A recent study indicates that despite a low prevalence of MRSA and Staphylococcus aureus, nearly 30% of patients hospitalized with community-acquired pneumonia received treatment regimens containing either vancomycin or linezolid.
“During the past decade, several reports described the emergence of community-acquired pneumonia (CAP) caused by [S. aureus], and specifically [MRSA], as a cause of severe pneumonia leading to critical illness and death,” Wesley H. Self, MD, associate professor at Vanderbilt University School of Medicine, and colleagues wrote. “Although the prevalence of MRSA among acute cases of CAP has not been fully elucidated, recent studies suggest MRSA is an uncommon cause of CAP in the United States.”
Although the Infectious Diseases Society of America and the American Thoracic Society currently do not recommend routine empirical anti-MRSA antibiotics for CAP, recently published data suggest clinicians often use vancomycin or linezolid due to concerns of potential MRSA pneumonia, the researchers said.
Researchers analyzed 2,259 CAP patients from the CDC’s Etiology of Pneumonia in the Community multicenter study. Of these, 0.7% were diagnosed with MRSA, 1% with methicillin-susceptible S. aureus (MSSA) and 5.1% with S. pneumoniae.
Empirical use of MRSA antibiotics exceeded incidence of the infection, the researchers wrote, with 29.8% of all patients given vancomycin or linezolid within their first 3 days of admission. Nearly all patients with MRSA CAP received these antibiotics, compared with just less than half of those with pneumococcal CAP.