# 6070
While the calendar says we are well into this year’s flu season, reported influenza activity in North America and Europe continues to run well below average.
Today the CDC’s latest FluView report indicates that most of the country is reporting minimal ILI influenza-like-illness activity.
The following chart shows that the seasonal spike normally seen during the winter in influenza-like-illness has yet to appear.
So far, what little influenza activity that has been documented has been predominantly influenza A, and the bulk of those H3N2.
Excerpts from this week’s FluView Report follows:
2011-2012 Influenza Season Week 1 ending January 7, 2012
All data are preliminary and may change as more reports are received.
Synopsis:
During week 1 (January 1-7, 2012), influenza activity increased in the United States, but remains relatively low.
- U.S. Virologic Surveillance: Of the 3,199 specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division, 108 (3.4%) were positive for influenza.
- Pneumonia and Influenza (P&I) Mortality Surveillance: The proportion of deaths attributed to P&I was below the epidemic threshold.
- Influenza-associated Pediatric Mortality: No influenza-associated pediatric deaths were reported.
- Outpatient Illness Surveillance:The proportion of outpatient visits for influenza-like illness (ILI) was 1.4%, which is below the national baseline of 2.4%. All 10 regions reported ILI below region-specific baseline levels. Two states experienced low ILI activity, New York City and 48 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in two states was reported as regional; seven states reported local activity; 37 states reported sporadic activity; the District of Columbia, Guam, the U.S. Virgin Islands and four states reported no influenza activity, and Puerto Rico did not report.
Similarly, influenza in Europe seems to be running below average as well, and unlike last year – where they saw mostly H1N1 – this year it is the H3N2 virus that dominates.
This is from the ECDC’s WISO report (Weekly influenza surveillance overview).
Weekly influenza surveillance overview, 2 - 8 January 2012 - Week 1
Surveillance reports - 13 Jan 2012
Available as PDF in the following languages:
This document is free of charge.
ABSTRACT
- During week 1/2012, low influenza activity was notified by all 26 of the 27 countries reporting (Malta reported medium activity) with five countries (Italy, Netherlands, Norway, Spain and Sweden) now indicating local or regional spread.
- Of 625 sentinel specimens collected and tested during week 1/2012, 81 (13%) were positive for influenza viruses. Though less than the percentage reported in week 52 (which will have been affected by the Christmas/New Year holiday), it shows an upward progression since last month.
- Of 632 influenza A viruses sub-typed from sentinel and non-sentinel sources since week 40/2011, 588 (93%) were of the H3 subtype. No antiviral resistance has been detected as yet.
- Since week 40/2011, 157 severe acute respiratory infection (SARI) cases have been reported by six countries. Fifty-five of them were confirmed influenza-positive cases and of those typed or sub-typed 14 were A(H1N1)pdm09, 17 were A(H3) and four were influenza B viruses.
Influenza transmission is showing some progression in Europe this season and is currently dominated by A(H3N2) viruses.
Given the unpredictability of influenza, it is too soon to know how the rest of the season will progress.
