Gastroenteritis Flashcards
Define gastroenteritis
Syndrome of diarrhoea and vomiting that refers to non-inflammatory involvement of the upper small bowel or inflammation of the colon.
What is the most common cause of gastroenteritis?
Infection.
The vast majority is caused by a virus.
Bacteria - 20%
Parasites < 6%
What percentage of gastroenteritis cases are not infectious?
15%
Give some non-infectious diarrhoea examples
GI bleed Ischaemic gut Diverticulitis Endocrine disorders Numerous drugs Fish toxins WIthdrawal
What is the approach to any clinical infection syndrome?
What are the key clinical symptoms and signs that suggest the infection?
Differential diagnosis
Severity of Infection
Site and microbiological diagnosis: investigations
Antibiotic and supportive management
Infection Control
Public Health
What is another name for the norovirus?
Norwalk agent
Which pathogens cause toxin-mediated food poisoning?
Which of these pathogens pre form toxins and which are formed in vivo?
Preformed: Staph aureus Clostridium perfringens Bacillus cereus In vivo production: Vibrio Enterotoxigenic E. coli
What are the presenting clinical syndromes of food poisoning?
1. Acute enteritis (i.e. inflammation of the small intestine): Fever Diarrhoea Vomiting Abdominal pain 2. Acute colitis: Fever Pain Bloody diarrhoea 3. Enteric fever-like illness: Fever Rigors Pain Little diarrhoea
List infective and non-infective causes of bloody diarrhoea
Infection: bloody diarrhoea usually indicates colonic inflammation Campylobacter. spp Shigella. spp E. coli 0157 Amoebiasis
Non infective:
IBD
Malignancy
Ischaemia
Describe the symptoms of enteric fever-like illness
Fever
Systemically unwell
Abdominal pain
Constipation but possibly short history of diarrhoea
What is typhoid?
A bacterial infection that can spread throughout the body involving multiple organs.
Where does Typhoid come from?
It is almost always imported
From:
Indian subcontinant, South East Asia, Far east, middle east, Africa, central/south america, Increasing in Eastern Europe.
How is typhoid transmitted?
Food, water or carrier
How can typhoid present?
It can be asymptomatic
It can be mild
It can cause bacteraemia
it can cause enterocolitis
How is typhoid diagnosed?
Blood cultures are the key to diagnosis.
Stool and urine cultures also done.
How is typhoid treated?
Chloramphenicol and ciprofloxacin- some strains resistant to this
Ceftriaxone or azithromycin
How can typhoid be prevented?
There is an IV or oral vaccine.
It is not effective against paratyphoid.
What are key features in a gastroenteritis history?
Diarrhoea: frequency, nocturnal, constistency, colour, presence of blood
Associated symptoms: abdominal pain, vomiting, fever, urgency, incontinence
Anyone in family or work with similar symptoms
Occupation
Pets and animal contact
Travel abroad
History of medication- particularly recent Abx and PPIs
What are key features in a gastroenteritis examination?
Fever
Skin rashes, e.g. rose spots, erythema nodosum
Dehydration: pulse, mental state, dry tongue, skin turgor, blood pressure, postural drop
Abdominal tenderness
Abdominal distension
PR exam: stool, blood, tenderness
What investigations are carried out to help diagnosis a gastroenteritis?
Stool microscopy when appropriate (e.g. history of travel, for giardia, amoeba etc)
Stool culture: Salmonella, Camppylobacter, Shigella
Stool toxin for C diff (culture not routinely done), adn cytotoxin for E. coli
Blood cultures (salmonella)
PCR : .e.g norovirus
FBC- wcc key in severity of CDI
U, Es - renal function important
AXR
What are severity markers of CDI?
One or more of the following:
Suspicion of PMC or toxic megacolon or ileus or colonic dilatation in CT/AXR of >6cm
WCC > 15 cells/mm3
Creatinine > 1.5 x baseline
What are intestinal complications of bacterial enteritis?
Severe dehydration and renal failure
Acute colitis, toxic dilatation
Post infective irritable bowel
Transient secondary lactase intolerance
What are extra-intestinal complications of bacterial enteritis?
Septicaemia Metastatic infection: meningitis, aortitis, osteomyelitis, endocarditis Reactive arthritis Meningism Neurological- Guillian-Barre syndrome haemolytic uraemic syndrome
What is supportive treatment for gastroenteritis?
Oral rehydration IV fluids (saline important)
