In Japan, prefectural and municipal public health institutes (PHIs) report detection of infectious agents from specimens collected by sentinel clinics and hospitals under the National Epidemiological Surveillance of Infectious Diseases, other medical institutions and health centers.
  From gastroenteritis cases, norovirus and other viruses (sapovirus, rotavirus, astrovirus etc.) are detected.

*Data for current and previous weeks will be updated by additional reports.

Figure 1. Weekly reports of norovirus, sapovirus and rotavirus detection, 2012/13 season

Figure 2. Detection of norovirus, sapovirus and rotavirus by prefecture, 2012/13 season

Figure 3. Weekly detection of norovirus, sapovirus and rotavirus by prefecture, week 42-week46 of 2012

  From week 36 (9/3-9) of 2012, the beginning of 2012/13 season, reports of norovirus detection continued and started to increase from week 44 (October 29-November 4) of 2012.

  Based on the Outbreak Summary Report (including food poisoning, food-related health complaints, and gastroenteritis with person-to-person infection or those with unknown transmission routes), 22 outbreak of norovirus gastroenteritis occurred at restaurants and banquet hall, nursery school, elementary school, junior high school, elderly care facility, etc. in 7 prefectures during weeks 37-46 of 2012 (onset week of outbreak) and norovirus genogroup (G) II/4 was detected [see fig. 1, fig. 2 and fig. 3 in reference (text in Japanese)] from 9 outbreaks and GI/3 from an outbreak.

  Based on the Individual Case Report, during weeks 36-46 of 2012 (week of specimen collection), detections of norovirus GII from 55 cases in 15 of 47 prefectures (including GII/4 from 15 cases and GII/7 from one case), norovirus GI from 4 cases in 2 prefectures (including GI/3 from 2 cases), norovirus genogroup unknown from 5 cases in 2 prefectures, sapovirus from 10 cases in 6 prefectures (including GI from 3 cases), and astrovirus from one case in Kumamoto Prefecture were reported.

  During five weeks from week 42 (October 15-21) to week 46 (November 12-18) of 2012, detections of norovirus from 48 cases in 13 prefectures and sapovirus from 5 cases in 3 prefectures were reported.

Detection of gastroenteritis viruses in Japan, 2011/12 season (as of November 8, 2012)

Infectious Agents Surveillance Report, Infectious Disease Surveillance Center,
National Institute of Infectious Diseases