Objective: To investigate the epidemiological characteristics of norovirus clustering and outbreaks in schools and kindergartens in China, so as to provide references for prevention and control of outbreaks. Methods: A descriptive epidemiological method was used to analyze outbreaks of Norovirus in schools and kindergartens in China during 2014-2018 , the indicators which was analyzed and compared including attack rate, duration of the outbreak, reporting interval. Results: A total of 832 Norovirus outbreaks were reported by schools and kindergartens in China from 2014 to 2018. The total number of outbreaks showed an upward trend with an average annual growth rate of 58%. The number of reported cases was 40 445 but there was no death. Norovirus outbreaks mainly occurred in primary schools (42%), followed by kindergartens and middle schools (both 24%), university (6%) and 77 outbreaks (4%) were reported in universities and other schools. The peak seasons were March to May, November and December each year. Jiangsu Province and Guangdong Province (both 22%) reported the largest number of outbreaks. The main transmission of norovirus outbreaks was through direct person contact (72%), foodborne (4%) and waterborne (3%) caused fewer outbreaks than direct person contact. The duration of the epidemic was positively correlated with the reporting interval (r=0.63, P<0.05) and the number of cases per outbreak (r=0.51, P<0.05). Conclusion Disinfection treatment of vomitus should be standardized in schools and kindergartens. Timely detection, reporting, disposal of the epidemic can effectively control the spread of norovirus outbreaks.

Objective: To understand prevention and control of infectious disease among primary schools in Xi’an. Methods: A total of 93 primary schools were selected through multi-stage stratified sampling method from 14 counties in Xi’an, then these schools are surveyed to meaure the classroom ventilation. Results: About 28.0% (26/93) of these schools met the national standard for health staffs, with 7.4%(4/54) in urban primary schools and 56.4% in rural primary schools (22/39), the difference between urban and rural areas is statistically significant(P<0.01). Urban primary schools were better than rural primary schools in morning inspection, registration and tracking for illness, verification of vaccination certificates, surveillance and reporting of epidemic outbreaks, verification of school recovery(P<0.05). The average per capita area among the 92 primary schools was (1.22±0.34) m2, with (1.08±0.26) m2 in urban primary schools and (1.42±0.33) m2 in rural primary schools, the difference between urban and rural areas was statistically significant (P<0.01). The average per capita ventilation area of 92 primary schools was (0.15±0.07) m2 with (0.13±0.04) m2 in urban primary schools and (0.19±0.08) m2 in rural primary schools, the difference between urban and rural areas was statistically significant (P<0.01). Conclusion School-based infectious diseases prevention and control needs to be improved in Xi’an, especially in health personnel. Urban schools appear superior in the prevention and control of infectious diseases and sanitary conditions, while rural schools appear superior in student density and classroom ventilation.

Objective: To investigate the health effects of air pollution on elementary school students with the indicator of absenteeism caused by respiratory symptoms and diseases, and to provide a reference for improving their physical health. Methods: Absenteeism, air pollutants, and meteorological data during Sep. 2015 to Jun. 2017 in Pudong, Shanghai were collected. Generalized additive model was used to estimate the effects of air pollution on students’ absenteeism caused by respiratory symptom and diseases, time trends, day of week and meteorological factors were controlled. Results: Totally 47 723 person-days of elementary school students’ absenteeism caused by respiratory symptoms and diseases were recorded during Sep.2015 to Jun. 2016 in Pudong, Shanghai, and the absenteeism rate was 0.07%. The PM2.5 concentration on lag0 and SO2 concentration on lag2 showed the most significant effects, the elementary school students’ absenteeism raised for 1.43% (95%CI=0.25%~2.62%)and 6.79% (95%CI=0.25%~13.32%) respectively with every 10 μg/m3 increment of PM2.5 and SO2. Conclusion Air pollution in Pudong new area have made a influence on the elementary school student’s respiratory symptoms and absenteeism, and the prevention work of air pollution should be strenghthened.

