Dept. of Infectious Diseases

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AMEBIASIS

• Dept. of Infectious Diseases
• ???

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Amebic dysentery

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

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

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• Epidemiology
• Source of infection
• Route of transmission
• Susceptibility
• Epidemiological characteristics

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

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• Clinical Manifestations
• Incubation period 14 weeks
• Clinical forms acute typical form
• mild form
• fulminant form
• asymptomatic form
• chronic form

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

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

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• Diagnosis
• Epidemiological data
• Clinical manifestations
• Laboratory findings

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

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• 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.

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

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• AMEBIC LIVER ABSCESS
• commonest complication of intestinal
  amebiasis

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

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

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• 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

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

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

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• SHIGELLOSIS

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

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

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

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• 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

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• Complications
• Shigella septicemia
• arthritis
• hemolytic uremic syndrome

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

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

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

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

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• Thank you for listening