A Day at the Fair

1
A Day at the Fair

• Dr. Jane Student
• Flamingham General Hospital

2
Patient Background

• Mr. Burgas upon hospital admission
• 75 year old man
• Acute abdominal discomfort
• Copious bloody diarrhea every 20 minutes
• 37.5o C temperature- normal
• Pulse and BP both normal

3
Later that Day

• Mr. B is displaying more symptoms
• Skin pale
• Urine output very low
• Lethargic
• Vomited once
• Still voiding bloody diarrhea

4
Where has He Been??

• After talking to Mr. Bs wife she tells us that
  they has been to a country fair in their town
  four days prior
• Their son-in-law, who had accompanied them, is
  also exhibiting these same symptoms
• Mrs. B is fine

5
Whats going on

• Mr. B has a gastrointestinal infection
• Most common are
• Shigella
• Salmonella
• Campylobacter jejuni
• E. coli

6
E. Coli 0157H7

• First recognized as a disease causing bug in 1982
• This was following an outbreak linked to a fast
  food chain

7
Escherichia Coli Serogroups

• Four main serogroups
• 026.H11- Enteropathogenic E. coli (EPEC)
• 0157.H7- Enterohemorragic E. coli (EHEC)
• 0148.H28- Enterotoxigenic E. coli (ETEC)
• 04.H5- Urinary Tract Infections (UTI's)

8
Enterohemorragic E. coli (EHEC)

• EHEC as typified by the serotype 0157H7
• Causes hemorrhagic colitis
• CHARACTERIZED BY COPIOUS BLOODY STOOL
• EHEC associates with cells through the afimbrial
  adhesion intimin and type 1 pili
• The defining characteristic of EHEC is the
  production of phage-encoded Stx

9
Enterohemorragic E. coli (EHEC)

• The Stx produced by the EHEC strains
• Responsible for the GI effects (pain, discomfort)
• After absorption-once in circulation appears to
  be responsible for most kidney damage during HUS

10
Enterohemorragic E. coli (EHEC) cont.

• Strain also express hemolysin intense
  inflammatory response
• EHEC also expresses a specialized iron transport
  system- it allows them to utilize the iron bound
  to heme ( derived from eukaryotic cells lysed by
  hemolysin)

11
Back to the Patient

• Blood Sample
• Blood
• CHOC
• MAC
• ANA-LIVER

• STOOL
• MAC-containing sorbitol instead of lactose
• BLOOD
• PEA
• HE
• SS
• XLD
• CAMPY

12
Self Limiting

• An infecting of E. coli 0157H7 is known to be
  self limiting and does not need antibiotic
  treatment just supportive care is needed
• Antimotility treatment is NOT to be utilized
• Antibiotic treatment is detrimental to the
  patient
• But HUS- Hemolytic-uremic Syndrome may result

13
Hemolytic-uremic Syndrome

• HUS is a direct result of the effects of
  verotoxin on renal endothelial cells
• Results in
• Cell swelling
• Local intervascular coagulation with platelet
  aggregation
• Damage to RBC
• Reduction in glomerular filtration

14
Hemolytic-uremic Syndrome

• Tends to appear in patients 5-9 days after the
  onset of GI symptoms
• Mostly in very young and elderly patients or
  those who are immunocompromised

15
Treatment of HUS

• Most commonly used treatments
• Kidney dialysis
• Hemofiltration
• Transfusion of packed erythrocytes
• Platelet infusions

16
Mr. Burgas.

• Patients stool tested positive for the verotoxin
  produced by E. coli 0157h7, as did his
  son-in-law
• After discussing these finding with the patient,
  it was determined that the father and son-in-law
  has shared a hamburger at the town fair days prior

17
WHERE DID IT COME FROM?

• Two possible case scenarios
• 1. Tainted meat- the hamburger shared by them men
  may have contained E coli 0157h7, and the meat
  was not adequately cooked
• 2. Well water from the site of the fair and be
  contaminated due to cattle farms near by
• These two case needed to be brought to the
  attention of the fair operator and land owner

18
Whats new with E. coli 0157H7

• One does not know if they have a product tainted
  with E. coli 0157H7 just by sight or smell
• A test is being designed to give and instant
  reading of E. coli 0157H7 contamination

19
Whats new with E. coli 0157H7

• The test uses thin layer film to act as the
  binding area fro the bacterial toxins
• When it binds to the film it triggers a color
  change

20
Whats new with E. coli 0157H7

• The film of composed of a long diacetylene lipid
• This molecule is similar to the building blocks
  for cell membrane

21
Whats new with E. coli 0157H7

• The red color change indicates a a presence of
  the toxin
• These sensors are so inexpensive they can be
  placed on all high risk good products