CP11-9 GI Infections Part 2 Flashcards
What is the second leading cause of death in children under 5?
Diarrhoeal disease
what is the most common cause of diarrhoeal disease?
Non-food bourne e.g. hand hygiene
What are some physical factors to prevent diarhoeal disease?
Food and water hygiene
Hand washing
Animal contact
What are some host factors that can prevent diarrhoeal disease?
Healthy Microbiome
Stomach acid barrier
Local immune responses
What are some interventions used to prevent diarrhoeal disease?
Vaccines
Antimicrobial treatments
Rehydration therapies
What are some categories of disease causing gastroenteritis/diarrhoea?
Food borne
Non-foodborne
Viral
Waterborne
Antibiotic-associated
What are two subtypes of food borne/waterborne gastroenteritis?
Intoxication
Infection
What is the difference between intoxication and infection gastroenteritis?
Intoxication = ingestion of pre formed toxin with a rapid incubation period. Non communicable and causes more systemic symptoms.
Infection = ingestion of bacteria, virus or parasite with a slow incubation period. Communicable, usually faecal-orally, causing more localised systems in GI tract.
What causes intoxication gastroenteritis?
Inadequate cooking
Improper hand,ink temperatures
What causes you to get pathogens causing infectious gastroenteritis?
Inadequate cooking
Cross contamination e.g. of cooked and raw meat
Poor hygiene and hand washing
What foods are associated with gastroenteritis?
Dairy
Eggs
Meats including ground beef, poultry, pork
Seafood especially oysters
Some vegetables
Mayonnaise
Rice
Canned food including honey
Who is not allowed to have honey?
Children under 1 due to risk of foodbourne gastroenteritis
How does staph aureus cause gastroenteritis?
Heat stable enterotoxin of staph aureus causes nausea and vomiting (no diarrhoea) around 4 hours after ingestion.
What are the two type of bacillus cereus associated GI infection?
Heat stable emetic toxin = vomiting without diarrhoea 1-4 hours after eating cooked rice usually
Heat labile toxin = little vomiting but precise diarrhoea 12-14 hours after eating
How does clostridium perfringens cause gastroenteritis?
Causes abdominal cramps and watery diarrhoea 1-4 hours caused by heat labile toxins of c. Perfringes after eating contaminated meat products
How does clostridium botulinum cause gastroenteritis in adults?
Neurotoxin produced by c. Botulinum causes blurred vision, respiratory failure and flaccid paralysis 1-2 days after eating contaminated canned food
How does clostridium botulinum cause gastroenteritis in infants?
C botulinum spores - usually in honey - colonise the infant’s GI tract and produces toxins causing constipation and neurological symptoms (milder disease than adults)
How does salmonella cause gastroenteritis?
6-8 hours after eating high dose from contaminated poultry, birds and some reptiles causing cramps, diarrhoea, fever, myalgia, nausea and vomiting
What is the most common type of salmonella?
Salmonella enteritidis
How are intoxification food borne gastroenteritis treated?
With supportive measures as contaminated with toxin not actual pathogen
When are antibiotics given to salmonella associated gastroenteritis?
If affected individual is:
>50
Immunocompromised
Has cardiac valve disease or e do vascular abnormalities
What antibiotic is given to those who need it for salmonella associated gastroenteritis?
Ciprofloxacin
What gastroenteritis occurs from shingella species?
Dysentery = watery, bloody, mucoid stool with associated stomach pain. Causes fluid and enterolyte loss. Only requires small dose to become ill 36-72 hours after infection.
How is shingella associated gastroenteritis treated?
Only with antibiotics if individual has sever disease, is immunocompromised or has bloody diarrhoea
What antibiotic is given to patients with shingella associated gastroenteritis?
Ciprofloxacin
What should not be prescribed to patients with shingella associated gastroenteritis?
Anti motility drugs e.g. loperamide or diphenoxylate
What is characteristic of campylobacter associated gastroenteritis?
Watery diarrhoea, nausea, vomiting, malaise and headache due to production of heat labile toxin 2-5 days after ingestion. Associated with poultry, birds and rascal oral transmission.
How should campylobacter associated gastroenteritis be treated?
With fluid and electrolyte replacement if necessary
Antibiotics if severe or worsening symptoms, immunocompromised, or symptoms lasting >1 week
What antibiotic is given to patients with campylobacter associated gastroenteritis who need it?
erythromycin
What e.coli can cause gastroenteritis?
E.coli 0157
How does e.coli 0157 cause gastroenteritis?
Found in contaminated cattle and meat and can produce shiga toxin causing watery diarrhoea and then bloody diarrhoea after 2-5 days.
What are complications of e.coli 0157 associated gastroenteritis?
10-15% develop haemolytic uraemic syndrome
Other complications include, acute renal failure, thrombocytopenia and microangiopathic haemolytic anaemia
How should e.coli 0157 associated gastroenteritis be treated?
Supportive only
NO antibiotics
NO anti mobility drugs e.g. loperamide or diphenoxylate, or opioids
NO NSAIDs
What are the 5 main types of e.coli associated gastroenteritis?
