Detection of gastroenteritis viruses in Japan, 2012/13 season (as of February 14, 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 2-week 6 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 6 of 2013 (week of specimen collection), detections of norovirus genogroup (G) II from 1,512 cases in 41 of 47 prefectures (including GII/4 from 343 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 37 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 70 cases in 19 prefectures (including GI from 20 cases and GII from 5 cases), group A rotavirus from 26 cases in 10 prefectures (including G1 from 8 cases, G2 and G9 from 2 each, G3 from one case) (Figure 2), and astrovirus from 9 cases in 4 prefectures (including type 8 from 2 cases) were reported.
During five weeks from week 2 (January 7-13) to week 6 (February 4-10) of 2013, detections of norovirus from 106 cases in 16 prefectures (Figure 3), sapovirus from 8 cases in 5 prefectures, group A rotavirus from 15 cases in 7 prefectures and astrovirus from one case in Kumamoto 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), 305 outbreaks 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 24 prefectures during week 36 of 2012 to week 6 of 2013 (onset week of outbreak). From 258 of these outbreaks, norovirus GII was detected including GII/4 from 95 outbreaks [see fig. 1, fig. 2 and fig. 3 in reference (text in Japanese)], GII/2 from 3 outbreaks, GII/6 from 2 outbreaks, GII/4+GII/6 and GII/5 from one each, and norovirus GI was detected from 10 outbreaks including GI/6 from 4 outbreaks and GI/3 from one. In addition, norovirus GI and GII were detected from 6 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
