Surveillance of enterovirus infections in Yokohama city from 2004 to 2008.

A survey of human enterovirus (HEV) infections from 2004 to 2008 was conducted in Yokohama City, Japan. A total of 260 clinical samples in 247 patients were shown to be positive for enterovirus. Among them, 25 serotypes were identified, including 3 serotypes of poliovirus (19 samples). The prevalence rates of hand-foot-and-mouth disease (HFMD), herpangina, and respiratory illness associated with nonpolio HEV infections were also analyzed. Seven serotypes were highly associated with HFMD or herpangina. These 7 virus serotypes were prevalent during summer and autumn with a peak in July, and were prevalent in children under 6 years old with a peak from 1 to 2 years old. HEV-related diseases were not limited to HFMD and herpangina but also included respiratory illnesses, such as the common cold. The results of this study suggested the importance of periodic surveys to monitor severe diseases caused by HEVs.