Surawicz C M, McFarland L V
University of Washington, Seattle, Wash., USA.
Digestion. 1999 Mar-Apr;60(2):91-100. doi: 10.1159/000007633.
Clostridium difficile is the most common nosocomial pathogen of the gastrointestinal tract and has increased in frequency over time. Typical symptoms of C. difficile infection include diarrhea, which is usually nonbloody, or colitis associated with severe abdominal pain, fever and/or gross or occult blood in the stools. Pseudomembranous colitis (PMC), the severest form of this disease, occurs as a result of a severe inflammatory response to the C. difficile toxins. This review focuses on PMC, as this severe form is associated with the greatest medical concern. Diagnosis rests on detection of C. difficile in the stool, either by culture, tissue culture assay for cytotoxin B or detection of antigens in the stool by rapid enzyme immunoassays. Oral therapy with metronidazole 250 mg 4 times a day for 10 days is the recommended first-line therapy. Vancomycin is also effective, but its use must be limited to decrease the development of vancomycin-resistant organisms such as enterococci. Vancomycin (125-500 mg 4 times a day for 10 days) should be limited to those who cannot tolerate or have not responded to metronidazole, or when metronidazole use is contraindicated, as in the first trimester of pregnancy. A therapeutic response within a few days is usual. Recurrence of symptoms after antibiotics occurs in 20% of cases and is associated with persistence of C. difficile in the stools. Further recurrences then become more likely. Therapy with antibiotics in a pulsed or tapered regimen is often effective as are efforts to normalize the fecal flora. The yeast Saccharomyces boulardii has been proven in controlled trials to reduce recurrences when given as an adjunct to antibiotic therapy. Careful hand washing and environmental decontamination are necessary to prevent epidemics.
艰难梭菌是胃肠道最常见的医院病原体，且其感染频率随时间有所增加。艰难梭菌感染的典型症状包括通常无血便的腹泻，或与严重腹痛、发热和/或粪便中肉眼可见或潜血相关的结肠炎。假膜性结肠炎（PMC）是该疾病最严重的形式，是对艰难梭菌毒素的严重炎症反应所致。本综述聚焦于PMC，因为这种严重形式引发了最大的医学关注。诊断依赖于粪便中艰难梭菌的检测，可通过培养、细胞毒素B的组织培养测定法或快速酶免疫测定法检测粪便中的抗原。推荐的一线治疗是口服甲硝唑，250毫克，每日4次，共10天。万古霉素也有效，但必须限制其使用以减少耐万古霉素微生物（如肠球菌）的产生。万古霉素（125 - 500毫克，每日4次，共10天）应仅限于那些不能耐受甲硝唑或对甲硝唑无反应的患者，或在甲硝唑使用禁忌的情况下（如妊娠早期）使用。通常在数天内会出现治疗反应。20%的病例在使用抗生素后会出现症状复发，且与粪便中艰难梭菌持续存在有关。随后进一步复发的可能性更大。采用脉冲式或递减式方案使用抗生素治疗通常有效，使粪便菌群正常化的措施也有效。在对照试验中已证实，作为抗生素治疗的辅助用药给予酵母布拉氏酵母菌可减少复发。仔细洗手和进行环境去污对于预防疫情很有必要。
