Norovirus GII/4 variants observed in outbreaks of gastroenteritis in Miyagi prefecture between November and December of 2006.

According to the Miyagi Prefectural Epidemiological Surveillance of Infection Agents, the number of weekly reported patients with gastroenteritis caused by Norovirus (NoV) has sharply increased in Miyagi Prefecture since the end of November 2006. The number reached 33.74 cases per clinic, which was about 1.6 times larger than that of last year, at the end of December 2006. Between November and December 2006, 16 outbreaks of gastroenteritis were reported to public health and welfare offices in the prefecture and stool specimens were collected from 113 patients. Viral RNA was extracted using a QIAamp Viral RNA Mini Kit (Qiagen, Valencia, Calif., USA) from