[22] Gastroenteritis Flashcards
(127 cards)
1
Q
What is gastroenteritis?
A
The general term used to describe inflammation of the gastrointestinal tract
2
Q
What is the origin of gastroenteritis?
A
Usually is infective in origin, although may have non-infective causes
3
Q
What is the most common cause of gastroenteritis?
A
Viral
4
Q
What % of cases of gastroenteritis are viral in developed countries?
A
30-40%
5
Q
What can reveal the causative agent in gastroenteritis?
A
Subtle differences between the length of time between ingestion of food and development of symptoms
6
Q
How long is there between the ingestion of food and the development of symptoms in bacterial toxins causing gastroenteritis?
A
Hours
7
Q
How long is there between the ingestion of food and the development of symptoms in viral gastroenteritis?
A
Days
8
Q
How long is there between the ingestion of food and the development of symptoms in bacterial gastroenteritis?
A
Weeks
9
Q
How long is there between the ingestion of food and the development of symptoms in parasitic gastroenteritis?
A
Months
10
Q
What is diarrhoea?
A
3 or more loose stools, or stools with increased liquid, per day
11
Q
What is acute diarrhoea?
A
Diarrhoea lasting less than 14 days
12
Q
What is chronic diarrhoea?
A
Diarrhoea lasting more than 14 days
13
Q
What is dysentery?
A
Gastroenteritis characterised by loose stools with blood and mucus
14
Q
What is travellers’ diarrhoea?
A
More than 3 loose stools commencing within 24 hours of foreign travel. with or without cramps, nausea, fever, or vomiting
15
Q
What is the most common cause of travellers’ diarrhoea?
A
Enterotoxigenic E. Coli
16
Q
How might travellers’ diarrhoea be prevented?
A
Patient’s travelling to at risk areas may be required to take prophylactic anti-microbials
17
Q
What are the risk factors for gastroenteritis?
A
Poor food preparation, handling, and cooking
Immunosuppression
Poor personal hygiene
18
Q
What are the symptoms of gastroenteritis?
A
Cramp-like abdominal pain Diarrhoea with or without blood or mucus Vomiting Pyrexia Night sweats Weight loss
19
Q
What will be found on examination in gastroenteritis?
A
The patient may be dehydrated, with possible pyrexia and/or hypovolaemia
20
Q
What specific features from the history should be elicited to help determine the cause of gastroenteritis?
A
Bowel movements
Affected family or friends
Recent travel
Recent use of antibiotics within previous 4 weeks
21
Q
What do you need to know about the bowel movements in gastroenteritis?
A
Quantity
Character - blood stained, mucus, profusely watery
22
Q
Why is it important to know if a person presenting with gastroenteritis has had any antibiotics within the previous 4 weeks?
A
It can suggest a potential C. difficile infection
23
Q
Why are investigations not necessary for most cases of gastroenteritis?
A
As the condition is usually self limiting
24
Q
What investigation may be required in gastroenteritis?
A
Stool culture
25
When might a stool culture be required in gastroenteritis?
If there is blood or mucus in stool
If patient is immunocompromised
If severe or persistent
26
What are the general points of management for any patient with gastroenteritis?
Rehydration
Education to prevent future episodes
Exclusion from work for 48 hours from last episode of vomiting or diarrhoea
27
How should dehydration be achieved in gastroenteritis?
Encourage oral fluids if possible
| If severe dehydration or unable to tolerate oral fluid, consider admitting patient for IV fluid
28
What needs to be considered when giving the patient IV fluids for rehydration following gastroenteritis?
Need to ensure suitable potassium replacement if severe or persistent vomiting or diarrhoea
29
Is gastroenteritis a notifiable disease in the UK?
Food poisoning and infectious bloody diarrhoea are
30
What is meant by food poisoning and infectious bloody diarrhoea being notifiable diseases?
It is the duty of the diagnosing doctor to notify the appropriate body
31
What organisms causing gastroenteritis are notifiable diseases?
Campylobacter
| Salmonella
32
Who is responsible for notifying Public Health about cases of campylobacter or salmonella?
The laboratory
33
What are the viral causes of gastroenteritis?
Norovirus
Rotavirus
Adenovirus
34
What is the most common form of viral gastroenteritis in adults?
Norovirua
35
What kind of virus is norovirus?
RNA virus
36
How does norovirus present?
