EuroFlu - Weekly Electronic Bulletin
Week 52 : 21/12/2009-27/12/2009 01 January 2010, Issue No. 338

Ongoing influenza activity with a high intensity in parts of central and southern Europe

Key points: week 52/2009
  • This report is based on data received from 39 of the 53 Member States in the WHO European Region.
  • Thirty-three per cent of specimens collected from sentinel sources tested positive for influenza virus.
  • The incidence of clinical respiratory illness has decreased over the past three weeks in 16 reporting countries.
  • Influenza transmission remains high in some areas, particularly in the central and southern part of the Region.
  • Out of 12 countries that reported testing at least 20 sentinel specimens for influenza this week, five reported that 30% of specimens or more had tested positive for influenza.
  • Four countries reported high intensity of influenza activity, with six reporting moderate impact on health services.
  • Pandemic (H1N1) 2009 was dominant in 27 countries and accounted 100% of influenza A virus subtype detections in sentinel specimens and 97% of detections in non-sentinel specimens.
  • 2555 laboratory confirmed pandemic (H1N1) 2009 deaths have been reported in the Region.
Current situation: week 52/2009

Clinical respiratory disease activity has declined over the past three weeks in 16 countries. In many of these countries, the clinical consultation rate in the 5-14 year age group has again dropped below rates observed in the 0-4 year age group. However four of these 16 countries (Poland, Portugal, Switzerland and the United Kingdom) also tested at least 20 sentinel specimens for influenza during week 52/2009 and the median influenza positivity rate was 37% (mean 33%), suggesting that influenza circulation is ongoing despite declining clinical trends. The intensity of influenza transmission also remains high in some areas, particularly in the central and southern parts of the Region. Although the increase in clinical consultation rates reported during week 51/2009 in Georgia and Montenegro have not continued, 54% of sentinel specimens collected in Georgia tested positive for influenza during week 52/2009. In addition, Greece has reported that 73% of sentinel specimens tested positive for influenza, reflecting the highest positivity rate of any country testing 20 or more sentinel specimens this week. Although clinical consultation rates for ARI appear to have reached a second peak in Ukraine, clinical consultation rates remain high, particularly in central and eastern Ukraine. Georgia, Poland, the Russian Federation (Urals Region), Ukraine and Serbia reported the intensity of influenza circulation as high. Estonia, France, Georgia, Romania, Turkey and Ukraine reported the impact of influenza on health care services to be moderate.

Reports of respiratory hospitalizations and deaths to EuroFlu indicate that deaths due to acute respiratory infection (ARI) have continued to decline in the Russian Federation during each week since week 48/2009. The weekly count of hospitalizations due to severe acute respiratory illness (SARI) reported by Slovakia has also decreased from a peak that was observed in week 50. However, sentinel SARI hospitalizations reported by Ukraine again increased during week 52/2009, largely due to increases reported at sentinel sites in Kyiv and Odessa. Weekly reports of SARI hospitalizations in Uzbekistan have remained stable at a level similar to a peak that was reached in week 49/2009.

Virological update: week 52/2009

Sentinel physicians collected 942 respiratory specimens this week, of which 312 (33%) were positive for influenza virus. Of these virus detections, 312 (100%) were type A (300 pandemic A(H1), 12 not subtyped). Of the 13 countries testing 20 or more sentinel specimens this week, influenza-positive rates ranged from 0% (Hungary) to 72% (Greece), with a median of 36% and a mean of 34%.

Based on the antigenic characterization of 799 influenza viruses reported from week 40/2009 to week 52/2009, 792 were pandemic A(H1N1), A/California/7/2009-like, 3 were A/Perth/16/2009 (H3N2)-like, 2 were A(H3) A/Brisbane/10/2007 (H3N2)-like, 1 was A/Brisbane/59/2007 (H1N1)-like, and 1 was B/Brisbane/60/2008-like. Genetic characterizations were available for 252 isolates; all belonged to the A/California/7/2009 A(H1N1) pandemic influenza lineage.

Ten countries have tested isolates of pandemic (H1N1) 2009 virus for oseltamivir resistance. Of the 1312 cases tested, 26 were resistant to oseltamivir. All viruses tested for resistance to zanamivir (346/346) have been found to be zanamivir-sensitive and all viruses tested for resistance to adamantanes (64/64) have been found to be resistant. This week the Netherlands reported that one additional patient was retrospectively diagnosed with a monopopulation of H275Y oseltamivir resistant virus. This patient did not receive oseltamivir therapy and the epidemiological investigation is ongoing.

