BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infections have become a major public health problem in both the community and hospitals. Few studies have characterized the incidence and clonal composition of disease-causing strains in an entire population. Our objective was to perform a population-based survey of the clinical and molecular epidemiology of MRSA disease in San Francisco, California. METHODS: We prospectively collected 3985 MRSA isolates and associated clinical and demographic information over a 12-month period (2004-2005) at 9 San Francisco-area medical centers. A random sample of 801 isolates was selected for molecular analysis. RESULTS: The annual incidence of community-onset MRSA disease among San Francisco residents was 316 cases per 100,000 population, compared with 31 cases per 100,000 population for hospital-onset disease. Persons who were aged 35-44 years, were men, and were black had the highest incidence of community-onset disease. The USA300 MRSA clone accounted for 234 cases of community-onset disease and 15 cases of hospital-onset disease per 100,000 population, constituting an estimated 78.5% and 43.4% of all cases of MRSA disease, respectively. Patients with community-onset USA300 MRSA versus non-USA300 MRSA disease were more likely to be male, be of younger age, and have skin and soft-tissue infections. USA300 strains were generally more susceptible to multiple antibiotics, although decreased susceptibility to tetracycline was observed in both community-onset (P = .008) and hospital-onset (P = .03) USA300 compared to non-USA300 strains. CONCLUSIONS: The annual incidence of community-onset MRSA disease in San Francisco is substantial, surpassing that of hospital-onset disease. USA300 is the predominant clone in both the community and hospitals. The dissemination of USA300 from the community into the hospital setting has blurred its distinction as a community-associated pathogen.
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infections have become a major public health problem in both the community and hospitals. Few studies have characterized the incidence and clonal composition of disease-causing strains in an entire population. Our objective was to perform a population-based survey of the clinical and molecular epidemiology of MRSA disease in San Francisco, California. METHODS: We prospectively collected 3985 MRSA isolates and associated clinical and demographic information over a 12-month period (2004-2005) at 9 San Francisco-area medical centers. A random sample of 801 isolates was selected for molecular analysis. RESULTS: The annual incidence of community-onset MRSA disease among San Francisco residents was 316 cases per 100,000 population, compared with 31 cases per 100,000 population for hospital-onset disease. Persons who were aged 35-44 years, were men, and were black had the highest incidence of community-onset disease. The USA300 MRSA clone accounted for 234 cases of community-onset disease and 15 cases of hospital-onset disease per 100,000 population, constituting an estimated 78.5% and 43.4% of all cases of MRSA disease, respectively. Patients with community-onset USA300 MRSA versus non-USA300 MRSA disease were more likely to be male, be of younger age, and have skin and soft-tissue infections. USA300 strains were generally more susceptible to multiple antibiotics, although decreased susceptibility to tetracycline was observed in both community-onset (P = .008) and hospital-onset (P = .03) USA300 compared to non-USA300 strains. CONCLUSIONS: The annual incidence of community-onset MRSA disease in San Francisco is substantial, surpassing that of hospital-onset disease. USA300 is the predominant clone in both the community and hospitals. The dissemination of USA300 from the community into the hospital setting has blurred its distinction as a community-associated pathogen.
Authors: Andrew E Simor; Lisa Louie; Christine Watt; Denise Gravel; Michael R Mulvey; Jennifer Campbell; Allison McGeer; Elizabeth Bryce; Mark Loeb; Anne Matlow Journal: Antimicrob Agents Chemother Date: 2010-03-15 Impact factor: 5.191
Authors: M Ender; S Burger; A Sokoli; R Zbinden; B Berger-Bächi; R Heusser; M M Senn; N McCallum Journal: Eur J Clin Microbiol Infect Dis Date: 2008-11-26 Impact factor: 3.267
Authors: Michael W Ellis; Matthew E Griffith; James H Jorgensen; Duane R Hospenthal; Katrin Mende; Jan E Patterson Journal: J Clin Microbiol Date: 2009-02-11 Impact factor: 5.948
Authors: Joan A Casey; Frank C Curriero; Sara E Cosgrove; Keeve E Nachman; Brian S Schwartz Journal: JAMA Intern Med Date: 2013-11-25 Impact factor: 21.873