The Centers for Disease Control and Prevention (CDC) recently published a study detailing the cause of pneumonia hospitalizations for adults in the U.S.
Compared to bacteria, viruses are more frequently the cause of adult pneumonia hospitalizations, but even though diagnostic tests are accurate, neither bacteria nor viruses are included as the main causes.
The study, which lasted over two years, included two hospitals in Nashville and three in Chicago. The data showed the burden of community-acquired pneumonia hospitalizations throughout U.S. adults.
“Pneumonia is a leading cause of hospitalization and death among adults in the United States and in 2011 the medical costs exceeded $10 billion,” Tom Frieden, M.D., M.P.H., director of the CDC, said. “Most of the time doctors are unable to pinpoint a specific cause of pneumonia. We urgently need more sensitive, rapid tests to identify causes of pneumonia and to promote better treatment.”
Twenty-seven percent of
the 2,488 adults enrolled in the study tested positively for viruses,
and 14 percent of the study patients tested for bacteria. The most
commonly found virus in pneumonia patients was human rhinovirus (HRV).
The second most common was influenza, which caused two times as many
pneumonia hospitalization than other viruses, excepting HRV, for adults
80 and older.
“The frequency with which respiratory viruses were detected in adults hospitalized with pneumonia was higher than previously documented," Dr. Seema Jain, lead author of the paper and medical epidemiologist in CDC's Influenza Division, said. "This may be due to improved molecular diagnostics for viruses and also to the benefits of bacterial vaccines. However, what’s most remarkable is that despite how hard we looked for pathogens, no discernible pathogen was detected in 62 percent of adults hospitalized with pneumonia in the EPIC study. This illustrates the need for more sensitive diagnostic methods that can both help guide treatment at the individual level as well as inform public health policy for adult pneumonia at a population level.”
Further details are available in the New England Journal of Medicine.