Comment

Sentinel surveillance systems throughout the Region suggest that influenza activity remains ongoing, and a high intensity of activity continues in parts of central and southern Europe. The percentage of sentinel specimens testing positive for influenza in the Region was 33% during week 52/2009. While this is lower than the peak of 45% that was reached during week 45/2009, this should be interpreted with caution as clinical consultation rates and the testing of sentinel specimens may be impacted by the holiday 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 and WHO headquarters web sites.



Map

The map presents the qualitative indicators of influenza activity (intensity, trend, geographical spread and impact) and the dominant virus as assessed by each of the countries.

Clicking on the map will, if available, take you through to the national web site. If 'regional' activity is reported, a pop-up text box will appear which describes the activity in greater detail.

Clicking on France, Russian Federation, Turkey and United Kingdom (England) will provide you with regional data.

Northern Ireland Iceland Denmark Norway Norway Sweden Sweden Denmark Scotland Scotland Finland Sweden England England England England Wales Ireland The Netherlands Belgium France France Switzerland Germany Germany Bulgaria Czech Republic Slovakia Slovenia Poland Poland Hungary France Italy Italy Italy Italy Italy Spain Spain Spain Spain Spain Portugal Portugal (Azores) Greece Estonia Albania FYROM Turkey Turkey Finland Finland Finland Romania Romania Malta Cyprus Austria Croatia Boznia and Herzegovina Montenegro Serbia Lithuania Luxembourg Latvia Denmark Norway
Type of map :   Intensity + virological          Geographical spread + virological          Impact
Europe Year 2009 / Week 52


A = Dominant virus A
H1N1 = Dominant virus A(H1N1)
H3N2 = Dominant virus A(H3N2)
H1N2 = Dominant virus A(H1N2)
B = Dominant virus B
A & B = Dominant virus A & B

= : stable clinical activity
+ : increasing clinical activity
- : decreasing clinical activity

Low = no influenza activity or influenza at baseline levels
Medium = usual levels of influenza activity
High = higher than usual levels of influenza activity
Very high = particularly severe levels of influenza activity

No activity = no laboratory-confirmed case(s) of influenza, or evidence of increased or unusual respiratory disease activity.
Sporadic = isolated cases of laboratory confirmed influenza infection
Localized = limited to one administrative unit of the country (or reporting site) only.
Regional = appearing in multiple but <50% of the administrative units of the country (or reporting sites).
Widespread = appearing in ≥50% of the administrative units of the country (or reporting sites).

Country comments (where available)

  Finland
due to the Christmas holidays, reports from the sentinel surveillance sites didn't arrive in time for this report
Netherlands
By week 53 in the Netherlands 15 patients were diagnosed with oseltamivir resistant pandemic A(H1N1) 2009 influenza virus. Compared to week 52, one additional patient was retrospectively diagnosed with a monopopulation of H275Y oseltamivir resistant virus. However, this patient did not receive oseltamivir therapy. Source and transmission investigation is ongoing. Eleven of the 15 patients were immunosuppressed due to cytostatic/immunosuppressive therapy, of which five died. Contact tracing identified no cases of onward transmission of the oseltamivir resistant viruses.
Table and graphs

