Detection of gastroenteritis viruses in Japan, 2012/13 season (as of January 31, 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 52 of 2012-week 4 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, and peaked in week 48-50 of 2012 and decreased thereafter (Figure 1).
Based on the Individual Case Report, during week 36 of 2012-week 4 of 2013 (week of specimen collection), detections of norovirus genogroup (G) II from 1,333 cases in 39 of 47 prefectures (including GII/4 from 304 cases, GII/13 from 12 cases, GII/6 from 7 cases, GII/3 from 4 cases, GII/2 from 3 cases, GII/7 from 2 cases), norovirus GI from 34 cases in 14 prefectures (including GI/3 and GI/6 from 2 cases, GI/4 and GI/13 from one each), norovirus genogroup unknown from 35 cases in 4 prefectures, sapovirus from 62 cases in 16 prefectures (including GI from 17 cases and GII from 4 cases), group A rotavirus from 11 cases in 5 prefectures (including G1 from 5 cases, G2 from 2 cases, G3 and G9 from one each) (Figure 2), and astrovirus from 8 cases in 4 prefectures (including type 8 from 2 cases) were reported.
During five weeks from week 52 (December 24-30) of 2012 to week 4 (January 21-27) of 2013, detections of norovirus from 165 cases in 17 prefectures (Figure 3), sapovirus from 7 cases in 4 prefectures and group A rotavirus from 6 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), 263 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 21 prefectures during week 36 of 2012 to week 4 of 2013 (onset week of outbreak). From 222 of these outbreaks, norovirus GII was detected including GII/4 from 80 outbreaks [see fig. 1, fig. 2 and fig. 3 in reference (text in Japanese)], GII/2 from 2 outbreaks, GII/6 from 2 outbreaks, GII/4+GII/6 and GII/5 from one each, and norovirus GI was detected from 7 outbreaks including GI/6 from 2 outbreaks and GI/3 from one. In addition, norovirus GI and GII were detected from 4 outbreaks including GI/1+GII/4 and GI/4+GII/13 from one each.
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
