Isolation/detection of influenza virus in Japan

	Isolation/detection of influenza virus in Japan, from week 36 (September 5-11)
	of 2011 to week 13 (March 26-April 1) of 2012

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 36 of 2011-week 13 of 2012
	Figure 2. Isolation/detection of influenza virus by prefecture, week 36 of 2011-week 13 of 2012
	Figure 3. Weekly isolation/detection of influenza virus by prefecture, week 9-week 13 of 2012

In the 2011/12 season, isolation/detection of AH3 continues from week 36 of 2011 and largely increased from week 2 of 2012 and decreased after the peak of week 3. Isolations/detections of B/Yamagata lineage and B/Victoria lineage were first reported in week 39 and week 40 of 2011, respectively, and slightly increased from week 2 of 2012. In addtion, isolations/detections of AH1pdm09 were sporadically reported in weeks 41-42 and 51-52 of 2011 and weeks 1, 3 and 6-8 of 2012 (Fig. 1).

From week 36 of 2011 to week 13 of 2012, isolations/detections of AH1pdm09 from 9 cases in 7 of 47 prefectures, AH3 from 4,200 cases in all prefectures, B/Victoria lineage from 562 cases in 39 prefectures, B/Yamagata lineage from 285 cases in 36 prefectures and B/lineage not determined from 188 cases in 28 prefectures were reported (Fig. 2).

From week 9 (February 27-March 4) to week 13 (March 26-April 1) of 2012
(as of April 5, 2012)

During five weeks from week 9 to week 13 of 2012, isolations/detections of AH3 from 224 cases in 30 prefectures, B/Victoria lineage from 166 cases in 23 prefectures, B/Yamagata lineage from 51 cases in 20 prefectures and B/lineage not determined from 96 cases in 14 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 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

	Graphs
		Updates (based on the data reported before yesterday)

By week and season		pdf	csv
By prefecture		pdf	csv
By week (AH1 includes AH1pdm09)		pdf	csv
Current & preceding 4 seasons (AH1 includes AH1pdm09)		pdf	csv
By week and prefecture :	AH1pdm09	pdf	csv
	AH1	pdf	csv
	AH3	pdf	csv
	B (Total)	pdf	csv
	B (Victoria lineage)	pdf	csv
	B (Yamagata lineage)	pdf	csv

Archives

	Tables
		Updates (based on the data reported before yesterday)

By season	pdf	csv
By month	pdf	csv
By year	pdf	csv

Archives

Antiviral resistance surveillance in Japan

[Background and objective]

Japan is the world's biggest consumer of four neuraminidase inhibitors, oseltamivir, peramivir, zanamivir and laninamivir, for chemotherapy against influenza and has a high potential to emerge the inhibitor-resistant influenza viruses. Consequently, sustained monitoring of the neuraminidase inhibitor-resistant viruses and sharing surveillance data are important for public health measures and therapeutic strategy at clinical hospitals.
To monitor neuraminidase inhibitor-resistant influenza viruses, we tested A(H1N1)pdm09, A(H3N2) and B viruses by a combination of phenotypic and genotypic assays. In the phenotypic assay, approximately 5-10% of total isolates were randomly selected and subjected to neuraminidase inhibition assays against oseltamivir, peramivir, zanamivir and laninamivir. In the genotypic assay, allele-specific TaqMan RT-PCR and/or partial sequencing of neuraminidase gene were performed to detect antiviral resistance mutations.

The data summarized below are results of phenotypic and genotypic assays reported and updated monthly.

	2011/2012 influenza season (Sep. 2011-Aug. 2012) (as of March 5, 2012)
		Table. Detection of antiviral drug-resistant viruses in Japan, [A(H1N1)pdm09, A(H3N2), B]
		Table 4. Detection of A(H1N1)pdm09 viruses with H275Y mutation in Japan, Report by prefecture
		Table 5. Detection of A(H1N1)pdm09 viruses with H275Y mutation in Japan, Report by week

	2010/2011 influenza season (Sep. 2010-Aug. 2011) (as of January 5, 2012)
		Table. Detection of antiviral drug-resistant viruses in Japan, [A(H1N1)pdm09, A(H3N2), B]
		Table 2. Detection of A(H1N1)pdm09 viruses with H275Y mutation in Japan, Report by prefecture
		Table 3. Detection of A(H1N1)pdm09 viruses with H275Y mutation in Japan, Report by week

	2009/2010 influenza season (Sep. 2009-Aug. 2010) (as of June 17, 2011)
		Table 1. Detection of A(H1N1)pdm09 viruses with H275Y mutation in Japan, Report by prefecture

Laboratory of influenza virus surveillance and WHO Collaborating Center
for Reference and Research on Influenza, Tokyo, Japan
at Influenza Virus Research Center,
National Institute of Infectious Diseases and
the Influenza Virus Surveillance Group of Japan

	2010/11 season
	2009/10 season
	2008/09 season
	Pandemic (H1N1) 2009 in Japan, May-September 2009
	2007/08 season

	National Epidemiological Surveillance of Infectious Diseases

	Flunet ⇒ View charts of Japan
	Global Influenza Surveillance and Response System (GISRS)
	Pandemic (H1N1) 2009