Optimal vaccination with time-varying based on immunity barrier in Hunan Province, China

The current outbreak of novel coronavirus disease 2019 (COVID-19) is already causing a serious disease burden worldwide, this paper analyzed data of a delta variant Covid-19 outbreak in Hunan, China, and proposed an optimal dose-wise dynamical vaccinating process based on local contact pattern and vaccine coverage that minimize the accumulative cases in a certain future time interval. The optimized result requires an immediate vaccination to that none vaccinated at age group 30 to 39, which is coherent to the prevailing strategies. The dose-wise optimal vaccinating process can be directive for countries or regions where vaccines are not abundant. We recommend that vaccination should be further intensified to increase the coverage of booster shots, thus effectively reducing the spread of COVID-19.

Spatial-temporal clustering analysis of hand, foot and mouth disease in Hunan Province in 2016 - 2020 / 公共卫生与预防医学

Objective To analyze the spatial and temporal characteristics of hand, foot and mouth disease (HFMD) in Hunan Province from 2016 to 2020. Methods The data of HFMD in Hunan Province from 2016 to 2020 were collected from China's Disease Prevention and Control Information System. HFMD spatial autocorrelation analysis was conducted by ArcGIS 10.2 software at county level, and spatial-temporal scan statistical analysis was performed by SaTScan 9.7 software. Results A total of 714 157 cases was reported in Hunan Province during 2016-2020, with an average annual incidence rate of 208.36/100 000. Global spatial autocorrelation showed that HFMD had a positive spatial correlation on the county scale in Hunan Province during this period. Local spatial autocorrelation indicated that the hot spots were mainly concentrated in the north of central Hunan, the east of central Hunan and the west of Hunan. Spatial-temporal scanning analysis revealed the first class clusters (RR = 6.65, P< 0.001) covering 34 counties in northern and central Hunan, mainly distributed in Yueyang City, Changsha City, Zhuzhou City, Yiyang City and Xiangtan City from May 2018 to June, and the second class clusters (RR = 3.02, P < 0.001) covering 40 counties in western Hunan and central and southwest Hunan from April 2016 to June 2016. Conclusion HFMD incidence exhibits seasonal and regional characteristics in Hunan Province. The prevention and control of HFMD should be guided by combining the characteristics of spatial-temporal clustering.

Transmission heterogeneities, kinetics, and controllability of SARS-CoV-2

A long-standing question in infectious disease dynamics is the role of transmission heterogeneities, particularly those driven by demography, behavior and interventions. Here we characterize transmission risk between 1,178 SARS-CoV-2 infected individuals and their 15,648 close contacts based on detailed contact tracing data from Hunan, China. We find that 80% of secondary transmissions can be traced back to 14% of SARS-CoV-2 infections, indicating substantial transmission heterogeneities. Regression analysis suggests a marked gradient of transmission risk scales positively with the duration of exposure and the closeness of social interactions, after adjusted for demographic and clinical factors. Population-level physical distancing measures confine transmission to families and households; while case isolation and contact quarantine reduce transmission in all settings. Adjusted for interventions, the reconstructed infectiousness profile of a typical SARS-CoV-2 infection peaks just before symptom presentation, with ~50% of transmission occurring in the pre-symptomatic phase. Modelling results indicate that achieving SARS-CoV-2 control would require the synergistic efforts of case isolation, contact quarantine, and population-level physical distancing measures, owing to the particular transmission kinetics of this virus.

Age profile of susceptibility, mixing, and social distancing shape the dynamics of the novel coronavirus disease 2019 outbreak in China

Strict interventions were successful to control the novel coronavirus (COVID-19) outbreak in China. As transmission intensifies in other countries, the interplay between age, contact patterns, social distancing, susceptibility to infection and disease, and COVID-19 dynamics remains unclear. To answer these questions, we analyze contact surveys data for Wuhan and Shanghai before and during the outbreak and contact tracing information from Hunan Province. Daily contacts were reduced 7-9 fold during the COVID-19 social distancing period, with most interactions restricted to the household. Children 0-14 years were 59% (95% CI 7-82%) less susceptible than individuals 65 years and over. A transmission model calibrated against these data indicates that social distancing alone, as implemented in China during the outbreak, is sufficient to control COVID-19. While proactive school closures cannot interrupt transmission on their own, they reduce peak incidence by half and delay the epidemic. These findings can help guide global intervention policies.