Objective: To explore the prevalence and associated distress of lower urinary tract symptoms among female college students in Xuzhou. Methods: Convenience sampling was used to recruit 1 000 female college students in Xuzhou China. Chinese versions of International Consultation on Incontinence Questionnaire LUTS and General Information Questionnaire was used. Results: The prevalence of lower urinary tract symptoms was 95.7%. The top ten prevalence rates were urgency (88.2%), hesitancy (65.4%), nocturia (48.5%), intermittent stream (47.3%), straining (30.5%), increased daytime frequency (30.1%), bladder pain (21.0%), SUI (18.5%), UUI (13.9%), nocturnal enuresis (7.5%). Urinary urgency was the most disturbing symptom (49.0%). Risk factors of urinary urgency included rural household registration (OR=1.67, 95%CI:1.10-2.55, P=0.017) and premature urination (OR=1.65, 95%CI:1.23-2.21, P=0.00). Conclusion Female college students have a high prevalence of lower urinary tract symptoms but with moderate severity and distress. Toileting behaviors affect bladder health, which require early intervention.

Objective: To analyze the accuracy of different BMI obesity screening criteria in discriminating the obesity of college students, and to provide a reference for formulation scientific and reasonable grouth and development evaluation criteria for students. Methods: The bioelectrical impedance analysis (BIA) was used to measure BF of 1 977 non-sports-major-students. Based on WHO "golden standard" of BF% (BF>25% for male and BF >35% for female) for obesity, the accuracy, reliability, and benefits of different BMI screening standards for obesity were evaluated. Results: The obesity rate was 11.6% according to the BF% standard, and was 2.0% and 8.2% based on BMI ≥28 kg/m2 and BMI ≥25 kg/m2, respectively; A higher specificity (0.999, 0.966) and a low sensitivity (0.175,0.450) were noticed when BMI≥28 kg/m2 and BMI≥25 kg/m2 was used as screening standard for obesity, especially among female(0.063,0.304); The reliability evaluation of consistency with "gold standard" of BMI≥25 kg/m2 was higher than BMI≥25 kg/m2; when BMI≥28 kg/m2 was used as screening standard for obesity, the positive predictive value was higher than negative predictive value, BMI≥25 kg/m2 was on the contrary. Conclusion BMI cannot adequately reflect body fat content of college students, especially for female; The standard for obesity diagnosis should be based on gender.

Objective: To analyze the current situation and characteristics of poor vision of students aged 7-18 in 26 ethnic minorities in China, and to provide scientific basis for the vision prevention and treatment measures for minority students. Methods: The 2014 national survey report on student physique and health was used to collect the data of 80 766 primary and secondary school students of poor vision selected from 26 ethnic minorities, The Chi-square test was used to compare and analyze the visual acuity of Han and Chinese students. Results: The rate of poor eyesight among primary and secondary school students of ethnic minorities was 39.17%. The girls were reported with higher rates of visual impairment than boys, and the difference was highly significant(χ2=1 127.28, P<0.01). High school girls (16-18 years old ) had the highest rate of visual impairment, reaching 63.13%. The rate of vision failure was the lowest among boys in the lower grades of primary school (7 to 12 years old), amounting to 20.50%. The detection rate of poor vision in all ethnic groups ranged from 14.68% to 62.94%. Among them, the top five groups with the highest detection rate of poor vision were Tibetan(62.94%), Zhuang(62.39%), Korean(57.92%), Hui(56.48%) and Naxi(51.35%). The five lowest ethnic groups were the aquarium(14.68%), Wa(17.96%), Kyrgyz(18.30%), Li(19.22%) and Hhani(22.30%). The differences among most ethnic groups were highly significant(χ2=7 910.34, P<0.01). Conclusion The vision level of 26 minority students in China is lower than that of the Han. But there are significant ethnic differences. While intervening in Tibet，Zhuang and other key ethnic students, we should pay attention to gender differences and strengthen the prevention and control of vision of students from all ethnic groups.

