# 4326
The key indicators for influenza activity around the country remained roughly the same in the latest reporting period as they were in week 2 and 3.
For the third consecutive week the P&I (pneumonia & influenza) Mortality levels remain above the epidemic threshold for this time of year. Not all P&I deaths can be attributed to influenza, however.
There were 9 influenza-related pediatric fatalities added last week, although roughly half appear to be older cases from 2009.
Overall, US flu activity continues to be considerably below the levels we saw last October and well below normal for this time of year.
Below you’ll find some excerpts from the CDC’s weekly FluView report. Follow the link to read it in its entirety.
2009-2010 Influenza Season Week 4 ending January 30, 2010
All data are preliminary and may change as more reports are received.
Synopsis:
During week 4 (January 24-30, 2010), influenza activity remained at approximately the same levels as last week in the U.S.
- 119 (3.2%) 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 were positive for influenza.
- All subtyped influenza A viruses reported to CDC were 2009 influenza A (H1N1) viruses.
- The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold.
- Nine influenza-associated pediatric deaths were reported. Eight deaths were associated with 2009 influenza A (H1N1) virus infection and one was associated with an influenza A virus for which the subtype was undetermined.
- The proportion of outpatient visits for influenza-like illness (ILI) was 1.9% which is below the national baseline of 2.3%. All regions reported ILI below their region-specific baseline.
- No states reported widespread influenza activity, six states reported regional influenza activity, Puerto Rico and 10 states reported local influenza activity, the District of Columbia, Guam, and 31 states reported sporadic influenza activity, and the U.S. Virgin Islands and three states reported no influenza activity.
U.S. Virologic Surveillance:
WHO and NREVSS collaborating laboratories located in all 50 states and Washington, D.C. report to CDC the number of respiratory specimens tested for influenza and the number positive by influenza type and subtype. The results of tests performed during the current week are summarized in the table below.
Pneumonia and Influenza (P&I) Mortality Surveillance
During week 4, 8.1% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 7.8% for week 4, and is the third consecutive week that the percentage of P&I deaths has been above the epidemic threshold.
Influenza-Associated Pediatric Mortality
Nine influenza-associated pediatric deaths were reported to CDC during week 4 (Colorado, California [6], Mississippi, and Texas). Eight deaths were associated with 2009 influenza A (H1N1) virus infection and one was associated with an influenza A virus for which the subtype was undetermined. The deaths reported during week 4 occurred between October 18, 2009 and January 23, 2010.
Outpatient Illness Surveillance:
Nationwide during week 4, 1.9% 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 below the national baseline of 2.3%.
