GI Infection

Question 1

Gastroenteritis is an infection of the GIT. What % of gastroenteritis cases do not isolate the pathogen?

1 - 5%
2 - 15%
3 - 25%
4 - 50%

Answer 1

4 - 50%

Question 2

All of the following are causes of gastroenteritis, an infection of the GIT. Which of the following is the most common cause?

1 - Viruses (Norovirus)
2 - Campylobacter
3 - Salmonella
4 - Shigella
5 - C.difficile

Answer 2

1 - Viruses (Norovirus)
– accounts for 50%

• Viruses (Norovirus) – 50%
• Campylobacter – 20%
• Salmonella – 15%
• Shigella – 5%
• C.difficile – 5%

Question 3

Which of the following are common precipitating factors in patients with suspected gastroenteritis?

1 - history of travel
2 - unusual food/takeaway
3 - other household members affected
4 - all of the above

Answer 3

4 - all of the above

Question 4

Which of the following is NOT a common symptoms patients with gastroenteritis present with?

1 - Diarrhoea
2 - Crampy abdominal pain
3 - Vomiting
4 - Fever, headache, myalgia
5 - AKI

Answer 4

5 - AKI

Question 5

The most common pathogens causing gastroenteritis are:

• Viruses (Norovirus)
• Campylobacter
• Salmonella
• Shigella
• C.difficile

Which 3 of these typically cause blood diarrhoea?

Answer 5

• Viruses (Norovirus), specifcally enterovirus
• Campylobacter
• Shigella

Question 6

The most common pathogens causing gastroenteritis are:

• Viruses (Norovirus)
• Campylobacter
• Salmonella
• Shigella
• C.difficile

Which of these is most likely to cause abdominal cramps?

Answer 6

• Campylobacter

Question 7

The most common pathogens causing gastroenteritis are:

• Viruses (Norovirus)
• Campylobacter
• Salmonella
• Shigella
• C.difficile
• Bacillus cereus

Which of these typically causes vomiting?

Answer 7

• Bacillus cereus

Question 8

The most common pathogens causing gastroenteritis are:

• Viruses (Norovirus)
• Campylobacter
• Salmonella
• Shigella
• C.difficile
• Bacillus cereus

Which of these typically causes systemic symptoms such as fever, headache and myalgia?

Answer 8

• Shigella

Question 9

Gastroenteritis is an infection of the GIT. These typically do not need treatment and resolve in what time period?

1 - 12-24h
2 - 24-48h
3 - 24-96h
4 - >120h

Answer 9

3 - 24-96h

Question 10

Gastroenteritis typically resolves within 24-96h and investigations are not required. However, if investigations are required which of the following is NOT typically performed?

1 - stool MC+S (microscopy, culture+sensitivity)
2 - flexible sigmoidoscopy
3 - abdominal MRI
4 - abdominal X-ray

Answer 10

3 - abdominal MRI

Question 11

Gastroenteritis typically resolves within 24-96h and investigations are not required. However, if diarrhoea continues for >2 weeks, what investigation can often be performed?

1 - colonoscopy
2 - flexible sigmoidoscopy
3 - abdominal MRI
4 - abdominal drain

Answer 11

2 - flexible sigmoidoscopy

Question 12

Gastroenteritis typically resolves within 24-96h and investigations are not required. However, an abdominal chest X-ray can often be performed to rule out what?

1 - blocked common bile duct
2 - gallstones
3 - dilation of the colon (toxic megacolon)
4 - all of the above

Answer 12

3 - dilation of the colon (toxic megacolon)
- >10cm in size

Question 13

Which of the following is NOT used in the management of acute gastroenteritis?

1 - anti-diarrhoeal
2 - oral intake
3 - IV fluids
4 - anti-emetics (metoclopramide)
5 - empirical antibiotics

Answer 13

1 - anti-diarrhoeal

Question 14

In the management of acute gastroenteritis, should anti-diarrhoeals be used?

Answer 14

• no
• we want to get rid of the pathogen in the diarrhoea

Question 15

Is metabolic alkalosis or acidosis more common in acute gastroenteritis?

Answer 15

• metabolic alkalosis
• due to loss of electrolytes, specifically HCO3-

Question 16

What acute disorder can occur due to gastroenteritis?

1 - acute liver failure
2 - acute cardiogenic shock
3 - acute kidney injury
4 - all of the above

Answer 16

3 - acute kidney injury
- loss of fluid causes dehydration and a drop in BP
- low BP causes reduces eGFR and AKI

Question 17

If a campylobacter, a bacteria causes of gastroenteritis is present then a Quinolones antibiotic, ciprofloxacin can be considered in all of the following except:

1 - patient is immunocompromised
2 - patient is pregnant
3 - patients symptoms are deteriorating
4 - patients symptoms are prolonged >1 week
5 - patient requests immediate treatment with antibiotics

Answer 17

5 - patient requests immediate treatment

Question 18

If salmonella, a bacteria is the causes of gastroenteritis, antibiotics should only be used in which 1 of the following?

