Johannes Richard S
Clinical Research Services, Cardinal Health, MediQual Services, Marlborough, MA 01752, USA.
Am J Infect Control. 2008 Dec;36(10):S171.e13-7. doi: 10.1016/j.ajic.2008.10.003.
HEALTH CARE-ASSOCIATED INFECTIONS: For over 35 years, infections have been divided into hospital acquired or community acquired. In 2002, in a study of bloodstream infections (BSIs), Friedman et al first suggested creating a new classification: health care-associated BSIs. Kollef et al furthered the concept of health care-associated infection in a 2005 population-based study of culture-positive pneumonia cases. Although the site of infection differed, Kollef et al's results supported Friedman et al's original concept. Then in 2006, Kollef et al reported a population-based study focused specifically on BSIs. Of 6697 reported cases, 468 (7%) had hospital-acquired BSIs; 3705 (55.3%) health care-associated BSIs; and 2524 (37.7%) community-acquired BSIs. The clinical features of those with health care-associated BSIs differed from those with community-acquired BSIs. For several organisms, including Staphylococcus aureus, Streptococcus pneumoniae, and gram-negative organisms, the frequencies for health care-associated and hospital-acquired BSIs were similar to each other but significantly different from community-acquired BSIs. After controlling for several clinical features, methicillin-resistant Staphylococcus aureus had the largest odds ratio for predicting in-hospital mortality. Both hospital-acquired and health care-acquired cases were independent risk factors for in-hospital mortality.
Is more aggressive, empiric, gram-positive therapy warranted for this potentially sicker patient group? Wunderink pointed out the potential unintended consequences of such an approach and the paucity of good tools for early recognition of sickest patients. A study by Shorr et al of systemic inflammatory response syndrome, organ dysfunction, and mortality suggested that there may be approaches that could be used to stratify cases into high-risk groups who may benefit from more aggressive therapy. Most recently, Micek et al found that in health care-associated pneumonia cases, inappropriate initial empiric antibiotic treatment is an independent predictor of mortality. Treatment recommendations are evolving.
For pneumonia and BSIs, health care-associated infections appear to be distinct entities. However, operational definitions still vary. Compared with hospital-acquired cases, health care-associated cases have different clinical characteristics. The outcomes of health care-associated infections tend to be intermediate of the community-acquired and hospital-acquired groups. Further research is urgently needed on the implications of health care-associated infection for early therapy.
医疗保健相关感染：35 多年来，感染一直被分为医院获得性感染或社区获得性感染。2002 年，在一项关于血流感染（BSIs）的研究中，弗里德曼等人首次建议创建一种新的分类：医疗保健相关血流感染。科勒夫等人在 2005 年一项基于人群的培养阳性肺炎病例研究中进一步拓展了医疗保健相关感染的概念。尽管感染部位不同，但科勒夫等人的研究结果支持了弗里德曼等人的最初概念。然后在 2006 年，科勒夫等人报告了一项专门针对血流感染的基于人群的研究。在报告的 6697 例病例中，468 例（7%）为医院获得性血流感染；3705 例（55.3%）为医疗保健相关血流感染；2524 例（37.7%）为社区获得性血流感染。医疗保健相关血流感染患者的临床特征与社区获得性血流感染患者不同。对于几种微生物，包括金黄色葡萄球菌、肺炎链球菌和革兰氏阴性菌，医疗保健相关血流感染和医院获得性血流感染的发生率彼此相似，但与社区获得性血流感染有显著差异。在控制了几种临床特征后，耐甲氧西林金黄色葡萄球菌在预测住院死亡率方面的优势比最大。医院获得性病例和医疗保健获得性病例都是住院死亡率的独立危险因素。
对于这个可能病情更严重的患者群体，更积极的经验性革兰氏阳性菌治疗是否必要？温德林克指出了这种方法可能产生的意想不到的后果以及缺乏用于早期识别病情最严重患者的良好工具。肖尔等人关于全身炎症反应综合征、器官功能障碍和死亡率的一项研究表明，可能有方法可用于将病例分层为可能从更积极治疗中获益的高危组。最近，米塞克等人发现，在医疗保健相关肺炎病例中，不适当的初始经验性抗生素治疗是死亡率的独立预测因素。治疗建议正在不断发展。
对于肺炎和血流感染，医疗保健相关感染似乎是不同的实体。然而，操作定义仍然各不相同。与医院获得性病例相比，医疗保健相关病例具有不同的临床特征。医疗保健相关感染的结局往往介于社区获得性和医院获得性组之间。迫切需要进一步研究医疗保健相关感染对早期治疗的影响。
