US Flu Cases on the Rise

By Vickie Frantz, AccuWeather.com Staff Writer

January 5,2013; 3:25PM,EST

Positive cases of influenza in the U.S. rose 60 percent during the last week of December.
In the week ending on Dec. 29, 2012, the Centers for Disease Control and Prevention (CDC) reported there were 2,961 positive influenza test results out of 9,363 specimens nationwide, or 31.6 percent.
This is an increase in cases since last week when the percentage of positive flu cases nationwide was 29.6 percent. The current baseline of outpatient visits for influenza-like illnesses is 5.6 percent which is above the national baseline of 2.2 percent.
The national baseline is determined by calculating the mean percentage of patient visits to health care providers for influenza-like illnesses (a temperature of 100 degrees F [37.8 degrees C] or greater and a cough and/or a sore throat without a known cause other than influenza) during non-influenza weeks for the previous three seasons and adding two standard deviations.
The CDC measures influenza cases broken into 10 geographical regions of the United States. During the last week of 2012, nine of the geographical regions were reporting elevated outpatient visits for people experiencing flu symptoms. The number of people experiencing flu-like illnesses is reported to be high in 29 states and New York City.
The number of positive flu cases for 2012 is higher than those reported during the same week in 2011.

This map represents the reported influenza-like illness levels by state for the week ending on Dec. 29. The white colored states had too little information to be measured, green colored states have the lowest levels of influenza reported and the red colored states represent the highest levels. The map is courtesy of the CDC.

The CDC began recording pediatric deaths in 2004, following 153 pediatric deaths reported during the 2003-04 influenza season.
At the time of this report, 18 pediatric deaths have been attributed to influenza. The total pediatric deaths attributed to influenza last season were 34.
The CDC closely monitors influenza cases nationwide from October through mid-May. However, there is no official period of time determined to be the flu season.
Cases of influenza in the U.S. typically peak during January.
The best way to prevent infection by influenza is to get a flu shot.