GIT Infections

Question 1

General Background about gut infections

Answer 1

Question 2

What Hx questions would you ask about GIT?

Answer 2

• Symptoms
• Travel
• Exposure
• Immune status
• Current Drugs Taken

Question 3

What is Gastroenteritis?

Answer 3

Characterised by GIT symptoms of nausea, vomiting, Abdom discomfort & diarrhoea

Question 4

What is Diarrhoea?

Answer 4

• Abnormal faecal discharge
• Usually disease of small intestine

Question 5

What is Dystentery?

Answer 5

= Blood and pus in the faeces
- Inflamm. disorder of GIT
- Pain, fever, abdom. cramps
- usually disease of large intestine

Question 6

Describe Typhoid and non-Typhoid Salmonella

Answer 6

Typhoidal Salmonella:
- causes Typhoid & Paratyphoid Salmonella -> Enteric Fever
- no animal resevoir
Non-typhoidal Salmonella:
- Majority of Salmonella
- Large animal resevoirs

Question 7

What is the diagnosis of Salmonella?

Answer 7

• Culture on selective media
• Rapid molecular methods
• Blood cultures

Question 8

What is the treatment of Salmonella?

Answer 8

• Diarrhoea usually resolves w/out treatment
• Fluid & electrolyte replacement
• Antibiotics is discouraged

Question 9

Describe Enteric Fever

Answer 9

• Salmonella typhi & Salmonella paratyphi
• No animal resevoir
• Spread via contaminated water/food

Question 10

What is the clinical manifestation of Enteric Fever?

Answer 10

• IP: 10-14 days
• Fever, malaise (general discomfort), aches
• Diarrhoea & constipation
• Rose spots on skin

Question 11

What is the diagnosis of Enteric Fever?

Answer 11

• Stool
• Blood Culture

Question 12

What is the treatment of Enteric Fever?

Answer 12

• Antibiotics (Ciprofloxacin, Ceftriaxone)

Question 13

What is the prevention of Enteric Fever?

Answer 13

• Public health measures
• Vaccination

Question 14

What are the types of Echerichia Coli and what do they do?

Answer 14

Question 15

What pathogens can cause Shigellosis (AKA Bacillary Dysentery)?

Answer 15

• Shigella sonnei (mild)
• Shigella flexnerni & Shigella boydii -> more severe
• Shigella dysenteriae -> most sever

Question 16

What are symptoms of Shigellosis?

Answer 16

• Gastroenteritis
• Diarrhoea
• Lower abdominal cramps

Question 17

Describe the pathogenesis of Shigellosis

Answer 17

• invasion of colonic mucosa
• cause inflam and mucosal ulceration (break on surface)
• cause dysentery

Question 18

What is the diagnosis of Shigellosis?

Answer 18

• Culture
• Rapid molecular tests

Question 19

What is the treatment of Shigellosis?

Answer 19

• Antibiotics for severe cases
• Rehydration

Question 20

What is Campylobacter jejuni?

Answer 20

• Curved gram negative bacteria
• large animal resevoir
• highly infectious

Question 21

Describe the pathology of Campylobacter

Answer 21

• ulceration and inflamed bleeding of mucosal surfaces in
  jejunum and ileum
• release of cytotoxins

Question 22

What are clinical symptoms of Campylobacter?

Answer 22

• Diarrhoea

Question 23

What is the treatment of Campylobacter?

Answer 23

• most recover w/out treatment
• antibiotics for severe cases

Question 24

What are clinical features of Cholera?

Answer 24

• severe watery diarrhoea

Question 25

What are treatments for Cholera?

Answer 25

- Oral or IV fluids - Antibiotics (Tetracycline, Azithromycin) - Vaccine

Question 26

Describe Staphylococcal food poisoning

Answer 26

- Staph aureus produces enterotoxin - Causes food poisoning as although food is cooked, bacteria dies but toxin still stable

Question 27

Symptoms of Staphylococcal food poisoning

Answer 27

- vomiting

Question 28

What is Bacillus cereus?

Answer 28

- Gram positive spore forming bacteria -> spores survive in cooking - Spores prod 2 enterotoxins

Question 29

What is Clostridium gastroenteritis?

Answer 29

- Caused by Clostridium perfringens - Anaerobic spore forming bacteria -> prod enterotoxins - Causes Abdominal pain and Diarrhoea

Question 30

Table of Different Pathogens and their symptoms

Answer 30

Question 31

What type of bacteria is Helicobacter pylori?

Answer 31

- Gram negative

Question 32

What are clinical features of H. pylori?

Answer 32

- Commonly asymptomatic - Upper abdom pain - Nausea - Frequent burping - Bloating

Question 33

Describe the pathophysiology of H. pylori

Answer 33

- uses Urease to break urea to ammonia and CO2 -> increases pH and provides protection against gastric acid

Question 34

What is the diagnosis of H.pylori?

Answer 34

- Non-invasive urea breath test - Faecal H.pylori antigen testing - Invasive Methods: - Rapid urease test of biopsy - PCR

Question 35

What is the treatment of H.pylori?

Answer 35

- Proton pump inhibitors - Antibiotics

Question 36

Describe Noravirus Diarrhoea

Answer 36

- most common cause of diarrhoea - also causes nausea, abdominal pain, vomiting & diarrhoea Diagnosis: - PCR - Electron microscopy

Question 37

Describe Rotavirus Dairrhoea

Answer 37

- Causes vomiting and Diarrhoea - Potentially some resp symptoms Pathophysiology: - Causes diarrhoea by damaging transport mechanisms in the gut Diagnosis: - PCR