Clostridium difficile is a major cause of antibiotics-associated diarrhea (AAD), and accounts for 15∼20% of all the cases. Especially, AAD caused by C. difficile is called as C. difficile-associated diarrhea (CDAD). Diagnosis of CDAD is made by identification of C. difficile in the feces obtained from the patients with diarrhea after administration of antibiotics. We herein compared 3 methods, detection of toxin A and glutamate dehydrogenase (GDH) as well as culture for C. difficile. Two hundred and thirty-two samples obtained from 148 patients with CDAD were investigated. Fifty-five (23.7%), 56 (24.1%), and 93 (40.1%) of the 232 samples were positive for toxin A, GDH, and culture, respectively. Sensitivity, specificity, predictive value of positive result, and predictive value of negative result of method of detection of toxin A were estimated to 53%, 96%, 90%, 75% and those of GDH were 56%, 99%, 98%, 78%. These results indicated that we should carefully interpret the results obtained by these methods, especially in the cases that showed negative for C. difficile.
The details on prevalence of heartburn and reflux esophagitis have not been clarified, since no large-scale survey has been conducted to date. Accordingly, we conducted the nationwide survey regarding prevalence of heartburn and reflux esophagitis by asking new outpatients and patients with the first endoscopy to be performed who visited the medical institutions participating in this survey to fill out the questionnaire and undergo endoscopy. The result showed that heartburn was reported from 1,994 patients (42.2%) out of 4,723, and reflux esophagitis classified as grade A-D was reported from 602 patients (16.7%) out of 3,608. Meanwhile, fat intake, sweet food and anti-inflammatory analgesics were proven to be causes of heartburn. Furthermore, frequency of heartburn and severity of reflux esophagitis were slightly correlated, although those were not necessarily obviously related.