《医学痢疾》PPT课件.ppt

Bacillary Dysentery(shigellosis),Dept.Of Infectious DiseaseHuang Fen,Definition,Acute infectious disease of intestine caused by dysentery bacilli(genus shigella)Place of lesion:sigmoid&rectum Pathological feature:diffuse fibrious exudative inflammation,Definition,Clinical manifestation:fever,abdominal pain,diarrhea,tenesmus,stool mixed with mucus blood,&pus.even companied with shock,toxic-encepholopthy.,Etiology,Causative organism:dysentery bacilli,genus shigella,gram-stained negative,non-motile short rod,Groups:4 serogroups&47 serotypes,Etiology,S.dysenteriae:the most severeS.flexneri:the epidemic group and easily turn to chronicS.boydii:tropical and subonS.sonnei:the most mild,Etiology,Pathogenicity:-virulence endotoxin-exotoxin-invasiveness(attach-penetrate-multiply)Resistance:Strong,1-2week in fruits,vegetable and dirty soil,heat for 60 30 min,Epidemiology,Source of infection:patients and carriersRoute of transmission:fecal-oral routeSuceptibility of population:immunity after infection is short and unsteady,no cross-immune,Epidemiology,Epidemic features:season:summer&fallFlexneri,Soneii,dysenteryage:younger children,Pathogenesis,number of bacteria toxicity invasivenessattachmentpenetrationmultiplication immunity,common,Bacteria,intestine,normal intestinal florasIg A,prevent attaching,penetrate mucus,multiply in epithelia cell&proper lamina,endotoxin,endogenous pyrogen,fever,inflammationvessel contraction,superficial mucosal necrosis and ulcer,diarrhea mixed with blood&pus,abdominal pain,Pathogenesis-toxic,strong-allergy to endotoxin,demethyl-adrenaline DIC,micro-circulatory failure,shock,cerebral edema cerebral hernia,Pathology,site of lesion:entire large bowel-sigmoid colon&rectum feature:acute:diffuse fibrinous exudative inflammation,Pathology,hyperemia,edema,leukocyte infiltration,superficial necrosis,ulcer.chronic:edema,polypoid hyperplasia,toxic:colon:hyperemia,edema,micro-capillary was invaded,Clinical manifestation,Incubation period:1-2 day,(hours to 7 days)Acute dysenterycommon type mild typetoxic type,Clinical manifestation,common type:(typical type)acute onset,shiver,high feverabdominal pain(tenderness)diarrhea:stool mixed with mucus,blood&pustenesmus,1 week,Clinical manifestation,mild type:(atypical type)caused by S.sonneilow fever or no feverabdominal pain is mildstool mixed with mucus,without blood&pusdiagnosis by isolation of bacteria37d,Clinical manifestation,toxic type:age:2 to 7 yrs.abrupt onset,high fever,T 40oCdysphoria,lethargy,convulsion repeatedly,coma.circulatory&respiratory collapsediarrhea mild or absent at beginning,Clinical manifestation,shock form:septic shock brain form:dysphoria,lethargy,convulsion repeatedly,coma,brain hernia.respiratory failure mixed form,Clinical manifestation,chronic dysentery:2 monthschronic delayed type:chronic obscure typeacute attack type,Clinical manifestation,chronic delayed type:long-time and repeated abdominal pain,diarrhea,stool mixed with mucus,blood&pus.with fatigue,anemia,malnutrition.,Clinical manifestation,chronic obscure type:acute history in 1 year,no symptoms,stool culture positive or sigmoidscopyacute attack type:same as common acute dysentery,Laboratory Findings,Blood picture:WBC count increase,(1020109/L)neutrophils increase Stool examination:gross examination:stool mixed with mucus,blood&pus.,Laboratory Findings,direct microscopic examination:WBC,RBC,pus cellsbacteria culture:PCR:DNASigmoidoscopy:chronic patients shallow ulcer scar polyp,Differential diagnosis,acute dysenteryamebic dysentery Entamoeba histolytica stool:reddish brown,like jam flask-shaped ulcer,amebic trophozoite,Differential diagnosis,enteritis caused by E.Coli,salmonella,virus.intussusception:jam-like stools,abdominal mass absence of fever,Differential diagnosis,chronic dysenteryrectal&colonic carcinoma:no cure for long-term,drop of weight of body non-specific ulcer colitis:no cure for long-term,culture of stool is negative,Differential diagnosis,sigmoidoscopy:hemorrhage,ulcer,lead pipe.chronic schistosomiasis Japonica contact with the contaminated water hepatomegaly and splenomegaly founding the ovum of schistosomiasis Japonica,Differential diagnosis,toxic dysentery encephalitis B:highfever,convulsion,coma.24hcirculatory failurestool examinationCSFmeningeal irritationSpecific IgM,Treatment,Common dysenteryToxic dysentery general treatmentpathogenic treatment:ofloxine Ampicillin given by IV,Treatment,symptomatic treatment:control of high fever,convulsion:subhibernation treatment of shock:same as ECMtreatment of cerebral edema:20%mannitol,Treatment,chronic dysenterygeneral therapy:live diet,nurishing avoid overwork exercise.,etiologic therapy:sensitive antibiotics used in turn or combined use according to results of culture enema expectant treatment.,Treatment,Prevention,Control the source of infection:until culture negative Interrupting the route of transmission:Protecting the susceptible population:F2a-secretary IgA protect 80%-6-12mon,