Binning M, John M A, Schieven B C, Austin T W, Lannigan R, Hussain Z
Department of Microbiology and Infection Control, Victoria Hospital; and Division of Infectious Disease, and Department of Microbiology and Immunology, The University of Western Ontario, London Ontario.
Can J Infect Dis. 1994 Jul;5(4):163-7. doi: 10.1155/1994/804205.
The most common etiology of infectious diarrhea in hospitalized patients is Clostridium difficile. No single laboratory test yields a definitive diagnosis. Four methods were evaluated for their sensitivity and specificity in patients who had clinically defined C difficile-associated diarrhea.
Clinical criteria for C difficile-associated diarrhea were defined. All adult in-hospital patients whose stools were tested for C difficile were prospectively followed. Stools were examined with culture on a selective medium, a commercial cytotoxicity assay (cta), and two commercially available enzyme immunoassays (eias) for toxin A (Meridian) and toxin AB (cbc).
During the study period 235 stool specimens from 185 patients were tested. Fifty-one patients were positive for C difficile or its markers, cta was most sensitive (80%), whereas cbc-eia was most specific (98%). Differences in the sensitivities of cta and Meridian-eia were minor (80% versus 73.3%) and they were equally specific (95.5%).
The sensitivity and specificity of eia for toxin A is similar to other tests. However, due to rapidity and ease of performance, it may be a more practical test for the diagnosis of C difficile-associated diarrhea, especially if the cytotoxin assay is not available.
住院患者感染性腹泻最常见的病因是艰难梭菌。没有单一的实验室检查能做出明确诊断。对四种方法在临床上确诊为艰难梭菌相关性腹泻的患者中的敏感性和特异性进行了评估。
定义了艰难梭菌相关性腹泻的临床标准。对所有粪便进行艰难梭菌检测的住院成年患者进行前瞻性随访。粪便在选择性培养基上进行培养检查，采用商业细胞毒性试验（cta），以及两种用于毒素A（Meridian）和毒素AB（cbc）的市售酶免疫测定法（eias）。
在研究期间，对185例患者的235份粪便标本进行了检测。51例患者的艰难梭菌或其标志物呈阳性，cta最敏感（80%），而cbc-eia最特异（98%）。cta和Meridian-eia的敏感性差异较小（80%对73.3%），特异性相同（95.5%）。
毒素A的酶免疫测定法的敏感性和特异性与其他检测方法相似。然而，由于操作快速简便，它可能是诊断艰难梭菌相关性腹泻更实用的检测方法，尤其是在无法进行细胞毒素检测的情况下。
