Lecture 15-GI Infections

Question 1

What are the main bacterial causes of infective diarrhoea?

Answer 1

• Salmonella
• Campylobacter
• Shigella
• E Coli
• Clostridium difficile

Question 2

What are the main viral causes of infective diarrhoea?

Answer 2

• Norovirus
• Adenovirus
• Rotavirus

Question 3

What are the main parasitic causes of infective diarrhoea?

Answer 3

• Cryptosporidium
• Giardia
• Cyclospora
• Entamoeba

Question 4

Describe the gram stain of Campylobacter

Answer 4

Gram negative

Question 5

Where is Campylobacter usually found?

Answer 5

GI tracts of animal hosts eg poultry

Question 6

How is Campylobacter transmitted?

Answer 6

• Contaminated food, water

- direct contact with animals/animal products

Question 7

Which two organisms usually cause Campylobacter enteritis?

Answer 7

C. jejuni

C. coli

Question 8

What are the symptoms of Campylobacter enteritis?

Answer 8

• abdo pain
• cramps
• diarrhoea
• nausea
• fever
• aches
• dizziness
• colitis

Question 9

What are the acute complications of Campylobacter enteritis?

Answer 9

Cholecystitis, peritonitis, rash, septic pseudoaneurysm, pericarditis, myocarditis, extraintestinal infections eg bursitis

Question 10

What are the late complications of Campylobacter enteritis?

Answer 10

Reactive arthritis, Guillain-Barre syndrome (muscle paralysis)

Question 11

What is the treatment for Campylobacter enteritis?

Answer 11

• supportive treatment

- antibiotics only for severe disease or with risk factors eg pregnancy/elderly - fluoroquinolones or macrolide

Question 12

What is Cyclospora cayetenesis?

Answer 12

Parasite -> travellers diarrhoea

Question 13

How is cyclospora spread?

Answer 13

Foeco-oral transmission (food or water)

Question 14

What are the symptoms of cyclospora?

Answer 14

Anorexia, nausea, flatulence, fatigue, cramps, watery diarrhoea, fever, weight loss

Question 15

What is the incubation period of cyclospora?

Answer 15

7 days after ingestion

Question 16

How long can a cyclospora infection last?

Answer 16

3 weeks

Question 17

How can a cyclospora infection be treated?

Answer 17

• rehydration

- trimethoprim: longer duration and higher dose if immunocompromised (HIV)

Question 18

Describe the gram stain of shigella

Answer 18

Gram negative bacillus

Question 19

What is the virulence of shigella?

Answer 19

Shigotoxin

Question 20

How does shigella cause diarrhoea?

Answer 20

• enters large intestinal and rectal cells by endocytosis
• escapes from the endocytic vesicles and multiplies inside cells
• invades neighbouring cells
• mucosal abscess forms as cells die -> diarrhoea with blood, mucus and painful abdo cramping

Question 21

Describe the gram stain of salmonella

Answer 21

Gram negative bacillus

Question 22

How does salmonella spread?

Answer 22

Contaminated meat, eggs or milk

Question 23

How is a salmonella infection treated?

Answer 23

• rehydration

- ceftriaxone

Question 24

What are the symptoms of a giardia infection?

Answer 24

Diarrhoea, abdo pain, weight loss

Question 25

How is giardia transmitted?

Answer 25

Foeco-oral

Question 26

How is a giardia infection treated?

Answer 26

Metronidazole

Question 27

How is entamoeba treated?

Answer 27

Metronidazole, nitrolmidazole

Question 28

Which part of the GI tract does cryptosporidium affect?

Answer 28

Distal small intestine

Question 29

True or false: cryptosporidium affects HIV patients

Answer 29

TRUE

Question 30

What are the symptoms of a cryptosporidium infection?

Answer 30

Diarrhoea, fever, abdo pain, dehydration, weight loss, fatigue, vomiting

Question 31

How is a cryptosporidium infection treated?

Answer 31

• fluids

- nitazoxanide (anti-parasitic)