The most widespread activity remains in the southern tier of states.
We also learn in this update of another variant flu infection, this time from Minnesota.
2012-2013 Influenza Season Week 49 ending December 8, 2012
All data are preliminary and may change as more reports are received.
During week 49 (December 2-8), influenza activity increased in the U.S.
- Viral Surveillance: Of 7,663 specimens tested and reported by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories during week 49, 2,172 (28.3%) 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: One influenza-associated pediatric death was reported and was associated with an influenza B virus.
- Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 2.8%, which is above the national baseline of 2.2%. Seven of ten regions reported ILI above region-specific baseline levels. Eight states experienced high ILI activity, 2 states experienced moderate ILI activity; New York City and 9 states experienced low ILI activity; 31 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in 18 states was reported as widespread; 17 states reported regional activity; the District of Columbia and 11 states reported local activity; Guam and 4 states reported sporadic activity, and Puerto Rico and the U.S. Virgin Islands did not report.
More than 28% of samples tested this past week were positive for influenza, with H3N2 leading the way. Here are the details on the novel flu infection.
One infection with an influenza A (H3N2) variant virus (H3N2v) was reported to CDC during week 49 by Minnesota. Close contact between the case patient and swine in the week preceding illness was reported. The patient has fully recovered and no further cases have been identified in contacts of the case patient. This is the second H3N2v infection reported for the 2012-13 influenza season, which began on September 30, 2012.
A total of 312 infections with variant influenza viruses (308 H3N2v viruses, 3 H1N2v viruses, and 1 H1N1v virus) have been reported from 11 states since July 2012. More information about H3N2v infections can be found at http://www.cdc.gov/flu/swineflu/h3n2v-outbreak.htm.
While it is obvious that flu season has started early this year, it is too soon to know how severe – or prolonged – this season will turn out to be.
The CDC would like you to know, however, that it isn’t too late to get a flu shot, as the peak of influenza activity often doesn’t occur until February or March.