Based on their findings, they estimated that for every 100,000 people living in the U.S. there were 32 cases of invasive MRSA in 2005.
An estimated 128 cases occurred for every 100,000 people aged 65 and over.
Infectious disease specialist Elizabeth A. Bancroft, MD, tells WebMD that as the U.S. population ages, rates of invasive MRSA are likely to climb even higher unless the nation's hospitals, nursing homes, and other high-risk health care settings take steps to limit its spread.
"Hand washing is one of the most important ways to decrease the spread of MRSA in hospitals, but hand washing compliance rates [among health care professionals] are rarely 100%," she says. "One thing a patient can do to reduce their risk is make sure everyone they come into contact with washes their hands or uses an alcohol hand rub."
The vast majority of MRSA infections occurring outside of the health care setting are noninvasive. These community-acquired infections generally take the form of skin infections and are more easily treated.
In the CDC study, people with what appeared to be community-acquired invasive MRSA infections had better outcomes than those with health care acquired infections, Klevens tells WebMD.
"Most severe infections are health care related, but that is not to trivialize community-associated infections," she says. "The vast majority of community infections are noninvasive, but our study shows that invasive MRSA disease does occur in people without established health care risk factors."