When combined, influenza and pneumonia are the leading cause of death from infectious diseases in the U.S., according to a study in BMC Infectious Diseases. And many people (29 percent) who wind up in the hospital from the flu also have pneumonia.
Researchers used the Emerging Infections Program to identify adults hospitalized with the flu from October 2005 to April 2008 who also had a chest radiograph performed.
They found that 29 percent of those adults had pneumonia as well as the flu. Researchers also found the following factors were associated with such patients:
- Being 75 years old or older
- Being white
- Living in a nursing home
- Having chronic lung disease
- Being immunosuppressed
- Having asthma
The presence of pneumonia as well as the flu was associated with admission to the intensive care unit and death, according to the study.
"Pneumonia is common among adults hospitalized with influenza and should be evaluated and treated promptly," the study concludes.