Age-specific disparity in life loss per death attributable to ambient temperature: A nationwide time-series study in China.

Age-specific discrepancy of mortality burden attributed to temperature, measured as years of life lost (YLL), has been rarely investigated. We investigated age-specific temperature-YLL rates (per 100,000) relationships and quantified YLL per death caused by non-optimal temperature in China. We collected daily meteorological data, population data and daily death counts from 364 locations in China during 2006-2017. YLL was divided into three age groups (0-64 years, 65-74 years, and ≥75 years). A distributed lag non-linear model was first employed to estimate the associations of temperature with age-specific YLL rates in each location. Then we pooled the associations using a multivariate meta-analysis. Finally, we calculated age-specific average YLL per death caused by temperature by cause of death and region. We observed greater effects of cold and hot temperature on YLL rates for the elderly compared with the young population by region or cause of death. However, YLL per death due to non-optimal temperature for different regions or causes of death decreased with age, with 2.0 (95 % CI:1.5, 2.5), 1.2 (1.1, 1.4) and 1.0 years (0.9, 1.2) life loss per death for populations aged 0-64 years, 65-74 years and over 75 years, respectively. Most life loss per death results from moderate temperature, especially moderate cold for all age groups. The effect of non-optimal temperature on YLL rates is smaller for younger populations than older ones, while the temperature-related life loss per death was more prominent for younger populations.

Effectiveness and associated factors of varicella vaccination on school outbreaks / 中国学校卫生

Objective@#To evaluate the effectiveness of varicella vaccine in varicella outbreaks and to analyze the influencing factors, and to provide a reference for making the targeted prevention and controlling measures.@*Methods@#A total of 3 888 students with no history of varicella were selected from 2 schools with varicella outbreak in Guangdong Province in 2021, a retrospective cohort study was conducted by using questionnaire survey, rate ratio ( RR ) and vaccine effectiveness ( VE ) values were calculated and Logistic regression was uses to analyze the factors influencing the protective effect of varicella.@*Results@#There were 138 confirmed cases of varicella among the participants. There was no significant sex difference in the vaccination rate( χ 2=1.36, P =0.51), but there was significant difference in the vaccinattion rate of different age groups( χ 2=555.82, P <0.01). The overall protective effect of VarV was 66.94%(95% CI =56.17%-77.71%), and the protective effect of 2 doses of vaccine( VE = 90.02% , 95% CI =83.13%-96.90%) was higher than that of 1 dose( VE =49.40%, 95% CI =32.36%-66.44%)( χ 2=24.93, P < 0.01 ). The high fever rates in the vaccinated and unvaccinated groups were 7.69% and 25.81%, with significant difference( χ 2= 6.29 , P <0.05). The rates of moderate and severe skin lesions of vaccinated and unvaccinated groups was 20.00% and 50.00%, respectively, and the difference was statistically significant( χ 2=11.32, P <0.01). The protective effects of varicella vaccine against high fever and moderate to severe rash were 70.19%(95% CI =42.11%-98.27%) and 60.00%(95% CI =38.15%-81.85%). Stratified analysis showed that there were significant differences in different years of vaccination( χ 2=37.87, P <0.05), while there were no significant differences in age of vaccination and vaccine manufacturer ( P >0.05).@*Conclusion@#Varicella vaccination can prevent chickenpox infection and reduce the severity of the disease. However, the efficacy of varicella vaccine was affected by vaccination years. It is recommended to improve the vaccination coverage of varicella vaccine to prevent the outbreak of the epidemic.