Study On The Epidemiological Characteristics And Pathogen Spectrum Of Severe And Dead Cases Of Hand-foot-mouth Disease

Objective By collecting and analyzing the report information of severe and fatal cases of HFMD in China from 2010 to 2019,the epidemic characteristics and trends of HFMD in China were systematically mastered.A prospective field investigation was carried out in sentinel hospitals to reveal the serotypes of enteroviruses in severe and fatal cases in China,and to explore the differences in clinical manifestations of different serotypes in severe and fatal cases of HFMD.Method 1.Collect the case data of severe and fatal cases of HFMD reported by medical institutions at all levels from January 1,2010 to December 31,2019 in the "Infectious Disease Reporting System" of the information system of Chinnese Center for Disease Control and Prevention,screen out the severe and fatal cases,and classify them according to the disease distribution and serotypes.The indicators included:the numbers of severe cases,severe rate,the numbers of laboratory confirmed cases,serotype composition ratio,etc2.The detailed case information of severe and fatal cases of HFMD from May 1,2019 to December 31,2019 in Henan,Hunan and Yunnan provinces was collected by means of on-the-spot investigation.The questionnaire included basic population information,clinical symptoms and treatment information.At the same time,the samples of severe and fatal cases were collected.In addition to the conventional EV-A71 and CV-A16 classification,the positive samples of enterovirus serotypes were classified into CV-A6 and CV-A10 serotypes.The results of virus serotyping and case investigation data were recorded into the database by EpiData to describe the composition of enterovirus serotypes and the distribution of clinical manifestations of different serotypes.Result 1.In 2010-2019 years,the average annual incidence rate of HFMD in China is about 151.19/10 million,and the reported severe rate is 1.05/10 million.On average,more than 300 people die each year,with an average annual mortality rate of 2.22%.The highest incidence rate was in 2014,and the reported severe rate was 1.81/10 million.From 2010 to 2011,the proportion of severe and fatal cases of EV-A71 infection was more than 80%,from 2012 to 2017,the proportion of EV-A71 was between 50.94%and 77.29%,and from 2018 to 2019,the proportion of EV-A71 dropped to 22.15%and 17.45%.The proportion of severe cases and fatal cases of EV-A71 infection decreased year by year,while the proportion of other enterovirus positive cases increased year by year.2.A total of 573 cases of severe and fatal cases of HFMD were collected.Among 511 cases of positive samples,CV-A6 accounted for 27.57%,CV-A16 21.82%,EV-A71 7.68%,CV-A10 3.49%and other serotypes 28.62%.The distribution of clinical symptoms,such as aspiration weakness,headache,ataxia and convulsion was statistically significant in different serotypes.The proportion of severe cases was 81.15%,the proportion of critical cases was 18.85%(among them,the proportion of 3 stages was 7.68%,the proportion of 4 stages was 11.17%)?Conclusion 1.The incidence rate of severe HFMD is decreasing year by year.Meanwhile,the number of fatal and severe mortality also showed a decreasing trend.The pathogen composition of severe cases changes greatly with time.While the proportion of severe cases infected by EV-A71 is decreasing year by year,the proportion of laboratory confirmed cases of HFMD infected by other enteroviruses is increasing year by year.It is necessary to strengthen the prevention and control of key populations,key areas and high incidence seasons,and further carry out other enterovirus surveillance2.CV-A6 has become the most common serotype among the four serotypes of CV-A6,CV-A16?EV-A71 and CV-A10 in the severe and fatal cases of HFMD,and 18.18%of the critical cases of EV-A71 positive patients are the most common among the four serotypes.