Gastroenteritis Flashcards
1
Q
What is gastrotenteritis?
A
- Inflammation of GI tract
- Considered infective in origin usually (but can be non-infective)
- Usually transient and associated with diarrhoea, vomitting and abdominal pain
2
Q
Most common cause of gastroenteritis
A
Viral
3
Q
Length of time between ingestion of food and development of symptoms - organism cause?
A
- Hours = bacterial toxins
- Days = viruses
- Weeks = bacteria
- Months = parasites
4
Q
Define diarrhoea
A
3 or more loose stools or stools with increased liquid per day
5
Q
Acute vs chronic diarrhoea
A
Chronic lasts more than 14 days
6
Q
What is dysentery?
A
- Gastroenteritis characterised by loose stools with blood and mucus
7
Q
What is travellers diarrhoea?
A
- More than 3 loose stools commencing within 24hrs of foreign travel
- With or without cramps, nausea, fever or vomiting
8
Q
RF for gastroenteritis
A
- Poor food preparation - esp in handling and cooking
- Immmunocompromised
- Poor personal hygiene
9
Q
Symptoms of gastroenteritis
A
- Cramp like abdominal pain
- Diarrhoea +/- mucus or blood
- Vomitting
- Night sweats
- Weight loss
10
Q
Examination of patient with gastroenteritis
A
Dehydrated and pyrexial
11
Q
Features from history to ask about re infective gastroenteritis
A
- Bowel movements - blood? watery?
- Affected family or friends?
- Recent travel abroad
- Recent use of abx within last 4 weeks - c.diff?
12
Q
Complications that can present from gastroenteritis
A
- Guillain Barre syndrome
- Reactive arthiritis
- Haemolytic ureamic syndrome
13
Q
Investigations for gastroenteritis presentation
A
- None usually needed as self limiting
- Stool culture if blood/mucus, immunocompromised or if severe/persistent
14
Q
Management - general gastroenteritis
A
- Rehydrate - encourage oral fluid intake, if severe and cannot tolerate oral fluids - admit for IV maybe
- Education to prevent further episodes
- Exclusion from work - 48hrs from last episode of vomitting or diarrhoea
15
Q
Notifiable disease - when?
A
- Food poisoning
- Infectious bloody diarrhoea
Diagnosing doctor has DUTY to inform
- Campylobacter and Salmonella also are but the lab inform public health about this
16
Q
Viral causes of gastroenteritis
A
- Norovirus
- Rotavirus
- Adenovirus
17
Q
Noravirus presentation
A
- Most common in adults - single stranded RNA virus
- Abdominal cramps, watery diarrhoea, vomitting
- Lasting 1-3 days
18
Q
Rotavirus - presentation
A
- Double stranded RNA virus
- Severe diarrhoea in infants and young children
- Generally self resolves in less than 1 week
19
Q
Adenovirus presentation
A
- Double stranded DNA virus
- Common cause of diarrhoea in children
20
Q
Bacterial causes of gastroenteritis
A
- Campylobacter
- E-coli
- Salmonella
- Shigella
21
Q
Campylobacter presentation
A
- Most common cause food poisoning - typically chicken, eggs or milk (gram -ve bacilli)
- Prodrome of fatigue, fever or myalgia, then nausea abdominal cramps and diarrhoea
22
Q
What complications can Campylobacter cause?
A
- Guillan Barre syndrome
- HUS
- Thrombotic thrombocytopaenic purpura
23
Q
E-coli presentation
A
- Transmitted through contaminated food usually (but can be from animals to human and person to person)
- Several forms exist - enterotoxigenic e-coli is most common cause travellers diarrhoea
24
Q
Which form of e-coli can cause HUS?
A
- Serotype 0157:H7
25
Salmonella presentation
* Undercooked poultry or raw eggs
* Fever, vomitting abdominal cramps and **bloody** diarrhoea
26
Shigella presentation
* Contaminated dairy products and water
* Fever, abdominal pain, bloody diarrhoea
27
Bacterial toxin causes of gastroenteritis
* Staphylococcus aureus - meat and dairy exotoxin not destroyed by heat
* Bacillus cereus - reheated rice
* Clostridium perfringens - reheating meat
* Vibrio cholera - contaminated water, oral vaccine available
28
Parasite causes of gastroenteritis
* Cryptosporidium
* Entamoeba histolytica
* Giardia intestinalis
* Schistosoma
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Cryptosporidium presentation
* Self limiting watery diarrhoea and abdominal cramps
* Diagnosis made by stool culture for ova, cysts and parasites
30
Entamoeba histolytica
* Ingestion of food/water contaminated with faeces
* Bloody diarrhoea, abdominal pain and fever
* Can also cause lliver absces
* Stool culture for ova, cysts and parasites needed for diagnosis - treat with Metronidazole
31
Giardia intestinalis
* Direct contact or faeco-oral route
* Acute disease - diarrhoea, fever, fatigue, nausea and bloating OR
* Chronic disease - steatorrhoea, malabsorption, weight loss
* Stool culture for ova, cysts and parasites for diagnosis - Metronidazole treats
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Schistosoma presentation
* Contaminated water
* Acute develops a month after initial infection = fever, malaise, abdominal pain, bloody diarrhoea
* Severe causes --> chronic liver disease
* Eosinophilia on FBC sometimes
* Stool culture for ova, cysts and parasites needed - treat with Praziquantel
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Hospital acquied gastroenteritis - main pathogens
* C.diff - then produces large amounts of exotoxins A&B
* Gram +ve organism
* Develops post use of broad spec abx distrupting normal microbiota of bowel
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What do the c.diff exotoxins do to the bowel?
* Trigger large immune response
* = inflammatory exudate on colonic mucosa
* This presents clinically with severe bloody diarrhoea and has potential to develop into toxic megacolon - bowel becomes severely dilated and high risk of perf if untreated
35
Investigations for ?c.diff
* Stool culture
* C.difficile toxin testing (CDT)
36
Non-infective causes of gastroenteritis
* Radiation colitits
* Inflammatory bowel disease
* Microscopic colitis - macroscopically normal on endoscopy but biopsy shows increase in inflammatory cells
* Chronic ischaemic colitis - usually splenic flexure watershed area, endoscopy may show blue swollen mucosa
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