Epidemiological Analysis On Hand-Foot-Mouth Disease From2008to2010in Kaifeng City

Background and objectiveHFMD (Hand-foot-mouth Disease, HFMD) is acommon infectious illness in infants and children. The disease is caused by a variety of viruses that belong to the human enterovirus. Most patients with mild symptoms whoes main symptoms are fever and rash or herpes in the hand, foot, mouth and other parts. Few patients may be aseptic meningitis encephalitis acute flaccid paralysis neurogenic pulmonary edema and myocarditis, etc. Very few children with severe symptoms quickly to death. HFMD is not a mew emerging infectious diseases. It has been more than fifty years of history. As early as1957, HFMD was first reported in New Zealand. At the same year, Canadian scientists have also reported an outbreak of HFMD. In1981, it was first reported in Shanghai in China. Then, Hebei Beijing Tianjin Shandong Jilin Hubei Guangdong and Xining, a dozen provinces have been discovered HFMD. Since2008, large outbreaks of HFMD occurred in several provinces in China. It attracted wide attention.The most common pathogens of HFMD is EV71(enterovirus71, EV71) or CAV16(Coxsackievirus A Group16Strain, CAV16). CAV16was first isolated in1958. EV71virus was first confirmed in the United States in1969. Later EV71has been classified into genotypes A, B,and C, which have been further divided into subtypes, designated A, Bl-5, and Cl-4. Zhejiang Center for Disease Control and Prevention collected nine cases stool specimens of HFMD for virus isolation and identification, the results was C4subtypes of EV71virus. There have been outbreaks and epidemic of HFMD in Kaifeng since2008. To investigate the dynamics and varieties of HFMD prevalence in Kaifeng City from2008to2010, providing evidence for the development of preventive intervention.Materials and methodsData was collected through the national Information management system for disease surveillance report (http://l.202.129.170/UVSSERVER2.0). Population data was collected from the National Bureau of Statistics. The HFMD patients’stool specimens within3days of onset were collected. One Step Real-time PCR method was used to detect pathogens. Data was exported to the form of microsoft excel2003database and further analyzed the data and draw statistical diagrams. Thex~2test was used to compare rates. An EV71virus was sequenced for whole genome and analyzed for gene evolution which was isolated from a severe case.Results1. The number of cases was a total of800with incidence of16.98/10million, no reported cases of severe disease and deaths in2008in Kaifeng. It’s5393with incidence of113.42/10million of which1051severe cases and6deaths in2009. In2010, it’s5207with incidence of108.66/10million of which779severe cases and2deaths.2. There were cases every month in2008-2010. It reached the peak in May2008and forward one month each year in the next two years. More cases occurred from March to June each year.3. There were cases in10counties under the jurisdiction of Kaifeng city. Cases was more in the rural area than that in the town.. But the incidence was higher in the town than that in the rural area. There were the largest number of cases in Lankao County but the highest incidence in Longting County in the three years.4. Sex ratio was approximation1.88:1of the case number and1.80:1of the incidence.5. Most cases were concentrated in5year age group and less than the age group. It was the highest of the case number or the incidence in2year age group.6. The advantages of strain was others intestinal virus in2008. But it was EV71from2009to2010. The percentage of the EV71positive was higher of deaths and severe cases than normal cases.7. Length of the whole genome of EV71Kaifeng-2010strains was7405bp. Its5’UTR and3’UTR contained742bp and84bp respectively. Its coding region contained6582bp which coded2193aa.8. The whole genome of EV71Kaifeng-2010strains, its5’UTR, PI, P2and P3had the highest homology (99.5%-98.8%) with the Fuyang strains(EU703814). It was closely with the previous isolated EV71virus strains in domestic but distance with Hubei strains (GU434678), Hungary strains, Switzerland strain and Norway strains.Conclusion1. The advantages of strain was others intestinal virus in2008. But it was EV71from2009to2010.2. More cases occurred from March to June in the past three years. It was the highest of the case number or the incidence in2year age group. Sex ratio was1.80:1of the incidence. There were the largest number of cases in Lankao County but the highest incidence in Longting County in the three years.3. Length of the whole genome of EV71Kaifeng-2010strains was7405bp. It was C4subtypes and had the closest relationship with Fuyang-2008strains. It had no major variation which compared with the previous epidemic strains in our province major variation which compared with the previous epidemic strains in our province and our country.