1 - extra intestinal infection is present
2 - patient is immunocompromised
3 - patient is pregnant
4 - patients symptoms are deteriorating

Answer 18

1 - extra intestinal infection is present
- if this is not present, antibiotics can just prolong the infection

Question 19

If shigella, a bacteria is the causes of gastroenteritis, antibiotics should only be used in which 1 of the following?

1 - extra intestinal infection is present
2 - patient is immunocompromised
3 - patient is pregnant
4 - patients symptoms are deteriorating
5 - patient is infected with virulent species

Answer 19

5 - patient is infected with virulent species
- Shigella shigae or Shigella dysenteriae

Question 20

If Yersinia enterocolitica, a bacteria is the causes of gastroenteritis, then antibody testing is required. Which GIT condition has this been shown to mimic by affecting the terminal ileum?

1 - coeliac disease
2 - ulcerative colitis
3 - crohns disease
4 - irritable bowel syndrome

Answer 20

3 - crohns disease

Question 21

If E. coli -157, a bacteria is the causes of gastroenteritis, this can lead to which of the following?

1 - hemorrhagic colitis
2 - thrombocytopenia
3 - microangiopathic hemolytic anemia
4 - haemolytic - uraemic syndrome (HUS)
5 - all of the above

Answer 21

5 - all of the above
- haemolytic - uraemic syndrome (HUS) is a syndrome characterised by AKI with thrombocytopenia and microangiopathic hemolytic anemia

Question 22

If Clostridium difficile, a bacteria is the causes of gastroenteritis, this can be very dangerous and can cause diarrhoea, systemic upset and colitis. What is the mortality of this condition?

1 - 0.3%
2 - 3%
3 - 13%
4 - 30%

Answer 22

4 - 30%
- can cause persistent diarrhoea following antibiotic treatment, especially in the elderly.

Question 23

Clostridium difficile, a bacteria can causes of gastroenteritis and is dangerous with a mortality of 30%. This can be detected using C.diff toxin A+B, but which of the following is the 1st line treatment for this typically?

1 - metronidazole
2 - vancomycin
3 - fidaxomicin
4 - co-amoxicillin

Answer 23

2 - vancomycin

• all 3 of these could be used though

Question 24

Norovirus is the most common non-bacterial cause of vomiting and diarrhoea. How is this typically transmitted?

1 - swimming pool water
2 - uncooked food
3 - inset bite
4 - contaminated drinking water

Answer 24

2 - uncooked food

Question 25

Mycobacterium tuberculosis or TB is bacterial species. Typically TB can infect the GIT at the ileocaecal valve. What symptoms can this cause? 1 - weight loss 2 - abdominal pain 3 - fevers 4 - palpable mass 5 - lymphocytosis 6 - all of the above

Answer 25

6 - all of the above

Question 26

Mycobacterium tuberculosis or TB is bacterial species. Typically TB can infect the GIT at the ileocaecal valve. Although it is able to cause all of the following, which GIT condition is TB most often confused with in the GIT? 1 - appendicitis 2 - bowel obstruction 3 - crohns disease 4 - perforation 5 - peritonitis

Answer 26

3 - crohns disease - treated with the same approach as pulmonary TB

Question 27

Mycobacterium tuberculosis or TB is bacterial species. Typically TB can infect the GIT at the ileocaecal valve. Imaging can be used, such as CT or MRI of the bowel to diagnose the patient. What is the most common finding on imaging? 1 - bowel obstruction 2 - perforation 3 - toxic megacolon 4 - bowel wall thickening

Answer 27

4 - bowel wall thickening - confirmed via biopsy using sigmoidoscopy or colonoscopy

Question 28

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica. What is the most common cause of this infection? 1 - swimming pool water 2 - uncooked food 3 - inset bite 4 - faecally contaminated food or water

Answer 28

4 - faecally contaminated food or water

Question 29

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica, which is transmitted by faecally contaminated food or water. What % of patients are asymptomatic despite being infected? 1 - 0.9% 2 - 9% 3 - 49% 4 - >90%

Answer 29

4 - >90%

Question 30

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica, which is transmitted by faecally contaminated food or water. Which GIT condition can this present in a similar way as when dysenteric symptoms are present? 1 - coeliac disease 2 - ulcerative colitis 3 - crohns disease 4 - irritable bowel syndrome

Answer 30

2 - ulcerative colitis - rare, but can cause toxic megacolon - dysentery = blood and mucus present in diarrhoea

Question 31

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica, which is transmitted by faecally contaminated food or water. Which GIT condition can this present in a similar way as when non-dysenteric symptoms are present? 1 - coeliac disease 2 - ulcerative colitis 3 - crohns disease 4 - irritable bowel syndrome

