伤寒typhoidfever.ppt

2018/9/22,1,伤寒 Typhoid fever,2018/9/22,2,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,2018/9/22,3,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,2018/9/22,4,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,2018/9/22,5,,表面抗原与毒力有关,具有 抗吞噬和抗溶菌的作用,Vi抗原,抗原性弱，刺激机体产生短暂低效价抗体 伴随活菌一起存在,测定Vi抗体有助于检出带菌者,,因为,,所以,,本质,Vi antigen impedes phagocytosis and contributes to the ability of S. typhi to survive normal host-defense mechanisms.,2018/9/22,6,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.,2018/9/22,7,,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),2018/9/22,8,Sources of contamination,Most common vehicles are beef, turkey, eggs, pork, and chicken,2018/9/22,9,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,2018/9/22,10,Epidemiology,In 2000, the global annual incidence of typhoid fever was estimated to be around 21.7 million cases with 216,510 deaths per year. DISTRIBUTION OF TYPHOID 我国发病率4.08-10.45/10万，每年报告病例5.1-12万例,2018/9/22,11,发病机制 Pathogenesis (一),潜伏期(第一次菌血症):人食入伤寒沙门菌后, 细菌在小肠淋巴组织内繁殖，经胸导管入血。

After being swallowed, the S. typhi bacteria are taken in by mononuclear phagocytes and multiply within these cells. This period of time is the 10 to 14-day incubation period of typhoid fever,,,2018/9/22,12,发病机制 Pathogenesis (二),初期(第二次菌血症):细菌随血液入肝脾,胆囊,骨髓等组织器官内并大量繁殖,再次入血并释放内毒素,引起临床症状 When huge numbers of bacteria fill an individual phagocyte, they spill out of the cell and into the bloodstream, where their presence begins to cause symptoms.,2018/9/22,13,发病机制 Pathogenesis (三),极期:细菌随血播散全身,部分经肠粘膜再次入侵肠道淋巴组织,产生严重的炎症反应;大量细菌经肠道随粪便排出。

The bacteria move from the bloodstream into certain tissues of the body, including the gallbladder and lymph tissue of the intestine. The tissue‘s response to this invasion causes severe inflammationand large of bacteria were secreted in patient’s stool.,2018/9/22,14,发病机制 Pathogenesis (四),恢复期:随着免疫反应(细胞免疫)的作用,细胞内伤寒杆菌被消灭,病变逐渐愈合,患者康复.仅少数患者(2%~5%) 因胆囊长期保留细菌并排菌而成为慢性带菌者2018/9/22,15,胆囊-----肠道-------粪排菌 皮肤----血栓出血--玫瑰疹 肾-----尿 肝脾-----肿大 骨髓,伤寒和副伤寒的致病过程,伤寒和甲型副伤寒杆菌,小肠上部粘膜,肠系膜淋巴结,固有层淋巴结,进入血液,再次进入血液,,,,,,第一次菌血症,第二次菌血症,2018/9/22,16,病理 Pathology（一）,全身单核-吞噬细胞系统的增生性反应,回肠下段淋巴组织最明显。

The reticuloendothelial system multiply.,2018/9/22,17,病理 Pathology（三）,第2周:肿大的淋巴结坏死 第3周:坏死组织脱落,溃疡形成，波及血管可致肠出血,侵入肌层和浆膜层可致肠穿孔 第4周:溃疡逐渐愈合,不留疤痕,2018/9/22,18,临床表现 Clinical characteristics,潜伏期7~23天,一般为10~14天The Incubation Period: From 7 days to over 23days, usual range 10-14 days.,2018/9/22,19,临床分期 Clinical classification,初期 Early period (第一周):发热:阶梯形上升,可高达39 ~40℃, 发热前可有畏寒,少有寒颤和大汗,伴全身不适,纳差,乏力,咽痛,咳嗽,2018/9/22,20,极期 Fastigium (第2,3周):高热,稽留热为主，持续10~14天 消化道症状：纳差,腹胀,便秘(少数有腹泻),可有右下腹轻压痛； 神经系统症状：淡漠表情,反应迟钝,听力下降,精神恍惚，重者有中毒性脑病:谵妄,昏迷,病理反射 循环系统症状：相对缓脉或重脉。

肝脾肿大，玫瑰疹2018/9/22,21,缓解期 period of decline(第3,4周):体温逐渐下降,食欲好转,腹胀逐渐消失,脾脏缩小，但本期仍可出现各种并发症 恢复期 Convalescent period(第5周):体温,食欲复常通常在1个月左右完全康复.有并发症,原有慢性病,体弱者病程较长.,2018/9/22,22,What are the signs and symptoms of typhoid fever?,a sustained fever as high as 39° to 40° C； feeling weak, or loss of appetite diarrhea constipation stomach pain headache malaise nonproductive cough slow heart rate (bradycardia) Hepatosplenomegalyrose spots,2018/9/22,23,五种临床类型 Clinical type,轻型 (mild type ): 发热38℃,全身毒血症状轻,病程短(1~3周)常见于早期已用有效抗生素治疗者和年幼儿童。

普通型(moderate type)： 迁延型(persistent type): 因机体免疫力低，病程迁延，可达5周以上甚至数月,肝脾大较明显 逍遥型(ambulatory type): 毒血症状轻；但部分患者可因肠出血或肠穿孔为首发症状 暴发型(fulmimant type):可有高热,休克,中毒性脑病,中毒性肝炎,中毒性心肌炎,DIC等2018/9/22,24,,复发(relapse): 退热后1~3周再现临床症状，血培养阳性,多见于免疫力低者，因潜伏于吞噬细胞中的细菌大量繁殖入血所致,症状较初发轻，病程短，并发症少 再燃(recrudescence) :病后2~3周体温未复常时，又再上升，持续5~7天后回到正常血培养阳性，可能与菌血症未完全控制有关，症状加重，常见于抗菌治疗不彻底者2018/9/22,25,辅助检查 Laboratory test（一）,外周血检查(Test of peripheral blood) 嗜酸性粒细胞减少或消失，随病情好转而恢复，复发时再减少或消失eosinophil reduce or disappear 白细胞总数、中性粒细胞减少leukocytopenia,。