Dept. of Infectious Diseases 杨绍基

Amebic dysentery Definition Parasitic disease, Entamoeba histolytica, trophozoites induce submucosal ulcerations abdominal pain, diarrhea, strawberry jam-like stool

Etiology Five species of Entamoeba: E. histolytica (Pathogenic), E. dispar E. coli, E. hartmanni, E. gingivalis Life cycle : cyst postcyst precyst large trophozoite

Epidemiology Source of infection Route of transmission Susceptibility Epidemiological characteristics

Pathogenesis E. histolytica trophozoites cytolytic enzymes and pseudopodia invade colonic tissue flask-shaped submucosal ulcerations may cause amebic liver abscess, bleeding, perforation, peritonitis

Clinical Manifestations Incubation period: 1~4 weeks Clinical forms: acute typical form mild form fulminant form asymptomatic form chronic form

Laboratory findings normal leukocyte count eosinophilia fecal microscopy: RBC, WBC and mucus erythrophagous mobile trophozoites cysts with four nucleuses

Complications amebic liver abscess intestinal perforation, peritonitis intestinal hemorrhage intestinal ameboma amebic appendicitis perianal rectal fistulas

Diagnosis Epidemiological data Clinical manifestations Laboratory findings

Differential Diagnosis Shigellosis Schistosomiasis Colonic carcinoma Rectal cancer Non-specific ulcerative colitis

Treatment Supportive treatment Symptomatic treatment Etiological treatment metronidazole 400mg tid for 10 days, for adults or tinidazole 2.0 qd 5 days, for adults furamide 500mg tid for 10 days Emetine chloroquine paromomycine chiniofon etc are out of day.

Prophylaxis To control the sources of infection To interrupt the routes of transmission No vaccine is available

AMEBIC LIVER ABSCESS commonest complication of intestinal amebiasis

Pathogenesis and pathology E. histolytica trophozoites portal vein pseudopodia amebic liver abscess liver tissue cytolytic enzymes rupture peritonitis

Clinical Manifestations gradual onset abdominal pain fever anemia lose of appetite and body weight

Diagnosis Epidemiological data eating habit, history of diarrhea Clinical manifestations gradual onset, pain in liver region, fever, anemia, lose of body weight, tenderness of the enlarged liver Laboratory findings liquefied space-occupying lesion, specific antibodies, specific antigen

Differential diagnosis bacterial liver abscess congenital liver cyst primary hepatocellular carcinoma liver metastasis of carcinomas liver hydatid disease liver tuberculosis

Treatment Supportive treatment Symptomatic treatment Etiological treatment metronidazole 400mg tid for 10 days or tinidazole 2.0 qd for 5 days antibiotics if necessary

SHIGELLOSIS

Etiology non-motile, non-spore-forming, Gram negative bacillus four species: Shigella dysenteriae S. flexneri S. boydii S. sonnei

Epidemiology Source of infection patients and carriers Route of transmission fecal-oral Susceptibility universal Epidemiological characteristics

Pathogenesis Shigella living in colonic epithelial cells release endotoxin multiply superficial mucosal ulcerations

Clinical Manifestations acute typical form: acute onset, high fever, abdominal pain, diarrhea, tenesmus, stool with blood, mucus, non-mixed with fecal material, little amount each time mild form toxic form chronic form

Complications Shigella septicemia arthritis hemolytic uremic syndrome

Diagnosis Epidemiological data Clinical manifestations Laboratory findings pathogenic bacteria culture yield Shigella

Differential diagnosis amebic dysentery bacterial food poisonings campylobacter enteritis Escherichia enteritis acute schistosomiasis ulcerative colitis rectal carcinoma Japanese encephalitis for toxic form

Treatment Supportive treatment Symptomatic treatment Etiological treatment quinolones: ofloxacin, ciprofloxacin ampicillin and gentamicin for toxic form cases

Prevention Control the source of infection Interrupt the route of transmission Protect susceptible persons

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