Epidemiologic features of hand-foot-mouth disease and herpangina caused by enterovirus 71 in Taiwan, 1998-2005

Objective: In 1998, an epidemic of hand-foot-mouth disease/herpangina was caused by human Enterovirus 71 Infection in Taiwan. The underlying factors of widespread emergence of viral Infection are unclear. The purpose of this study was to assess the epidemiology of hand-foot-mouth disease/herpangina in Taiwan between March 1998 and December 2005.

Methods: We analyzed data reported to surveillance systems at the Taiwan Center for Disease Control. Viral isolation was performed by 11 reference virus laboratories at medical centers as well as the Taiwan Center for Disease Control.

Results: During the 8-year study period, the reported incidence of mild cases of hand-foot-mouth disease/herpangina varied from 0.8 to 19.9 cases per sentinel physician per week, peaking in 1998. Seasonal variations in incidence were observed, with an incidence peak observed during the summer season. Annual incidence changed significantly from 1998 to 2005. Both age-specific incidence and fatality of severe hand-foot-mouth disease/herpangina decreased as age increased. Most (93%) cases occurred in children who were aged 4 years and younger. Inpatients had a higher rate of Enterovirus 71 Infection than outpatients. Among severe cases, the majority (80%) had pulmonary edema/hemorrhage and encephalitis.

Conclusions: Hand-foot-mouth disease/herpangina is a common disease in Taiwan. Enterovirus 71 Infection has emerged as an important public problem causing serious clinical illness and, potentially, death in young children. Vaccine development is recommended for prevention of Enterovirus 71 Infection in the future.