GI infection and Gastroenteritis

Question 1

What is the commonest bacterial cause of food poisoning?

Answer 1

Campylobacter

Question 2

What food poisoning pathogens have a short incubation period and why is this?

Answer 2

Staph aureus, bacterius cerus

They are pre formed toxins

Question 3

What is a short incubation time?

Answer 3

1 - 6 hours

Question 4

Describe the presentation of bacillus cerus infection

Answer 4

1. Common after eating rice/pasta
2. Initially vomitting
3. Diarrheoa within 1 - 6 hours
   (usually not bloody)

Question 5

Describe how a campylobactor infection would present?

Answer 5

Long incubation time (2 - 14 days following exposure)
Blood diarrhoea
Usually due to eating raw poultry

Question 6

What antibiotics would you use to treat campylobactor?

Answer 6

Ciproflaxin
Erythromycin
(but only in some circumstances - very old/very young)

Question 7

What is the incubation period of salmonella enteritidis?

Answer 7

12 - 48 hours

Question 8

How do you determine the type of infecting salmonella?

Answer 8

1. Antigen on body, 0 antigen/ serotype (B, C and D most common) allows to follow outbreak
2. Antigen on tail (serotype) allows you to decide the most likely origin

Question 9

How do you test for the body antigen in salmonella?

Answer 9

Slide agglutination test

Question 10

Give two serotypes of salmonella

Answer 10

Salmonella enteritidis

Salmonella Typhimurium

Question 11

What are the key features of E Coli 0157?

Answer 11

Bloody diarrhea, most often in children under 16 (especially those under 5. Recent contact with farm animals/raw milk.

Question 12

What is the increased risk with E Coli infection?

Answer 12

Release of verotoxins with can then cause Haemolytic uraemia syndrome.

Question 13

What is HUS?

Answer 13

Verotoxins act to cause apoptosis in RBC’s and kidney causing the patient pain fever and bloody diarrhoea

Question 14

What is a marker for cell damage that will be raised in HUS?

Answer 14

lactate dehydrogenase

Question 15

What tests would you perform on a patient you suspect has HUS?

Answer 15

Stool culture
U & E
FBC
Clotting
Lactate dehydrogenase
Urine dipstick

Question 16

How do you treat HUS?

Answer 16

Monitioring/ rehydration
 NO antibiotics
NO anti motility
NO NSAIDS
Inform Health protection unit

Question 17

How does rotavirus present?

Answer 17

Watery diarrhoea (no blood)
Children under 5

Question 18

How is rota virus spread?

Answer 18

Faecal oral

Question 19

How do you test for rotavirus?

Answer 19

PCR on faeces

Question 20

How do you treat rotavirus?

Answer 20

Hydration

Question 21

How is the rotavirus vaccine given?

Answer 21

Orally given live attenuated vaccine given at 2 and 3 months old

Question 22

How is noro virus spread?

Answer 22

faecal oral/droplet

Question 23

How is noro virus tested for?

Answer 23

PCR of faeces

Question 24

How do you treat norovirus?

Answer 24

Rehydration

Question 25

What toxins does C Diificile produce?

Answer 25

Entero/cytotoxins

Question 26

What does C Difficile produce that makes the infection so difficult to contain?

Answer 26

Spores

Question 27

What kind of colitis is found in C Difficile infection?

Answer 27

Pseudomembranous colitis

Question 28

How do you test for C Difficile?

Answer 28

1. Sensitive screening test (detects antigen and toxin) 2. More specific test (done when screening is positive to test for further toxins) 3. Stool culture

Question 29

What do you do if the screening test in positive but the toxin is negative?

Answer 29

Re assess and repeat tests

Question 30

What tests do all stools get tested for?

Answer 30

Salmonella, Shigella, Campylobactor, E Coli 0157 and cryptomagalovirus Anyone over 15 years gets C Diff test also

Question 31

What is acute enteritis?

Answer 31

Fever, D &V, abdominal pain

Question 32

What is acute colitis?

