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Flashcards in Infections Deck (115)
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1
Q

What ae 5 important things to ask about in a history of a suspected GI infection?

A

Travel, pets, contacts, functions and food history

2
Q

What is gastroenteritis?

A

Inflammation of the lining of the stomach, small intestine and large intestine

3
Q

Most cases of gastroenteritis are infectious, but what are two other less common causes?

A

Drugs and chemical toxins

4
Q

What are the 8 scenarios in which you WOULD give antibiotics?

A

Shigellosis, enterotoxic E. coli, C. diff, Amoebiasis, giardiasis, enteric fever, cholera, invasive salmonellosis

5
Q

What do all stool samples get tested for?

A

Shigella, campylobacter, salmonella, E.coli 0157, cryptosporidium

6
Q

What do all stool samples in patients over 15 years get tested for? Why is this the case?

A

C. diff- this is a normal finding in young people

7
Q

How long does it take for a stool sample result?

A

48 hours

8
Q

Patients with what infections should get a side room and transfer to infectious diseases?

A

C. diff and norovirus

9
Q

What are other infection control procedures which are important to remember?

A

Cohort nursing, PPE, hand hygiene, maybe closing wards

10
Q

What bacteria can survive against alcohol hand gel?

A

C. diff

11
Q

What are short term infecting organisms? What is the incubation period of these?

A

Staph aureus and bacillus cereus- 1 to 6 hours

12
Q

Where is staph aureus found?

A

Preformed toxin in food, meat, potato salads, cream and eggs

13
Q

What are common and less common symptoms of staph aureus?

A

Common- abdominal pain and vomiting

May be present- non-bloody diarrhoea and fever

14
Q

Where is bacillus cereus mainly found?

A

Rice and other starchy foods

15
Q

What does bacillus cereus cause?

A

Profuse vomiting and maybe non-bloody diarrhoea

16
Q

What is a medium term infecting organism and what is the incubation time?

A

Salmonella- 12-48 hours

17
Q

What is there a risk of with salmonella?

A

Bacteraemia

18
Q

Where does salmonella come from?

A

Poultry, meat and raw egg. Also common in reptiles

19
Q

What does salmonella cause?

A

Diarrhoea which can sometimes be bloody, vomiting and fever

20
Q

What is used for testing salmonella?

A

O antigen found on the organism surface

21
Q

What is the commonest cause of food poisoning?

A

Campylobacter (jejuni)

22
Q

What is the incubation time of campylobacter?

A

2-5 days

23
Q

Where is campylobacter usually found?

A

Poultry and raw milk

24
Q

How is campylobacter treated?

A

No treatment really/ Only give clarithromycin in very sick or immunocompromised patients

25
Q

What is a rare but important complication of campylobacter?

A

Guillain-Barre syndrome

26
Q

What may been seen on an AXR of campylobacter?

A

Indentations of the bowel-thumbprint colitis

27
Q

What does E.coli 0157 produce?

A

Shiga-like/verotoxins

28
Q

What does giving antibiotics in E.coli 0157 do?

A

Increases shiga-like toxins

29
Q

What agar is used to make a diagnosis of E.coli 0157 and what colour would this show up?

A

McConkey agar which will show up pink

30
Q

What other studies can be used to identify toxins in E.coli 0157?

A

DNA studies or ELISA

31
Q

What causes E.coli 0157?

A

Beef, raw milk, animal contact, person to person

32
Q

Who are many cases of E.coli in?

A

< 16

33
Q

What is the incubation period of E.coli 0157?

A

1-14 days

34
Q

Does E.coli 0157 cause bloody diarrhoea?

A

Yes

35
Q

What is the major complication of E. coli 0157 and how does this happen?

A

Haemolytic ureamic syndrome- toxins bind to receptors on renal cells and inhibit protein synthesis

36
Q

What will be some test results of HUS?

A

Increased WCC, low platelets, low Hb, red cell fragments and increased lactate dehydrogenase (LDH)

37
Q

What should not be given in E. coli 0157?

