Every additional day of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in hospitalized children was associated with a 50% increased risk of developing a complication, reported Rana F. Hamdy, MD, of Children’s National Health System, Washington, and her associates.
That was one of the findings of a study performed to determine the epidemiology, clinical outcomes, and risk factors for treatment failure in pediatric MRSA bacteremia. It took place in three hospitals, one each in Philadelphia, Baltimore, and Salt Lake City.
In the 174 hospitalized children (all were younger than 19 years) with MRSA bacteremia, 78% of infections were community onset. The primary sources of infection were osteomyelitis (31%), catheter-related bloodstream infections (22%), and skin and soft tissue infections (16%); endocarditis occurred in only 2%. The median duration of MRSA bacteremia was 2 days; only 10% lasted beyond 7 days.
“This finding is in contrast to the epidemiology of MRSA bacteremia in adults, in whom bacteremia is more frequently attributed to catheter-related infections (31%-36%), endovascular infections (13%-15%), or an unknown source (15%-20%), and the durations of MRSA bacteremia are typically more prolonged (median duration of bacteremia is 8-9 days),” Dr. Hamdy and her associates wrote.
“Differences in the epidemiology of MRSA bacteremia between children and adults emphasize the need for dedicated pediatric studies to better understand the clinical characteristics and outcomes specific to children,” the researchers noted.
Musculoskeletal infections and endovascular infections were linked with treatment failure, possibly reflecting “the relatively higher burden of bacteria and/or decreased drug penetration into bone and endovascular infection sites,” the investigators said. Catheter-related infections were tied to reduced odds of treatment failure, “these episodes being localized to the catheter and therefore potentially less-invasive S. aureus infections.”
Mortality among these children with MRSA bacteremia was low, at 2%, but “nearly one-quarter of all patients experienced complications,” the study authors said (Pediatrics. 2017 May 5. doi: 10.1542/peds.2017-0183).
There was progression of infection in 7% of cases, and hematogenous complications or sequelae occurred in 23%. Twenty percent of children developed septic emboli or another metastatic focus of infection.
“This association between the duration of bacteremia and the development of complications has been previously reported among adults with S. aureus bacteremia,” Dr. Hamdy noted, “and provides important epidemiologic data that could inform decisions relating to the timing of additional imaging, such as echocardiograms, to identify metastatic foci.”
The children were treated with vancomycin, and some received additional anti-MRSA antibiotics. “Vancomycin trough concentrations or [minimum inhibitory concentrations] were not associated with treatment failure,” the investigators said. “Future studies to determine the appropriate vancomycin dose, duration, and approach to therapeutic drug monitoring are warranted to optimize patient outcomes.”
The National Institutes of Health funded the study. Dr. Hamdy and her associates disclosed they have no relevant financial relationships.