In Japan, prefectural and municipal public health institutes (PHIs) report isolation/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 (Reference figure).
Figure 1. Weekly reports of influenza virus isolation/detection, week 19/2012-week 52/2012
Figure 2. Isolation/detection of influenza virus by prefecture, week 36/2012-week 52/2012
Figure 3. Weekly isolation/detection of influenza virus by prefecture, weeks 47-51/2012

  After week 19/2012, a small number of influenza virus isolations/detections was reported (Fig. 1).  In Okinawa and Osaka Prefectures, local outbreak of influenza AH3 occurred in summer and detection of AH3 was dominant from week 26/2012 till now, the early 2012/13 season (from week 36/September of 2012 to week 35/August of 2013).

  In the 2012/13 season, from week 36 (September 3-9) to week 52 (December 24-30) of 2012, isolations/detections of AH1pdm09 from 19 cases in 11 prefectures, AH3 from 308 cases in 34 prefectures, B/Victoria lineage from 15 cases in 3 prefectures, B/Yamagata lineage from 12 cases in 4 prefecture and B/lineage not determined from 6 cases in 4 prefectures were reported (Fig. 2). 

From week 47 (November 19-25) to week 51 (December 17-23) of 2012  (as of January 3, 2013)

  During five weeks from week 47 to week 51 of 2012, isolations/detections of AH1pdm09 from 5 cases in 3 prefectures, AH3 from 181 cases in 22 prefectures, B/Victoria lineage from 12 cases in 3 prefectures, B/Yamagata lineage from 11 cases in 4 prefectures and B/lineage not determined from 5 cases in 4 prefectures were reported (Fig. 3).

[Reference figure] Weekly cases of influenza and isolation/detection of influenza viruses from week 36 of 2008 to week 41 of 2011

Isolation/detection of influenza virus in Japan, from week 36 (September 5-11) of 2011 to week 25 (June 18-24) of 2011 (as of July 19, 2012)
Isolation/detection of influenza virus in Japan, from week 36 (September 6-12) of 2010 to week 19 (May 9-15) of 2011 (as of September 6, 2011)
Isolation/detection of influenza virus in Japan, from week 19 (May 4-10) of 2009 to week 19 (May 10-16) of 2010 (as of May 13, 2010)
Infectious Agents Surveillance Report, Infectious Disease Surveillance Center, 
National Institute of Infectious Diseases
 

Copyright 1998 National Institute of Infectious Diseases, Japan