Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
University of Rochester Medical Center, New York.
Clin Infect Dis. 2020 Jan 1;70(1):19-25. doi: 10.1093/cid/ciz158.
Previous reports suggested that US methicillin-resistant Staphylococcus aureus (MRSA) strain epidemiology has changed since the rise of USA300 MRSA. We describe invasive MRSA trends by strain type.
Data came from 5 Centers for Disease Control and Prevention Emerging Infections Program sites conducting population-based surveillance and collecting isolates for invasive MRSA (ie, from normally sterile body sites), 2005-2013. MRSA bloodstream infection (BSI) incidence per 100 000 population was stratified by strain type and epidemiologic classification of healthcare exposures. Invasive USA100 vs USA300 case characteristics from 2013 were compared through logistic regression.
From 2005 to 2013, USA100 incidence decreased most notably for hospital-onset (6.1 vs 0.9/100 000 persons, P < .0001) and healthcare-associated, community-onset (10.7 vs 4.9/100 000 persons, P < .0001) BSIs. USA300 incidence for hospital-onset BSIs also decreased (1.5 vs 0.6/100 000 persons, P < .0001). However, USA300 incidence did not significantly change for healthcare-associated, community-onset (3.9 vs 3.3/100 000 persons, P = .05) or community-associated BSIs (2.5 vs 2.4/100 000 persons, P = .19). Invasive MRSA was less likely to be USA300 in patients who were older (adjusted odds ratio [aOR], 0.97 per year [95% confidence interval {CI}, .96-.98]), previously hospitalized (aOR, 0.36 [95% CI, .24-.54]), or had central lines (aOR, 0.44 [95% CI, .27-.74]), and associated with USA300 in people who inject drugs (aOR, 4.58 [95% CI, 1.16-17.95]).
Most of the decline in MRSA BSIs was from decreases in USA100 BSI incidence. Prevention of USA300 MRSA BSIs in the community will be needed to further reduce burden from MRSA BSIs.
此前的报告表明，自 USA300 型耐甲氧西林金黄色葡萄球菌（MRSA）出现以来，美国的 MRSA 菌株流行病学发生了变化。我们描述了不同菌株类型的侵袭性 MRSA 趋势。
数据来自美国疾病控制与预防中心五个开展人群为基础的监测并收集侵袭性 MRSA （即来自正常无菌体部位的分离株）的新兴感染项目地点，时间为 2005 年至 2013 年。按菌株类型和医疗保健暴露的流行病学分类对每 10 万人中侵袭性 MRSA 血流感染（BSI）的发病率进行分层。通过逻辑回归比较 2013 年侵袭性 USA100 与 USA300 病例特征。
2005 年至 2013 年，医院获得性（6.1 比 0.9/100000 人，P <.0001）和医疗保健相关性、社区获得性（10.7 比 4.9/100000 人，P <.0001）BSI 中 USA100 的发病率显著下降。医院获得性 BSI 中 USA300 的发病率也有所下降（1.5 比 0.6/100000 人，P <.0001）。然而，医疗保健相关性、社区获得性（3.9 比 3.3/100000 人，P =.05）或社区相关性（2.5 比 2.4/100000 人，P =.19）BSI 中 USA300 的发病率没有显著变化。年龄较大（校正优势比 [aOR]，每年 0.97 [95%置信区间 {CI}，0.96-0.98]）、既往住院（aOR，0.36 [95% CI，0.24-0.54]）或存在中央导管（aOR，0.44 [95% CI，0.27-0.74]）的侵袭性 MRSA 患者更不可能是 USA300 型，而注射毒品的患者更有可能是 USA300 型（aOR，4.58 [95% CI，1.16-17.95]）。
大多数 MRSA BSI 的减少归因于 USA100 BSI 发病率的下降。需要预防社区获得性 USA300 型 MRSA BSI，以进一步降低 MRSA BSI 的负担。
