《医学痢疾》课件.ppt

1、Bacillary Dysentery(shigellosis)Dept.Of Infectious DiseaseHuang FenHuang FenDefinitionAcute infectious disease of intestine caused by dysentery bacilli(genus shigella)Place of lesion:sigmoid&rectum Pathological feature:diffuse fibrious exudative inflammationDefinition Clinical manifestation:fever,ab

2、dominal 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 serotypesEtiologyS.dysenteriae:the most severeS.flexneri:the e

3、pidemic group and easily turn to chronicS.boydii:tropical and subonS.sonnei:the most mildEtiologyPathogenicity:-virulence endotoxin-exotoxin -invasiveness (attach-penetrate-multiply)Resistance:Strong,1-2week in fruits,vegetable and dirty soil,heat for 60 30 min EpidemiologySource of infection:patien

4、ts and carriersRoute of transmission:fecal-oral routeSuceptibility of population:immunity after infection is short and unsteady,no cross-immuneEpidemiology Epidemic features:season:summer&fallFlexneri,Soneii,dysenteryage:younger children Pathogenesis number of bacteria toxicity invasivenessattachmen

5、tpenetrationmultiplication immunity commonBacteriaintestinenormal intestinal florasIg A prevent attachingpenetrate mucusmultiply in epithelia cell&proper laminaendotoxinendogenous pyrogenfeverinflammationvessel contractionsuperficial mucosal necrosis and ulcerdiarrhea mixed with blood&pus,abdominal

6、painPathogenesis-toxicstrong-allergy to endotoxindemethyl-adrenaline DICmicro-circulatory failure shock,cerebral edema cerebral herniaPathology site of lesion:entire large bowel-sigmoid colon&rectum feature:acute:diffuse fibrinous exudative inflammation,Pathology hyperemia,edema,leukocyte infiltrati

7、on,superficial necrosis,ulcer.chronic:edema,polypoid hyperplasia,toxic:colon:hyperemia,edema,micro-capillary was invadedClinical manifestationIncubation period:1-2 day,(hours to 7 days)Acute dysenterycommon type mild typetoxic typeClinical manifestationcommon type:(typical type)acute onset,shiver,hi

8、gh feverabdominal pain(tenderness)diarrhea:stool mixed with mucus,blood&pustenesmus,1 week Clinical manifestationmild type:(atypical type)caused by S.sonneilow fever or no feverabdominal pain is mildstool mixed with mucus,without blood&pusdiagnosis by isolation of bacteria37dClinical manifestationto

9、xic 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 fa

10、ilure mixed formClinical manifestation chronic dysentery:2 monthschronic delayed type:chronic obscure typeacute attack typeClinical manifestationchronic delayed type:long-time and repeated abdominal pain,diarrhea,stool mixed with mucus,blood&pus.with fatigue,anemia,malnutrition.Clinical manifestatio

11、nchronic obscure type:acute history in 1 year,no symptoms,stool culture positive or sigmoidscopyacute attack type:same as common acute dysenteryLaboratory Findings Blood picture:WBC count increase,(1020109/L)neutrophils increase Stool examination:gross examination:stool mixed with mucus,blood&pus.La

12、boratory Findingsdirect microscopic examination:WBC,RBC,pus cellsbacteria culture:PCR:DNASigmoidoscopy:chronic patients shallow ulcer scar polypDifferential diagnosis acute dysenteryamebic dysentery Entamoeba histolytica stool:reddish brown,like jam flask-shaped ulcer,amebic trophozoiteDifferential

13、diagnosisenteritis caused by E.Coli,salmonella,virus.intussusception:jam-like stools,abdominal mass absence of feverDifferential 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 negat

14、ive,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.24h cir

15、culatory failure stool examination CSF meningeal irritation Specific IgM TreatmentCommon dysenteryToxic dysentery general treatmentpathogenic treatment:ofloxine Ampicillin given by IVTreatmentsymptomatic treatment:control of high fever,convulsion:subhibernation treatment of shock:same as ECM treatme

16、nt of cerebral edema:20%mannitolTreatment 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.TreatmentPrevention Control the source of infection:until culture negative Interrupting the route of transmission:Protecting the susceptible population:F2a-secretary IgA protect 80%-6-12mon