痢疾Bacillaryysentery.ppt

Bacillary Dysentery (shigellosis),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 severe S. flexneri: the epidemic group and easily turn to chronic S. boydii: tropical and subon S. 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 carriers Route of transmission: fecal-oral route Suceptibility of population: immunity after infection is short and unsteady, no cross-immune,Epidemiology,Epidemic features: season: summer & fall Flexneri, Soneii, dysentery age: younger children,Pathogenesis,number of bacteria toxicity invasiveness attachment penetration multiplication immunity,common,Bacteria,intestine,normal intestinal flora sIg A,prevent attaching,penetrate mucus,multiply in epithelia cell & proper lamina,endotoxin,endogenous pyrogen,fever,inflammation vessel 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 dysentery common type mild type toxic type,Clinical manifestation,common type: (typical type) acute onset , shiver, high fever abdominal pain(tenderness) diarrhea: stool mixed with mucus, blood & pus tenesmus, 1 week,Clinical manifestation,mild type: ( atypical type) caused by S. sonnei low fever or no fever abdominal pain is mild stool mixed with mucus, without blood & pus diagnosis by isolation of bacteria 37d,Clinical manifestation,toxic type: age: 2 to 7 yrs. abrupt onset, high fever, T 40oC dysphoria, lethargy, convulsion repeatedly,coma. circulatory & respiratory collapse diarrhea 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 months chronic delayed type:chronic obscure type acute 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 sigmoidscopy acute 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 cells bacteria culture: PCR:DNA Sigmoidoscopy: chronic patients shallow ulcer scar polyp,Differential diagnosis,acute dysentery amebic 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 dysentery rectal & 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. 24h circulatory failure stool examination CSF meningeal irritation Specific IgM,Treatment,Common dysentery Toxic dysentery general treatment pathogenic treatment : ofloxine Ampicillin given by IV,Treatment,symptomatic treatment: control of high fever,convulsion: subhibernation treatment of shock: same as ECM treatment of cerebral edema: 20% mannitol,Treatment,chronic dysentery general therapy: live diet, nurishing avoid overwork exercise.,etiologic therapy: sensitive antibiotics used in turn or combined