An enterovirus 71 epidemic in Guangdong Province of China, 2008: epidemiological, clinical, and virogenic manifestations

Abstract

Enterovirus 71 (EV71) is shown to be a major causative agent in outbreaks of hand, foot, and mouth disease (HFMD) reported in Guangdong (GD) Province of China in 2008. A total of 48,876 HFMD cases (131 severe and 21 fatal) were reported to the GD HFMD web-based surveillance system, which covers 871 clinics. The main causes of death included central nervous system damage, heart failure, and pulmonary edema. The incidence rate was 52 per 100,000, and the epidemic peak appeared in May and June. EV71 was found in 59% and coxsackievirus A16 in 26% of 936 laboratory-confirmed cases. Other viruses are likely to be responsible for the remaining 15% of cases. Of the 185 EV71 cases collected, 62% were mild, 27% were severe, and the remaining 11% were fatal. A total of 17 EV71 isolates were subjected to nucleotide sequencing of the entire VP1 gene. Phylogenetic analysis showed that the GD EV71 strains belonged to the C4 subgenotype and that EV71 circulates at a national rather than a regional level. A Comparison with the VP1 gene from a different clinical case showed that there was no obvious virulence determinant in this locus. Furthermore, this study found that most deaths occurred in rural areas, thereby indicating that delayed diagnosis and incorrect treatment may play an important role.