1. Bacillary Dysentery (shigellosis)

2. Definition
Acute infectious disease of intestine caused by dysentery bacilli(genus shigella)
Place of lesion: sigmoid & rectum
Pathological feature:
diffuse fibrious exudative
inflammation

3. Definition Clinical manifestation: fever, abdominal pain, diarrhea,
tenesmus , stool mixed with
mucus blood, & pus.
shock,
toxic-encepholopthy.

4. Etiology Causative organism: dysentery bacilli, genus shigella,
gram-stained negative,
non-motile short rod,
Groups: 4 serogroups &47 serotypes

5. 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

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

7. 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

8. Epidemiology Epidemic features: season: summer & fall
Flexneri, Soneii, dysentery
age: younger children

9. Pathogenesis toxicity invasiveness immunity number of bacteria
attachment
penetration
multiplication
immunity

10. common Bacteria intestine penetrate mucus normal intestinal flora
sIg A
multiply in epithelia cell & proper lamina
prevent attaching
endotoxin
inflammation
vessel contraction
endogenous pyrogen
fever
superficial mucosal necrosis and ulcer
diarrhea mixed with blood & pus, abdominal pain

11. Pathogenesis-toxic strong - allergy to endotoxin
demethyl-adrenaline DIC
micro-circulatory failure
shock, cerebral edema
cerebral hernia

12. Pathology site of lesion: entire large bowel- sigmoid colon & rectum
feature:
acute: diffuse fibrinous
exudative inflammation,

13. Pathology hyperemia, edema, leukocyte
infiltration, superficial necrosis,
ulcer.
chronic: edema,
polypoid hyperplasia,
toxic:
colon: hyperemia, edema,
micro- capillary was invaded

14. Clinical manifestation
Incubation period:
1-2 day, (hours to 7 days)
Acute dysentery
common type
mild type
toxic type

15. Clinical manifestation
common type: (typical type)
acute onset ,
shiver, high fever
abdominal pain(tenderness)
diarrhea: stool mixed with
mucus, blood & pus
tenesmus,
1 week

16. 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
3~7d

17. 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

18. Clinical manifestation
shock form: septic shock
brain form:
dysphoria,lethargy,convulsion
repeatedly,coma, brain hernia.
respiratory failure
mixed form

19. Clinical manifestation
chronic dysentery: > 2 months
chronic delayed type:chronic obscure type
acute attack type

20. Clinical manifestation
chronic delayed type:
long-time and repeated abdominal
pain, diarrhea, stool mixed with
mucus, blood & pus.
with fatigue, anemia, malnutrition.

21. 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

22. Laboratory Findings WBC count increase, (10~20×109/L)
Blood picture:
WBC count increase,
(10~20×109/L)
neutrophils increase
Stool examination:
gross examination: stool mixed with
mucus, blood & pus.

23. Laboratory Findings Sigmoidoscopy: direct microscopic examination:
WBC, RBC, pus cells
bacteria culture:
PCR:DNA
Sigmoidoscopy:
chronic patients
shallow ulcer
scar
polyp