ABSTRACT
To investigate the duration of humoral immune response in convalescent coronavirus disease 2019 (COVID-19) patients, we conduct a 12-month longitudinal study through collecting a total of 1,782 plasma samples from 869 convalescent plasma donors in Wuhan, China and test specific antibody responses. The results show that positive rate of IgG antibody against receptor-binding domain of spike protein (RBD-IgG) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the COVID-19 convalescent plasma donors exceeded 70% for 12 months post diagnosis. The level of RBD-IgG decreases with time, with the titer stabilizing at 64.3% of the initial level by the 9th month. Moreover, male plasma donors produce more RBD-IgG than female, and age of the patients positively correlates with the RBD-IgG titer. A strong positive correlation between RBD-IgG and neutralizing antibody titers is also identified. These results facilitate our understanding of SARS-CoV-2-induced immune memory to promote vaccine and therapy development.
ABSTRACT
Objective To investigate the awareness status of iodine deficiency disorders (IDD) prevention and treatment knowledge of target population in Hubei Province, and to evaluate the intervention effect of IDD health education. Methods From 2013 to 2016, 13 counties (cities and districts) were selected as project counties in Hubei Province each year and 7 counties (cities and districts) were selected each year in 2017-2018. Three townships (towns) were chosen in each project county, and the health education activities were carried out among the grade 4-6 students in the central primary school of each township (town). Three administrative villages were selected in each township (town) to carry out community health education activities. Before and after the implementation of health education, 30 students in a fifth grade class from each central elementary school, and 15 housewives around the school were selected to conduct a questionnaire survey on IDD prevention and control knowledge. Results Totally 5 940 elementary school students and 2,970 housewives were investigated from 2013-2018. After carrying out IDD health education activities, the awareness rates of IDD prevention knowledge among primary school students and housewives were 94.28% (16 801/17 820) and 93.20% (8 304/8 910), respectively, which increased significantly compared with those before the health education intervention [71.60% (12 759/17 820) and 70.93% (6 320/8 910), respectively]. The differences were statistically significant (χ2=3,239.83, 1,500.78，P<0.01). Among the primary school students and housewives, the knowledge awareness rates of IDD prevention and treatment were increased by 22.68% and 22.27%, respectively. Conclusion Health education intervention could significantly increase the awareness of IDD among primary school students and housewives, and it is an important measure to maintain IDD elimination status.
ABSTRACT
Objective To systematically review the correlation between fluoride exposure through drinking water and dental fluorosis of school-age children,and to provide a theoretical basis for further development of prevention strategies against dental fluorosis.Methods Such databases as China National Knowledge Infrastructure (CNKI),WanFang Data,VIP Database and China Biology Medicine Disc (CBM) were searched through computer to find out the relationship between fluoride exposure through dringking water and occurrence of dental fluorosis.The retrieval time was from January 1,2000 to January 1,2018.Meta-analysis was performed using RevMan 5.3.Funnel plot and fail-safe method were used to evaluate publication bias,and these data were analyzed sensitivity with random and fixed effect models.Results Totally 20 literatures entered into this study,79 814 people in fluoride exposure group,and 181 876 people in control group.The meta-analysis showed that,20 literatures were inhomogeneous through the heterogeneity test,which was analyzed in the random effect model,the pooled odds ratio (OR) value and 95％ confidence interval (95％CI) was 4.25 (3.66-4.94),which suggested that the risk of dental fluorosis in the fluoride exposure group was 4.25 times higher than that in control group.Funnel plot was asymmetrical,the fail-safe number was 47 791.56,which was 2 389.6 (47 792/20) times higher than included literatures.Literatures publication bias was small,sensitivity analysis revealed that the results were basically reliable.Conclusion Excessive fluoride exposure through dringking water could be one of the main risk factors leading to dental fluorosis.
