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Weekly influenza surveillance overview - 12 November 2010 (ECDC, 11/13/10, extract, edited)
Weekly influenza surveillance overview - 12 November 2010 (ECDC, 11/13/10, extract, edited)
[Source: European Centre for Disease Prevention and Control (ECDC), full PDF document, (LINK). Extract, edited.]
SURVEILLANCE REPORT
Weekly influenza surveillance overview - 12 November 2010
Main surveillance developments in week 44/2010 (01 Nov 2010 ? 07 Nov 2010)
This first page contains the main developments of this week and can be printed separately or together with the more detailed information following.
Sentinel surveillance (ILI/ARI) - Weekly analysis ? epidemiology
During week 44/2010, 25 of 29 countries reported epidemiological data. Twenty-four countries continued to experience low intensity (Map 1, Table 1), and one, Bulgaria, reported medium intensity based on consultations for ARI.
For the geographic spread indicator, Malta reported local spread, and Cyprus, Czech Republic, France, Norway, and the UK reported sporadic cases. All other countries reported no activity (Map 2, Table 1).
Bulgaria and UK (Scotland) reported an increase in consultation rates for ILI/ARI compared to the previous week. The remaining countries reported stable or decreasing trends (Map 1 and Table 1). Consultation rates continue to be at or below national baseline levels for all countries that reported.
For comparison with the 2009-2010 season, please refer to the ECDC special report on the 2009 influenza A(H1N1) pandemic: (LINK)
(...)
Description of the system
This surveillance is based on nationally organized sentinel networks of physicians, mostly general practitioners (GPs), covering at least 1?5% of the population in their countries. All EU/EEA Member States (except Liechtenstein) are participating. Depending on their country?s choice, each sentinel physician reports the weekly number of patients seen with influenza-like illness (ILI), acute respiratory infection (ARI) or both to a national focal point. From the national level, both numerator and denominator data are then reported to the European Surveillance System (TESSy) database. Additional semi-quantitative indicators of intensity, geographic spread and trend of influenza activity at the national level are also reported.
Virological surveillance - Weekly analysis ? virology
In week 44/2010, 24 countries reported virological data. Sentinel physicians collected 309 specimens, fifteen (4.9%) of which were positive for influenza virus (Tables 1 and 2). In addition, 26 non-sentinel source specimens (e.g., specimens collected for diagnostic purpose in hospitals) were reported positive for influenza virus. Of the 41 influenza viruses detected from sentinel and non-sentinel sources during week 44/2010, twenty-seven (66%) were type A and fourteen (34%) were type B. These detections were reported by the Czech Republic, France, Norway, Portugal, Spain, Sweden and the UK (England, Northern Ireland and Scotland).
Sixteen of the 27 influenza A viruses detected in week 44/2010 were subtyped: fifteen as the 2009 pandemic influenza A(H1) virus and one as A(H3). Table 2 shows the distribution of both sentinel and non-sentinel specimens by type and subtype. Figures 1?3 show the trends of virological detections since week 40/2010.
Since week 40/2010, twenty-three viruses from sentinel and non-sentinel specimens were characterised antigenically (Table 3), 15 (65.2%) of which were A/California/7/2009 (H1N1)-like virus. Among the five influenza B viruses characterised so far, both the Yamagata- and the Victoria-lineage were represented.
More details on circulating viruses can be found in the report prepared by the Community Network of Reference Laboratories coordination team.
In week 44/2010, 185 detections of respiratory syncytial virus were reported; this number is within the range of the previous season for this time of the year (Figure 4).
Table 2: Weekly and cumulative influenza virus detections by type, subtype and surveillance system, weeks 40/2010?44/2010
[Virus type - Current period: Sentinel - Non-sentinel / Season: Sentinel - Non-sentinel]
Note: A(pandemic H1), A(H3) and A(H1) includes both N-subtyped and not N-subtyped viruses
(...)
Table 3: Results of antigenic characterisations of sentinel and non-sentinel influenza virus isolates, weeks 40/2010?44/2010
[Strain name - Number of strains]
(...)
