The number of elderly hospitalized for pneumonia has increased significantly in recent years, according to a report from the U. S. Centers for Disease Control.

Hospital stays for people aged 65 to 84 suffering from pneumonia jumped 20% between the late 1980s and 2002, the CDC report said.  Researchers found that one in 83 people aged 65 to 74 is hospitalized each year because of pneumonia. The incidence rises to 1 in 38 people in the 74 to 84 age bracket, and 1 in 20 for those 85 and older.

Researchers cite the increasing number of elderly with chronic medical conditions as a contributing factor in the rise in hospitalizations for the illness, which is caused by viruses, bacteria and other organisms that produce inflammation. About 80% of older adults hospitalized for pneumonia also grapple with at least one other chronic disease, according to the study.