Tweet
EuroFlu - Weekly Electronic Bulletin - Week 17 : 23/04/2012-29/04/2012 - 04 May 2012, Issue N? 444 (edited)
[Source: EuroFlu, full page: (LINK). Extracts, edited.]
EuroFlu - Weekly Electronic Bulletin - Week 17 : 23/04/2012-29/04/2012 - 04 May 2012, Issue N? 444
Influenza activity continues to decline in the WHO European Region
Current situation: week 17/2012
Outpatient surveillance for ILI and ARI
35 countries reported on trends in clinical activity: 18 were stable, 2 increasing and 15 decreasing.
Of the 35 countries reporting on the geographical spread of influenza, 11 reported no activity; 16, sporadic activity; 4, local activity; 2, regional activity; and 2, widespread activity.
All countries reported either medium (1) or low intensity (34).
During week 17/2012 sentinel outpatient clinics collected 308 respiratory specimens, of which 56 (18%) tested positive for influenza viruses, a slight decrease from the previous week.
Of the positive specimens, 32 (57%) were influenza type A and 24 (43%) were influenza B (Table 1, Fig. 1).
In the 6 countries testing 20 or more sentinel specimens, influenza positivity ranged from 5% to 27%, with a median of 12% (mean: 14%).
Hospital surveillance for SARI
8 countries reported data for hospital-based sentinel surveillance of SARI: Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, the Republic of Moldova, Romania, and the Russian Federation.
68 respiratory specimens were collected from SARI patients, of which 11 (16%) were positive for influenza: 9 were type A and 2 were type B.
All influenza A viruses were subtyped as A(H3). (Fig. 2).
Further information on the sentinel SARI surveillance systems represented in the EuroFlu bulletin can be found in ?Overview of sentinel SARI systems in EuroFlu?.
Virological overview
During week 17/2012, 34 countries reported on whether there was a dominant virus, based on both sentinel and non-sentinel detections.
6 countries reported influenza A and/or A(H3N2); 2 reported influenza B as the dominant virus. 26 countries reported that no virus was dominant.
Influenza virus type and subtype detections
Table 1 provides an overview of the influenza virus detections by type and subtype in sentinel ILI/ARI and SARI surveillance for both the current week and the period since week 40/2011.
Table 1. Influenza virus detections in sentinel specimens
[Specimens tested and viruses - Current week (number and %): ILI/ARI ? SARI - Cumulative since week 40 (number and %): ILI/ARI ? SARI]
Since week 40/2011, 41 844 influenza viruses from sentinel and non-sentinel sources have been typed: 38 195 (91%) were influenza A and 3649 (9%) were influenza B.
Of the influenza A viruses, 20 691 were subtyped: 19 844 (96%) as A (H3N2) and 847 (4%) as A(H1N1)pdm09.
Virus strain characterizations
Influenza viruses are monitored each season for antigenic and genetic characteristics, to determine the extent to which they correspond with the viruses included in the seasonal influenza vaccine as well as the occurrence of mutations that affect pathogenicity or that are associated with susceptibility to antiviral drugs.
Since week 40/2011, 17 countries (Austria, the Czech Republic, Denmark, the United Kingdom (England), France, Germany, Greece, Hungary, Italy, Latvia, Portugal, Romania, the Russian Federation, Slovakia, Slovenia, Sweden, Switzerland) have characterized 1906 influenza viruses antigenically (Fig. 3).
17 countries (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Norway, Portugal, Romania, the Russian Federation, Spain, Sweden, Switzerland) have characterized 1141 influenza viruses genetically (Fig. 4).
# Included in the WHO-recommended composition of influenza virus vaccines for use in the 2011/2012 northern hemisphere influenza season.
* Included in the WHO-recommended composition of influenza virus vaccines for use in the 2012 southern hemisphere influenza season.
Further information
The EuroFlu bulletin describes and comments on influenza activity in the 53 countries in the WHO European Region. Further information can be obtained from the WHO/Europe, WHO headquarters and European Centre for Disease Prevention and Control web sites.
(?)
-
------
EuroFlu - Weekly Electronic Bulletin - Week 17 : 23/04/2012-29/04/2012 - 04 May 2012, Issue N? 444
Influenza activity continues to decline in the WHO European Region
Current situation: week 17/2012
- This issue is based on data for week 17/2012 reported by 44 Member States in the WHO European Region.
- Clinical consultation rates for influenza-like illness (ILI) and acute respiratory infection (ARI) continue to decrease or have stabilized in most countries.
- The number of hospitalizations due to severe acute respiratory infection (SARI) and the influenza-positivity rate are decreasing.
