DALLAS -- June 30, 2008 -- The emergence of methicillin-resistant Staphylococcus aureus (MRSA) as a major pathogen has led to more complications and longer hospital stays for children with acute bone infections, UT Southwestern Medical Center researchers report.
"This study shows the transition from the normal S aureus to the methicillin-resistant one that everybody calls the superbug," said senior author of the study Octavio Ramilo, MD, UT Southwestern Medical Center, Dallas, Texas. "What's important about this is not only that MRSA infections are harder to treat because they are more resistant to the traditional antibiotics, but they are also more aggressive and cause more severe disease manifestations. This is reflected very clearly in this study."
Researchers culled the medical records of 290 children admitted to Children's Medical Center, Dallas, Texas, between January 1999 and December 2003 with acute osteomyelitis. The median age of those surveyed was 6 years and most children were white or Hispanic. Symptoms such as localised pain, fever, tenderness, swelling, and limping were observed in more than half the patients.
The researchers divided the patient population into 2 groups according to study periods to verify whether MRSA infections were becoming more common and more severe. They then compared patients with MRSA osteomyelitis to children with non-MRSA osteomyelitis, which included those with methicillin-sensitive S aureus (MSSA) infections. They also reviewed outcomes, including duration of fever, the type and length of antibiotic therapy, and the frequency of complications, such as muscle inflammation, bone abscesses, disseminated disease, and the need to drain the bone surgically.
Though the clinical characteristics of the participants didn't change significantly between the first and second study periods, children who were treated in the latter period for osteomyelitis fared far worse, possibly because MRSA infections were more common, Dr. Ramilo said.
In the second study period, bone abscesses were observed in 69% of the patients with MRSA osteomyelitis versus 26% among those with MSSA infections. Children admitted with MRSA osteomyelitis during the second study period also spent an average of 42 days on antibiotics, almost 2 weeks longer than those diagnosed with MSSA.
Dr. Ramilo said the number of children who needed surgery was also striking. Seventy-eight percent of the patients with MRSA required surgery, compared with 49% of those with MSSA.
He said the findings underscore the need for multicentre studies to identify the best antibiotic regimens as well as the best surgical approaches for complications.
"For now, the key is to treat the infection as early as possible with appropriate antibiotics and if needed, surgical drainage of the bone," Dr. Ramilo concluded.
SOURCE: UT Southwestern Medical Center
E-Mail this DGNews to a colleague
