周口市疾病预防控制中心

ObjectiveTo establish a reverse osmosis technology-based method for enrichment of virus in water samples. MethodsTwo inactivated virus vaccines and two viral nucleic acid plasmids were added into simulated water samples and detected with real-time quantitative reverse transcriptase PCR (qRT-PCR) after reverse osmosis-based enrichment. Reverse osmosis membrane material, membrane pore size, and filtration time were optimized in the enrichments. ResultsThe enrichment efficiency increased with the decrease of pore size of the reverse osmosis membrane. The average virus enrichment efficiency of reverse osmosis membrane with the pore size of 0.10 μm was 22.86 ± 0.84% for 2 simulated water samples. The virus enrichment efficiency of nylon, cellulose acetate and polyethersulfone membranes were similar between each other. The enrichment efficiency goes up with the increase of filtration times, but the difference in the efficiency was not significant between two and three times of filtration. ConclusionThe efficiency can be up to 32.64% for the enrichment of polio virus in water samples using cellulose acetate filter membrane with 0.10 μm aperture and two times of filtration.

Objective To analyze the trajectory changes of body mass index（BMI） and its association with further overweight and obesity among non-overweight and non-obesity primary and secondary school students at baseline, in order to provide basis for controlling the incidence of overweight and obesity among children and adolescents in China. Methods The physical examination data of primary and secondary school students were collected from a cohort study designed in Longkou City from 2015 to 2022, and 7 346 non-overweight and non-obesity students at baseline were included in thus study. The Generalized linear model was used to analyze the effect of baseline BMI level on further BMI level after 8 years of follow-up, and stratified analysis was performed according to age groups. Linear trend test was used to analyze the influence of baseline BMI level on end-stage BMI change trend. Results During the follow-up period, the detection rates of overweight and obesity were 14.6%, 17.9%, 17.7%, 17.7%, 18.3%, 20.4%, and 18.3% from 2016 to 2022, respectively. Among these, the detection rate of overweight and obesity in 2021 was highest. At different baseline ages, changes with follow-up years followed the same pattern, with overweight and obesity rate trend firstly up and then down with age, with the rate of increase peaking at around 10 years old. After 8 years of follow-up, compared with the baseline, the further new-onset overweight and obesity rate was 18.3%, and boys（21.5%） were higher than girls（15.8%）. Compared with the baseline BMI-Z level＜-2, the correlation of primary BMI-Z with final BMI-Z level was stronger(P trend ＜0.001) in baseline BMI-Z＞-1 group（β=1.191, 95%CI:0.853-1.529）. When baseline BMI level was 1-2, it had a greater impact on the final BMI level for students agded 9-11 than students agde 6-8（β=1.600, 95%CI:1.360-1.839）. Conclusions The new-onset overweight and obesity rate of boys in Longkou City was higher than girls. The incidence of overweight and obesity in the age group of 9-11 years increases rapidly, and it was closely correlated with the level of further BMI. Comprehensive prevention and control strategies should be implemented to focus on prevention and control, and to reduce the risk of overweight and obesity effectively.