Figures on flu deaths are misleading, usually too high, CDC says

[tetano]

Most reports about seasonal influenza cite an average of about 36,000 deaths in a typical season, but that number is both too high and grossly misleading, the Centers for Disease Control and Prevention said Thursday.

The actual average is a little over 23,000, the agency reported in its Morbidity and Mortality Weekly Report. But even that figure is misleading, the report added, because the actual numbers have ranged from as low as 3,300 deaths up to nearly 50,000 over the last 30 years. The period covered in the analysis goes up to 2007 and does not include last year's H1N1 influenza pandemic.

"There is no average flu season," lead author Dr. David Shay of the CDC's National Center for Immunization and Respiratory Diseases said in a news conference. The number of deaths "can vary dramatically" from year to year, Shay said.


http://www.latimes.com/news/science...ies+(Los+Angeles+Times+-+Most+Viewed+Stories)

 

[Giuseppe]

Re: Figures on flu deaths are misleading, usually too high, CDC says

See also on FT the MMWR article: http://www.flutrackers.com/forum/showthread.php?t=151627

 

[tetano]

Re: Figures on flu deaths are misleading, usually too high, CDC says

Estimating Seasonal Influenza-Associated Deaths in the United States: CDC Study Confirms Variability of Flu


What are seasonal influenza-related deaths?

Seasonal influenza-related deaths are deaths that occur in people for whom seasonal influenza infection was likely a contributor to the cause of death, but not necessarily the primary cause of death.
Does CDC know the exact number of people who die from seasonal flu each year?

CDC does not know exactly how many people die from seasonal flu each year. There are several reasons for this. First, states are not required to report individual seasonal flu cases or deaths of people older than 18 years of age to CDC. Second, seasonal influenza is infrequently listed on death certificates of people who die from flu-related complications. Third, many seasonal flu-related deaths occur one or two weeks after a person?s initial infection, either because the person may develop a secondary bacterial co-infection (such as bacterial pneumonia) or because seasonal influenza can aggravate an existing chronic illness (such as congestive heart failure or chronic obstructive pulmonary disease). Also, most people who die from seasonal flu-related complications are not tested for flu, or they seek medical care later in their illness when seasonal influenza can no longer be detected from respiratory samples. Sensitive influenza tests are only likely to detect influenza if performed within a week after onset of illness. In addition, some commonly used tests to diagnose influenza in clinical settings are not highly sensitive and can provide false negative results (i.e. the misdiagnose flu illness as not being flu.) For these reasons, many flu-related deaths may not be recorded on death certificates. These are some of the reasons that CDC and other public health agencies in the United States and other countries use statistical models to estimate the annual number of seasonal flu-related deaths. (Flu deaths in children were made a nationally notifiable condition in 2004, and since then, states have been required to report flu-related child deaths in the United States through the Influenza Associated Pediatric Mortality Surveillance System).

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http://www.cdc.gov/flu/about/disease/us_flu-related_deaths.htm