young men who have sex with men （YMSM） and analyze factors influencing channels of prevention and treatment information access. Method YMSM aged 15 to 24 years in Mianyang City， Sichuan Province were recruited by the snowball sampling method. Prevention services， information access channels， and sexual behavior were investigated and serological tests were conducted among the selected subjects. Data were analyzed using the chi?square test or multivariate logistic regression model. Results A total of 362 YMSMs were surveyed， with a median age of 21.0 years. Of the respondents， 224 （61.9%） had the educational level of college degree or above and 213 （58.8%） were students. The coverage of prevention services was 78.6% （278/362）. The main channels of obtaining information were the internet， accounting for 62.4% of the participants （226/362）， followed by friends （46.6%； 168/362）， television （41.4%； 150/362）， publicity materials （40.6%； 147/362）， and schools （34.0%； 123/362）. The HIV antibody positive rate in those who took the television and publicity materials as the information dissemination channels was lower than those who did not （all P＜0.05）. Multivariate logistic regression showed that， YMSMs who had a college degree or above （OR＝1.814）， were students （OR＝1.880）， had HIV tested （OR＝1.807） or searched for sexual partners through the internet （OR＝2.328） were more likely to take the internet as the main information channel， but those who had depressive symptoms were less likely （OR＝0.579）； those who accepted peer education （OR＝3.391）， had fixed sexual behavior （OR＝3.269） or occasional sexual behavior （OR＝2.756） were more likely to take friends as the main information channel， while those who had more than 2 anal sexual partners （OR＝0.475） were less likely； those who insisted on using condoms （OR＝0.280）， had occasional sexual partners （OR＝0.301） or were positive for HIV?antibody （OR＝0.142） were less likely to take the television as the main information channel； the persons accepting peer education （OR＝5.022） were more likely to take publicity materials as the main information channel， while those with anxiety symptoms （OR＝0.151） and positive HIV antibody （OR＝0.177） were less likely. Conclusion The coverage of AIDS prevention services for YMSM was not high. The internet played an obvious role in information dissemination. The disseminations of television and publicity materials were more prompt and efficient in communication.

Objective To investigate the prevalence and influencing factors of type 2 diabetes mellitus among college students in Guangdong Province， so as to provide theoretical basis for preventing this disease in college students. Method From July 2016 to December 2017， using a multistage stratified cluster random sampling method， the prevalence of type 2 diabetes among college students in Guangdong Province was investigated by conducting questionnaire survey， physical examination and laboratory testing. Univariate and multivariate logistic regressions were used to analyze the influencing factors. Results A total of 2 196 college students aged 18-23 years were investigated， including 1 208 males and 988 females. Of the participants， 83 students were diagnosed with type 2 diabetes， with a prevalence of 3.78% （83/2 196）. Multivariate logistic regression showed that family history of diabetes （OR＝3.982，95%CI：1.395-6.773），overweight and obesity （OR＝1.746， 95%CI：1.355-2.160）， centripetal obesity （OR＝2.881，95%CI：1.204-4.956）and dyslipidemia （OR＝1.987，95%CI：1.260-2.748） were risk factors for diabetes mellitus， but physical exercise （OR＝0.762，95%CI：0.554-0.983） was protective factor for diabetes mellitus. Conclusion The prevalence of type 2 diabetes was high among college students in Guangdong Province. Family history of diabetes， physical exercise， overweight and obesity， centripetal obesity and dyslipidemia were the factors influencing type 2 diabetes mellitus among the college students. Comprehensive measures should be taken to prevent diabetes.

Objective To analyze the relationship between the dietary intake of sodium and potassium and hypertension among residents aged 18 years and above in Zhongshan City. Method Multistage cluster random sampling method was used to select residents aged 18 years and above from 400 households in 5 urban districts in Zhongshan. A questionnaire survey was conducted for collecting the basic information of the respondents， prevalence of hypertension， and intake and frequency of various types of food in one year. Descriptive epidemiological analysis was used to analyze the survey results. Multivariate logistic regression analysis was used to analyze the relationship between hypertension and sodium-potassium ratio. Results A total of 984 residents aged 18 and over in Zhongshan City were investigated， including 463 males （47.1%） and 521 females （52.9%）. The prevalence of hypertension was 8.2% （81/984）. The median intakes of the sodium and potassium were 2 501.5 （2 265.7-2 988.8） mg/day and 1 962.4 （1 313.6-2 775.6） mg/day， respectively. Of the residents， 93.6% had dietary sodium intake exceeding the recommended adequate intake （AI）， while 52.4% consumed dietary potassium below the recommended AI. The main resources of dietary sodium were edible salt （63.4%）， and then followed by livestock and poultry meat （8.8%）， and aquatic products （8.3%）. The resources of dietary potassium were cereals （20.9%）， vegetables （17.4%）， and livestock and poultry meat （15.5%）. Logistic regression analysis showed that， if the dietary sodium potassium ratio increased by 1 unit， the risk of hypertension increased 0.341 time （OR＝1.341）. Conclusion The dietary intake of sodium was slightly high and that of potassium was slightly low in the residents aged 18 years and above in Zhongshan. The dietary sodium potassium ratio increased the risk of hypertension.It is necessary to intensify health education on nutrition and to advocate low sodium and high potassium diet.

