Detection of gastroenteritis viruses in Japan, 2012/13 season (as of January 10, 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 48-week 52 of 2012
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 976 cases in 37 of 47 prefectures (including GII/4 from 215 cases, GII/13 from 8 cases, GII/6 from 7 cases, GII/3 from 4 cases, GII/2 from 3 cases, GII/7 from one case), norovirus GI from 28 cases in 11 prefectures (including GI/3 from 2 cases and GI/4 and GI/13 from one case each), norovirus genogroup unknown from 28 cases in 4 prefectures, sapovirus from 49 cases in 12 prefectures (including GI from 12 cases and GII from 3 cases), group A rotavirus from 3 cases in 3 prefectures (including GI from one case) (Figure 2), and astrovirus from 6 cases in 4 prefectures (including type 8 from 2 cases) were reported.
During five weeks from week 48 (November 26-December 2) to week 52 (December 24-30) of 2012, detections of norovirus from 549 cases in 30 prefectures (Figure 3), sapovirus from 20 cases in 9 prefectures, group A rotavirus from one case in Kanagawa Prefecture and astrovirus from 3 cases in 2 prefectures 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), 159 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 weeks 36-52 of 2012 (onset week of outbreak). From 127 of these outbreaks, norovirus GII was detected including GII/4 from 38 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.
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
