カナダの第45週11月07日ー11月13日の風邪インフルエンザ感染状況

2010年11月22日月曜日16:56(JST;00:56) 晴れ最低気温;07ºC 最高気温;17ºCBARCELONA県から
カナダの第45週11月07日ー11月13日の風邪インフルエンザ感染状況
Flu Watch
http://www.phac-aspc.gc.ca/fluwatch/index-eng.php
> Current Weekly Report
http://www.phac-aspc.gc.ca/fluwatch/10-11/w45_10/index-eng.php
カナダでは、第45週11/07ー11/13には、風邪インフルエンザ感染は、ちょっと増加した。
45週11/07ー11/13には、風邪症状による医師への診察率は、1000人(1'000)の患者のうち、17'4件で先週などの診察率と同じくらいで、例年並みである。5歳以下の子供たちの診察率が最も高い診察率で、1000人(1'000)の患者のうちの47'1件で、つぎに、5歳以上19歳以下の年齢層で、1000人の患者に付き44'0件である。
第45週11/07ー11/13では、検査された1951件(1'951)の患者の試料のうち、2'15%の42件がインフルエンザ陽性反応がでて、先週より増加した。42件の風邪陽性反応のうち、15件は インフルエンザA2(H3N2)で、23件は インフルエンザA型未分類(未確認)で、4件がインフルエンザB型である。風邪流行期が始まってから97%の分類検査されたヴィールスはインフルエンザA(H3N2)である。風邪流行期が始まってから97%の分類検査されたヴィールスはインフルエンザA(H3N2)である。2010年08月29日から11月13日までの合計149件イのンフルエンザ陽性反応のうち、7件がインフルエンザB型で、142件がインフルエンザA型で、そのうち、インフルエンザA(H3N2)は57件で
、新型インフルエンザは 2件で 、インフルエンザA型未分類は83件である。
   45週11/07ー11/13では、パラインフルエンザ(PARAINFLUENZA)は、2'8%で、アデノビールス(ADENOVIRUS)は、2'7%で、RESPIRATORY SYNCYTIAL VIRUS(RSV)は、2'5%で、HUMAN METAPNEUMOVIRUSは、0'1%が検出され報告されている。リノビールス(RHINOVIRUS)の検出結果は、風邪流行期が始まってから高く、今週は16%である。今週は、詳しい検査結果が報告された6件のインフルエンザA(H3N2)のうち、100%の6件が65歳以上の患者である。一方2010年08月29日以来、65歳以上の患者は64件のうちの55%の35件である。
カナダでの第45週11/07ー11/13の18歳以下の未成年の入院患者は、1人で、年齢は2歳と4歳の間で、インフルエンザA(H3N2)である。風邪流行期が始まってから、4歳以下の3人の入院患者が報告されて、すべてインフルエンザA(H3N2)である。
   カナダでの第45週11/07ー11/13の16歳以上の成年の入院患者は2人で、2人とも、男性患者で、1人は45歳から64歳の間で、インフルエンザA型未分類(未確認)で、もう1人は80歳以上で、インフルエンザA(H3N2)である。
風邪流行期が始まってから合計13件の入院患者が報告されて、そのうち、3件は、インフルエンザA(H3N2)で、1件は新型インフルエンザで、9件はインフルエンザA型未分類である。13件の入院患者のうち、69%の13件は65歳以上の患者である。


Sale of antivirals (AV)
During week 45, antiviral prescriptions monitoring results demonstrated a plateau in antiviral prescription rates at the national level and among the provinces and territories, although daily and weekly antiviral data at the Health Region level showed low antiviral prescription rates compared to this time last year.
Antigenic Characterization
Since September 1, 2010, National Microbiology Laboratory (NML) has antigenically characterized 24 influenza viruses (21 A/H3N2 from BC, AB, MB, ON & QC, 1 pandemic H1N1 2009 in ON and 2 B viruses from BC and QC) that were received from provincial laboratories. The 21 influenza A/H3N2 viruses characterized were related to A/Perth/6/2009, which is the influenza A/H3N2 component recommended for the 2010-11 influenza vaccine. The pandemic H1N1 2009 characterized was antigenically related to the pandemic vaccine virus A/California/7/2009, which is the recommended H1N1 component for the 2010-11 Northern Hemisphere influenza vaccine. The two influenza B viruses characterized was antigenically related to B/Brisbane/60/08 (Victoria lineage), which is the recommended influenza B component for the 2010-11 influenza vaccine.
Antiviral Resistance 
Since the beginning of the 2010-2011 season, no oseltamivir resistant pandemic H1N1 2009 have been reported. So far this season, the NML has tested 22 influenza A/H3N2 and one pandemic H1N1 isolates for amantadine resistance and found that all isolates were resistant to amantadine. 22 influenza isolates (19 A/H3N2, 1 pandemic H1N1 and 2 B) were also tested for oseltamivir and zanamivir resistance and found that all isolates were sensitive to both antivirals.