Objective: To analyze the prevalence and associated factors of hypertension among primary and secondary school students aged 9-18 years in Henan province, and to provide scientific evidence for targeted hypertension prevention strategies. Methods: Data of 34 840 students aged 9-18 years with physical examination and questionnaire information came from National School Student Physical Fitness and Health Survey in 2014. Results: The prevalence of hypertension among primary and secondary school students aged 9-18 years in Henan Province was 11.5%. The prevalence of boys and girls was 13.1% and 9.9%, respectively, and boy’s was higher than girl’s (χ2=89.04, P<0.01). The prevalence of primary school, junior high school and senior high school was 13.0%, 12.1% and 9.2%, respectively, and primary school was higher compared with junior and senior high school (χ2=89.66, P<0.01). Binary logistic regression analysis showed that high BMI (OR=1.97), eating eggs every day (OR=1.11), attending more physical education classes every week (OR=1.16), doing more setting-up exercises during the break (OR=1.08) and playing electronic products for longer time (OR=1.09) were positively associated with risk of hypertension (P<0.05). While longer sleep time (OR=0.83) and more serious attitude toward setting-up exercises during the break (OR=0.91) were negatively associated with risk of hypertension (P<0.05). Conclusion The study documents a high prevalence of hypertension among primary and secondary school students in Henan Province, which is associated with multifarious factors. Therefore, effective prevention and control measures should be taken for different populations to prevent high blood pression.

Objective: To explore the relationship between dietary patterns and non-alcoholic fatty liver disease(NAFLD) among college freshmen of Hangzhou area, and provide scientific evidence for the prevention of NAFLD in universities. Methods: The 1 752 freshmen students from six universities were selected to perform a questionnaire survey, including general information, and dietary survey in the last year, by using a random sampling method. Factor analysis was used to achieve the major dietary patterns. Results: Three dietary patterns were obtained from the analysis, including the animal food, Western fast food, and traditional Chinese patterns. After adjusting for confounding factors, participants in the highest tertile of the animal food and Western fast food pattern had significantly higher BMI (P<0.01). Besides, participants in the highest tertile of the Western fast-food pattern had higher ALT and AST than those in the lowest tertile(P<0.05). Conversely, participants in the highest tertile of the traditional Chinese pattern had lower BMI, ALT and AST than those in the lowest tertile(P<0.05). Logistic regression analysis showed that Western pattern might increase the risk of NAFLD (OR=1.26, 95%CI=1.09-1.72, P<0.05), whereas the traditional Chinese pattern might decrease the risk of NAFLD (OR=0.51, 95%CI=0.38-0.74, P<0.05). Conclusion Different dietary patterns are closely related to NAFLD in college freshmen. Chinese traditional food should be kept their diet, red meat and fried food should be reduced to decrease. the risk of NAFLD.

Objective: To understand reason for the difference of supplementary immunization activities (SIA) using measles-containing vacline (MV) among different types of universities in China. Methods: Ten universities from one city were selected by using purposive sampling method. Qualitative interviews were conducted on the implementation of MV SIA in universities, and the differences of measles vaccination and the reasons were analyzed. Results: The MV vaccination rates in the 10 universities in 2017 were 54%, 96%,95%,97%,81%,93%,13%,12%,10% and 21% respectively.The rate of four-year universities was higher than that of three-year colleges; and the rate of public universities was higher than that of private schools; the rate of provincial universities was higher than that of central government administered universities; the vaccination rates also vary within central government administered universities.The level, ownership and affiliation of colleges and universities led to the differences in medical qualification, administrators’ risk perception of disease and vaccines, and the relationship between the schools and local CDC, which in turn affected the implementation of vaccination in universities. Conclusion The different attributes of universities are the fundamental reasons that lead to the differences in the rate of MV SIA in Chinese universities. It is suggested that the differences of university attributes should be considered in the process of implementation of the policy of immunization in universities.And the vaccination policy in universities should be strengthened, the risk communication of universities, especially private universities, should be improved, and the working relationship of the Ministry of Health and the Ministry of Education should be enhanced.

Abstract Dietary behavior is developed and formed during childhood, and is closely related to individual, family, school, community, society, culture, policy and other factors. Unhealthy dietary behaviors will lead to overweight, obesity, malnutrition, and affect children’s health.Without effective intervention, unhealthy dietary behaviors often extend into adulthood, affecting adults’ health as well. Therefore, the development of healthy dietary behavior must be started early. In order to promote healthy dietary behavior, many interventions have been carried out in different countries with remarkable results.We should draw lessons from the existing experience, adopt comprehensive intervention measures to promote children to form healthy dietary behavior.