Objective To investigate the work stress and sleep quality in community nurses， so as to provide evidence for effective interventions. Method A stratified random sampling method was adopted to select nurses working in 21 community health service centers in Sichuan Province to conduct a questionnaire survey. The survey contents included basic information， the Work Stress Rating Scale for Medical Staff and the Pittsburgh Sleep Quality Index （PSQI）. The rank correlation analysis was used to analysis the relationship of stress and sleep.Data were analyzed using univariate and multivariate logistic regressions. Results A total of 175 valid questionnaires were collected and all the respondents were females aged 18-54 years. The total scores of work stress of community nurses were （58.73 ± 9.00）， the score of sleep quality was 7， and the incidence of sleep disorder was 40.00% （70/175）. Spearman’s rank correlation analysis showed that the scores of work stress were positively correlated with the scores of sleep quality （Rs＝0.223）. The higher the stress， the worse the sleep quality. Multivariate logistic regression analysis showed that nurses with fixed term labor contracts were 3.038 times more likely to have sleep disorders than those without the fixed term labor contracts （OR＝3.038）. The higher the total scores of the stress， the greater the likelihood of sleep disorders （OR＝1.020）. Conclusion The incidence of sleep disorders among community nurses in Sichuan Province was relatively high. The greater the work stress， the worse the quality of sleep.

Objective To understand the use of vitamin D （VD） supplements in primary and secondary school students in Guangzhou and explore factors influencing the VD supplement use. Method A cross?sectional survey was conducted among students of the second?grade in primary school， the first?grade in junior high school， and the first?grade in senior high school from 39 schools in Guangzhou. The survey included students' basic information， height， weight and the use of VD supplements， the educational level of parents and the average monthly per capita household income. Multivariate logistic regression was used to analyze the factors influencing VD supplement use. Results A total of 14 038 students were included in the study， including 7 178 boys （51.13%） and 6 860 girls （48.87%）. The utilization rates of VD supplements were 17.8%（2 500/14 038） among all the respondents， and 28.5% （544/1 910）， 19.7% （1 240/6 308） and 12.3% （716/5 820） for the second?grade students in primary school， first?grade students in junior high school and first?grade students in senior high school， respectively （P＜0.01）. Multivariate logistic regression showed that the utilization rate of VD supplements was higher in the first?grade junior high school （OR＝1.63） and first?grade senior high school （OR＝1.64） students whose parents' educational level was college and above， compared with the students whose parents' educational level was junior high school and below. Compared with those whose average monthly per capita household income was below 5 000 Yuan， the utilization rates of VD supplements for first?grade junior high school students whose average monthly per capita household income was ≥10 000 Yuan was higher （OR＝1.50）. Among the second?grade primary school students， overweight and obese students were less likely to use VD supplements than the normal weight ones （OR＝0.73）.Conclusion The use rate of VD supplements in primary and secondary school students in Guangzhou was low， and parents’ educational level and family income may be the factors influencing the use of VD supplements. The use of VD supplements should be increased appropriately for senior and overweight or obese students.

Objective To determine the specific parameters of mosquito trap luring system， air?drying killing system and filtration system of a new type mosquito trap. Method A parallel test was used to compare the numbers of mosquitoes caught in the two trapping combinations， i.e.， Kung Fu handsome photocatalytic mosquito trap+Domestic Qi Dong trap as Group A and Kung Fu handsome photocatalytic mosquito trap+BG lure as Group B， within 24 hours under laboratory conditions； an air?dried execution experiment was carried out to compare the number of deaths at different levels at wind speed within 24 hours under laboratory conditions； both indoor and outdoor experiments were used to compare the number of mosquitoes and insects captured by mosquito traps with different sizes of filters. Results The numbers of mosquitoes captured by Group A were （57.40 ± 19.71）， higher than that by Group B （42.80 ± 15.83）（P＜0.05） . The average numbers of mosquitoes killed were 18.67， 25.33 and 30.00 at the wind velocity of 0， 1.4 and 3.0 m/s， respectively（P＜0.01）. The average numbers of mosquitoes captured at 24 hours were 2.00， 15.67， 60.33 and 68.00 in apertures of 3.0， 4.5， and 6.0 mm， and blank control group， respectively （all P ＜ 0.01）. The average numbers of mosquitoes captured in apertures of 3.0 and 4.5 mm were lower than those in the blank control group （P＜0.01 for both）. In outdoor experiment， there was no significant difference in the numbers of mosquitoes captured by different aperture screens （P > 0.05）. The average numbers of insects captured in groups with 4.5， 6.0， and 7.8 mm apertures were lower than those in the control group （P ＜ 0.01）. Conclusion The effect of the trap with Qi Dong lure is better than that with BG lure. The number of mosquitoes killed by air drying was the most at the wind speed of 3.0 m/s. And the filter of 6-7.8 mm size has the best filtering effect.