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International influenza update

Global information

WHO: Worldwide, overall influenza activity remained low, except in parts of the tropics, most notably in Southeast Asia, and to a lesser extent in the tropical areas of the Americas. After late winter and springtime influenza epidemics in several countries of the temperate Southern Hemisphere, influenza activity has returned to near or below baseline in most places. However, a recent post-season rise in cases has been noted across parts of southern Africa associated with localized outbreaks of pandemic H1N1 2009. Seasonal influenza A/H3N2 viruses continued to be the predominant circulating strain of influenza viruses worldwide, however, in many countries there has been co-circulation of seasonal influenza B viruses and to a lesser extent, pandemic H1N1 2009. The latter has been recently predominant in a limited
number of countries, including in India.
<http://www.who.int/csr/disease/influenza/2010_11_08_GIP_surveillance/en/index.html>

Geographic update

Northern hemisphere

United States: During week 44, influenza activity remained low in the United States. The geographic spread of influenza in three states was reported as local; the District of Columbia, Puerto Rico and 34 states was assessed as sporadic; Guam and 13 states reported no influenza activity and the US Virgin Islands did not report. 185 (6.8%) specimens were tested positive for influenza this week. Two human infections with novel influenza A viruses were reported. The proportion of outpatient visits for influenza-like illness (ILI) and the proportion of deaths attributed to pneumonia and influenza (P&I) were both below the national baseline. One influenza-associated pediatric death was reported and was associated with an influenza A virus for which the subtype was undetermined.
<http://www.cdc.gov/flu/weekly/index.htm>
Latin America: In the tropics of the Americas, between late July and early October, many countries or parts of countries experienced periods of active circulation of influenza viruses, including but not limited to southern Mexico, Costa Rica, Nicaragua, El Salvador, Honduras, Jamaica, Cuba, Peru, Colombia, and Bolivia. In most of these countries, seasonal influenza A/H3N2 was the predominant circulating influenza virus. Notably, Nicaragua observed circulation of predominantly influenza B viruses, while Colombia and Bolivia experienced circulation of predominantly pandemic H1N1 2009. In most countries of the region, overall influenza virus transmission has declined substantially or returned to very low levels. <http://www.who.int/csr/disease/influenza/2010_11_08_GIP_surveillance/en/index.html>
Europe: Rare detections of influenza virus along with sporadic detections of respiratory syncytial virus in a number of European countries suggested that the low influenza-like illness and acute respiratory infection activity currently observed was likely due to respiratory pathogens other than influenza. Epidemiological indicators showed no or only sporadic influenza activity in 24 of the 25 reporting EU countries.
Malta reported local spread and Bulgaria reported medium intensity of acute respiratory infection. During week 44, 15 (4.9%) of 309 sentinel specimens tested positive for influenza virus. 27 of 41 influenza viruses detected in sentinel and non-sentinel specimens were type A, and 14 were type B. Of the 16 subtyped influenza A viruses, 15 were pandemic H1N1 2009 and one was A/H3N2. Three SARI cases, not related to influenza were reported during week 44.
<http://ecdc.europa.eu/en/publications/Publications/101119_SUR_Weekly_Influenza_Surveillance_Overview.pdf>
Asia: In the tropics of Asia, the most active reported circulation of influenza viruses continued to be in Thailand. Since late July 2010, pandemic H1N1 2009 has been the predominant circulating influenza viruses in Thailand, however, more recently beginning in early October 2010, seasonal influenza A/H3N2, B, and pandemic H1N1 2009 viruses began to co-circulate at similar levels. In southern China and Hong Kong (SAR), recent periods of active circulation of seasonal influenza A/H3N2 viruses during late summer and autumn appeared to have largely subsided. In India, the national epidemic of pandemic H1N1 2009 which began during June 2010 and lasted until late September 2010 has largely subsided but small numbers of new cases continued to reported weekly. In Bangladesh, there has been persistent influenza virus transmission since the early part of 2010, however; only in recent months has circulation of seasonal influenza A/H3N2 become predominant.
<http://www.who.int/csr/disease/influenza/2010_11_08_GIP_surveillance/en/index.html>

Southern hemisphere

South America: In Chile, an unusually late winter and springtime influenza epidemic, characterized by predominance of circulating seasonal influenza A/H3N2 viruses, and to a lesser extent seasonal influenza B and pandemic H1N1 2009, appears to have largely subsided. A similarly timed influenza epidemic was also observed in Paraguay and Uruguay. In Argentina, however, little winter and springtime influenza activity was observed during 2010, with influenza B viruses accounting for the majority of sporadic influenza virus detections.
<http://www.who.int/csr/disease/influenza/2010_11_08_GIP_surveillance/en/index.html>