Detection of gastroenteritis viruses in Japan, 2012/13 season (as of January 17, 2013)
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 50 of 2012-week 2 of 2013
From week 36 (September 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 (Figure 1).
Based on the Individual Case Report, during week 36 of 2012-week 2 of 2013 (week of specimen collection), detections of norovirus genogroup (G) II from 1071 cases in 37 of 47 prefectures (including GII/4 from 231 cases, GII/13 from 9 cases, GII/6 from 7 cases, GII/3 from 4 cases, GII/2 from 3 cases, GII/7 from one case), norovirus GI from 30 cases in 12 prefectures (including GI/3 from 2 cases and GI/4, GI/6 and GI/13 from one case each), norovirus genogroup unknown from 28 cases in 4 prefectures, sapovirus from 50 cases in 12 prefectures (including GI from 12 cases and GII from 4 cases), group A rotavirus from 3 cases in 3 prefectures (including GI from one case) (Figure 2), and astrovirus from 8 cases in 4 prefectures (including type 8 from 2 cases) were reported.
During five weeks from week 50 (December 10-16) of 2012 to week 2 (January 7-13) of 2013, detections of norovirus from 324 cases in 22 prefectures (Figure 3), sapovirus from 9 cases in 5 prefectures and astrovirus from 2 cases in Fukuoka Prefecture were reported.
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), 192 outbreak of norovirus gastroenteritis occurred at restaurants and banquet hall, business olace, nursery school, kindergarten, elementary school, junior high school, high school, elderly care facility, nursing care facility, hospital, hotel, etc. in 19 prefectures during week 36 of 2012 to week 2 of 2013 (onset week of outbreak). From 157 of these outbreaks, norovirus GII was detected including GII/4 from 44 outbreaks [see fig. 1, fig. 2 and fig. 3 in reference (text in Japanese)], GII/2 from 2 outbreaks, GII/4+GII/6, GII/5 and GII/6 from one each, and norovirus GI was detected from 5 outbreaks including GI/6 from 2 outbreaks and GI/3 from one. In addition, norovirus GI/NT and GII/NT were detected from one outbreak.
Link to Detection of norovirus GII/4 2012 variant in Japan (National Institute of Health Sciences)
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
