Infections of the GIT and Hepatobiliary system Flashcards
Bacteria are protective against most intraluminal infection however can also be pathogenic if in the wrong part of the body such as
peritoneum
How many species of bacteria are found in the GI tract?
Over 400, predominantly anaeobes
What is ‘normal flora’
the community of microorganisms that live on another living organism without causing disease
Stable normal flora produces antimicrobial substances such as … which discourage infection
bacteriocins and short chain fatty acids
Bacteriocins and short chain fatty acids made by normal flora inhibit overgrowth of e______ pathogens and prevent colonisation by e____ pathogens
endogenous,
exogenous
What kills most swallowed pathogens?
Gastric acid
What increases the risk of intraluminal infection?
Less gastric acid or broad spectrum antibiotics
Clostridium difficile contains e___ that can survive the acidity of the stomach and reach the large intestine
endospores
C. difficile is gram _____, spore forming bacteria
positive
Many with c diff can be asymptomatic but can become a problem if the normal gut flora is altered, notably due to….
broad spectrum antibiotics
What is the rule of Cs?
clindamycin, ciproflxacin, co-amoxiclav and cephalosporins
Altered gut flora can also occur due to acid reducing drugs such as…
PPIs, NG feeding and immunocompromise
How do you treat C. diff?
Metronidazole
or
oral vancomycin
(in refractory cases sometimes faecal transplant)
What is the definition of diarrhoea?
3 or more loose/liquid stools within 24 hours
What are some infective causes of diarrhoea?
campylobacter, salmonella, HIV, bacterial or amoebic dysentery, cholera, systemic infections
What are some non-infective causes of diarrhoea?
Inflammatory:
Ulcerative colitis, Chron’s, Diverticular disease
Loss of absorptive area: coeliac, small bowel resection, tropical sprue
Pancreatic disease: pancreatitis, cancer
Drugs: antibiotics, magnesium, digoxin
Colon cancer
Systemic disease (thyrotoxicosis, uraemia, carcinoid
IBS, gastrectomy
What may floating stool indicate?
Fat content, malabsorption, Coeliac?
Blood or mucous in stool may indicate…
inflammatory/invasive infection, cancer?
True or false: puppies can carry campylobacter
True
True or false: reptiles can carry salmonella
True
What infection commonly comes from cooked meats?
Clostridium perfringens
What bacteria comes from reheated rice and causes lots of vomiting?
Bacillus cereus
Giardia causes offensive diarrhoea, chronic bloating, flatulence and is more common in…
nurseries or old age facilities
Where can cryptosporidium be found?
Cryptosporidium
Which food is salmonella commonly from?
Poultry, eggs and dairy
Where is vibrio parahaemolyticus often from?
Shellfish
What is a common cause of food poisoning, especially from meats and BBQs
campylobacter
In the UK, __-__% of diarrhoea are caused by viruses eg rotavirus, norovirus
50-70%
What are common causes of Traveller’s diarrhoea?
Enterotoxigenic e.coli
Campylobacter
Shigella
Non-tymphoidal salmonella
V. parahaemolyticus
Viral
Protozoal
Cholera
What are symptoms of traveller’s diarrhoea?
Abdominal pain, cramps, nausea, vomiting, dysentry
True or false: most strains of E. coli are harmless
True, some serotypes are pathogenic
Is cholera found in the UK?
Not really but can be seen in travellers
What causes vibrio cholerae?
Vontaminated food/water
What are symptoms of cholera?
Profuse watery “rice water” diarrhoea, up to 20 litres a day!!
Vomiting
Rapid dehydration
What is used to treat cholera?
Doxycycline and fluids
Oral rehydration therapy
What are 3 more common protozoa (parasites)?
Crytpo
Giardia
Entamoeba
What are the 2 more common worms (parasites)?
Schistosomiasis
Strongyloides
Who is most at risk to both common and rarer infections?
Immunosuppressed patients
What are red flags for diarrhoea?
Dehydration
Electrolyte imbalance
Renal failure
Immunocompromise
Sever abdominal pain (c. diff can cause toxic megacolon and can perforate)
Cancer risk factors: over 50, chronic diarrhoea, weight loss, blood in stool, Fhx cancer, change in bowel symptoms
What other infections may cause pain in the Right Upper Quadrant?
Biliary sepsis (aka ascending cholangitis)
Liver abscess
Pneumonia
What other infections may cause lower abdominal pain?
Pelk inflammatory disease
Pain in the Left or right upper quadrant may be peptic ulcer disease caused by…
Helicobacter pylori
Where does helicobacter pylori live?
Within mucous layer overlying the gastric mucosa
How to diagnose peptic ulcer disease
Stool antigen test
Breath test
Blood test for antibodies (can be positive for a year after)
Endoscopy with biopsy
How to diagnose a biliary tract infection?
Ultrasound
How to treat biliary tract infection
IV fluids, analgesia and antibiotics
or cholecystectomy
Obstruction of the common bile duct is called…
Ascending Cholangitis
What is Charcot’s triad?
Fever, abdominal pain and jaundice seen with ascending cholangitis
Management of ascending cholangitis
Prompt admission with IV antibiotics
ERCP
Cholecystectomy
(has high mortality)
Liver abscess can be seen on…
ultrasound of CT
What is the management of a liver abscess?
Antibiotics and drainage
What are 3 main causes of liver abscess?
Bacterial (faecal flora eg E. Coli)
Amoebic
Hydatid (dog tapeworm)
What is the other name for enteric fever?
Typhoid
What is Enteric fever caused by
Salmonella typhi
What are symptoms of enteric fever?
Generalised or right lower quadrant pain, high fever, “relative bradycardia”, headache, myalgia, rose spots, constipation/green diarrhoae
How is enteric fever diagnosed?
Through blood cultures
What are complications of enteric fever?
GI bleed, perforation, myocarditis, abscesses
How do you treat enteric fever?
Emergency surgery
Antibiotics
Biliary sepsis, peritonitis and liver abscess patients all…
get sick quickly!
