[Epidemiology and etiology of hand-foot-and-mouth disease in Hainan, 2010].

ABSTRACT

To reveal the epidemiological and pathogenic characteristics of Hand-foot-and-mouth disease (HFMD) in Hainan province in 2010, epidemiology data of HFMD reporting cases were analyzed, clinical specimens from 1346 HFMD cases were collected for enterovirus (EV) detection. Viral isolation was performed for EV nucleic acid positive samples. Complete VP1 encoding region of EV71 were sequenced and analyzed with Sequencher (version 5.0) and MEGA software (version 5.0). The epidemiology data showed that all 18 prefectures in Hainan had reporting cases during 2010, with higher incidence in the northeast; and the children less than 4 years old accounted for the majority of the suffered; the epidemic reached peak during September to October, which was different from other Provinces in China. The laboratory results indicated that EV71 and CA16 were identified as the major causative pathogens in Hainan in 2010, however, EV71 infection was absolutely dominant among severe and fatal cases. In addition, some HFMD cases were identified associated with other serotypes of EV infections. Molecular epidemiological analysis showed that all the EV71 strains belonged to C4a evolutionary branch, which is the dominant evolutionary branch in China in recent years, and at least three transmission chains existed. This study has an important information in clarifying the characteristics of epidemics and transmission of HFMD in Hainan, and to provide the guidance for HFMD prevention and control in the future.