Giuseppe
Emeritus
[Source: EuroFlu, full page: (LINK). Edited.]
EuroFlu - Weekly Electronic Bulletin - Week 49 : 02/12/2013-08/12/2013 - 13 December 2013, Issue No. 508
Sporadic influenza activity in the WHO European Region
Summary, week 49/2013
For a description of influenza surveillance in the WHO European Region see below.
Virological surveillance for influenza
During week 49/2013 the number of influenza detections in the Region remained low despite a slight increase in number of specimens tested for influenza in comparison with previous weeks.
In total, 7121 specimens from sentinel and non-sentinel sources were tested for influenza during the week, 106 (1.5%) of which were positive: 92 (87%) for influenza A and 14 (13%) for influenza B (Fig.1 and 2).
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Of the 61 influenza A viruses that were subtyped during week 49/2013, 29 (48%) were A(H1N1)pdm09 and 32 (52%) A(H3N2) (Fig. 2a).
Since the beginning of the season (week 40/2013), sentinel and non-sentinel sources have yielded 655 influenza detections: 489 (74%) were influenza A viruses and 166 (26%) influenza B (Fig. 2b).
Of the 318 influenza A viruses that have been subtyped, 152 (48%) were A(H1N1)pdm09 and 166 (52%) were A(H3N2).
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_________
(?)
Since the number of influenza detections remained low in week 49/2013, only 3 countries reported a dominant virus, influenza A (Norway), and influenza A, subtype H3N2 (Italy and Turkey), as shown in Map 1.
Virus strain characterizations
Circulating influenza viruses are assessed each season for their antigenic and genetic characteristics, to determine the extent of their antigenic similarity to the viruses included in the seasonal influenza vaccine, and determine the prevalence of mutations that affect pathogenicity or are associated with susceptibility to antiviral drugs.
Since week 40/2013, 3 countries (Germany, Portugal and the United Kingdom (England)) have characterized 12 influenza viruses antigenically:
All showed susceptibility to both drugs.
The 12 influenza A(H1N1)pdm09 and 8 influenza A(H3N2) viruses screened for susceptibility to adamantanes were found to be resistant.
For the 2013/2014 northern hemisphere influenza season, WHO recommended inclusion of A/California/7/2009 (H1N1)pdm09-like, A/Texas/50/2012 (H3N2)-like (an egg-adapted virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011) and
B/Massachusetts/2/2012-like (Yamagata lineage) viruses in vaccines (see the WHO headquarters web site).
Outpatient surveillance for influenza-like illness (ILI) and/or acute respiratory infection (ARI)
Similarly to previous weeks, during week 49/2013 almost all of the European countries reporting qualitative indicators indicated low influenza activity (Map 2) and mainly stable trends (Map 4), with predominantly no or sporadic influenza activity (Map 3).
During week 49/2013, consultation rates for influenza-like illness (ILI) and/or acute respiratory infection (ARI) remained below the national baselines or at pre-season levels in all countries reporting clinical data except for the Republic of Moldova.
(?)
The number of ILI and ARI cases testing positive for influenza in the Region remained low. Only 31 sentinel samples tested positive for influenza during week 49/2013, reported mainly by a few western European countries.
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During week 49/2013, 31 (4.1%) of the 750 specimens collected from sentinel sources tested positive for influenza, with the majority being influenza A(H3). Click here for a detailed overview in a table format. _________
_________
Hospital surveillance for SARI
The number of SARI hospitalizations was similar to previous weeks during week 49/2013. It remained at interseason levels in reporting countries participating in hospital surveillance for SARI in the WHO European Region (Fig. 7).
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Similarly to previous weeks, none of the 123 SARI samples collected in Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, the Republic of Moldova, Romania, the Russian Federation, Serbia and Ukraine tested positive for influenza during week 49/2013. Click here for a detailed overview in table format.
(?)
