Main developments in past 24 hours
- Update from U.S.A. indicates ILI rates above threshold and pneumonia and influenza-related mortality above threshold level for season;
- Total of 280 fatal cases in Europe and EFTA countries and 5 642 in the rest of the world have been reported up to date.
This report is based on official information provided by the national public health websites or through other official communication channels. An update on the number of confirmed fatal cases, as of 26 October 2009 16:00 hours CEST, for the world, and 27 October 09:00 hours CEST, for Europe is presented in Table 2.
Updates from U.S.A. and Canada
United States Update
Data as of 23 October 2009 16:00 CEST, for week ending 17 October, 2009 (Week 41)
Virology: 100% of all subtyped influenza A viruses reported to CDC were 2009 influenza A (H1N1) viruses. 99.8% of all specimens were type A and 0.2% were type B. 2009 influenza A (H1N1) viruses continue to be similar to the strain chosen for the vaccine. Since September 1, 2009, five infections with oseltamivir resistant 2009 influenza A (H1N1) viruses have been identified in the United States. The 5 cases represent an increase of one case over the previous week. Since the emergence of the 2009 influenza A (H1N1), all isolates tested have been resistant to the adamantanes (amantadine and rimantadine).
Mortality Surveillance: Pneumonia and Influenza Hospitalization and Deaths:
From August 30 – October 17, 2009, 8,204 laboratory-confirmed influenza associated hospitalizations, 411 laboratory-confirmed influenza associated deaths, 21,823 pneumonia and influenza syndrome-based hospitalizations, and 2,416 pneumonia and influenza syndrome-based deaths, were reported to CDC.Pneumonia and Influenza (P&I) Mortality Surveillance: During week 41, 6.9% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 6.6% for week 41 and the percentage has been above the threshold for three weeks. Influenza-associated Pediatric Deaths: Influenza-Associated Pediatric Mortality: Eleven influenza-associated pediatric deaths were reported to CDC during week 41. Nine of these deaths were associated with 2009 influenza A (H1N1) virus infection and two were associated with an influenza A virus for which the subtype is undetermined. These deaths occurred between 14 June and 10 October 2009. One death reported during week 41 occurred during the 2008-09 season. Since 30 August 2009, CDC has received 53 reports of influenza-associated pediatric deaths that occurred during the current influenza season (47 due to 2009 influenza A(H1N1) and 6 due to undetermined subtype influenza A). Among the 53 deaths in children, 32 children had specimens collected for bacterial culture from normally sterile sites and seven (21.9%) of the 32 were positive; Staphylococcus aureus was identified in five (71.4%) of the seven children. A total of 95 deaths in children associated with 2009 H1N1 virus have been reported to CDC.
Influenza-associated hospitalizations: Laboratory-confirmed influenza-associated hospitalizations are monitored in the U.S. using a population-based surveillance network comprising 10 Emerging Infections Program sites and 6 new sites. Laboratory-confirmed influenza-associated hospitalization rates were reported during 01 September – 17 October 2009 (rates include influenza A, influenza B, and 2009 influenza A (H1N1)). Rates [EIP (new sites)] for children aged 0-4 years and 5-17 years were 1.9 (3.0) and 0.9 (1.6) per 10,000, respectively. Rates [EIP (new sites)] for adults aged 18-49 years, 50-64 years, and = 65 years were 0.6 (0.6), 0.6 (0.6) and 0.5 (0.4) per 10,000, respectively.
Influenza-like Illness (ILI): Nationwide during week 41, 7.1% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is above the national baseline of 2.3%. On a regional level, the percentage of outpatient visits for ILI ranged from 2.7% to 12.5% during week 41.
Geographic spread: Widespread influenza activity was reported by 46 states. Regional influenza activity was reported by Guam and three states. Local influenza activity was reported by the District of Columbia, Puerto Rico, and one state. The U.S. Virgin Islands did not report.
Other information:
- President Barack Obama declared the swine flu outbreak a national emergency on 23 October, giving the Secretary of the Department of Health and Human Services the power to let hospitals move emergency rooms offsite to speed treatment and protect noninfected patients.
- The 2009-2010 U.S. Influenza Season (for purposes of surveillance and reporting) began 4 October 2009.
For more information:
U.S. Centers for Disease Control and Prevention "What's New on the H1N1 Flu Site" http://www.cdc.gov/h1n1flu/whatsnew.htm
U.S. Centers for Disease Control and Prevention Weekly Influenza Surveillance Report
http://www.cdc.gov/flu/weekly/
Overview of Influenza Surveillance in the United States
http://www.cdc.gov/flu/weekly/pdf/overview.pdf
Canada Update
Data as of 23 October 2009, for week ending 17 October, 2009 (Week 41)
Virology: 99.9% of all subtyped influenza A viruses being reported to Public Health Agency of Canada (PHAC) were 2009 influenza A (H1N1) viruses. One type B was reported. The proportion of tests that were positive for influenza was 16.9% which was a significant increase to the previous week. 2009 influenza A (H1N1) viruses continue to be similar to the strain chosen for the vaccine. Of 2009 influenza A (H1N1) viruses tested by PHAC for resistance to neuraminidase inhibitors (oseltamivir and zanamivir) one were found resistant tooseltamivir. Hospitalizations and Deaths: 64 hospitalizations and 3 deaths were reported for week 41. Paediatric Influenza Hospitalizations and Deaths: No laboratory-confirmed influenza-associated paediatric hospitalizations or deaths were reported through the Immunization Monitoring Program Active (IMPACT) network. Influenza-like Illness (ILI): The national ILI consultation rate increased to 48 consultations per 1,000 patient visits this week which was an increase for a fifth consecutive week and was above the expected range for this time of the year.
Geographic spread: Four regions reported widespread activity and 14 regions reported localized activity, while 23 regions reported sporadic activity and 13 regions reported no activity. 57 influenza outbreaks in schools and one outbreak in a long-term care facility were reported.
Other information:
- The Minister of Health announced on October 21, 2009, that Health Canada has approved AREPANRIX, a vaccine against the Pandemic (H1N1) 2009 virus.
For more information: Public Health Agency of Canada
http://www.phac-aspc.gc.ca/influenza/
Public Health Agency of Canada FluWatch
http://www.phac-aspc.gc.ca/fluwatch/09-10/w41_09/index-eng.php
