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1、傷寒Typhoidfever6/12/20211概述(Introduction)為傷寒沙門桿菌所致的急性傳染病Typhoidisaserious,acuteinfectiousdisease,causedbythebacteriumSalmonellatyphi.臨床特點:持續(xù)發(fā)熱,相對緩脈,全身中毒癥狀和消化道癥狀,玫瑰疹,肝脾腫大,白細胞減少ClinicalFeatures:sustainedfever,markedheadache,malaise,anorexia,relativebradycardia,hepatosplenomegaly,rosespots,
2、leukocytopenia并發(fā)癥:腸出血,腸穿孔Complications:gastrointestinalhaemorrhageorperforation6/12/20212病原學EtiologyD群沙門菌,革蘭陰性短桿菌,長1~3.5μm,寬0.5~0.8μm。無芽胞、無莢膜,有鞭毛。Salmonellatyphi,gramnegativerod,motilebyperitrichousflagella.普通培養(yǎng)基中可生長,含膽汁培養(yǎng)基更佳抵抗力強:喜濕冷(水中:2~3周冰凍:數(shù)月)怕干熱(60℃15分鐘或煮沸即可滅活)化學消毒劑可滅活6/12/20213Vir
3、ulencecharacteristics毒素:菌體裂解時釋放cytotoxins,Invasionfactors三種抗原抗體系統(tǒng):菌體O抗原、鞭毛H抗原、表面Vi抗原somaticOantigen,surfaceViantigen,flagellarHantigen.菌體O抗體、鞭毛H抗體、表面Vi抗體somaticOantibody,surfaceViantibody,flagellarHantibody6/12/20214表面抗原與毒力有關(guān),具有抗吞噬和抗溶菌的作用Vi抗原抗原性弱,刺激機體產(chǎn)生短暫低效價抗體伴隨活菌一起存在測定Vi抗體有助于檢出帶菌者因為所以本
4、質(zhì)ViantigenimpedesphagocytosisandcontributestotheabilityofS.typhitosurvivenormalhost-defensemechanisms.6/12/20215流行病學Epidemiology(一)Howistyphoidfeverspread?傳染源:患者和帶菌者ThecarriersandthepeoplewhohaveactivetyphoidfevershedS.Typhiintheirstoolsorurine.慢性帶菌者:排菌期3個月以上(主要傳染源)Asymptomaticcarriers,
5、whohaverecoveredfromthesymptomsofthediseasebutcontinuetocarrythebacteria.Thiscarrierstateoccursinabout3%ofallindividualsrecoveredfromtyphoidfever.6/12/20216傳播途徑:消化道傳播如污染的水源(重要途徑,爆發(fā)流行)污染的食物(也可引起流行)日常生活接觸(散發(fā)病例)另外:蒼蠅,蟑螂也可傳遞病菌Typhoidisspreadviathefecal-oralrouteandthiscanbethroughfoodordrin
6、kthathasbeencontaminatedbythefaecesofatyphoidpatientorcarrierofthebacteria.易感人群:普遍易感,病后獲持久免疫力(僅2%的人第二次發(fā)病)6/12/20217SourcesofcontaminationMostcommonvehiclesarebeef,turkey,eggs,pork,andchicken6/12/20218流行病學Epidemiology(二)世界各地均有本病發(fā)生,熱帶和亞熱帶為多常年發(fā)病,夏秋為多兒童和青壯年為多,無性別差異發(fā)病與衛(wèi)生、經(jīng)濟條件相關(guān)6/12/20219Epid
7、emiologyIn2000,theglobalannualincidenceoftyphoidfeverwasestimatedtobearound21.7millioncaseswith216,510deathsperyear.DISTRIBUTIONOFTYPHOID我國發(fā)病率4.08-10.45/10萬,每年報告病例5.1-12萬例6/12/202110發(fā)病機制Pathogenesis(一)潛伏期(第一次菌血癥):人食入傷寒沙門菌后,細菌在小腸淋巴組織內(nèi)繁殖,經(jīng)胸導管入血。Afterbeingswallowed,theS.typhibacte