Objective: To summarize the clinical characteristics and laboratory diagnostic methods of infant botulism caused by Clostridium botulinum type B. Methods: Clinical data of 3 infants with type B botulism who were admitted to Children's Hospital Affiliated to Capital Institute of Pediatrics from May to November 2018 were retrospectively analyzed. Botulinum toxin was detected in fecal samples or fecal enrichment solution of the patients, and Clostridium botulinum was cultured and isolated from fecal samples. Results: The age of onset of the patients (two boys and one girl) was 3, 3 and 8 months old, respectively. Two cases had the onset in May and one case had the onset in November. There were two cases with mixed feeding and one case with breast feeding. One case's family members engaged in meat processing. All of them were previously healthy. All the children presented with acute flaccid paralysis, cranial nerve involvement and difficult defecation. Two cases had secondary urinary tract infection. Electromyograms of two cases showed that action potential amplitude of the motor nerve were lower than those of their peers. After treatments including intravenous human immunoglobulin, respiratory tract management, urethral catheterization, nasal feeding, etc., three cases recovered completely 2 to 4 months later. Type B botulinum toxin was detected in the fecal diluent of one patient, and the TPGYT enrichment solution and cooked meet medium of the feces of 3 patients, respectively. Clostridium botulinum B was identified from the feces of 3 infants after culture, isolation and purification. Conclusions: Combined with typical clinical manifestations including acute flaccid paralysis, cranial nerve involvement symptoms and difficult defecation examination, infant botulism can be clinically diagnosed. The detection of fecal botulinum toxin and the culture and isolation of Clostridium botulinum are helpful for the diagnosis.
目的： 总结B型肉毒梭菌致婴儿肉毒中毒的临床特点和实验室诊断结果。 方法： 对首都儿科研究所附属儿童医院于2018年5至11月收治的3例B型肉毒梭菌致肉毒中毒婴儿临床资料进行回顾性分析，检测患儿的粪便样品或粪便增菌液的肉毒毒素，同时从粪便样本中培养、分离肉毒梭菌。 结果： 3例患儿中男2例、女1例，发病年龄分别为3、3、8月龄。5月份发病2例，11月份发病1例。混合喂养2例，母乳喂养1例。家属从事肉制品加工1例。3例患儿既往均健康，均表现为急性弛缓性麻痹、颅神经受累、排粪困难等表现，2例继发泌尿系统感染，2例患儿肌电图提示运动神经动作电位波幅较同龄儿低。经过静脉注射人免疫球蛋白、呼吸道管理、排粪和（或）导尿、鼻饲等处理，3例患儿于发病2~4个月后痊愈。1例患儿的粪便稀释液以及3例患儿粪便的TPGYT增菌液和庖肉增菌培养基样品中均检测到B型肉毒毒素，培养、分离纯化后鉴定为B型肉毒梭菌。 结论： 结合典型临床表现（急性弛缓性麻痹、颅神经受累表现、排便困难）可临床拟诊婴儿肉毒中毒，其中粪便肉毒毒素检测和肉毒梭菌的培养及分离则有助于确诊。.
Keywords: Botulism; Clostridium botulinum; Infant.