Clinical features of Clostridium difficile-associated infections and molecular characterization of strains:: Results of a retrospective study, 2000-2004
Clinical features of Clostridium difficile-associated infections and molecular characterization of strains:: Results of a retrospective study, 2000-2004
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DOI：
10.1086/511794
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发表时间：
2007-02-01
影响因子：
4.5
通讯作者：
Petit, Jean-Claude
中科院分区：
文献类型：
--
作者：
Barbut, Frederic;Gariazzo, Beatrice;Petit, Jean-Claude
背景最近在北美、英国和荷兰报告的艰难梭菌相关腹泻（CDAD）严重病例的暴发强调了持续进行CDAD流行病学监测的重要性。了解2000-2004年CDAD的流行病学特征及院内感染率。difficile.Design. CDAD住院患者的回顾性调查和分离菌株的分子特征。760张床位的教学医院。回顾性分析了2000年1月1日至2004年12月31日诊断的所有CDAD病例。CDAD病例定义为粪便标本检测为C阳性的住院患者腹泻。艰难梭菌细胞毒素或具有阳性促癌性培养结果。如果患者满足以下3个标准中的至少一个，则认为CDAD是重度的：（1）存在发热（定义为温度高于38.5 ℃），腹痛和白细胞计数大于10，000个细胞/mm（3）;（2）内窥镜或组织学证实的假膜性结肠炎;或（3）并发症（定义为C.艰难梭菌感染作为主要或促成原因、中毒性巨结肠、穿孔、中毒性休克和/或结肠切除术）。如果患者在入院后72小时内发生腹泻，并且如果患者在前一个月内没有住院史，则认为CDAD是社区获得性的;否则，认为CDAD与医疗保健相关。所有分离的菌株进行血清分型，并通过毒素分型和PCR核糖体分型的特点。用PCR法检测毒素A、毒素B和二元毒素。共诊断CDAD 151例，可查阅147份临床记录，研究131株。CDAD的总发病率为1.1例/1,000例入院患者，但2003-2004年的发病率高于2000-2002年（P = 0.017）。28例患者（19%）发生社区获得性腹泻。对于医疗保健相关CDAD患者，在12例病例（10.1%）中证实了菌株在患者之间的传播（即，感染了与前2个月内从同一病房或相连病房住院的另一名患者中分离出的菌株具有相同血清群和PCR核糖体型的菌株）。11%的菌株对二元毒素呈阳性。二元毒素阳性菌株与更严重的腹泻（P = 0.01）和更高的病死率（P = 0.03）相关。C.艰难梭菌（血清群H，PCR核糖体型sa 026）占所有分离菌株的35（26.7%），但该克隆在医疗保健相关和社区获得性病例中均被发现。3株属于毒素III型，但只有1株与最近爆发的高毒力克隆有关。结论。我院CDAD发病率低，交叉感染少。这些结果还表明，具有二元毒素的菌株可能更具毒性。
Background. Recent outbreaks of severe cases of Clostridium difficile-associated diarrhea (CDAD) reported in North America, the United Kingdom, and The Netherlands have emphasized the importance of an ongoing epidemiological surveillance of CDAD.Objective. To determine the epidemiology of CDAD over the years 2000-2004 and the rate of nosocomial transmission of C. difficile.Design. Retrospective survey of inpatients with CDAD and molecular characterization of the strains isolated.Setting. A 760-bed teaching hospital.Methods. All CDAD cases diagnosed from January 1, 2000, to December 31, 2004, were reviewed. A CDAD case was defined as diarrhea in a hospitalized patient who had a stool specimen that tested positive for C. difficile cytotoxin or had a positive toxigenic culture result. CDAD was considered to be severe if a patient fulfilled at least 1 of the following 3 criteria: (1) presence of a fever (defined as temperature higher than 38.5 degrees C), abdominal pain, and leukocyte count greater than 10,000 cells/mm(3); (2) endoscopically or histologically proven pseudomembranous colitis; or (3) complications (defined as death with C. difficile infection as the primary or a contributing cause, toxic megacolon, perforation, toxic shock, and/or colectomy). CDAD was considered community-acquired if the diarrhea occurred in the patient within 72 hours after admission and if the patient had no history of hospitalization in the previous month; otherwise, CDAD was considered healthcare-associated. All the strains isolated were serogrouped and were characterized by toxinotyping and PCR ribotyping. Detection of toxin A, toxin B, and binary toxin was performed by PCR.Results. One hundred fifty-one cases of CDAD were diagnosed; 147 clinical records could be reviewed, and 131 strains were studied. The overall incidence of CDAD was 1.1 cases per 1,000 patients admitted, but incidence rates were higher in 2003-2004, compared with 2000-2002 (P = .017). Diarrhea was community acquired in 28 patients (19%). For patients with healthcare-associated CDAD, transmission of the strain from patient to patient (ie, infection with a strain of the same serogroup and PCR ribotype as the strain isolated from another patient hospitalized in the same ward or in a linked ward in the previous 2 months) was demonstrated in 12 cases (10.1%). Eleven percent of strains were positive for binary toxin. Binary toxin-positive strains were associated with more-severe diarrhea (P = .01) and with a higher case-fatality rate (P = .03). A specific clone of C. difficile (serogroup H, PCR ribotype sa026) accounted for 35 (26.7%) of all the strains isolated, but this clone was found both in healthcare-associated and community-acquired cases. Three strains belonged to toxinotype III, but only 1 was related to the hypervirulent clone involved in recent outbreaks.Conclusion. The incidence of CDAD is low in our hospital, and cross-infection is limited. These results also suggest that strains with binary toxin might be more virulent.