Country comments
In the Netherlands in week 43, sentinel surveillance detected the first influenza viruses of this season. Two type B influenza viruses were detected: one in a patient with ILI and one in a patient with another acute respiratory infection. The viral load was too low for determination of the lineage. Both patients did not report travel abroad in the weeks before they became ill.
Description of the system
According to the nationally defined sampling strategy, sentinel physicians take nasal or pharyngeal swabs from patients with ILI, ARI or both and send the specimens to influenza-specific reference laboratories for virus detection, (sub-)typing, antigenic or genetic characterisation and antiviral susceptibility testing.
Hospital surveillance ? severe acute respiratory infection (SARI) - Weekly analysis ? SARI
During week 44/2010, three sentinel SARI cases were reported in Romania. Since week 40/2010, seven sentinel SARI cases have been reported. Influenza virus was not detected in any of these cases and none of the individuals had been vaccinated against influenza (Tables 4, 5 and 6).
Table 4: Number of SARI cases by age and gender, week 44/2010
[Age groups - Male - Female]
Table 5: Number of SARI cases by influenza type and subtype, week 44/2010
[Virus type/subtype - Number of cases during current week - Cumulative number of cases since the start of the season]
Note: A(pandemic H1), A(H3) and A(H1) includes both N-subtyped and not N-subtyped viruses
Table 6: Number of SARI cases by vaccination status, week 44/2010
[Vaccination Status - Number Of Cases - Percentage of cases]
Description of the system
A number of Member States carry out hospital-based surveillance of severe acute respiratory infection (SARI) exhaustively or at selected sentinel sites. SARI surveillance serves to monitor the trends in the severity of influenza and potential risk factors for severe disease to help guide preventive measures and health care resource allocation.
The report text was written by an editorial team at the European Centre for Disease Prevention and Control (ECDC): Eeva Broberg, Flaviu Plata, Phillip Zucs and Ren? Snacken. The bulletin text was reviewed by the Community Network of Reference Laboratories for Human Influenza in Europe (CNRL) coordination team: Adam Meijer, Rod Daniels, John McCauley and Maria Zambon. On behalf of the EISN members the bulletin text was reviewed by Bianca Snijders (RIVM Bilthoven, The Netherlands) and Thedi Ziegler (National Institute for Health and Welfare, Finland)
Maps and commentary used in this Weekly Influenza Surveillance Overview (WISO) do not imply any opinions whatsoever of ECDC or its partners on the legal status of the countries and territories shown or concerning their borders.
All data published in the WISO are up-to-date on the day of publication. Past this date, however, published data should not be used for longitudinal comparisons as countries tend to retrospectively update their numbers in the database.
? European Centre for Disease Prevention and Control, Stockholm, 2010
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[Source: European Centre for Disease Prevention and Control (ECDC), full PDF document, (LINK). Extract, edited.]
SURVEILLANCE REPORT
Weekly influenza surveillance overview - 12 November 2010
Main surveillance developments in week 44/2010 (01 Nov 2010 ? 07 Nov 2010)
This first page contains the main developments of this week and can be printed separately or together with the more detailed information following.
- Epidemiological indicators show 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, fifteen (4.9%) of 309 sentinel specimens tested positive for influenza virus. Twenty-seven of 41 influenza viruses detected in sentinel and non-sentinel specimens were type A, and 14 were type B. Of the 16 viruses subtyped influenza A viruses, 15 were 2009 pandemic A(H1) and one was A(H3). Since week 40/2010, influenza A(H3), 2009 pandemic A(H1) as well as influenza B viruses of the Yamagata- and the Victoria-lineages have been detected.
- Three SARI cases, not related to influenza, were reported during week 44/2010.
- Rare detections of influenza virus along with sporadic detections of respiratory syncytial virus in a number of European countries suggest that the low influenza-like illness and acute respiratory infection activity currently observed is likely due to respiratory pathogens other than influenza.
