Clostridium difficile感染症

Clostridium Difficile Infection

要旨　Clostridium difficile感染症の現状について最近の文献を中心に概説した．従来は偽膜性大腸炎の起炎菌として注目されてきたが，近年では無症候性保菌者を含めた院内感染の原因菌であること，集団発生が起こりうることなどから医療施設における感染制御の対象となっている．その病態は，① 単純性抗菌薬関連下痢症，② 非偽膜形成性下痢症，③ 偽膜性大腸炎，および ④ 劇症偽膜性大腸炎に至るまで多彩である．さらに，近年では炎症性腸疾患の増悪因子としても着目されている．偽膜性大腸炎は病歴と大腸内視鏡検査下の偽膜の確認で確定診断できるが，その他，病型の診断には組織培養ないし免疫法による便中毒素の証明が必要である．metronidazoleないしvancomycinの経口投与が第1選択の治療であり，難治例や再発例ではvancomycinの長期投与とプロバイオティクスや毒素吸着療法などを併用し，確実な治療を目指す必要がある．

　We reviewed recent advance in the diagnosis and the management of Clostridium difficile infection. While Clostridium difficile has been regarded as one of the major causes of nosocomial infection following the use of antibiotics, asymptomatic carriers and outbreaks of the infection have recently been drawing much attention. Clostridium difficile-associated disease（CDAD）is clinically classified into that of asymptomatic carriers, simple antibiotic-associated diarrhea, diarrhea without pseudomembrane formation, pseudomembranous enterocolitis, and fulminant colitis. It has also been reported that the infection is associated with the deterioration of inflammatory bowel disease. Although pseudomembranous colitis can easily be diagnosed through the patients' history and colonoscopic findings, toxins of the bacteria should be proven for the diagnosis of other types of the infection. Either oral metronidazole or vancomycin is the first choice for the management of infection. In cases of intractable or recurrent infections, tapered-pulsed vancomycin with concomitant probiotics or toxin-binding compounds is recommended.