Prevalence of MRSA in US Healthcare Facilities

Jarvis, W.R., Schlosser, J., Chinn, R.Y., Tweeten, S.M, & Jackson, M. National prevalence of methicillin-resistant Staphylococcus aureus in inpatients at US health care facilities. Am J Infect Control, 2006; 35(10), 631-637.

This key article describes the prevalence of MRSA infection or colonization in US healthcare facilities. This was a cross-sectional study that evaluated prevalence in every state. The overall prevalence of infection and/or colonization was reported to be 46.3 per 1,000 inpatients. This prevalence is higher than previous findings.

The highest rates of infection were found in Hawaii, New York, Maine, and South Carolina. The lowest rates of infection were found in Western states including Idaho, Montana, North Dakota, Wyoming, South Dakota, Utah, and New Mexico. MRSA infection sites included skin and soft tissue (28%), pulmonary (17%), bloodstream (13%), urinary tract (10%), and surgical site (8%). Of the MRSA isolates, 70% were consistent with hospital-acquired MRSA as opposed to community-acquired MRSA.

Patients in the study were not routinely tested for MRSA colonization and, therefore, prevalence may be higher than reported. Furthermore, due to the cross-sectional design, there was the potential for prevalent case bias which occurs when diseases that last for longer durations are found to be more prevalent by this method of assessment.