Abdominal cramps
Watery diarrhoea
Vomiting
37
How long does gastroenteritis caused by norovirus last?
Usually about 1-3 days
38
What is the most common cause of severe diarrhoea in infants and young children?
Rotavirus
39
What kind of virus is rotavirus?
A double stranded RNA virus
40
How long does rotavirus last?
Generally less than a week
41
What develops from rotavirus infection in childhood?
LIfelong immunity
42
Where is adenovirus a common cause of diarrhoea?
In children
43
What are the bacterial causes of gastroenteritis?
Campylobacter
E. Coli
Salmonella
Shigella
44
What is the most common cause of food poisoning?
Campylobacter
45
What kind of bacteria is campylobacter?
A gram negative bacillus
46
What does campylobacter infection typically result from?
Ingestion of chicken, eggs, or milk
47
What symptoms are caused by campylobacter?
May be a prodrome of fatigue, fever, and myalgia, followed by nausea, abdominal cramps, and diarrhoea
48
How is gastroenteritis caused by campylobacter treated?
If severe, treat with IV erythromycin
49
What kind of bacteria is E. Coli?
Gram -ve
50
How is E. Coli transmitted?
Typically through contaminated foodstuffs
| Can also be from infected animals and from person-to-person
51
Which type of E. Coli is the most common form of travellers diarrhoea?
Enterohaemorrhaigc E. Coli (EHEC)
52
What kind of bacteria is salmonellla?
A gram negative flagellated bacillus
53
What are the two serotypes of salmonella most commonly associated with gastroenteritis?
S. typhimurium
| S. enteriditis
54
How is salmonella transmitted?
Through undercooked poultry or raw eggs
55
What are the symptoms of gastroenteritis caused by salmonella?
```
Fever
Nausea
Vomiting
Abdominal pain
Cramps
Bloody diarrhoea
```
56
How is gastroenteritis caused by salmonella managed?
Management is generally conservative
57
How long does gastroenteritis caused by salmonella generally last?
<7 days
58
What kind of bacteria is shigella?
Gram -ve bacillus
59
What is the most common serotype of shigella?
S sonnei
60
How is shigella acquired?
From contaminated dairy products and water
61
How does gastroenteritis caused by shigella present?
Fever
Abdominal pain
Rectal pain
Bloody diarrhoea
62
How is gastroenteritis caused by shigella managed?
Management is usually conservative
63
What complications can campylobacter infections lead to?
Reactive arthritis
Guillan Barre syndrome
Haemolytic uraemic syndrome
Thrombotic thrombocytopaenic purpura
64
What complications can EHEC cause?
Haemorrhagic uraemic syndrome
65
What do toxins from bacteria often cause?
An acute onset of diarrhoea and vomiting
66
How long do symptoms tend to last in gastroenteritis caused by bacterial toxins?
Less than 24 hours
67
What bacteria produce toxins that can cause gastroenteritis?
Staphylococcus aureus
Bacillus cereus
Clostridium perfringens
Vibrio cholera
68
Where are staphylococcus aureus toxins typically found?
In cooked meat and cream products
69
Does reheating cooked food destroy the staphylococcus aureus exotoxin?
No, even if the bacteria are destroyed
70
How are toxins from bacillus cereus typically acquired?
Through reheating cooked rice
71
What do the toxins from bacillus cereus cause?
Rapid onset nausea and vomiting
72
How are clostridium perfringes toxins typically acquired?
From reheating cookd meat dishes
73
What symptoms are caused by the toxins from clostridium perfringes?
Causes diarrhoea, but vomiting is unusual
74
How are toxins from vibrio cholera obtained?
Typically from contaminated water supplies
75
What symptoms do the toxins from vibrio cholerae typically cause?
Profound watery diarrhoea, often described as rice water, yet painless in nature
76
How can gastroenteritis caused by toxins from vibrio cholera be avoided?
An oral vaccine is available
77
When are parasites a much more likely causative organism in gastroenteritis
In any patient with Travellers' diarrhoea
78
What parasites can cause gastroenteritis?
Cryptosporidium
Entamoeba histolytica
Giardia intestinalis
Schistosoma
79
What kind of parasite is cryptosporidium?
A protozoa
80
What can cryptosporidium cause in most patients?
A self-limiting watery diarrhoea with abdominal cramps
81
What can cryptosporidium cause in immunocompromised patients?