Since week 40/2013, Ireland, France, Spain, Sweden and the United Kingdom have reported 30 hospitalized laboratory-confirmed influenza cases in total, with 11 being influenza B, 7 A(H1N1)pdm09, 1 A(H3) and 11 type A not subtyped.
For more information on surveillance of confirmed hospitalized influenza, please see ECDC?s Weekly Influenza Surveillance Overview (WISO) at European Centre for Disease Prevention and Control web site.
Respiratory syncytial virus (RSV)
Based on the data presented by countries reporting on RSV, the positivity rate has been gradually increasing since week 40/2013 with a slightly later start compared with the previous season. For more information please click here.
EuroMOMO (European Mortality Monitoring Project)
EuroMOMO is a project set up to develop and operate a routine public health mortality monitoring system to detect and measure, on a real-time basis, excess deaths related to influenza and other possible public health threats across 20 European Union (EU) countries.
Pooled analysis of week data for 49/2013 showed that all-cause mortality was within the normal range for all reporting countries. Results of pooled analysis may vary, depending on which countries are included in the weekly analysis. For more information about the EUROMOMO mortality monitoring system please click here.
(?)
Country comments (where available)
Republic of Moldova: 20 samples were tested for Influenza A and B - none of them were positive. 2 samples were positive for RNA hRSV, 1 sample - positive for RNA Rhinovirus, 1 - positive for RNA hRhinovirus and DNA hBocavirus, 1- positive for DNA hBocavirus, and 1- positive for RNA hMetapneumovirus.
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EuroFlu - Weekly Electronic Bulletin - Week 49 : 02/12/2013-08/12/2013 - 13 December 2013, Issue No. 508
Sporadic influenza activity in the WHO European Region
Summary, week 49/2013
- Influenza activity in the WHO European Region remains at pre-season levels, with sporadic detections of influenza viruses being reported mainly from countries in western Europe.
- Influenza A was detected in the majority of cases testing positive for influenza this week.
- The number of hospitalizations due to severe acute respiratory infection (SARI) remains stable, with no influenza detected among SARI cases.
For a description of influenza surveillance in the WHO European Region see below.
Virological surveillance for influenza
During week 49/2013 the number of influenza detections in the Region remained low despite a slight increase in number of specimens tested for influenza in comparison with previous weeks.
In total, 7121 specimens from sentinel and non-sentinel sources were tested for influenza during the week, 106 (1.5%) of which were positive: 92 (87%) for influenza A and 14 (13%) for influenza B (Fig.1 and 2).
__________
________
Of the 61 influenza A viruses that were subtyped during week 49/2013, 29 (48%) were A(H1N1)pdm09 and 32 (52%) A(H3N2) (Fig. 2a).
Since the beginning of the season (week 40/2013), sentinel and non-sentinel sources have yielded 655 influenza detections: 489 (74%) were influenza A viruses and 166 (26%) influenza B (Fig. 2b).
Of the 318 influenza A viruses that have been subtyped, 152 (48%) were A(H1N1)pdm09 and 166 (52%) were A(H3N2).
_________
_________
(?)
Since the number of influenza detections remained low in week 49/2013, only 3 countries reported a dominant virus, influenza A (Norway), and influenza A, subtype H3N2 (Italy and Turkey), as shown in Map 1.
Virus strain characterizations
Circulating influenza viruses are assessed each season for their antigenic and genetic characteristics, to determine the extent of their antigenic similarity to the viruses included in the seasonal influenza vaccine, and determine the prevalence of mutations that affect pathogenicity or are associated with susceptibility to antiviral drugs.
Since week 40/2013, 3 countries (Germany, Portugal and the United Kingdom (England)) have characterized 12 influenza viruses antigenically:
- 10 were A(H1N1)pdm09 viruses (A/California/7/2009 (H1N1)-like) and
- 2 B/Yamagata/16/88 lineage viruses (1 B/Massachusetts/2/2012-like and 1 B/Wisconsin/1/2010-like).
