Epidemiology And Etiology Of Hand Foot And Mouth Disease In Hainan,2010

ObjectivesThe aim of this study is to reveal the epidemiological and pathogeniccharacteristics of HFMD in Hainan province in2010. In order to deeplyunderstand the epidemiological manifestation and characteristics, we furtherdiscusses the features of HFMD outbreak of Hainan province in2010. At thesame time, in order to formulate reasonable treatment measures and providescientific basis for the prevention and control of HFMD, the present paper triesto summarize and analyze the all kinds of methods of prevention and treatmentof HFMD on domestic and foreign in a systematic way.MethodThe data of reported cases of HFMD collected from the Chinese diseaseprevention and control information system were analyzed. At the same time, thedescriptive analysis of data was conducted using Excel and MapInfoProfessional software to describe the characteristic of HFMD. The clinicalspecimens of1346HFMD cases from the18cities in Hainan province werecollected for enterovirus (EV) detection. Viral isolation was performed for EVnucleic acid positive samples. Complete VP1encoding region of EV71weresequenced and analyzed with Sequencher (version5.0) and MEGA software(version5.0).ResultEpidemiological analysis results showed that the31provinces of Chinahave HFMD cases in2010, and the top five provinces with high incidence rate were Guangxi, Hainan, Beijing, Tianjin, Guangdong. The age distribution wasmainly concentrated in0-5years. the HFMD cases are being reported eachmonth throughout the year in2010, but the highest peak was in May.Epidemiological analysis results showed that HFMD cases were reported by all18prefectures of Hainan Province in2010, with higher incidence in thenortheast. The reported cases were mainly composed of infants and youngchildren under the age of4. HFMD incidence of Hainan Province were at higherlevels in every month of2010, and reached peak during September and October,which is different from other provinces in China.Etiology results indicated that EV71and CA16were the major causativepathogens of HFMD epidemic in Hainan Province in2010, and EV71infectionwas absolutely dominant among severe and fatal cases. In addition, some HFMDcases were identified associated with other serotypes of EV infections.Molecular epidemiological analysis showed that all the EV71strainsbelonged to C4a evolutionary branch, which is the dominant evolutionarybranch in China in recent years. These strains belong to three differentevolutionary branches with different epidemics and transmission range, andthere are at least three transmission chains.ConclusionThe31provinces in China have HFMD cases in2010. Therefore, we shouldstrengthen the detection and prevention of HFMD in the key areas. The Hainanprovince is located in the southof China with special geographical and climaticconditions, so that the weather is very hot and humid all the year. The HFMDincidence of Hainan remained in a high level throughout the year, and the peakoccured in October, which is different from the national average; Childrenunder the age of four is the high risk group with HFMD in Hainan, which isconsistent with the national situation. The compositions of pathogens arecomplex in Hainan Province, and the dominant pathogen remains diversity indifferent prefectures and different months. However, EV71was the mainpathogen of most severe and fatal cases.Molecular epidemiological analysis based on VP1region showed that allthe EV71strains in Hainan and other places of China belonged to C4a evolutionary branch, which is the dominant evolutionary branch in China since2004. EV71isolates which caused mild, severe and fatal cases have no obviouscharacteristics in affinity.