Life threatening infections
82
What does the diagnosis of cryptosporidium involve?
Stool culture for ova, cysts, and parasites
83
What is the organism Entamoeba Histolytica responsible for?
Amoebiasis
84
How is entamoeba histolytica acquired?
From the ingestion of food/water contaminated with faeces
85
How does ameobiasis present?
Bloody diarrhoea
Abdominal pain
Fever
86
How does an amoebic liver abscess present?
RUQ pain
Swinging pyrexia
Hepatomegaly
87
What is required for the diagnosis of amoebiasis?
Stool culture for ova, cysts, and parasites
88
What is the recommended treatment for amoebiasis?
Metronidazole or tinidazole
89
What is the giardia intestinalis organism responsible for?
Giardiasis
90
How is giardia intestinalis transmitted?
Through direct contact, or faecal-oral route
91
What can giardia intestinal cause?
Acute disease or chronic disease
92
What are the symptoms of acute giardiasis?
```
Explosive diarrhoea
Fever
Fatigue
Nausea
Bloating
```
93
What are the symptoms of chronic giardiasis?
Steatorrhoea
Malabsorption
Weight loss
94
What might stool culture for ova, cysts, and parasites show in giardiasis?
Trophozoites
95
How do trophozoites appear on microscopy?
'Tear drop' shaped
96
What might be shown on duodenal biopsy in giardiasis?
Villous atrophy
97
How is giardiasis managed?
Usually metronidazole or tinidazole
98
What does the organism schistosoma cause?
Schistosomiasis
99
How is schistosoma acquired?
Contaminated water
100
How long after infection does acute schistosomiasis present?
About a month
101
How does acute schistosomiasis present?
```
Fever
Malaise
Abdominal pain
Bloody diarrhoea
Hepatosplenomegaly
```
102
What can the hepatosplenomegaly in acute schistosomiasis develop into?
Chronic liver disease and portal hypertension
103
What may be found on FBC in schistosomiasis?
Eosinophilia
104
What is required for the diagnosis of schistosomiasis?
Stool culture for ova, cysts, and parasites
105
How is schistosomiasis treated?
Praziquantel
106
What are the major species for hospital acquired gastroenteritis?
C. difficile
107
What kind of bacteria is C. difficile?
A gram +ve organism
108
When does C. difficile typically develop?
After treatment with broad-spectrum antibiotics, particularly cephalosporins
109
Why does C. difficile develop after treatment with broad-spectrum antibiotics?
They disrupt the normal microbiota of the bowel
110
What toxins are produced by C. difficile?
Exotoxins A and B
111
What do exotoxins A and B cause?
An inflammatory response in the bowel, that results in an inflammatory exudate on the colonic mucosa with intervening areas of normal mucosa
112
What does the inflammatory response cause by exotoxins A and B culminate in?
Severe bloody diarrhoea
113
What does the bloody diarrhoea in C. difficile have the potential to develop into?
Toxic megacolon
114
What is toxic megacolon?
A severely dilated bowel with a high risk of perforation
115
What does investigation of C. difficile require?
Stool culture specificially including the C. difficile toxin
116
What may the results of C. difficile stool culture show?
The presence of the bacteria, but absence of toxin
117
What should be done if the stool culture results show the presence of C. difficile bacteria, but not the toxin?
The results should be interpreted relative to the clinical picture
118
How is C. difficile treated?
IV fluid rehydration
Oral metronidazole
Isolation
119
When is vancoymycin used in C. difficile?
In severe disease, or if no improvement seen after 72 hours
120
What are the non-infective causes of gastroenteritis?
Radiation colitis
Inflammatory bowel disease
Microscopic colitis
Chronic ischaemic colitis
121
What is radiation colitis?
Inflammation of the gastrointestinal tract secondary to radiation therapy
122
What does microscopic colitis cause?
A chronic watery diarrhoea
123
Who does microscopic colitis typically affect?
Females
124
What happens to the colon in microscopic colitis?
It appears normal on endoscopy, however biopsy demonstrates an increase in the number of inflammatory cells
125
What is chronic ischaemic colitis caused by?
A compromise in blood supply to the colon
126
Where does chronic ischaemic colitis commonly affect?
The watershed area around the splenic flexure
127
How is a diagnosis of chronic ischaemic colitis confirmed?
On endoscopy, where one might observe 'blue swollen mucosa'
