Hospital-acquired infection discovered in community

By Sherri McGinnis
Medical Center Public Affairs

Drug-resistant Staphylococcus aureus, a predominantly hospital-acquired Staph infection, has been identified in children outside of the hospital setting who have no apparent risk factors, according to a study by researchers at the University of Chicago Children's Hospital. The study was published in the Feb. 25 issue of the Journal of the American Medical Association.

"This is the first published study to indicate that methicillin-resistant Staphylococcus aureus [MRSA] infections are now found in non-chronically ill children outside of the hospital environment," said Robert Daum, Professor in Pediatrics and a co-author of the study. "This suggests a significant change in the way the organism is spread among the population. We need additional research focused on the mechanisms of community-acquired infections."

Reviewing medical records of children hospitalized for MRSA at the University of Chicago Children's Hospital, the researchers compared cases from two time periods, August 1988 to July 1990, and August 1993 to July 1995. The researchers found that among the children with community-acquired MRSA, only one out of eight cases lacked an identified risk factor in the first two-year period, compared to 25 out of 35 cases in the second two-year period.

Risk factors for MRSA infection include previous hospitalization or frequent antibiotic use, history of intubation, an underlying chronic disorder, presence of a catheter, history of any surgical procedure, or household contact with a person who has identified risk factors.

The researchers also found interesting differences between hospital-acquired and community-acquired MRSA infections. Although hospital-acquired MRSA infections appeared to be drug resistant to many antibiotics, community-acquired MRSA infections were susceptible to drugs other than methicillin. However, the researchers predict this may change over time.

"This study should make physicians aware that community-acquired MRSA infections exist, but it should not change their current practice for treating the infection," said Betsy Herold, Assistant Professor in Pediatrics and lead author of the study. "First-line antibiotics are still the best initial therapy for these presumptive Staphylococcus aureus infections."

The researchers conclude that the results of this study underscore the need for further investigation. They have already begun a study to evaluate the transmission of these organisms by identifying children colonized with Staphylococcus aureus who do not have symptoms of illness.