临床医学传染病学PPT课件伤寒.pptVIP

医学课件园 伤寒Typhoid fever 概述(Introduction) 为伤寒沙门杆菌所致的急性传染病 Typhoid is a serious, acute infectious disease , caused by the bacterium Salmonella typhi. 临床特点: 持续发热,相对缓脉,全身中毒症状和消化道症状, 玫瑰疹,肝脾肿大,白细胞减少 Clinical Features: sustained fever, marked headache, malaise, anorexia, relative bradycardia, hepatosplenomegaly, rose spots ，leukocytopenia 并发症: 肠出血,肠穿孔 Complications：gastrointestinal haemorrhage or perforation 病原学 Etiology D群沙门菌，革兰阴性短杆菌，长1～3.5μm，宽0.5～0.8μm。无芽胞、无荚膜，有鞭毛。 Salmonella typhi, gram negative rod, motile by peritrichous flagella. 普通培养基中可生长，含胆汁培养基更佳 抵抗力强： 喜湿冷(水中:2~3周 冰冻:数月) 怕干热(60℃ 15分钟或煮沸即可灭活) 化学消毒剂可灭活 Virulence characteristics 毒素：菌体裂解时释放 cytotoxins , Invasion factors 三种抗原抗体系统： 菌体O抗原、鞭毛H抗原、 表面Vi抗原 somatic O antigen, surface Vi antigen， flagellar H antigen. 菌体O抗体、鞭毛H抗体、表面Vi抗体 somatic O antibody, surface Vi antibody ， flagellar H antibody 流行病学 Epidemiology （一） How is typhoid fever spread? 传染源:患者和带菌者 The carriers and the people who have active typhoid fever shed S. Typhi in their stools or urine. 慢性带菌者:排菌期3个月以上(主要传染源) Asymptomatic carriers, who have recovered from the symptoms of the disease but continue to carry the bacteria. This carrier state occurs in about 3% of all individuals recovered from typhoid fever. 传播途径: 消化道传播 如污染的水源(重要途径,爆发流行) 污染的食物(也可引起流行) 日常生活接触(散发病例) 另外:苍蝇,蟑螂也可传递病菌 Typhoid is spread via the fecal-oral route and this can be through food or drink that has been contaminated by the faeces of a typhoid patient or carrier of the bacteria. 易感人群:普遍易感,病后获持久免疫力(仅2%的人第二次发病) 流行病学 Epidemiology （二） 世界各地均有本病发生，热带和亚热带为多 常年发病，夏秋为多 儿童和青壮年为多，无性别差异 发病与卫生、经济条件相关 Epidemiology ? In 2000, the global annual incidence of typhoid feve