Answer 32

Fever, pain, bloody diarrhoea

Question 33

What is enters fever like illness?

Answer 33

fever, rigors, pain, little diarrhoea

Question 34

What are the most common infectious causes of bloody diarrhoea?

Answer 34

Campylobactor, shigella, e coli, amoebiasis

Question 35

Give some non infectious causes for bloody diarrhoea?

Answer 35

IBD Malignancy Ischaemia

Question 36

What is a further disease that could develop as a result of campylobactor infection?

Answer 36

Guillain barre syndrome

Question 37

What tests would you need to diagnose typhoid?

Answer 37

``` Blood cultures (most important) Stool and urine cultures ```

Question 38

How does typhoid present?

Answer 38

Traveller (e.g. india) | Mile bacteraemia, enterocolitis

Question 39

How effective is the typhoid vaccine?

Answer 39

70% against typhoid but not effective against parathyroid

Question 40

When would you order a stool microscopy?

Answer 40

Suspicion of parasites

Question 41

When would you do a stool culture?

Answer 41

Salmonella, campylobacter, shigella

Question 42

When would you do a stool toxin?

Answer 42

C Difficiile

Question 43

When would you do blood cultures?

Answer 43

Salmonella, Typhoid

Question 44

Why would you do a FBC?

Answer 44

Asses severity of C Diff infection

Question 45

Why would you do U & E tests?

Answer 45

Assess renal function (e.g. from dehydration)

Question 46

When would you want to give antibiotics?

Answer 46

``` Typhoid Shigella E coli (sometimes) Cholera C Diff Giardiasis Amoediasis Invasive Salmonella ```

Question 47

WHat antibiotic would you give to patients with gastroenteritis

Answer 47

Ciprofloxacin for 3 - 5 days

Question 48

What is the gram stain of c diff?

Answer 48

Gram positive, spore forming, bacillis

Question 49

What antibiotics precipitate C diff?

Answer 49

fluoroquinolones, cephalosporins, clindamycins, broad spectrum penicillins (most begin with C)

Question 50

What other medication can precipitate C diff?

Answer 50

PP1 Histamine 2 antagonist Chemotherapy

Question 51

What are the four C antibiotics?

Answer 51

ANTIBITOICS- CEPHALOSPROINS, CLINDAMYCIN, CIPROFLOXACIN [QUINOLONES] , CLARITHROMYCIN [ MACROLIDES]

Question 52

How do you treat pseudomembranous colitis?

Answer 52

``` Discontinue current antibiotics, PPIs Avoid opiates and anti peristaltic drugs Non severe: Metronidazole (10 - 14 dyas) Severe: Vancomycin (orally) ```

Question 53

What is a future drug that could be used to treat C Diff?

Answer 53

Fidaxamicin

Question 54

When will fidaxomicin be used?

Answer 54

For first relapse within 12 weeks of initial infection

Question 55

What is amoebiasis?

Answer 55

Protozoal infection spread by faecal oral route seen in areas of poor sanitation

Question 56

How do you diagnose amoebiasis?

Answer 56

Hot stool microscopy | Also serology

Question 57

How do treat amoebiasis?

Answer 57

Metronidazole | Removal from lumen using diloxanide furoate or paromomycin

Question 58

What are the symptoms of giardiasis?

Answer 58

Foul smelling diarrhoea | mal absorption

Question 59

How is giardiasis spread?

Answer 59

By cysts in normal drinking water

Question 60

How is the diagnosis of giardiasis made?

Answer 60

Hot stool microscopy | Duodenal aspiration

Question 61

How do you treat giardiasis?

Answer 61

Metronidazole

Question 62

What is cryptosporidiosis?

Answer 62

A parasite that is one of the main causes of travel related diarrhoea infection. Usually self limiting

Question 63

How do you treat cryptosporidosis?

Answer 63

Supportive | Nitizoxamide?

Question 64

How do you diagnose cryptosporidosis?

Answer 64

Duodenal aspirate | Stool microscopy