Not Too Bad a Year for the Flu

Flu season was mild with fewer deaths and hospitalizations

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) If you were laid up with the flu this year, you didn't have as much company. This past flu season was a mild one, according to the Centers for Disease Control and Prevention.

The 2011-2012 flu season saw a lower rate of outpatient visits for flu-like illnesses, a lower rate of hospitalizations for the flu and fewer deaths resulting from influenza and pneumonia.

"Get your flu shot every year."

The season ran from October 2, 2011 to May 19, 2012, and peaked in mid-March. A total of 22,417 cases tested positive for flu by the World Health Organization and the National Respiratory and Enteric Virus Surveillance System laboratories.

A total of 26 children died of the flu (confirmed by laboratory tests), and their average age was 7 years old. This was far lower than the 2010-11 season in which 122 children died of the flu and the 348 children who died of it in the 2009 pandemic.

Three children who died were under 6 months, and the deaths were about equally attributed to the three main strains of the virus.

There are two basic types of flu virus - influenza A and influenza B - and then subcategories within these, including two strains of influenza A. The vast majority of the cases this year were influenza A, with 86 percent of the positive tested specimens. The other 3,132 specimens were influenza B.

Of the influenza A virus subtypes that were identified (78 percent of all of them), 74 percent were H3N2 and 3,966 were pH1N1.

Researchers use this data and other historical flu data to help determine which influenza strains will be included in the annual flu vaccine.

The CDC also reported on whether the various strains of the flu virus were resistant to oseltamivir (Tamiflu) and zanamivir (Relenza), two drugs used to treat the flu.

Of all the influenza A and B strains tested, only 16 of the influenza A pH1N1 viruses (1.4 percent) were resistant to Tamiflu, and the other strains were all sensitive to both medications.

The CDC report included commentary reminding all people over 6 months old to get the flu vaccine each year, ideally in the fall before the season starts.

The report appeared in the CDC's June 8 issue of the Morbidity and Mortality Weekly Report.

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Review Date: 
June 6, 2012
Last Updated:
October 19, 2012