Incidence and case-fatality rates resulting from the 1998 enterovirus 71 outbreak in Taiwan.
In 1998, an epidemic of hand-foot-and-mouth disease and herpangina caused by enterovirus 71 occurred in Taiwan, leaving many fatalities and severely handicapped survivors in its wake. The reasons this rather common pathogen would cause such a large-scale epidemic remain unknown. A seroepidemiological survey to elucidate the epidemiological characteristics of this outbreak, including its incidence and case-fatality rates was undertaken. Microneutralization tests for antibodies against enterovirus 71 were used to screen four collections of serum samples: 1) 202 specimens taken from individuals > or = 4 years old in 1994; 2) 245 specimens collected from individuals of all ages in 1997; 3) 1,258 specimens collected from individuals of all ages in 1999; and 4) sera samples from a birth cohort of 81 children who had yearly blood samples taken from 1988-98. After the maternal antibody had declined, the seropositive rates began to increase with age. Approximately half of all children aged 6 years or older were enterovirus 71 seropositive. Significantly higher seropositive rates were noted in 1999 than in 1997, in children aged 0.5-3 years. The incidence of enterovirus 71 infection during the epidemic was estimated to be 13-22%, with the higher rates in younger children. The case-fatality rate was highest (96.96 per 100,000) in infants aged 6-11 months, and declined in older children. The results showed that enterovirus 71 is endemic in Taiwan. The apparent lack of large-scale enterovirus 71 activity in the 3 years before 1998 might have been the prelude to the epidemic's appearance in 1998, and might suggest that enterovirus 71 infection will reappear every few years. The lack of a protective antibody in younger children may account for the high incidence and case-fatality rate in this age group.
Lu
Chun-Yi
CY
Department of Pediatrics, National Taiwan University Hospital, Taiwan.
Lee
Chin-Yun
CY
Kao
Chuan-Liang
CL
Shao
Wen-Yi
WY
Lee
Ping-Ing
PI
Twu
Shiing-Jer
SJ
Yeh
Chin-Chuan
CC
Lin
Shang-Ching
SC
Shih
Wen-Yi
WY
Wu
Shiow-Ing
SI
Huang
Li-Min
LM
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004770:Enterovirus / Q000276:immunology*; D004769:Enterovirus Infections / Q000453:epidemiology* / Q000401:mortality / Q000821:virology; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology* / Q000401:mortality / Q000821:virology; D006557:Herpangina / Q000453:epidemiology* / Q000401:mortality / Q000821:virology; D006801:Humans; D015994:Incidence; D007223:Infant; D008875:Middle Aged; D009500:Neutralization Tests; D016036:Seroepidemiologic Studies; D013624:Taiwan / Q000453:epidemiology
D000914:Antibodies, Viral