6. Pathogen Incubation Period
Bacillus cereus, Staphylococcus aureus 1-8 hr
Clostridium perfringens 8-24 hr
Vibrio cholerae, enterotoxigenic
Escherichia coli, Klebsiella pneumoniae,
Aeromonas species
8–72 h
Enteropathogenic and enteroadherent E.
coli, Giardia organisms
1-8 days
C. difficile 1–3 d
Hemorrhagic E. coli 12–72 h
Rotavirus and norovirus 1–3 d
Salmonella, Campylobacter, and
Aeromonas species, Vibrio
parahaemolyticus, Yersinia
12 h–11 d
11. 3 . Cytoxin Producers
C. difficile
4 . Invasive
Rotavirus,Salmonella,Campylobacter
V
. parahmolyticus,Shigella
12. • Infectious diarrhea may be associated with
systemic manifestations
– Reiter's syndrome - arthritis, urethritis, and
conjunctivitis may accompany or follow infections
by Salmonella, Campylobacter, Shigella, and
Yersinia.
– Hemolytic-uremic syndrome - enterohemorrhagic
E. coli (O157:H7) and Shigella
13. Clinical features
⚫Preformed & Entero toxin
Profusewaterydiarrhoea + vomitting
•Enteroadherant
High fever + Abdominal cramps
•Invasive – Bloodydiarrhoea
14. Other Causes
⚫A/E of certain drugs – Antibiotics,NSAIDs,
Antiarrythmics, Bronchodialaters,Antacids
⚫Occlusiveor Non occlusivecolitis
Above 50 years
Lowerabdominal pain preceeding
watery, then bloodydiarrhoea
16. • Most episodes of acute diarrhea are mild and self-limited
and do not justify the cost and potential morbidity rate of
diagnostic or pharmacologic interventions.
• Indications for evaluation include
– profuse diarrhea with dehydration,
– grossly bloody stools,
– fever 38.5°C (101°F),
– duration >48 h without improvement,
– recent antibiotic use,
– new community outbreaks,
– associated severe abdominal pain in patients >50 years,
– elderly (70 years)
– immunocompromised patients.
17.
18. History and Physical Exam
⚫Main goals
⚫Estimate the level of dehydration
⚫Identify likely causes on the basis of
history and clinical findings
21. Investigations
• The cornerstone of diagnosis in those
suspected of severe acute infectious diarrhea
is microbiologic analysis of the stool.
• Workup includes
a) cultures for bacterial and viral pathogens,
b) direct inspection for ova and parasites
c) immunoassays for certain bacterial toxins (C.
difficile), viral antigens (rotavirus), and protozoal
antigens (Giardia, E. histolytica).
22. • If stool studies are unrevealing, flexible sigmoidoscopy
with biopsies and upper endoscopy with duodenal
aspirates and biopsies may be indicated.
• Structural examination by sigmoidoscopy, colonoscopy,
or abdominal CT scanning (or other imaging
approaches) may be appropriate in patients with
uncharacterized persistent diarrhea to exclude IBD or
as an initial approach in patients with suspected
noninfectious acute diarrhea caused by ischemic colitis,
diverticulitis, or partial bowel obstruction.
25. ⚫Empirical therapy
Febrile – Ciprofloxacin 500 mg bid for 3-5 days
Suspected giardiasis – Metronidasole
250 mg qid for 7 days
⚫Antibioticprophylaxis
Cotrimoxazole,Ciprofloxacin
26.
27. In Summary
⚫Extremelycommon
⚫Most isviral in origin and self-limited
⚫A good H&P iscrucial
⚫Warning signs include high fever, severe
abd. pain, dehydration, and bloody stool
⚫Fluid replacement is most important
⚫Antibioticsare usually not necessary
