难辨梭状芽胞杆菌相关性腹泻及其防治

难辨梭状芽孢杆菌（CD）相关性腹泻（CDAD）主要由应用广谱抗菌药物而引起,其发生率呈上升趋势。引起CDAD的常用药物有阿莫西林、克林霉素、林可霉素和头孢菌素类等。CDAD大多发生在应用抗菌药物治疗后5～10d。住院患者发生CDAD占抗菌药相关性腹泻（AAD）的15%～25%,病死率约为6%～30%。其发病机制为应用抗菌药后肠道正常菌群被抑制,使CD繁殖并产生毒素A（肠毒素）及毒素B（细胞毒素）,引起肠黏膜损伤,上皮细胞变性、坏死和纤维素渗出而导致腹泻及其他症状。主要临床表现为腹泻（水样便）、发热、腹痛、结肠炎、伪膜性肠炎（PMC）、中毒性巨结肠、脓毒血症甚至死亡。老年、严重的基础疾病、长期住院、应用广谱抗菌药及免疫功能低下的患者是感染CD的危险因素。CDAD确诊后应停用可疑抗菌药物,可用甲硝唑或万古霉素等药物治疗。CDAD复发者可增加10～14d疗程甲硝唑或万古霉素治疗,多次复发者可应用考来烯胺、益生菌及人免疫球蛋白治疗。

Clostridium difficile-associated diarrhea: prevention and management

Clostridium difficile-associated diarrhea （ CDAD） mainly occurs in association with the administration of broad-spectrum antibiotics. The incidence of CDAD has been trending upward. The antibiotics frequently implicated in Clostridium difficile-associated diarrhea are amoxicillin,clindamycin,lincomycin,cephalosporins. The time to CDAD onset generally is 5-10 days after antibiotics treatment. CDAD in inpatients is 15% ～ 25% of antibacterial-associated diarrhea（ AAD） patients and the mortality is about 6% ～ 30% . The mechanism of the occurrence of CDAD is that antibiotics inhibit normal gastrointestinal flora and enable Clostridium difficile to multiple and release toxin A （ enterotoxin） and toxin B （ cytotoxin） that induce intestinal mucosal injury as well as degeneration,necrosis,and fibrinous exudation of epithelial cells,leading to diarrhea and other symptoms. Clinical presentations mainly include diarrhea（ watery stools） ,fever,abdominal pain,colitis,pseudomembranous （ PMC） ,toxic megacolon,sepsis,and even death. The risk factors for CDAD are the elderly,serious underlying diseases,a prolonged hospitalization,administration of broad-spectrum antibiotics and weakened immune function. If CDAD is confirmed,the suspected antibiotics should be withdrawn and metronidazole or vancomycin could be given. The patients with relapse may be treated with another 10 ～ 14 days course of metronidazole or vancomycin. The patients with multiple relapses may be treated with cholestyramine,probiotics,and human immulloglobulin.