Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, 49 Jesse Hill Jr. Dr. Atlanta, GA 30303, USA.
J Infect. 2010 Nov;61(5):372-81. doi: 10.1016/j.jinf.2010.09.021. Epub 2010 Sep 22.
To evaluate the association of USA300 genotype with outcomes in persons with MRSA bacteremia and examine the epidemiology of MRSA bacteremia over time.
Population-based surveillance for MRSA bacteremia was performed in 8-county Atlanta from 2005 to 2008. Cases of MRSA bacteremia were classified as healthcare-associated hospital-onset (HAHO), healthcare-associated community-onset (HACO), or community-associated (CA) disease. A survival analysis was performed on a nested cohort of cases with isolates characterized by pulse field gel electrophoresis (PFGE).
4344 MRSA bacteremia cases were identified; 2579 (59.4%) HACO, 1144 (26.3%) HAHO; and 601 (13.8%) CA. Overall incidence rates of MRSA bacteremia declined from 33.9/100,000 in 2005-24.8/100,000 in 2008. Rates were highest in persons ≥ 65 years, blacks, males, and persons with AIDS. In multivariate analysis of 1104 cases, USA300 genotype was associated with increased in-hospital mortality (HR 1.63, 95% CI 1.19-2.23). USA300 strains were also associated with increased mortality when compared to USA100 strains (HR 1.79, 95% CI 1.24-2.58).
MRSA bacteremia incidence declined over 4 years but CA disease rates remained stable. Persons with HIV, the elderly, and blacks were disproportionately affected. Bacteremia due to USA300 MRSA strains was associated with increased mortality, suggesting that USA300 strains may be more virulent.
评估 USA300 基因型与耐甲氧西林金黄色葡萄球菌菌血症患者结局的相关性，并研究耐甲氧西林金黄色葡萄球菌菌血症的流行病学随时间的变化情况。
2005 年至 2008 年，在亚特兰大的 8 个县进行了耐甲氧西林金黄色葡萄球菌菌血症的基于人群的监测。耐甲氧西林金黄色葡萄球菌菌血症病例分为与医疗保健相关的医院获得性发病（HAHO）、与医疗保健相关的社区获得性发病（HACO）或社区获得性（CA）疾病。对经脉冲场凝胶电泳（PFGE）鉴定的分离株具有嵌套队列的病例进行生存分析。
共确定 4344 例耐甲氧西林金黄色葡萄球菌菌血症病例；2579 例（59.4%）为 HACO、1144 例（26.3%）为 HAHO、601 例（13.8%）为 CA。耐甲氧西林金黄色葡萄球菌菌血症的总发病率从 2005-2004 年的 33.9/100000 下降到 2008 年的 24.8/100000。发病率在年龄≥65 岁、黑人、男性和艾滋病患者中最高。在对 1104 例病例的多变量分析中，USA300 基因型与住院死亡率增加相关（HR 1.63，95%CI 1.19-2.23）。与 USA100 株相比，USA300 株也与死亡率增加相关（HR 1.79，95%CI 1.24-2.58）。
耐甲氧西林金黄色葡萄球菌菌血症的发病率在 4 年内下降，但 CA 疾病的发病率保持稳定。艾滋病毒感染者、老年人和黑人受影响的比例不成比例。由 USA300 耐甲氧西林金黄色葡萄球菌株引起的菌血症与死亡率增加相关，这表明 USA300 株可能更具毒性。
