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Flashcards in Diarrhoea Deck (64)
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1
Q

Describe campylobacter

A

Curved gram negative bacillus

2
Q

Name the commonest cause of bacterial GI infection

A

Campylobacter

3
Q

What is the incubation period of campylobacter

A

3-10 days

4
Q

Describe the mechanism of campylobacter

A

Inflammation of the colon and rectum causing bloody diarrhoea.

5
Q

Can campylobacter infect the blood stream

A

Yes (occasionally)

6
Q

What is the vehicle of campylobacter?

A

Farm animals especially undercooked poultry

7
Q

What is the management of campylobacter?

A

Usually self limiting- if systemic effects occur offer citrofloxacin or erythromycin for 5 days

8
Q

What is the mechanism of Salmonella Enterica?

A

Causes inflammation of the ileum and colon. The bacteria multiply in the gut causing mucosal damage. This means there is decreased absorption and increased fluid secretion

9
Q

Can salmonella enterica invade the blood steam?

A

Yes (occasionally)

10
Q

Symptoms of campylobacter

A

Abdominal pain, diarrhoea (could be with or without blood)

11
Q

What is the incubation period of salmonella enterica?

A

12-48 hours

12
Q

What is the vehicle for salmonella infection?

A

Farm animals especially undercooked poultry

13
Q

Symptoms of salmonella enterica

A

Abdominal pain, diarrhoea (occasionally bloody), vomiting

14
Q

Management of salmonella enterica

A

Generally self limiting

Systemic- use ciprafloxacin for 5 days

15
Q

What is the only species of Shigella spp seen in the UK?

A

Shigella sonnei

16
Q

Mechanism of shigella

A

Invades intestinal mucosa causing severe inflammation but does not invade further.

17
Q

What would be seen in stools of a person with shigella?

A

Blood and pus cells

18
Q

What is the incubation period of shigella?

A

1-9 days

19
Q

How is shigella spread?

A

Human contact- common amongst young children at school.

20
Q

Management of shigella

A

Self limiting

21
Q

Why is Escherichia Coli O157 called ‘O157’?

A

O antigen on the surface

22
Q

What does E.coli do to the body?

A

They produce a toxin (verotoxin or VTEC) that damages red blood cells and the kidney. There is an increase in blood urea, red cell haemolysis and thrombocytopenia.

23
Q

Who are most effected by E coli?

A

The elderly and young children.

24
Q

Symptoms of E.coli?

A

Abdominal pain, bloody diarrhoea

25
Q

Vehicle of E.coli

A

Part of the normal gut flora of cattle.

There is an increased risk when eating meat or visiting farms

26
Q

Management of E.coli

A

Symptomatic and supportive treatment- antibiotics are contraindicated.

27
Q

What makes E.coli so high in prevalence?

A

It has a low infectious dose.

28
Q

What is haemolytic uraemic syndrome?

A

Associated with progressive renal failure and red blood cell lysis (prematurely)

29
Q

Symptoms of haemolytic uraemic syndrome

A
Abdominal pain
Fever
Pallor
Petechiae (haemorrhaged skin)
Oliguria
Bloody diarrhoea
30
Q

When will HUS present?

A

7-10 days after an E-coli infection.

31
Q

What will HUS blood tests show?

A

Increased WCC
Decreased platelets
Decreased Hb
Increased lactate dehydrogenase

32
Q

What is typhoid/paratyphoid fever caused by?

A

Caused by salmonella typhi or salmonella paratyphi A or B

33
Q

What is the incubation period for typhoid/paratyphoid fever?

A

14-21 days

34
Q

What is the mechanism of typhoid/paratyphoid fever

A

Organism invades from the gut lumen. Goes into the lymphatic system, back into the blood stream and into the Peyers patches in the gut.

35
Q

Management of typhoid/paratyphoid

A

antibiotics

36
Q

Which organism causes cholera?

A

Vibrio cholera

37
Q

Where is cholera likely to present

A

Outbreaks present in recent disaster zones

38
Q

Describe the mechanism of cholera

A

Causes outputting of fluid from cells in the gut due to an exotoxin.

39
Q

Symptoms of cholera?

A

Watery, constant diarrhoea. Rice water stools

40
Q

Vehicle of cholera

A

Human

41
Q

Management of cholera

A

Fluid and electrolyte replacement

42
Q

Describe the mechanism of staph aureus

A

Some strains produce enterotoxins. Toxin is absorbed quickly which affects the vagus nerve and vomiting centre.

43
Q

Symptoms of staph aureus

A

Vomiting within 1-2 hours

44
Q

Describe the mechanism of clostridium perfingens

A

Belongs in the normal gut flora of humans and animals. Some spores survive cooking then turn into vegetative organisms. Also some strains produce enterotoxins

45
Q

How can you be infected by clostridium perfingens

A

Inadequately refrigerated meat gravy

46
Q

Describe the mechanism of bacillus cereus.

A

Can muiltiply in the intestine producing a toxin that is absorbed by the gut.

47
Q

How can you be infected by bacillus cereus

A

Inadequately cooked re-heated rice.

48
Q

Describe the mechanism of a protozoal infection.

A

Cysts are ingested. They hatch into trophozoites that invade the cells in the small intestine.

49
Q

Source of protozoal infection

A

Domestic animals.
Person-person
Swimming pools
Contaminated water.

50
Q

Symptoms of protozoal infection

A

Diarrhoea

51
Q

Treatment of protozoal infection

A

Symptomatic treatment

52
Q

Describe the mechanism of giardia lamblia

A
Protozoal infection (single celled parasite)
Cysts hatch into trophozoites
53
Q

How is giardia lamblia spread?

A

Human to human

54
Q

What are the symptoms of giardia lamblia

A

Diarrhoea, malabsorption syndrome, anorexia, abdominal pain, flatulence

55
Q

Treatment of giardia lamblia

A

Oral metronidazole

56
Q

Mechanism of enterobius vermicularis (threadworms)

A

Ova ingested
Hatch in the small intestine and live in the caecum and colon. Adult females come out of the perianal skin at nigt to lay ova causing perianal itchiness.

57
Q

How are threadworms spread?

A

Human to human

58
Q

Symptoms of threadworms

A

Perianal itch

Worms in stool

59
Q

Treatment of threadworms

A

Oral metronidazole

60
Q

How is norovirus spread?

A

Faecal oral- common on cruise ships

61
Q

Symptoms of norovirus?

A

Abrupt vomiting, nausea, myalgia, cramps

62
Q

Incubation period of norovirus

A

24-48 hours

63
Q

Investigations into norovirus

A

PCR

64
Q

Treatment of norovirus

A

Self limiting