Hand, foot, and mouth disease in China, 2008–12: an epidemiological study

Abstract

Summary Background Hand–foot–and–mouth disease (HFMD) is a common childhood illness caused by enteroviruses. Increasingly it imposes a substantial disease burden throughout East and Southeast Asia. To better inform vaccine and other interventions, we characterized the epidemiology of HFMD in China based on enhanced surveillance. Methods We extracted epidemiological, clinical and laboratory data from reported HFMD cases during 2008–2012 and compiled climatic, geographic and demographic information. All analyses were stratified by age, disease severity, laboratory confirmation status and enterovirus subtype. Findings The surveillance registry captured 7,200,092 probable HFMD cases (annualized incidence, 1·2 per 1,000), of whom 3·7% were laboratory–confirmed and 0·03% died. Incidence and mortality were highest in children aged 12–23 months (in 2012: 38·2 cases per 1,000 and 1·5 death per 100,000). Median durations from onset to diagnosis and death were 1·5 days and 3·5 days respectively. The risk of cardiopulmonary or neurological complications was 1·1% and the severe-case fatality risk was 3·0%, with >90% of deaths associated with enterovirus 71. HFMD peaked annually in June in the North, whereas Southern China experienced semi-annual outbreaks in May and September/October. Geographic differences in seasonal patterns were weakly associated with climate and demographic factors (variance explained 8-23% and 3–19%, respectively). Interpretation This is the largest population-based study to date of the epidemiology of HFMD. Future mitigation policies should take full account of the heterogeneities of disease burden identified. Additional epidemiologic and serologic studies are warranted to elucidate local HFMD dynamics and immunity patterns and optimize interventions. Funding China–US Collaborative Program on Emerging and Re-emerging Infectious Diseases; World Health Organization; The Li Ka Shing Oxford Global Health Programme and Wellcome Trust; Harvard Center for Communicable Disease Dynamics; Health and Medical Research Fund, Government of the Hong Kong Special Administrative Region.