Some States Showing Elevated Numbers of Influenza Cases

Some states are showing elevated levels of influenza according to officials from the Centers for Disease Control and Prevention (CDC).  In a media briefing held on Dec. 3, 2012, Thomas R. Frieden, MD, MPH, director of the CDC, and Melinda Wharton, MD, acting director of CDCs National Center for Immunization and Respiratory  Diseases, provided mid-season figures on U.S. influenza activity and vaccination rates.

Here are the details for influenza activity during week 47 (Nov. 18-24, 2012) in the U.S.:
- Viral Surveillance: Of 5,342 specimens tested and reported by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories during week 47, 812 (15.2 percent) were positive for influenza.
- Novel Influenza A Virus: One human infection with a novel influenza A virus was reported.
- Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the epidemic threshold.
- Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
- Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 2.2 percent, which is at the national baseline of 2.2 percent. Five regions reported ILI above region-specific baseline levels. Five states experienced high ILI activity, two states experienced moderate ILI activity; four states experienced low ILI activity; New York City and 39 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in four states was reported as widespread; seven states reported regional activity; 19 states reported local activity; the District of Columbia and 18 states reported sporadic activity; Guam and one state reported no influenza activity, and Puerto Rico, the U.S. Virgin Islands and 1 state did not report.

During week 47, the following influenza activity was reported:
Widespread influenza activity was reported by four states (Alaska, Mississippi, New York, and South Carolina).
Regional influenza activity was reported by seven states (Alabama, Idaho, Iowa, Maine, Massachusetts, North Carolina, and Ohio).
Local influenza activity was reported by 19 states (Arkansas, Colorado, Connecticut, Georgia, Illinois, Kansas, Kentucky, Louisiana, Minnesota, Missouri, Oregon, Rhode Island, South Dakota, Tennessee, Texas, Utah, Virginia, Wisconsin and Wyoming).
Sporadic influenza activity was reported by the District of Columbia, and 18 states (Arizona, California, Florida, Hawaii, Indiana, Maryland, Michigan, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, North Dakota, Oklahoma, Pennsylvania, Washington, and West Virginia).
No influenza activity was reported by Guam and one state (Vermont).
Puerto Rico, the U.S. Virgin Islands, and one state (Delaware) did not report.

The CDC has antigenically characterized 140 influenza viruses [two 2009 H1N1 viruses, 90 influenza A (H3N2) viruses, and 48 influenza B viruses] collected by U.S. laboratories since Oct. 1, 2012. 2009 H1N1 [2]:

Both 2009 H1N1 viruses tested were characterized as A/California/7/2009-like, the influenza A (H1N1) component of the 2012-2013 influenza vaccine for the Northern Hemisphere.

Influenza A (H3N2) [90]:
All 90 H3N2 influenza viruses tested so far have been characterized as A/Victoria/361/2011-like, the influenza A (H3N2) component of the 2012-2013 Northern Hemisphere influenza vaccine.

Influenza B (B/Yamagata/16/88 and B/Victoria/02/87 lineages) [48]:
Yamagata Lineage [34]: Thirty-four (70.8 percent) of the 48 influenza B viruses tested so far this season have been characterized as B/Wisconsin/1/2010-like, the influenza B component of the 2012-2013 Northern Hemisphere influenza vaccine.

Victoria Lineage [14]: Fourteen (29.2 percent) of 48 influenza B viruses tested have been from the B/Victoria lineage of viruses

An annual flu vaccination is recommended for everyone six months of age and older as the first and most important step in protecting against flu viruses.

National Influenza Vaccination Week (NIVW) is being observed December 2-8, 2012.  National Influenza Vaccination Week was established in 2005 to highlight the importance of continuing influenza vaccination in December and beyond.

For more statistics, visit: http://www.cdc.gov/flu/weekly/