- Both the total number of influenza virus detections and the percentage influenza-positive detections are decreasing
- Influenza A(H3N2) continues to be the dominant virus in circulation, followed by influenza B, with relatively few A(H1N1)pdm09 viruses reported
Outpatient surveillance for ILI and ARI
35 countries reported on trends in clinical activity: 18 were stable, 2 increasing and 15 decreasing.
Of the 35 countries reporting on the geographical spread of influenza, 11 reported no activity; 16, sporadic activity; 4, local activity; 2, regional activity; and 2, widespread activity.
All countries reported either medium (1) or low intensity (34).
During week 17/2012 sentinel outpatient clinics collected 308 respiratory specimens, of which 56 (18%) tested positive for influenza viruses, a slight decrease from the previous week.
Of the positive specimens, 32 (57%) were influenza type A and 24 (43%) were influenza B (Table 1, Fig. 1).
In the 6 countries testing 20 or more sentinel specimens, influenza positivity ranged from 5% to 27%, with a median of 12% (mean: 14%).
Hospital surveillance for SARI
8 countries reported data for hospital-based sentinel surveillance of SARI: Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, the Republic of Moldova, Romania, and the Russian Federation.
68 respiratory specimens were collected from SARI patients, of which 11 (16%) were positive for influenza: 9 were type A and 2 were type B.
All influenza A viruses were subtyped as A(H3). (Fig. 2).
Virological overview
During week 17/2012, 34 countries reported on whether there was a dominant virus, based on both sentinel and non-sentinel detections.
6 countries reported influenza A and/or A(H3N2); 2 reported influenza B as the dominant virus. 26 countries reported that no virus was dominant.
Influenza virus type and subtype detections
Table 1 provides an overview of the influenza virus detections by type and subtype in sentinel ILI/ARI and SARI surveillance for both the current week and the period since week 40/2011.
Table 1. Influenza virus detections in sentinel specimens
[Specimens tested and viruses - Current week (number and %): ILI/ARI ? SARI - Cumulative since week 40 (number and %): ILI/ARI ? SARI]
- Specimens tested ? 308 - 68 - 35225 - 4118
- Influenza A + B - 56 (18.2%) - 11 (16.2%) ? 10783 (30.6%) ? 641 (15.6%)
- Influenza A - 32 (57.1%) - 9 (81.8%) - 9454 (87.7%) - 604 (94.2%)
- Influenza B ? 24 (42.9%) - 2 (18.2%) - 1329 (12.3%) - 37 (5.8%)
- Influenza A subtyped ? 28 - 9 - 8524 - 571
- A (H1N1)pdm09 - 2 (7.1%) - 0 (0.0%) - 173 (2.0%) - 64 (11.2%)
- A (H3N2) - 26 (92.9%) - 9 (100.0%) - 8351 (98.0%) - 507 (88.8%)
- A (H1N1) - 0 (0.0%) - 0 (0.0%) - 0 (0.0%) - 0 (0.0%)
Since week 40/2011, 41 844 influenza viruses from sentinel and non-sentinel sources have been typed: 38 195 (91%) were influenza A and 3649 (9%) were influenza B.
Of the influenza A viruses, 20 691 were subtyped: 19 844 (96%) as A (H3N2) and 847 (4%) as A(H1N1)pdm09.
Virus strain characterizations
Influenza viruses are monitored each season for antigenic and genetic characteristics, to determine the extent to which they correspond with the viruses included in the seasonal influenza vaccine as well as the occurrence of mutations that affect pathogenicity or that are associated with susceptibility to antiviral drugs.
Since week 40/2011, 17 countries (Austria, the Czech Republic, Denmark, the United Kingdom (England), France, Germany, Greece, Hungary, Italy, Latvia, Portugal, Romania, the Russian Federation, Slovakia, Slovenia, Sweden, Switzerland) have characterized 1906 influenza viruses antigenically (Fig. 3).
17 countries (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Norway, Portugal, Romania, the Russian Federation, Spain, Sweden, Switzerland) have characterized 1141 influenza viruses genetically (Fig. 4).
# Included in the WHO-recommended composition of influenza virus vaccines for use in the 2011/2012 northern hemisphere influenza season.
* Included in the WHO-recommended composition of influenza virus vaccines for use in the 2012 southern hemisphere influenza season.
Further information
The EuroFlu bulletin describes and comments on influenza activity in the 53 countries in the WHO European Region. Further information can be obtained from the WHO/Europe, WHO headquarters and European Centre for Disease Prevention and Control web sites.
(?)
-
------