A

Antibiotics, anti-motility agents or NSAIDs

38
Q

What should you always do in a case of E.coli 0157?

A

Report to public health

39
Q

What is a common healthcare acquired infection causing diarrhoea which can be transmitted person to person?

A

C. difficile

40
Q

What 2 toxins does C. diff contain?

A

Toxin A- enterotoxin

Toxin B- cytotoxin

41
Q

What brings about infection of C. diff?

A

Antibiotics are prescribed which kill off the normal competitive gut flora which allows C. diff to overgrow

42
Q

What type of organism is C. diff?

A

Gram + spore bearing bacillus

43
Q

What is important about the spores of C. diff?

A

Commonly antibiotic resistant

44
Q

What is C. diff colitis commonly?

A

Pseudomembranous

45
Q

What antibiotic is given in less severe C. diff?

A

Oral metronidazole

46
Q

What antibiotic is given in more severe C. diff?

A

Oral vancomycin

47
Q

How can C, diff infection be prevented?

A

Good hand hygiene, avoid broad spectrum antibiotics- especially 4 C’s, isolate patients

48
Q

1 or more of what markers suggests C. diff infection?

A

Pseudomembranous colitis
WCC > 15
Creatinine 1.5 x baseline
Persistent symptoms of C. diff despite 2 treatments

49
Q

What virus is most common in children under 3?

A

Rotavirus

50
Q

How is rotavirus spread?

A

Faecal-oral

51
Q

What does rotavirus cause in the body?

A

Affects absorption and secretion in the bowel

52
Q

How does rotavirus present?

A

Moderate fever, vomiting and then non-bloody diarrhoea

53
Q

How long does rotavirus last?

A

About a week- self-limiting

54
Q

What commonly occurs in children following rotavirus infection?

A

Post infection malabsorption which leads to further diarrhoea

55
Q

How is rotavirus and norovirus diagnosed?

A

PCR of faeces

56
Q

What is the key to rotavirus and norovirus treatment?

A

Hydration

57
Q

Does a vaccine for rotavirus exist?

A

Yes-live attenuated, only given to children of 2-3 months

58
Q

How can norovirus be spread?

A

Faecal oral or droplet

59
Q

How does norovirus occur?

A

Asymptomatic shedding for 48 hours followed by a sudden explosive onset of V and D

60
Q

How long does norovirus last?

A

2-4 days

61
Q

What should you ask for in a history of a returned traveller with an infection?

A

Where, when, accommodation, is anyone else ill, insect bites, what did they do, did they take precautions

62
Q

What are pre-hepatic causes of jaundice in a returned traveller?

A

Malaria, HUS, sickle cell crisis

63
Q

What are hepatic causes of jaundice in a returned traveller?

A

Hepatitis A and E, malaria, enteric fever, rickett’s,

64
Q

What are post-hepatic cause of jaundice in a returned traveller?

A

Helminths

65
Q

What is acute traveller’s diarrhoea defined as?

A

3 loose stools in 24 hours

66
Q

What is the most common cause of acute traveller’s diarrhoea?

A

E.coli

67
Q

If diarrhoea in a returned traveller is profuse and watery what is this likely to be?

A

Cholera

68
Q

What investigations should be done on acute traveller’s diarrhoea?

A

Stool culture and wet stool prep for amoebiasis

69
Q

What is the treatment for acute traveller’s diarrhoea?

A

Supportive, hydration and ciprofloxacin in severe cases

70
Q

Where is enteric fever most common?

A

Indian subcontinent and SE asia

71
Q

What is the typical incubation period of enteric fever?

A

7-18 days

72
Q

What are symptoms of enteric fever?

A

Fever, dry cough, headache, constipation/diarrhoea

73
Q

What are complications of enteric fever?

A

GI bleed, perforation, encephalopathy and bone/joint infection

74
Q

What causes enteric fever?

A

Salmonella Typhi/Paratyphi

75
Q

If a patient with enteric fever is unstable, what should you give them?

A

IV ceftriaxone (azithromycin can also be useful orally)

76
Q

What tests should be taken for enteric fever?

