Etiological Characteristics Investigation Of Hand,Foot And Mouth Disease In Hang Zhou City And Analysis Of Indices Of Laboratory Severe Cases,2016-2018

Objective:1.We aims to describe the epidemiological characteristics and the relationship between severe and common HFMD in Hangzhou Children's Hospital from Jan 2016 to Dec 2018,which would provide relevant evidences for the prevention and treatment of hand-foot-mouth disease.2.We aims to compare the differences of cerebrospinal fluid(CSF)routine biochemical tests and cerebrospinal fluid-specific IgM antibody among different types of HFMD,in order to provide a new reference for the diagnosis of severe HFMD.Method:1.4760 specimens of HFMD cases were collected and the pathogen was classified by RT-PCR.Then EV71,CoxA16,CoxA6,CoxA10,CoxA2,and CoxA5 pathogens were tested and the pathogen distribution and clinical status of children with HFMD were described.2.For other untyped specimens,specific primers were used to PCR-amplify the samples,and the amplified products were electrophoresed.Then the positive sample were sequenced by Shanghai ShengGong Gene Co,Ltd.3.Critically ill children's routine cerebrospinal fluid biochemical were tested.The differences of CSF routine biochemical tests and cerebrospinal fluid-specific IgM antibody among different types of HFMD were analysised.The differences of serum and cerebrospinal fluid specific IgM antibody were also analysised.Result:1.A total of 4760 HFMD clinical diagnosis cases were collected from 1 Jan 2016 to 31 Dec 2018.Although HFMD cases occurred throughout the year,we observed the first peak in May and July,the second peak in October and September.2.Among 4760 patients with HFMD,there were 3559 cases were detected,accounting for 74.8%of the total.426 cases of EV71 positive were detected,accounting for 8.9%of the total,249 cases of CoxA16 for 5.2%of the total,and other enteroviruses accounted for 60.6%of the total.More than 80%of EV positive HFMD cases were not EV71 or CoxA16,which increases year by year.However,EV71 decreased year by year in the last three years,especially in 2018,only 13 cases were detected.3.Among1297 samples with HFMD,there were 835cases of CoxA6 positive were detected,accounting for64.4%of the total,177cases of CoxA10 for 13.6%of the total,100 cases of CoxA2 for 7.7%of the tota,140 cases of CoxA5 for 3.7%of the total,3 cases of mix for 0.02%of the total and other enteroviruses accounted for 11.0%in 2017 and 2018.4.Preschool children were still the primary group of infections,and the age of the children(not EV71 or CoxA16)tends to be younger.There is no gender difference in the rate of infection of different enteroviruses.5.Most of the 3559 HFMD patients were pathomeiosis(82.6%),only a few came up with complication of nervous system and respiratory system(17.4%).In severe cases,EV71 infection was the main cause.6.The CSF nucleated cells count and nucleated cells positive rates in EV71 positive subgroup were higher than those in the CoxA16 positive subgroup and other enteroviruses subgroup(Z=-4.472;Z=-9.991,p<0.05;?2=43.857;?2=133.078,p<0.05).The CSF protein quantity and positive rates in EV71 positive subgroup were higher than those in the CoxA16 positive subgroup and other enteroviruses subgroup(Z=-3.151;Z=-5.255,p<0.05;?2=4.956;?2=11.795,p<0.05).7.The CSF nucleated cells count and positive rates in antibody-positive group were more higher than those in antibody-negative group in EV71 type HFMD,(p<0.05),the CSF protein quantity and positive rates in antibody-positive group were more higher than those in antibody-negative group(p<0.05).EV71-IgM in serum were significantly correlated with the antibody in CSF(r=0.600,p<0.05).conclusions:1.From 1 Jan 2016 to 31 Dec 2018,the incidence and prevalence of HFMD were seasonal each year.The main peak of onset was in the alternate seasons of spring and summer and autumn and winter.2.2016-2018,the predominant pathogen of diagnosis cases was CoxA6,which increased significantly.The positive rate of EV71 decreased significantly in 2018.The predominant of HFMD were changed(not EV71 or not CoxA16).3.The age of the children(not EV71 or CoxA16)tends to be younger.4.Severe HFMD involve the nervous system,which would increased nucleated cells and protein in cerebrospinal fluid.The nucleated cells and proteins increased significantly in critical condition(EV71-IgM positive).There is a good correlation between serum and cerebrospinal fluid IgM antibody.