Gastroenteritis Flashcards
What is acute diarrhoea?
sudden onset and lasts less than 2 weeks
90% are infectious
10% are caused by medications, toxin ingestions and ischaemia
What is chronic diarrhoea?
Diarrhoea which lasts for more than 4 weeks
Most of the causes are non-infectious
What is persistent diarrhoea?
Diarrhoea lasting between 2-4 weeks
What might cause acute diarrhoea?
Viral, bacterial, protozoa, medications Laxatives or diuretic abuse Ingestion of environmental preferomed toxin such as seafood Ischemic colitis Graft verus host
What might cause chronic diarrhoea?
IBS Diverticular disease colorectal cancer Bowel resection Malabsorption IBD Coeliac disease Carcinoid tumour
What is gastroenteritis?
Inflammation of the lining of the stomach, small and large intestine
What is acute gastroenteritis common in?
Young children and elderly, and those who are immunocompromised.
What are most causes of gastroenteritis?
Most are infectious (90%), some acute may follow ingestion of drugs and chemical toxins (10%)
What are the causative pathogens of gastroenteritis?
Bacteria
Viral
Protozoa
What specific viral organisms can cause gastroenteritis?
Rotovirus
Norovirus
Adenovirus
What specific protozoa can cause gastroenteritis?
Entamoeba histolytica
Cryptosporidium
Giardia intestinalis
Schistosomiasis
What specific bacterial organisms can cause gastroenteritis?
Campylobacter jejunei** Salmonella sp. Shigella Escherichia coli** Clostridium difficile** Staphylococcal enterocolitis Bacillus cereus Clostridium perfringens Clostridium botulinum
What are the different mechanisms by which enteric pathogens can cause diarrhoea?
- stimulation of net fluid and electrolyte secretion
- Increased propulsive muscle contractions
- Mucosal destruction and increased permeability
- Nutrient alabsorption
What is enteric pathogen?
Pathogens of the intestine - may also refer to the gut flora
Describe toxin mediated food poisoning?
Differentiation from acute toxin mediated Food poisoning Pre formed staph.A Onset 1-6 hours after exposure Diarrhoea and adobe pain Resolves in 6-10 houes No blood or pus in faeces
What is the most common cause of travellers diarrhoea?
Enterotoxigenic E.Coli
what does enterotoxigenic E.coli produce?
Enterotoxins - increase intracellular levels of cAMP
Causes cell leakage
What is the major reservoir for human infection?
Cattle
(deer, sheep, goats, horses, dogs, birds, flies)
Bacterial can survive in manure and water troughs
What symptoms can E.Coli 015:H7 give you?
Adobe cramps
diarrhoea +/- blood
Where might you get E.Coli from?
Beef, raw milk
Where are you likely to get salmonella from?
Poultry, raw eggs, meat
What is the most common cause of food poisoning?
Campylobacter
Describe campylobacter in more detail?
Poultry, raw milk
Blood bowel movements, abdo pain
(can mimic appendicitis)
How would you treat severe campylobacter?
Clarithromycin or azithromycin
What might diarrhoea from the small bowel and colon present like?
Large volume stool Moderate increase in number Minimal urgency No tenesmus Little mucus
What might diarrhoea from the recto-sigmoid present like?
Small amount of stool Frequency Urgency Tenesmus Mucus Blood
Describe enteric fever like illness?
Fever
Systemically unwell
Abdo pain
Constipation but possibly short history of diarrhoea
Describe typhoid?
Almost always imposed (far eat)
Food and water or carrier
How does typhoid present?
Asymptomatic, mild, bacteramia, enterocolitis
What would you do to diagnose typhoid?
Blood cultures
Stool and urine cultures
What are the 3 different presenting clinical syndrome of food poisoning?
Acute enteritis : fever. D&V, abdominal pain
Acute colitis: fever, pain, bloody diarrhoea
Enteric fever like illness : fever, rigors, pain but little diarrhoea
What are some complications of bacterial enteritis - intestinal?
Severe dehydration and renal failure
Acute colitis, toxic dilatation
Post infective irritable bowel (very common)
Transient secondary lactase intolerance
What are some complications of bacterial enteritis - extra-intestinal?
Bacteriaemia leading to sepsis +/_ metastatic infection: meningitis, aortitis. Ostyeomyelitis, endocarditis Reactive arthritis Meningism Neurological [Guillian Barre syndrome] Haemolytic uraemic syndrome Others
What type of organism is C.diff?
Anaerobic gram positive spore forming bacillus
What are the 4 antibiotic Cās that should be reduced at all costs?
Cephalosporins
Clindamycin
Co-Amoxiclav
Cirpofloxacin
What are the main drivers for CDI?
A. BROAD SPECTRUM ANTBIOTIC THERAPY
B. SPECIFIC ANTIBIOTIC TYPES E.G QUINOLONES, CEPHALOSPORINS
C. LONG DURATION OF THERAPY
VULENRABLE POPULATION E.G ELDERLY, NURSING HOME, CO-MORBIDITIES, HOSPITALISED
E. ROUTE OF THERAPY MAKES NO DIFFERENCE
F. TOTAL AMOUNT OF ANTIBIOTIC USE ā number of exposures
G. GIVING ANTIBIOTIC IN THE ABSENCE OF INFECTION
What are 4 different types of travel related diarrhoea?
ETEC (E.Coli)
AMOEBIASIS
GIARDIASIS
CRYPTOSPORIDIOSIS
What is the average duration of travellers diarrhoea?
Around 4 days
Describe what amoebiasis is?
It is a protozoal infection spread by the feacal-oral route or by an ill or asymptomatic carrier
It is common in areas of poor sanitation
What symptoms might you get with amoebiasis?
Acute bloody diarrhoea
extra-intestinal spread can produce abscess
What is the treatment of amoebiasis?
Metronidazole
What is giardia lamblia?
Flagellated protozoan infection of the duodenum and proximal jejunum
Cysts found in water and food
What is the spread of giardia lamblia?
Person to person infection
Intestinal parasite
What are the symptoms of giardia lamblia?
Acute infectious diarrhoea, no mucus or blood
Malabsorption due to diarrhoea
How might you diagnose giardia lamblia?
Stool analysis/duodenal aspirate
How would you treat giardia lamblia?
Metronidazole
What is Cryptosporidiosis?
Travel related diarrhoea
How is Cryptosporidiosis spread?
Water food contract with animals
It is highly infectious
What might be the symptoms of Cryptosporidiosis?
Diarrhoea
Self limiting
How would you diagnose Cryptosporidiosis?
Duodenal aspirate/stool
How would you treat Cryptosporidiosis?
Supportive
Antimicrobials are virtually ineffective