Epidemiology and etiology of hand, foot and mouth disease in Hunan province, 2008-2017 / 中华实验和临床病毒学杂志

Objective@#To understand the epidemiologic characteristics and pathogen spectrum of hand, foot and mouth disease (HFMD) in Hunan Province during 2008—2017 and provide the basis for the prevention and control strategy of hand, foot and mouth disease.@*Methods@#Collecting data from national disease reporting information system throughout 2008—2017, the descriptive epidemiological method were used to analyze the data of HFMD monitoring and the result of pathogenic agent detection.@*Results@#A total of 1, 255, 530 HFMD cases were reported throughout 2008—2017, including 10097 severe cases and 394 deaths. The average annual attack rate is 190.38/100, 000. The peak incidence of HFMD occurred in summer and fall. The reported incidence is on the rise. The number of critically ill and the number of deaths is declining. Proportion of male cases was higher than that of females. The majority of the children were those under 5 years of age. Enterovirus (EV)-A71, coxsackievirus (CV)-A16 and other other EV positive cases accounted for 33.29%, 20.04% and 46.67% of laboratory diagnosed cases.@*Conclusions@#The epidemic of hand, foot and mouth disease in Hunan has obvious seasonal and population characteristics. There are different dominant pathogens causing HFMD in different years.

Surveillance data on typhoid fever and paratyphoid fever in 2015, China / 中华流行病学杂志

Objective Through analyzing the surveillance data on typhoid fever and paratyphoid fever in 2015 to understand the related epidemiological features and most possible clustering areas of high incidence.Methods Individual data was collected from the passive surveillance program and analyzed by descriptive statistic method.Characteristics on seasonal,regional and distribution of the diseases were described.Spatial-temporal clustering characteristics were estimated,under the retrospective space-time method.Results A total of 8 850 typhoid fever cases were reported from the surveillance system,with incidence rate as 0.65/100 000.The number of paratyphoid fever cases was 2 794,with incidence rate as 0.21/100 000.Both cases of typhoid fever and paratyphoid fever occurred all year round,with high epidemic season from May to October.Most cases involved farmers (39.68％),children (15.89％) and students (12.01％).Children under 5 years showed the highest incidence rate.Retrospective space-time analysis for provinces with high incidence rates would include Yurnan,Guangxi,Guizhou,Hunan and Guangdong,indicating the first and second class clusters were mainly distributed near the bordering adjacent districts and counties among the provinces.Conclusion In 2015,the prevalence rates of typhoid fever and paratyphoid fever were low,however with regional high prevalence areas.Cross regional transmission existed among provinces with high incidence rates which might be responsible for the clusters to appear in these areas.

Surveillance data on typhoid fever and paratyphoid fever in 2015, China / 中华流行病学杂志

Objective Through analyzing the surveillance data on typhoid fever and paratyphoid fever in 2015 to understand the related epidemiological features and most possible clustering areas of high incidence.Methods Individual data was collected from the passive surveillance program and analyzed by descriptive statistic method.Characteristics on seasonal,regional and distribution of the diseases were described.Spatial-temporal clustering characteristics were estimated,under the retrospective space-time method.Results A total of 8 850 typhoid fever cases were reported from the surveillance system,with incidence rate as 0.65/100 000.The number of paratyphoid fever cases was 2 794,with incidence rate as 0.21/100 000.Both cases of typhoid fever and paratyphoid fever occurred all year round,with high epidemic season from May to October.Most cases involved farmers (39.68％),children (15.89％) and students (12.01％).Children under 5 years showed the highest incidence rate.Retrospective space-time analysis for provinces with high incidence rates would include Yurnan,Guangxi,Guizhou,Hunan and Guangdong,indicating the first and second class clusters were mainly distributed near the bordering adjacent districts and counties among the provinces.Conclusion In 2015,the prevalence rates of typhoid fever and paratyphoid fever were low,however with regional high prevalence areas.Cross regional transmission existed among provinces with high incidence rates which might be responsible for the clusters to appear in these areas.