Answer 31

3 - crohns disease - fistulas and strictures are present - fistula = abnormal connection between bowel and other organ - stricture = narrowing of the bowel due to fibrotic tissue

Question 32

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica, which is transmitted by faecally contaminated food or water. What clinical feature will help determine that Amoebiasis is the cause of the gastroenteritis? 1 - dysentery diarrhoea 2 - diarrhoea with liver abscess 3 - diarrhoea with toxic megacolon 4 - constipation and liver abscess

Answer 32

2 - diarrhoea with liver abscess

Question 33

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica, which is transmitted by faecally contaminated food or water. How can Amoebiasis typically be diagnosed? 1 - biopsy 2 - serology from stool 3 - urinalysis 4 - non-responsive to antibiotics

Answer 33

2 - serology from stool - specifically E.histolytica-specific antigen by ELISA

Question 34

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica, which is transmitted by faecally contaminated food or water. Once confirmed how is amoebiasis treated? 1 - wait and see approach 2 - anti-diarrhoeals 3 - anti-virals 4 - antibiotic (metronidazole)

Answer 34

4 - antibiotic (metronidazole) - a Nitroimidazole - release nitrosa free radicals, damaging DNA - without function DNA the cell cannot replicate and will die

Question 35

Which of the following are parasites identified in the aetiology of parasitic causes of gastroenteritis? 1 - Giardia - small bowel malabsorption 2 - E.histolytica – amoebic dysentery and liver abscesses 3 - Hookworm – iron deficiency anaemia 4 - Hydatid disease – hydatic cysts 5 - Liver Flukes – biliary obstruction 6 - Shistosomiasis – non-cirrhotic portal hypertension 7 - all of the above

Answer 35

7 - all of the above

Question 36

Human immunodeficiency virus (HIV) can cause gastroenteritis. Typically is a pathogen identified though?

Answer 36

- no

Question 37

Human immunodeficiency virus (HIV) can cause gastroenteritis. Although no pathogen is commonly reported, which 2 of the following findings are commonly observed upon biopsy? 1 - crypt malabsorption 2 - villous atrophy 3 - granulomas 4 - cobblestone inflammation

Answer 37

1 - crypt malabsorption 2 - villous atrophy

Question 38

In 2009, 76 children in East Surrey became unwell and 10 seriously ill following a visit to a farm, resulting in a thrombotic cause of renal failure. What GI infection were they found to have? 1. Clostridium Difficile 2. Ecoli 0157 3. Shigella 4. Yersinia enterocolitica 5. Campylobacter

Answer 38

2. Ecoli 0157 - can cause haemolytic - uraemic syndrome (HUS) is a syndrome characterised by AKI with thrombocytopenia and microangiopathic hemolytic anemia

Question 39

A 42 year old male presented to hospital with a 6 week history of diarrhoea, fever and weight loss. Imaging showed thickening of the terminal ileum. A subsequent colonoscopy showed inflammation of the ileocaecal valve, biopsies of which showed chronic inflammation without granulomas. What infection can mimic terminal ileal Crohn’s Disease? 1. Clostridium Difficile 2. Ecoli 0157 3. Shigella 4. Yersinia enterocolitica 5. Campylobacter

Answer 39

4. Yersinia enterocolitica - presents in a similar way as crohns disease

Question 40

A 25 year old presented 2 days after a barbecue with bloody diarrhoea and severe abdominal cramps. What is the most likely GI infection? 1. Clostridium Difficile 2. Ecoli 0157 3. Shigella 4. Yersinia enterocolitica 5. Campylobacter

Answer 40

5. Campylobacter - most likely to cause abdominal cramps with bloody diarrhoea

Question 41

A 75 year old lady is readmitted to hospital with watery diarrhoea a week after being in hospital for an hip operation, complicated by an infection for which she received clindamycin. What is the most likely cause for her GI infection? 1. Clostridium Difficile 2. Ecoli 0157 3. Shigella 4. Yersinia enterocolitica 5. Campylobacter

Answer 41

1. Clostridium Difficile - clindamycin often reduces pathogens and health flora, so opportunistic pathogens can flourish

Question 42

A 35 year old lady with UC is admitted with a flare which fails to respond to intravenous steroids. Rectal biopsies should be taken to exclude which pathogen? 1. Clostridium Difficile 2. HSV 3. CMV 4. Amoebiasis 5. HIV

Answer 42

3. CMV - can cause proctocolitis with bloody or watery diarrhoea - inclusion bodies are found when stained for on rectal biopsies

Question 43

A 50 year old man present with right upper quadrant pain, jaundice and fevers. A CT scan shows a large collection in the right lobe of his liver. What is the most likely cause for this collection? 1. Hydatid disease 2. E.coli 3. Shistosomiasis 4. Amoebiasis 5. HIV

Answer 43

4. Amoebiasis - only pathogen that causes diarrhoea and liver abscess