Liu Catherine, Graber Christopher J, Karr Michael, Diep Binh An, Basuino Li, Schwartz Brian S, Enright Mark C, O'Hanlon Simon J, Thomas Jonathon C, Perdreau-Remington Francoise, Gordon Shelley, Gunthorpe Helen, Jacobs Richard, Jensen Peter, Leoung Gifford, Rumack James S, Chambers Henry F
Div. of Infectious Diseases, University of California, San Francisco, 513 Parnassus Ave., S-380, Box 0654, San Francisco, CA 94143, USA.
Clin Infect Dis. 2008 Jun 1;46(11):1637-46. doi: 10.1086/587893.
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.
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.
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.
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.
耐甲氧西林金黄色葡萄球菌（MRSA）感染已成为社区和医院中的一个主要公共卫生问题。很少有研究对整个人口中致病菌株的发病率和克隆组成进行特征描述。我们的目标是对加利福尼亚州旧金山的MRSA疾病进行基于人群的临床和分子流行病学调查。
在12个月期间（2004 - 2005年），我们在旧金山地区的9家医疗中心前瞻性地收集了3985株MRSA分离株以及相关的临床和人口统计学信息。从这些分离株中随机抽取801株进行分子分析。
旧金山居民中社区获得性MRSA疾病的年发病率为每10万人316例，而医院获得性疾病的发病率为每10万人31例。年龄在35 - 44岁、男性和黑人的社区获得性疾病发病率最高。USA300 MRSA克隆株在社区获得性疾病中每10万人有234例，在医院获得性疾病中每10万人有15例，分别占所有MRSA疾病病例的约78.5%和43.4%。社区获得性USA300 MRSA疾病患者与非USA300 MRSA疾病患者相比，更可能为男性、年龄较轻且患有皮肤和软组织感染。USA300菌株通常对多种抗生素更敏感，不过与非USA300菌株相比，在社区获得性（P = .008）和医院获得性（P = .03）的USA300菌株中均观察到对四环素的敏感性降低。
旧金山社区获得性MRSA疾病的年发病率很高，超过了医院获得性疾病。USA300是社区和医院中的主要克隆株。USA300从社区传播到医院环境中，模糊了其作为社区相关病原体的区别。
