Bacillary Dysentery (shigellosis)

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Bacillary Dysentery (shigellosis)

• Dept. Of Infectious Disease
• Wang Jingyan

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Definition

• Acute infectious disease of intestine caused by
  dysentery bacilli
• Place of lesion sigmoid rectum
• Pathological feature diffuse fibrious exudative
  inflammation
• Clinical manifestation fever, abdominal pain,
  diarrhea, tenesmus , stool mixed with blood,
  mucus pus. Even companied with marked toxicity
  and shock,toxic-encepholopthy.

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Etiology

• Causative organism dysentery bacilli, genus
  shigella, gram-stain negative, short
  rod,non-motile
• Groups 4 groups 50 serotypes
• - S. Dysenteriae-the most sever
• - S. Flexnerii-the epidemic group
  and easily turn to chronic
• - S. Boydii-tropical and subon
• - S. sonnei-the most mild

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Etiology

• Pathogenicity
• - virulence
• (endotoxin) - interotoxin (exotoxin)
• - invasiveness
• (attach-penetrate-multiply)
• Resistance Strong.1-2week in fruits,vegetable
  and dirty soil. heat for 60? 30 min

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Epidemiology

• Source of infection
• - patients
• - carriers
• Route of transmission fecal-oral route
• Suceptibility of populationimmunity after
  infection is short and unstead,no cross-immune
• Epidemic features
• - season summer fall
• - Flexneri, Soneii, dysentery
• - age younger children

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Pathogenesis

• Number of bacteria
• toxicity
• immunity
• invasiveness
• - attachment
• - penetration
• - multiplication

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Pathogenesis-common
Bacteria
intestine
Penetrate mucus
Normal bacteria flora sIg A
Multiply in epithelia cell proper lamina
Prevent attaching
endotoxin
Inflammation vessel contraction
Endogenous pyrogen
fever
Superficial mucosal in,nec and ulcer
Diarrhea mixed with blood pus, abdominalache
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Pathogenesis-toxic
Strong - allergy to endotoxin
Demethyl-adrenaline
Micro-circulatory failure
Shock, DIC, cerebral edema
cerebral hernia
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Pathology

• Site of lesion entire large bowel-colone,
  sigmoid rectum
• Feature
• acute diffuse fibrinous exudative inflammation,
  hyperemia, edema, leukocyte infiltration,
  superficial necrosis
• chronic edema, polypoid hyperplasis
• toxic endothelial cell of micro-capillary
  necrosis

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Clinical manifestation

• Incubation period 1-2 day, (Hrs. To 7 days)
• Acute dysentery
• common type
• onset in sudden, shiver, high fever
• abdominal pain
• diarrheastool mixed with blood, mucus pus
• tenesmus, continence

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Clinical manifestation

• Acute dysentery
• mild type
• caused by S. sonnei
• low fever or no fever
• Abdominal pain is mild
• stool mixed with mucus, without blood pus
• diagnosis by isolation bacteria

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Clinical manifestation

• Acute dysentery
• Toxic type
• Age 2 to 7 yrs.
• Abrupt onset, high fever, Trise to 40oC
• Listlessness,lethargy,convulsion,coma.
• circulatory respiratory collapse
• diarrhea mild or absent at beginning
• shock form septic shock
• brain form respiratory failure
• mixed form

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Clinical manifestation

• Chronic dysentery gt 2 months
• Chronic delayed typediahhrea long-time and
  repeated
• Chronic obscure type acute history in 1 year, no
  symptoms, stool culture Pos. or sigmoidscopy
• Acute attack type same as common acute dysentery

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Laboratory Findings

• Blood picture total WBC count increase,
• neutrophils
  increase
• Stool examination
• direct microscopic exam. WBC, RBC, pus cells
• bacteria culture
• Sigmoidoscope shallow ulcer,scar, polyps

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Differential diagnosis

• Acute dysentery
• Amebic dysentery
• Entameba histolytica
• stool reddish brow, like jam
• flask-shaped ulcer,Amebic trophozoite
• Enteritis caused by E. Coli, salmonella,viral
  diarrhea
• Intussusception jelly-like stools, abdominal
  mass and absence of fever

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Differential diagnosis

• Chronic dysentery
• Rectal colonic carcinoma no cure for
  long-term,drop of weiht of body
• non-specific ulcer colitis no cure for
  long-term,culture of stool is negetive,
  sigmoidoscopehemorrhage, ulcer,lead pipe.
• Chronic schistosomiasis Japonica
• a. co ntact with the disease-water
• b. hepatomegaly and splenomegaly
• c .founding the ova of schistosomiasis
  Japonica

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• Toxic dysentery
• Encephalitis B
• brain formJapaness B encephalitis
• a.stool
• b.CFS-IgM
• c.slowly
• d.shock rarely

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Treatment

• Common dysentery
• Toxic dysentery
• general treatment
• Pathogenic treatment ofloxine or Amp. Given by
  IV
• Synptomatic treatmentControl high fever,
  convulsion sub-winter sleep
• Treatment of shocksame as ECM
• Treatment of cerebral edema same as EBC

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Treatment

• Chronic dysentery
• General therapylive,nurishing,diet,avoid
  overwork,excise.
• Etiologic therapy sensitive antibiotics used in
  turn or combined useaccording to results of
  cultureenemaexpectant treatment.

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Prevention

• Control the source of infection until culture
  negative
• Interruptted the route of transmission method of
  mainly
• Protct the susceptabilityF2a-secratory IgA
  protect 80-6-12mon
• return