Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada.
BMC Infect Dis. 2012 Apr 9;12:85. doi: 10.1186/1471-2334-12-85.
Bloodstream infections (BSI) have been traditionally classified as either community acquired (CA) or hospital acquired (HA) in origin. However, a third category of healthcare-associated (HCA) community onset disease has been increasingly recognized. The objective of this study was to compare and contrast characteristics of HCA-BSI with CA-BSI and HA-BSI.
All first episodes of BSI occurring among adults admitted to hospitals in a large health region in Canada during 2000-2007 were identified from regional databases. Cases were classified using a series of validated algorithms into one of HA-BSI, HCA-BSI, or CA-BSI and compared on a number of epidemiologic, microbiologic, and outcome characteristics.
A total of 7,712 patients were included; 2,132 (28%) had HA-BSI, 2,492 (32%) HCA-BSI, and 3,088 (40%) had CA-BSI. Patients with CA-BSI were significantly younger and less likely to have co-morbid medical illnesses than patients with HCA-BSI or HA-BSI (p < 0.001). The proportion of cases in males was higher for HA-BSI (60%; p < 0.001 vs. others) as compared to HCA-BSI or CA-BSI (52% and 54%; p = 0.13). The proportion of cases that had a poly-microbial etiology was significantly lower for CA-BSI (5.5%; p < 0.001) compared to both HA and HCA (8.6 vs. 8.3%). The median length of stay following BSI diagnosis 15 days for HA, 9 days for HCA, and 8 days for CA (p < 0.001). Overall the most common species causing bloodstream infection were Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. The distribution and relative rank of importance of these species varied according to classification of acquisition. Twenty eight day all cause case-fatality rates were 26%, 19%, and 10% for HA-BSI, HCA-BSI, and CA-BSI, respectively (p < 0.001).
Healthcare-associated community onset infections are distinctly different from CA and HA infections based on a number of epidemiologic, microbiologic, and outcome characteristics. This study adds further support for the classification of community onset BSI into separate CA and HCA categories.
血流感染（BSI）传统上分为社区获得性（CA）或医院获得性（HA）。然而，越来越多的人认识到第三类与医疗保健相关的（HCA）社区发病疾病。本研究的目的是比较和对比 HCA-BSI 与 CA-BSI 和 HA-BSI 的特征。
从加拿大一个大卫生区的医院入院成人中确定了 2000-2007 年所有首次发生的 BSI 病例。使用一系列经过验证的算法将病例分类为 HA-BSI、HCA-BSI 或 CA-BSI，并在许多流行病学、微生物学和结局特征上进行比较。
共纳入 7712 例患者；2132 例（28%）为 HA-BSI，2492 例（32%）为 HCA-BSI，3088 例（40%）为 CA-BSI。与 HCA-BSI 或 HA-BSI 相比，CA-BSI 患者年龄明显较小，合并疾病的可能性较低（p < 0.001）。HA-BSI 中男性病例比例较高（60%；p < 0.001 与其他病例相比），而 HCA-BSI 或 CA-BSI 中男性病例比例为 52%和 54%（p = 0.13）。CA-BSI 的多微生物病因比例明显低于 HA 和 HCA（5.5%；p < 0.001）。BSI 诊断后住院时间中位数为 15 天（HA）、9 天（HCA）和 8 天（CA）（p < 0.001）。总体而言，引起血流感染的最常见物种是大肠杆菌、金黄色葡萄球菌和肺炎链球菌。根据获得途径的分类，这些物种的分布和相对重要性排名有所不同。28 天全因病死率分别为 HA-BSI、HCA-BSI 和 CA-BSI 的 26%、19%和 10%（p < 0.001）。
基于一些流行病学、微生物学和结局特征，HCA 社区发病感染与 CA 和 HA 感染明显不同。本研究进一步支持将社区发病 BSI 分为单独的 CA 和 HCA 类别。