A

Blood cultures first followed by urine and stool samples

77
Q

How is amoeba spread?

A

Faecal-oral (associated with poor hygiene)

78
Q

How is a diagnosis of Amoebiasis made?

A

Hot stool sample for ova and cysts

79
Q

How is Amoebiasis treated?

A

Metronidazole

80
Q

What investigations would be done for Amoebiasis?

A

Stool microscopy, AXR and endoscopy

81
Q

What can severe or untreated Amoebiasis lead to?

A

Amoebic liver abscess

82
Q

Who are amoebic liver abscessed more common in?

A

Men

83
Q

How will an amoebic liver abscess present?

A

Subacutely over 2-4 weeks, fever, sweats, upper abdominal pain, GI upset, hepatomegaly

84
Q

What will you see on an X-ray of Amoebic liver abscess?

A

Raised right hemi-diaphragm

85
Q

What investigations should you do for Amoebic liver abscess?

A

US, CT, serology for IgG and stool microscopy

86
Q

How do you treat amoebic liver abscess?

A

Metronidazole or tinidazole

87
Q

How is giardia spread and what is its incubation period?

A

Faecal-oral, around 7 days

88
Q

What is a feature of a giardia protozoa?

A

Flagellated

89
Q

What are some symptoms of giardiasis?

A

Watery, malodourous diarrhoea, bloating, flatulence, abdominal cramps and weight loss

90
Q

How do you investigate for giardia?

A

Stool microscopy

91
Q

How do you treat giardia?

A

Metronidazole or tinidazole

92
Q

What is cryptosporidiosis transmitted from?

A

Water, food, animal contact

93
Q

How is cryptosporidium diagnosed?

A

Duodenal aspirate or stool samples

94
Q

What is the treatment for cryptosporidium?

A

Supportive

95
Q

What are helminths often associated with?

A

Eosinophilia

96
Q

What are nematodes and trematodes?

A

Nematodes- roundworms

Trematodes- flukes

97
Q

What is an example of a fluke which is associated with fresh water exposure which can cause a rash and portal hypertension?

A

Schistosomiasis

98
Q

Where do tapeworms commonly come from and what can they cause?

A

Undercooked meat and seizures

99
Q

What is colonisation?

A

Bug present but no inflammatory response

100
Q

What is infection?

A

Inflammatory response as a result of a bug

101
Q

What is bacteraemia?

A

Bacteria growing in blood culture

102
Q

What is sepsis?

A

Infection resulting in a systemic infection. Life threatening organ dysfunction- dysregulated host response

103
Q

What is septic shock?

A

Subset of sepsis with circulatory and cellular dysfunction

104
Q

What causes difficult infections?

A

An abnormal host response e.g. immunocompromised, co-morbidity drugs, genetics or an abnormal microbe response

105
Q

What is SIRS?

A
Systemic inflammatory response syndrome. 2 or more of the following suggests SIRS:
Temp <36 or >38
Heart rate > 90
Resp rare > 20/PaCO2 < 32
Abnormal white cell count
106
Q

Can a patient have sepsis without an infection?

A

No

107
Q

What must a patient have to be defined as being in septic shock?

A

Infection, 2 SIRS criteria and at least one organ in failure

108
Q

What is an important sign of septic shock?

A

Hypotension

109
Q

What are common bacteroides?

A

Coliforms and anaerobes from perforated large bowel

110
Q

What antibiotics should be given for an intra-abdominal infection?

A

Amoxicillin/Vancomycin, gentamycin, metronidazole

111
Q

What do amoxicillin/vancomycin target?

A

Streptococci and enterococci

112
Q

What does gentamycin target?

A

Aerobic coliforms

113
Q

What does metronidazole target?

A

Anaerobes

114
Q

What is the sepsis 6?

A

Give high flow oxygen (target 94-98%), start IV fluids (500mls IV saline), take blood cultures, IV antibiotics, measure lactate and FBC, monitor hourly urine output

115
Q

What does a creatinine > 150 suggest?

A

Kidney damage