Intensity Geographic
spread
Impact Trend Dominant
type
Sentinel
swabs
Percentage
positive
ILI per
100 000
ARI per
100 000
Virology graph
and pie chart
AlbaniaType A, Subtype pH116822.6% (graphs)Click here
BelarusLowSporadicDecreasing877.9 (graphs)Click here
BulgariaLowSporadicDecreasingNone582.5 (graphs)Click here
CroatiaMediumWidespreadLowDecreasing24.1 (graphs)Click here
CyprusLowSporadicStable (graphs)Click here
Czech RepublicLowLocalDecreasing84.9 (graphs)725.9 (graphs)Click here
EstoniaMediumWidespreadModerateDecreasingType A, Subtype pH1N11526.7%21.6 (graphs)267.0 (graphs)Click here
FinlandLowLocalLowDecreasingType A, Subtype pH1 (graphs)Click here
FranceMediumWidespreadModerateDecreasing1838.7 (graphs)Click here
GeorgiaHighWidespreadModerateDecreasingType A, Subtype pH15653.6%387.5 (graphs)Click here
GermanyType A, Subtype pH14447.7% (graphs)Click here
GreeceType A, Subtype pH1N12972.4% (graphs)Click here
HungaryLowLocalLowDecreasingNone390%152.3 (graphs)Click here
IrelandMediumLocalLowDecreasingType A, Subtype pH1N150%21.2 (graphs)Click here
IsraelMediumWidespreadLowDecreasing65.6 (graphs)Click here
ItalyType A, Subtype pH1N1616.7% (graphs)Click here
KyrgyzstanType A, Subtype pH170% (graphs)Click here
LatviaMediumRegionalDecreasingType A, Subtype pH100%19.8 (graphs)505.2 (graphs)Click here
LithuaniaLowSporadicLowDecreasingNone633.3% (graphs)Click here
LuxembourgLowRegionalLowType A, Subtype pH12040.0% (graphs)Click here
Montenegro283.6 (graphs)633.4 (graphs)Click here
NetherlandsLowRegionalLowDecreasingType A, Subtype pH11010.0%36.6 (graphs)Click here
NorwayLowDecreasingType A, Subtype pH1N150%55.8 (graphs)Click here
PolandHighRegionalLowDecreasingType A, Subtype pH12825.0%91.8 (graphs)Click here
PortugalLowSporadicDecreasingType A, Subtype pH12548.0%26.4 (graphs)Click here
Republic of MoldovaWidespreadDecreasingNone155.8 (graphs)158.7 (graphs)Click here
RomaniaMediumRegionalModerateDecreasingType A, Subtype pH18636.1%2.5 (graphs)697.4 (graphs)Click here
Russian FederationMediumLocalDecreasingType A, Subtype pH1630.2 (graphs)Click here
SerbiaHighRegionalLowDecreasing173.0 (graphs)Click here
SlovakiaLowLocalLowDecreasingType A, Subtype pH1250.0%210.2 (graphs)1469.6 (graphs)Click here
SloveniaLowWidespreadDecreasingType A, Subtype pH1560.0%23.7 (graphs)647.0 (graphs)Click here
SwedenLowLocalLowDecreasingType A, Subtype pH1140%4.3 (graphs)Click here
SwitzerlandMediumWidespreadLowDecreasingType A, Subtype pH13748.7%240.9 (graphs)Click here
The former Yugoslav Republic of MacedoniaType A, Subtype pH1 (graphs)Click here
TurkeyMediumWidespreadModerateStableType A, Subtype pH18919.1%63.1 (graphs)Click here
United Kingdom - EnglandLowLocalDecreasingType A, Subtype pH1N11329.1%12.7 (graphs)410.4 (graphs)Click here
United Kingdom - Northern IrelandLowSporadicDecreasingType A, Subtype H1N1812.5%30.6 (graphs)Click here
United Kingdom - ScotlandMediumRegionalStableType A, Subtype pH1N110617.9%8.8 (graphs)Click here
United Kingdom - Wales7.5 (graphs)Click here
UkraineHighRegionalModerateDecreasingType A, Subtype pH11301.2 (graphs)Click here
UzbekistanLowNoneLowDecreasingNone31.9 (graphs)Click here
Europe94233.1% Click here
Preliminary data

Intensity: Low = no influenza activity or influenza activity at baseline level; Medium = usual levels of influenza activity; High = higher than usual levels of influenza activity; Very high = particularly severe levels of influenza activity.
Geographical spread: No activity = no laboratory-confirmed cases, or evidence of increased or unusual respiratory disease activity; Sporadic = isolated cases of laboratory-confirmed influenza infection; Localized = limited to one administrative unit in the country (or reporting site) only; Regional = appearing in multiple but <50% of the administrative units of the country (or reporting sites); Widespread = appearing in >=50% of the administrative units of the country (or reporting sites).
Impact: Low = demands on health-care services are not above usual levels; Moderate = demands on health-care services are above the usual demand levels but still below the maximum capacity of those services; Severe = demands on health care services exceed the capacity of those services.
Trend: Increasing = evidence that the level of respiratory disease activity is increasing compared with the previous week; Stable = evidence that the level of respiratory disease activity is unchanged compared with the previous week; Decreasing = evidence that the level of respiratory disease activity is decreasing compared with the previous week.
Dominant type: this assessment is based on data from sentinel and non-sentinel sources.
Sentinel swabs (% pos.): number of sentinels swabs tested for influenza and percentage that tested positive for influenza A or B.
ILI: influenza-like illness.
ARI: acute respiratory infection.
Sentinel SARI: severe acute respiratory illness.
Population: per 100 000 population.
* The value in the table for these countries reflects the percentage (e.g. from 0.0 to 100.0) of total outpatient encounters that were due to ILI/ARI rather than a consultation rate per 100 000 population.
- Not applicable.

The bulletin text was written by an editorial team at the WHO Regional Office for Europe (Caroline Brown and Joshua Mott), the Netherlands Institute for Health Services Research (NIVEL; John Paget and Tamara Meerhoff, Temporary Advisers to WHO) and the WHO Collaborating Centre for reference and research on influenza, Mill Hill, United Kingdom (Rod Daniels). The bulletin was reviewed by Douglas Fleming (Royal College of General Practitioners, United Kingdom), Lars Nielsen (Statens Serum Institute, Denmark) and Anne Mosnier (Open Rome, France) on behalf of the data contributors.

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EuroFlu : Weekly Electronic Bulletin