Epidemic Hand, Foot and Mouth Disease Caused by Human Enterovirus 71, Singapore

Abstract

Singapore experienced a large epidemic of hand, foot and mouth disease (HFMD) in 2000. After reviewing HFMD notifications from doctors and child-care centers, we found that the incidence of HFMD rose in September and declined at the end of October. During this period, 3,790 cases were reported. We performed enteroviral cultures on 311 and 157 specimens from 175 HFMD patients and 107 non-HFMD patients, respectively; human enterovirus 71 (HEV71) was the most frequently isolated virus from both groups. Most of the HFMD patients were <4 years of age. Three HFMD and two non-HFMD patients died. Specimens from two HFMD and both non-HFMD patients were culture positive for HEV71; a third HFMD patient was possibly associated with the virus. Autopsies performed on all three HFMD and one of the non-HFMD case-patients showed encephalitis, interstitial pneumonitis, and myocarditis. A preparedness plan for severe HFMD outbreaks provided for the prompt, coordinated actions needed to control the epidemic. and, foot and mouth disease (HFMD) is typically a benign and common self-limiting childhood disease, characterized by rapidly ulcerating vesicles in the mouth and lesions, usually vesicular, on the hands and feet (1). Lesions also frequently occur on the buttocks, but other parts of the body are usually not affected (2). HFMD is caused by a few serotypes of enteroviruses, most frequently coxsackie virus A16 (CAV16) and human enterovirus 71 (HEV71). Other viruses associated with the syndrome are coxsackie virus A (CAV) 4, 5, 9, and 10 and coxsackie virus B (CBV) 2 and 5 (1). The first recognized HFMD outbreak in Singapore occurred in 1970; the etiologic agent was unknown (3). Two other outbreaks were reported in 1972 and 1981 and involved 104 and 742 persons, respectively; in both outbreaks, CAV16 was implicated as the cause (4,5).