艰难梭菌感染：症状患者不再是主要传染源（摘要，N Engl J Med ）

拙凌

Diverse Sources of C. difficile Infection Identified on Whole-Genome Sequencing

David W. Eyre, B.M., B.Ch., Madeleine L. Cule, Ph.D., Daniel J. Wilson, D.Phil., David Griffiths, B.Sc., Alison Vaughan, B.Sc., Lily O'Connor, B.Sc., Camilla L.C. Ip, Ph.D., Tanya Golubchik, Ph.D., Elizabeth M. Batty, Ph.D., John M. Finney, B.Sc., David H. Wyllie, Ph.D., Xavier Didelot, D.Phil., Paolo Piazza, Ph.D., Rory Bowden, Ph.D., Kate E. Dingle, Ph.D., Rosalind M. Harding, Ph.D., Derrick W. Crook, M.B., B.Ch., Mark H. Wilcox, M.D., Tim E.A. Peto, D.Phil., and A. Sarah Walker, Ph.D.

N Engl J Med 2013; 369:1195-1205September 26, 2013DOI: 10.1056/NEJMoa1216064

BackgroundIt has been thought that Clostridium difficile infection is transmitted predominantly within health care settings. However, endemic spread has hampered identification of precise sources of infection and the assessment of the efficacy of interventions.

MethodsFrom September 2007 through March 2011, we performed whole-genome sequencing on isolates obtained from all symptomatic patients with C. difficile infection identified in health care settings or in the community in Oxfordshire, United Kingdom. We compared single-nucleotide variants (SNVs) between the isolates, using C. difficile evolution rates estimated on the basis of the first and last samples obtained from each of 145 patients, with 0 to 2 SNVs expected between transmitted isolates obtained less than 124 days apart, on the basis of a 95% prediction interval. We then identified plausible epidemiologic links among genetically related cases from data on hospital admissions and community location.

ResultsOf 1250 C. difficile cases that were evaluated, 1223 (98%) were successfully sequenced. In a comparison of 957 samples obtained from April 2008 through March 2011 with those obtained from September 2007 onward, a total of 333 isolates (35%) had no more than 2 SNVs from at least 1 earlier case, and 428 isolates (45%) had more than 10 SNVs from all previous cases. Reductions in incidence over time were similar in the two groups, a finding that suggests an effect of interventions targeting the transition from exposure to disease. Of the 333 patients with no more than 2 SNVs (consistent with transmission), 126 patients (38%) had close hospital contact with another patient, and 120 patients (36%) had no hospital or community contact with another patient. Distinct subtypes of infection continued to be identified throughout the study, which suggests a considerable reservoir of C. difficile.

ConclusionsOver a 3-year period, 45% of C. difficile cases in Oxfordshire were genetically distinct from all previous cases. Genetically diverse sources, in addition to symptomatic patients, play a major part in C. difficile transmission. (Funded by the U.K. Clinical Research Collaboration Translational Infection Research Initiative and others.)

liuyings

版主是否能将此英文版有个正文对照,可以更方便大家阅读

拙凌

liuyings 发表于 2013-10-11 08:41

                               
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版主是否能将此英文版有个正文对照,可以更方便大家阅读

大概意思是（以下内容并非摘要的翻译）：
研究者从2007至2011年开展了一项全基因组测序研究，从所有症状CDI患者中获取分离株，这些患者来自医疗机构或社区。   

研究者成功对1250例艰难梭菌病例进行了测序，在和957株来自研究期间任意时间点获取的症状患者样本细菌进行测序比较后发现，其中333株（35%）具有2种或少于2种的来自至少1例先前病例的单核苷酸变异（SNVs），这说明这些病例具有相关性。共有428例（45%）分离菌株具有超过10个的和所有早期病例相关的SNVs，这说明这些病例和早期病例无相关性。  

两组的发生率都随时间而下降，说明阻止传播的干预措施有效。333例具有2种或少于2种SNVs的患者中有126例（38%）和另一患者有过亲密院内接触，120例（36%）与医院或社区的其他患者没有接触。

之前认为，新发病例可能主要来源于其他的症状病例，但该研究发现并非如此。

田田~

关注难辨梭菌感染，谢谢啦