- The 14 A(H3N2) viruses belonged to subgroup 3C, represented by A/Texas/50/2012 in the A/Perth/16/2009, A(H3) clade;
- the 16 A(H1N1)pdm09 viruses belonged to genetic group 6, represented by A/St Petersburg/27/2011;
- 2 influenza B viruses belonged to clade 2, represented by B/Massachusetts/02/2012 and 1 to clade 3, represented by B/Wisconsin/1/2010, all in the Yamagata lineage.
All showed susceptibility to both drugs.
The 12 influenza A(H1N1)pdm09 and 8 influenza A(H3N2) viruses screened for susceptibility to adamantanes were found to be resistant.
For the 2013/2014 northern hemisphere influenza season, WHO recommended inclusion of A/California/7/2009 (H1N1)pdm09-like, A/Texas/50/2012 (H3N2)-like (an egg-adapted virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011) and
B/Massachusetts/2/2012-like (Yamagata lineage) viruses in vaccines (see the WHO headquarters web site).
Outpatient surveillance for influenza-like illness (ILI) and/or acute respiratory infection (ARI)
Similarly to previous weeks, during week 49/2013 almost all of the European countries reporting qualitative indicators indicated low influenza activity (Map 2) and mainly stable trends (Map 4), with predominantly no or sporadic influenza activity (Map 3).
During week 49/2013, consultation rates for influenza-like illness (ILI) and/or acute respiratory infection (ARI) remained below the national baselines or at pre-season levels in all countries reporting clinical data except for the Republic of Moldova.
(?)
The number of ILI and ARI cases testing positive for influenza in the Region remained low. Only 31 sentinel samples tested positive for influenza during week 49/2013, reported mainly by a few western European countries.
_________
_________
During week 49/2013, 31 (4.1%) of the 750 specimens collected from sentinel sources tested positive for influenza, with the majority being influenza A(H3). Click here for a detailed overview in a table format. _________
_________
Hospital surveillance for SARI
The number of SARI hospitalizations was similar to previous weeks during week 49/2013. It remained at interseason levels in reporting countries participating in hospital surveillance for SARI in the WHO European Region (Fig. 7).
_________
________
Similarly to previous weeks, none of the 123 SARI samples collected in Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, the Republic of Moldova, Romania, the Russian Federation, Serbia and Ukraine tested positive for influenza during week 49/2013. Click here for a detailed overview in table format.
(?)
Since week 40/2013, Ireland, France, Spain, Sweden and the United Kingdom have reported 30 hospitalized laboratory-confirmed influenza cases in total, with 11 being influenza B, 7 A(H1N1)pdm09, 1 A(H3) and 11 type A not subtyped.
For more information on surveillance of confirmed hospitalized influenza, please see ECDC?s Weekly Influenza Surveillance Overview (WISO) at European Centre for Disease Prevention and Control web site.
Respiratory syncytial virus (RSV)
Based on the data presented by countries reporting on RSV, the positivity rate has been gradually increasing since week 40/2013 with a slightly later start compared with the previous season. For more information please click here.
EuroMOMO (European Mortality Monitoring Project)
EuroMOMO is a project set up to develop and operate a routine public health mortality monitoring system to detect and measure, on a real-time basis, excess deaths related to influenza and other possible public health threats across 20 European Union (EU) countries.
Pooled analysis of week data for 49/2013 showed that all-cause mortality was within the normal range for all reporting countries. Results of pooled analysis may vary, depending on which countries are included in the weekly analysis. For more information about the EUROMOMO mortality monitoring system please click here.
(?)
Country comments (where available)
Republic of Moldova: 20 samples were tested for Influenza A and B - none of them were positive. 2 samples were positive for RNA hRSV, 1 sample - positive for RNA Rhinovirus, 1 - positive for RNA hRhinovirus and DNA hBocavirus, 1- positive for DNA hBocavirus, and 1- positive for RNA hMetapneumovirus.
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