- Sentinel surveillance of influenza-like illness (ILI)/ acute respiratory infection (ARI):
- Bulgaria reported medium activity based on consultations for ARI. The other 24 countries reported low activity of ILI/ARI and most of them observed unchanging trends. Malta reported local geographic spread.
- Virological surveillance:
- Sentinel physicians collected 309 specimens, fifteen (4.9%) of which were positive for influenza virus. Of the 41 influenza viruses detected from sentinel and non-sentinel sources during week 44/2010, 27 were type A and 14 were type B. During the current season, influenza A(H3), 2009 pandemic A(H1) as well as influenza B viruses of the Yamagata- and the Victoria-lineages have been detected.
- Hospital surveillance of severe acute respiratory infection (SARI):
- Three SARI cases were reported during week 44/2010; no influenza virus was detected from these patients.
Sentinel surveillance (ILI/ARI) - Weekly analysis ? epidemiology
During week 44/2010, 25 of 29 countries reported epidemiological data. Twenty-four countries continued to experience low intensity (Map 1, Table 1), and one, Bulgaria, reported medium intensity based on consultations for ARI.
For the geographic spread indicator, Malta reported local spread, and Cyprus, Czech Republic, France, Norway, and the UK reported sporadic cases. All other countries reported no activity (Map 2, Table 1).
Bulgaria and UK (Scotland) reported an increase in consultation rates for ILI/ARI compared to the previous week. The remaining countries reported stable or decreasing trends (Map 1 and Table 1). Consultation rates continue to be at or below national baseline levels for all countries that reported.
For comparison with the 2009-2010 season, please refer to the ECDC special report on the 2009 influenza A(H1N1) pandemic: (LINK)
(...)
Description of the system
This surveillance is based on nationally organized sentinel networks of physicians, mostly general practitioners (GPs), covering at least 1?5% of the population in their countries. All EU/EEA Member States (except Liechtenstein) are participating. Depending on their country?s choice, each sentinel physician reports the weekly number of patients seen with influenza-like illness (ILI), acute respiratory infection (ARI) or both to a national focal point. From the national level, both numerator and denominator data are then reported to the European Surveillance System (TESSy) database. Additional semi-quantitative indicators of intensity, geographic spread and trend of influenza activity at the national level are also reported.
Virological surveillance - Weekly analysis ? virology
In week 44/2010, 24 countries reported virological data. Sentinel physicians collected 309 specimens, fifteen (4.9%) of which were positive for influenza virus (Tables 1 and 2). In addition, 26 non-sentinel source specimens (e.g., specimens collected for diagnostic purpose in hospitals) were reported positive for influenza virus. Of the 41 influenza viruses detected from sentinel and non-sentinel sources during week 44/2010, twenty-seven (66%) were type A and fourteen (34%) were type B. These detections were reported by the Czech Republic, France, Norway, Portugal, Spain, Sweden and the UK (England, Northern Ireland and Scotland).
Sixteen of the 27 influenza A viruses detected in week 44/2010 were subtyped: fifteen as the 2009 pandemic influenza A(H1) virus and one as A(H3). Table 2 shows the distribution of both sentinel and non-sentinel specimens by type and subtype. Figures 1?3 show the trends of virological detections since week 40/2010.
Since week 40/2010, twenty-three viruses from sentinel and non-sentinel specimens were characterised antigenically (Table 3), 15 (65.2%) of which were A/California/7/2009 (H1N1)-like virus. Among the five influenza B viruses characterised so far, both the Yamagata- and the Victoria-lineage were represented.
More details on circulating viruses can be found in the report prepared by the Community Network of Reference Laboratories coordination team.
In week 44/2010, 185 detections of respiratory syncytial virus were reported; this number is within the range of the previous season for this time of the year (Figure 4).
Table 2: Weekly and cumulative influenza virus detections by type, subtype and surveillance system, weeks 40/2010?44/2010
[Virus type - Current period: Sentinel - Non-sentinel / Season: Sentinel - Non-sentinel]
- Influenza A - 9 - 18 / 29 - 52
- A (pandemic H1N1) - 9 - 6 / 19 - 16
- A (subtyping not perfomed) - 0 - 11 / 3 - 30
- A (H3) - 0 - 1 / 7 - 6
- A (H1) - 0 - 0 / 0 - 0
- Influenza B - 6 - 8 / 18 - 19
- Total Influenza - 15 - 26 / 47 - 71
Note: A(pandemic H1), A(H3) and A(H1) includes both N-subtyped and not N-subtyped viruses
(...)
