1. Bacillary Dysentery (shigellosis)
Dept. Of Infectious Disease
Wang Jingyan

2. 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.

3. 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

4. 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

5. Epidemiology Source of infection: - patients - carriers
Route of transmission: fecal-oral route
Suceptibility of population:immunity after infection is short and unstead,no cross-immune
Epidemic features:
- season: summer & fall
- Flexneri, Soneii, dysentery
- age: younger children

6. Pathogenesis Number of bacteria toxicity immunity invasiveness
- attachment
- penetration
- multiplication

7. 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

8. Pathogenesis-toxic Strong - allergy to endotoxin Demethyl-adrenaline
Micro-circulatory failure
Shock, DIC, cerebral edema
cerebral hernia

9. 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

10. Clinical manifestation
Incubation period: 1-2 day, (Hrs. To 7 days)
Acute dysentery
common type:
onset in sudden, shiver, high fever
abdominal pain
diarrhea:stool mixed with blood, mucus & pus
tenesmus, continence

11. 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

12. 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

13. Clinical manifestation
Chronic dysentery: > 2 months
Chronic delayed type:diahhrea 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

14. 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

15. 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

16. 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, sigmoidoscope:hemorrhage, ulcer,lead pipe.
Chronic schistosomiasis Japonica
a. co ntact with the disease-water
b. hepatomegaly and splenomegaly
c .founding the ova of schistosomiasis Japonica

17. Toxic dysentery Encephalitis B brain form:Japaness B encephalitis
a.stool
b.CFS-IgM
c.slowly
d.shock rarely

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

19. Treatment Chronic dysentery
General therapy:live,nurishing,diet,avoid overwork,excise.
Etiologic therapy: sensitive antibiotics used in turn or combined use;according to results of culture;enema;expectant treatment.

20. Prevention Control the source of infection: until culture negative
Interruptted the route of transmission: method of mainly
Protct the susceptability:F2a-secratory IgA protect 80%-6-12mon
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