Risk factors among pediatric patients affect treatment for MRSA

DALLAS — Patient risk factors affect treatment when it comes to methicillin-resistant Staphylococcus aureus infections in children, according to study results presented here.

Researchers found differences in clinical characteristics, treatment regimens and outcomes between high-risk patients compared with patients without risk factors, which may have implications when treating children with MRSA, according to a poster presentation at the Annual Scientific Meeting of the Society for Healthcare Epidemiology of America.

“Differences in treatment regimens may reflect more intense therapy associated with high-risk patients or more hospital-acquired MRSA infections,” according to Laura A. Puzniak, PhD, MPH,of Pfizer in New York.

In the single-site study, Puzniak and colleagues aimed to compare the clinical characteristics, treatment differences and outcomes between high-risk and low-risk pediatric patients with MRSA infections.

High-risk patients — defined as those with a previous MRSA infection, diabetes, renal failure, cardiovascular disease, genetic disorder and immunosuppression — who also had an MRSA-positive culture were compared with patients at lower risk. Low-risk patients were defined as those without existing co-morbidities and previous MRSA admissions. The researchers compared patients and clinical characteristics for pneumonia and skin infections.

From Jan. 1, 2004, to May 1, 2009, the researchers collected clinical characteristics and treatment regimens from patients hospitalized with confirmed MRSA cultures at the Children’s Hospital at St. Francis Medical Center in Tulsa, Okla.

Results of the study revealed 225 patients with MRSA infections, 57 of whom had pneumonia, 155 had skin and skin structure infections (SSSI), and 40 had other types of infections. Of the patients with pneumonia, 37 were high-risk patients and 20 were low-risk patients; of the skin infections, 44 were high risk and 111 were low risk; in addition, 32 high-risk and eight low-risk patients accounted for the other infections. Thus, patients with MRSA pneumonia were predominantly high risk, whereas MRSA SSSI patients were predominantly low risk.

In the pneumonia cohort, compared with patients with lower-risk factors, high-risk patients were older (5.2 vs. 2.3 years; P=.05), more often Caucasian, had a longer length of stay (18.3 vs. 12.4 days), received multiple antibiotics, had a higher mortality rate, and a lower platelet count on admission (369 vs. 523; P<.05). In addition, 83% of the high-risk patients received vancomycin compared with 10% of the low-risk patients (P<.01), whereas low-risk patients were more likely to receive bactrim than high-risk patients (45% vs. 19%; P<.05). Low-risk patients had more consults, were discharged more often with antibiotics, had a higher rate of empyema and better baseline laboratory values than high-risk patients.

In the SSSI cohort, both groups had similar age, gender and baseline laboratory values, but significant difference in race (61% vs. 37% Caucasian; P<.01). High-risk patients had a longer length of stay (8.4 vs. 3.6 days; P<.01), had more consults (1.86 vs. 1.03; P=.01) and more home health referrals (18% vs. 4%; P=.01) than low-risk patients.

Compared with 5% of low-risk patients (P<.01), 82% of the high-risk patients received vancomycin, and high-risk patients were more likely to receive cefepime than low-risk patients (16% vs. 5%; P=.03). Only 14% of low-risk patients received discharge laboratory values, and they had more pediatric ICU consults and received more discharge antibiotics, specifically trimethoprim-sulfamethoxazole and clindamycin compared with high-risk patients. In addition, the researchers said there were no inpatient deaths in either of the SSSI groups.

Overall, genetic disorder (32%) was the most common characteristic for entry into the high-risk group, followed by neurologic disorder (31%) and cardiovascular disease (30%). Further, there were 27 patients with multiple sites of infections — 67% of high-risk patients and 33% of low-risk patients.

“This single-site study showed differences in resource utilization, treatment regimens and outcomes in patients with co-morbidities, previous hospitalizations and previous MRSA infections compared to those without,” according to Puzniak. “Evaluating these characteristics may assist clinicians in the identification and management of MRSA infections in the pediatric patient population.” – by Ashley DeNyse

Disclosure: Dr. Puzniak reports that the study was sponsored in part by a grant from Pfizer and an intramural grant from Oklahoma State University Center for Health Sciences.

For more information:

Puzniak L. #490. Presented at: SHEA 2011 Annual Scientific Meeting; April 1-4, 2011; Dallas.

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