Table 3: Results of antigenic characterisations of sentinel and non-sentinel influenza virus isolates, weeks 40/2010?44/2010
[Strain name - Number of strains]
- A(H1)v California/7/2009-like - 15
- A(H3) A/Brisbane/10/2007 (H3N2)-like - 0
- A(H3) A/Perth/16/2009 (H3N2)-like - 3
- B/Brisbane/60/2008-like (B/Victoria/2/87 lineage) - 4
- B/Florida/4/2006-like (B/Yamagata/16/88 lineage) - 1
(...)
Country comments
In the Netherlands in week 43, sentinel surveillance detected the first influenza viruses of this season. Two type B influenza viruses were detected: one in a patient with ILI and one in a patient with another acute respiratory infection. The viral load was too low for determination of the lineage. Both patients did not report travel abroad in the weeks before they became ill.
Description of the system
According to the nationally defined sampling strategy, sentinel physicians take nasal or pharyngeal swabs from patients with ILI, ARI or both and send the specimens to influenza-specific reference laboratories for virus detection, (sub-)typing, antigenic or genetic characterisation and antiviral susceptibility testing.
Hospital surveillance ? severe acute respiratory infection (SARI) - Weekly analysis ? SARI
During week 44/2010, three sentinel SARI cases were reported in Romania. Since week 40/2010, seven sentinel SARI cases have been reported. Influenza virus was not detected in any of these cases and none of the individuals had been vaccinated against influenza (Tables 4, 5 and 6).
Table 4: Number of SARI cases by age and gender, week 44/2010
[Age groups - Male - Female]
- Under 2 - 1
- 2-17 - 2
- Total - 3
Table 5: Number of SARI cases by influenza type and subtype, week 44/2010
[Virus type/subtype - Number of cases during current week - Cumulative number of cases since the start of the season]
- Influenza A
- A (pandemic H1N1) - ...
- A(subtyping not performed) - ...
- A(H3) - ...
- A(H1) - ...
- Influenza B - ...
- Unknown - 3 - 7
- Total 3 - 7
Note: A(pandemic H1), A(H3) and A(H1) includes both N-subtyped and not N-subtyped viruses
Table 6: Number of SARI cases by vaccination status, week 44/2010
[Vaccination Status - Number Of Cases - Percentage of cases]
- Vaccinated - 0 - 0
- Not vaccinated - 3 - 100
- TOTAL - 3
Description of the system
A number of Member States carry out hospital-based surveillance of severe acute respiratory infection (SARI) exhaustively or at selected sentinel sites. SARI surveillance serves to monitor the trends in the severity of influenza and potential risk factors for severe disease to help guide preventive measures and health care resource allocation.
The report text was written by an editorial team at the European Centre for Disease Prevention and Control (ECDC): Eeva Broberg, Flaviu Plata, Phillip Zucs and Ren? Snacken. The bulletin text was reviewed by the Community Network of Reference Laboratories for Human Influenza in Europe (CNRL) coordination team: Adam Meijer, Rod Daniels, John McCauley and Maria Zambon. On behalf of the EISN members the bulletin text was reviewed by Bianca Snijders (RIVM Bilthoven, The Netherlands) and Thedi Ziegler (National Institute for Health and Welfare, Finland)
Maps and commentary used in this Weekly Influenza Surveillance Overview (WISO) do not imply any opinions whatsoever of ECDC or its partners on the legal status of the countries and territories shown or concerning their borders.
All data published in the WISO are up-to-date on the day of publication. Past this date, however, published data should not be used for longitudinal comparisons as countries tend to retrospectively update their numbers in the database.
? European Centre for Disease Prevention and Control, Stockholm, 2010
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