Epidemiology of hand, foot and mouth disease in Zhejiang, 2010-2011

Objective To understand the epidemiological characteristics and epidemic pattern of hand foot and month disease (HFMD) in Zhejiang province. Methods Descriptive epidemiological analysis was conducted on the incidence data of HFMD reported in Zhejiang during 2010-2011 through disease surveillance information system. Results A total of 200 641 HFMD cases, including 1248 severe cases and 61 deaths, were reported during this period. The reported incidence was 188.88/lakh and the case fatality was 0.03%. The cases (124 921) reported from April to July accounted for 62.26% of the total. The cases in children aged 5 years accounted for 94.6% and the cases in children aged 3 years accounted for 79.23%. The severe cases in children aged 3 years accounted for 80.12% and the deaths in children aged 3 years accounted for 84.48%, the medians of age of these children were 1.99 and 1.52 years respectively. Among the reported cases, 12 295 were laboratory confirmed. Among the mild cases, 51.60% were caused by EV71, 28.49% by Cox A16 and 19.91% by other enteric viruses. Among the severe and death cases, the positive rates of EV71 were 85.53% and 96.08% respectively. Conclusion HFMD cases occurred all the year round with obvious seasonality and geographic differences. The children outside child care settings are the high-risk population; The major pathogens of HFMD epidemic were EV71 and Cox A16, the change of the predominant virus influenced the epidemic trend and severity.