Enterohaemorrhagic (VTEC)
Enterotoxigenic (ETEC)
enteropathogenic (EPEC)
enteroaggregative(EAEC)
enteroinvasive (EIEC)
What can yersinia enterocolitica cause?
In young children = fever, abdo pain, diarrhoea +/- blood
Older children and adults = fever, pain on right abdomen
What can listeria monocytogenes cause?
Serious gastroenteritis in pregnant women, newborns, immunocompromised and people >65 from unpasteurised dairy products e.g. soft cheese
How does vibrio parahaemolyticus and plesiomomas shigelloides cause gastroenteritis?
Comes from raw seafood and can cause severe disease in immunocompromised. Symptoms include abdo pain, fever, nausea, vomiting, muscle aches and headaches lasting 24hours-3 days.
What are the 5 main viruses causing viral gastroenteritis?
Rotavirus
Adenovirus
Norovirus
Astrovirus
Calicivirus
How does rotavirus associated gastroenteritis present?
With diarrhoea, vomiting and fever (usually in children) lasting 5-7 days
How does adenovirus associated gastroenteritis present?
With diahrroea, vomiting and fever in infants and young children lasting 5-12 days
How does norovirus associated gastroenteritis present?
With acute vomiting, diarrhoea, fever, myalgia, headache lasting 1-2 days affecting everyone and especially rife in hospitals, nurseries, nursing homes and cruise ships
How does entamoeba histolytica associated gastroenteritis present?
With water diarrhoea and then bloody diarrhoea, nausea, vomiting, tenesmus and malaise after ingesting contaminated food or water usually 15 days after exposure.
What is a complication of entamoeba histolytica?
Liver abscesses
How is entamoeba histolytica associated gastroenteritis also known?
Amoebic dysentery
How is amoebic dysentery treated?
Always prescribe antibiotics for confirmed cases
If acute invasive or liver abscesses with metronidazole or tinidazole followed by 10 days of diloxanide furoates.
Asymptomatic with cysts in faeces = diloxanide furoate.
How does cryptosporidosis present?
Watery diarrhoea, weight loss and low grade fever or severe chronic diahroea in immunocompromised which develops 2-10 days after exposure from animals, fish, reptiles or contaminated water.
Who is treated for cryptosporidosis and how?
Only necessary for immunocompromised and treatment is aimed at underlying condition, and very occasionally patients are given nitazoxanide but unproven benefit
What is giardiasis?
Giardia intestinalis associated gastroenteritis presenting with foul-smelling, watery diarrhoea, cramps, steatorrhoea and flatulence that has a sudden onset 1-4 weeks after exposure with contaminated water and can lead to chronic relapsing of diarrhoea
How is giardiasis treated?
Metronidazole for all confirmed cases or tinidazole
What is cholera?
Abrupt, ‘rice water’ stool causing significant fluid loss and hypovolemic shock 12 hours-5 days after ingestion of cholera toxin from water or food (especially shellfish)
How is cholera treated?
Oral rehydration if not severe
Antibiotics for moderate to severe dehydration e.g. with tetra/doxycycline or ciprofloxacin
What causes enteric fevers?
Infection with salmonella typhi causing fever, headache, malaise, anorexia, constipation/diarrhoea 6-30 days after exposure
Infection with salmonella paratyphi causing diarrhoea, splenomegaly, high fever and rose spots 1-10 days after exposure
What is the immune response to salmonella typhi/paratyphi?
Engulfed by macrophages and migrate to the liver, spleen and bone marrow
How should enteric fever be treated?
Immediate antibiotics - usually azithromycin - for all confirmed cases unless, multiple resistant then have fluoroquinolone or cefixime,or quinlone resistant then prescribe azithromycin or ceftriaxone
What is the most common bacteria associated with antibiotic associated diarrhoea?
Clostridium difficile
How does c. Diff associated gastroenteritis present?
Foul smelling, watery diarrhoea, Cramps and Low grade fever + potentially PMS, toxic megacolon or death due to toxin mediated inflammation and spores aid transmission
What are risk factors for c. Diff associated diarrhoea?
Antibiotics
Age >65
Hospital stays
How is c. Diff associated gastroenteritis diagnoses?
By demonstration of toxin as well as organism
How is c.diff/antibiotic associated gastroenteritis treated?
Stopping current antibiotics predisposing the diarrhoea
Start on vancomycin or fidaxomicin
What is strep gallolyticus associated with?
Infective endocarditis and septicaemia in elderly
Associated with colorectal cancer
How is strep gallolyticus modelled to promote colorectal cancer?
1 - metabolite production by s. gallolyticus causes gallocin secretion by pre-neoplastic epithelium causing microbial imbalance which may lead to malignancy
2- high colonisation induces inflammation accelerating transformation of pre-malignant to malignant epithelium
How does mycobacterium tuberculosis associated gastroenteritis present?
With abdominal pain, weight loss, anaemia , tiredness and night sweats.
How is gastrointestinal TB treated?
If no CNS involvement with isoniazid, rifampicin, pyrazinamide and ethambutol for 2 months then isoniazid and rifampicin for a further 4 months
How often does c.diff infection recur?
30%
