Asymptomatic carriers are a potential source for transmission of epidemic and nonepidemic Clostridium difficile strains among long-term care facility residents
Asymptomatic carriers are a potential source for transmission of epidemic and nonepidemic Clostridium difficile strains among long-term care facility residents
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DOI：
10.1086/521854
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发表时间：
2007-10-15
影响因子：
11.8
通讯作者：
Donskey, Curtis J.
中科院分区：
文献类型：
--
作者：
Riggs, Michelle M.;Sethi, Ajay K.;Donskey, Curtis J.
背景资料。艰难梭菌无症状粪便携带者在住院患者中很常见，但无症状携带者在疾病传播方面的重要性尚不清楚。在艰难梭菌相关疾病暴发的背景下，我们前瞻性地检查了长期护理患者中流行性北美脉冲场凝胶电泳1型和非流行性产毒艰难梭菌菌株的无症状携带率，并评估了皮肤和环境污染的频率。采用脉冲场凝胶电泳法进行分子分型。用Logistic回归分析无症状携带者的相关因素，并建立敏感和特异的预测规则来识别高危患者。在68例无症状患者中，35例(51%)携带艰难梭菌，其中13例(37%)携带流行菌株。与非携带者相比，无症状携带者的皮肤比例(61%比19%；P=.001)和环境污染(59%比24%；P=0.004)更高。在皮肤样本中发现的87%的分离物和在环境样本中发现的58%的分离物与在粪便样本中发现的同时存在的分离物相同。无症状患者皮肤上的孢子很容易转移到调查人员手中。既往艰难梭菌相关疾病(P<；.001)和抗生素使用史(P=.017)与无症状携带者相关，这两个变量的组合对无症状携带者有预测作用(敏感度，77%；特异度，58%；阳性预测值，66%；阴性预测值，70%)。我们的发现表明，艰难梭菌流行和非流行菌株的无症状携带者有可能在长期护理机构中对疾病传播做出重大贡献。临床因素，如以前的艰难梭菌相关疾病和最近使用的抗生素，可能预示着无症状携带者。
Background. Asymptomatic fecal carriage of Clostridium difficile is common in patients staying in health care facilities, but the importance of asymptomatic carriers with regard to disease transmission is unclear.Methods. We prospectively examined the prevalence of asymptomatic carriage of epidemic North American pulsed-field gel electrophoresis type 1 and nonepidemic toxigenic C. difficile strains among long-term care patients in the context of an outbreak of C. difficile-associated disease and evaluated the frequency of skin and environmental contamination. Molecular typing was performed by pulsed-field gel electrophoresis. Logistic regression was used to assess factors associated with asymptomatic carriage, and a sensitive and specific prediction rule was developed to identify high-risk patients.Results. Thirty-five (51%) of 68 asymptomatic patients were carriers of toxigenic C. difficile, and 13 (37%) of these patients carried epidemic strains. Compared with noncarriers, asymptomatic carriers had higher percentages of skin (61% vs. 19%; P = .001) and environmental contamination (59% vs. 24%; P = .004). Eighty-seven percent of isolates found in skin samples and 58% of isolates found in environmental samples were identical to concurrent isolates found in stool samples. Spores on the skin of asymptomatic patients were easily transferred to investigators' hands. Previous C. difficile-associated disease (P < .001) and previous antibiotic use (P = .017) were associated with asymptomatic carriage, and the combination of these 2 variables was predictive of asymptomatic carriage (sensitivity, 77%; specificity, 58%; positive predictive value, 66%; negative predictive value, 70%).Conclusions. Our findings suggest that asymptomatic carriers of epidemic and nonepidemic C. difficile strains have the potential to contribute significantly to disease transmission in long-term care facilities. Clinical factors, such as previous C. difficile-associated disease and recent antibiotic use, may be predictive of asymptomatic carriage.