Epidemiological survey of enterovirus infections occurring in Taiwan between 2000 and 2005: Analysis of sentinel physician surveillance data

Enterovirus (EV) infections are common. There are more than 60 known serotypes, and each has different epidemiologic or medical importance. Over 700 physicians from 75% of basic administrative units of Taiwan participated in the "Sentinel Physician Surveillance of Infectious Disease" and reported weekly to the Center for Disease Control-Taiwan with data on various infections. Data of laboratory-confirmed EV infections from this surveillance between 2000 and 2005 was analyzed. EV serotypes were determined by immunofluorescence staining and/or viral VP1 sequence analysis. A total of 12,236 EV cases, or approximately 1,300-2,500 per year, were identified, and 52% of the cases occurred between April and July. The median age was 3 years, and 57.6% of patients were male. Coxsackievirus A (CA) 16 and EV71, which primarily manifest as hand-foot-and-mouth disease, were the most prevalent serotypes every year except 2004. Other prevalent serotypes and associated symptoms varied from year to year. Echovirus (E) 30 and E6, which are associated with aseptic meningitis, were prevalent in 2001 and 2002, CA4 and CA10, which cause herpangina, were predominant in 2004, and coxsackievirus B (CB) 4 and CB3, which are associated with neonatal febrile disease, were most common in 2004 and 2005, respectively. Some of these epidemics overlapped with outbreaks of the same serotypes in other Asian Pacific countries. Of all serotypes, EV71 was associated with the highest number of severe complications in patients. Surveying the epidemic pattern, disease spectra, and severity associated with each EV serotype provided important information for public health and medical personnel.