An epidemic of enterovirus 71 infection in Taiwan

Background Enteroviruses can cause outbreaks of hand-foot-and-mouth disease (characterized by vesicular lesions on the hands, feet, and oral mucosa) o r herpangina, usually without life-threatening manifestations. In 1998 an e pidemic of enterovirus 71 infection caused hand-foot-and-mouth disease and herpangina in thousands of people in Taiwan, some of whom died. Methods We assessed the epidemiologic aspects of this outbreak. Cases of ha nd-foot-and-mouth disease or herpangina in ambulatory patients were reporte d to the Taiwan Department of Health by a mean of 818 sentinel physicians. Severe cases in hospitalized patients were reported by 40 medical centers a nd regional hospitals. Viruses were isolated by 10 hospital laboratories an d the department of health. Results The sentinel physicians reported 129,106 cases of hand-foot-and-mou th disease or herpangina in two waves of the epidemic, which probably repre sents less than 10 percent of the estimated total number of cases. There we re 405 patients with severe disease, most of whom were five years old or yo unger; severe disease was seen in all regions of the island. Complications included encephalitis, aseptic meningitis, pulmonary edema or hemorrhage, a cute flaccid paralysis, and myocarditis. Seventy-eight patients died, 71 of whom (91 percent) were five years of age or younger. Of the patients who d ied, 65 (83 percent) had pulmonary edema or pulmonary hemorrhage. Among pat ients from whom a virus was isolated, enterovirus 71 was present in 48.7 pe rcent of outpatients with uncomplicated hand-foot-and-mouth disease or herp angina, 75 percent of hospitalized patients who survived, and 92 percent of patients who died. Conclusions Although several enteroviruses were circulating in Taiwan durin g the 1998 epidemic, enterovirus 71 infection was associated with most of t he serious clinical manifestations and with nearly all the deaths. Most of those who died were young, and the majority died of pulmonary edema and pul monary hemorrhage. (N Engl J Med 1999;341:929-35.) (C) 1999. Massachusetts Medical Society.