Theme 11 L5, L9: GI Infections Flashcards
Which sites of the GI tract are sterile?
- peritoneal space
- pancreas
- gall bladder
- liver
Which sites of the GI tract are non- sterile?
- mouth
- oesophagus
- stomach
- small bowel
- large bowel
What are 3 types of dentoalveolar infections?
- Caries (decay/ cavities) - breakdown of teeth due to acids made by bacteria
- Pulpitis - inflammation of the dental pulp (tissue at centre of tooth)
- Periapical abscess
What are the signs of peridontal infection?
- plaque beneath the gingival margin
- gingivitis (inflammation of gums)
- periodontitis
- periodontal abscess
- acute necrotising ulcerative gingivitis (Vincent’s angina)
Name 2 deep neck space infections?
- Peri tonsillar/ quinsy abscess
2. Acute suppurative parotitis
What is Lemierre’s syndrome?
suppurative jugular thrombophlebitis –> bacteria seen in jugular vein
What is an iatrogenic cause of mucositis? (inflammation of mucous membranes of the GI tract)
-chemotherapy induced
What is a risk factor of chemotherapy induced mucositis?
caries, peridontal diseases
What is Boerhaave syndrome?
rupture of the oesophagus –> a sponteanous perforation of the oesophagus that results from an increase in intra oesophageal pressure
How can oesophageal rupture lead to infection?
-results in contamination of the mediastinal cavity with gastric contents
How do you manage oesophageal rupture?
- avoidance of all oral intake
- nutritional support
- antibiotics, PPI
- drainage of fluid collections
- debridement of infected and necrotic tissue
How is H.pylori transmitted?
person-to-person through faecal-oral / oral-oral
Explain the pathogenesis of H.pylori infection?
bacterial urease hydrolyses gastric luminal urea to form ammonia that helps neutralise gastric acid and form a protective cloud against the organism
What is the classical presentation of cholangitis?
Charcot’s triad:
fever, abdominal pain, jaundice
In a biliary tract infection, what will be elevated in an LFT?
- ALP
- GGT
- billirubin (predominately conjucated)
Explain the symptoms and clinical findings in cholecysitis?
- abdo pain, fever, history of fatty food ingestion one hour or more before initial onset of pain
- elevation in the serum total bilirubin and ALP
- normally associated with gall stones
- +ve murphy’s sign
What can an overgrowth of bacteria result from?
achlorhydia (e.g after gastric surgery) impaired motility blind loops of bowel surgery radiation damage
What is the causative agent of Whipple’s disease?
tropheryma whipplei - ubiquitous in environment
What is Whipple’s diseased characterised by?
rare, multi-system process characterised by four manifestations: joint symptoms (arthralgia), chronic diarrhoea, malabsorption/abdo pain and weight loss
Which parasite can cause liver abscesses?
entamoeba histolytica
What are liver abscesses associated with?
an increased risk of colonic malignancy
What will be elevated in liver abscesses?
serum alkaline phosphatase
How is mycobacterium tuberculosis associated with the GI tract?
-can affect any of the GI tract (ileo-caecal) is most common site
What is pancreatitis mostly associated with?
alcohol use
What is a ‘complicated intra-abdominal infection’?
defined as infection that extends beyond the hollow viscus of origin into the peritoneal space and is associated with either abscess formation or peritonitis
e.g appendicitis is uncomplicated but perforated appendicitis is
What is the difference between complicated and uncomplicated diverticulitis?
-antibiotics have no proven efficacy for uncomplicated diverticulitis
What is the difference between diverticulosis and diverticulitis?
Diverticulosis = mere presence of diverticula
Diverticulitis = inflammation and complications of diverticula
What is an intra-peritoneal abscess?
localised area of peritonitis with a build up of pus
What are the pre-disposing factors to intra-peritoneal abscess?
perforation, peptic ulcer, perforated appendix or diverticulum, bowel infarction, pancreatitis, penetrating trauma, post-operative anastomotic leak
How do we treat an intra-abdominal abscess?
drainage combined with therapy
How does an intra-peritoneal abscess present?
- Non-specific
- Sweating, anorexia, wasting
- Swinging pyrexia
- Localising features
- Subphrenic abscess: pain in shoulder on affected side, persistent hiccup, intercostal tenderness, apparent hepatomegaly (liver displaced downwards, ipsilateral lung collapse with pleural effusion)
- Pelvic abscess: urinary frequency, tenesmus
What is SBP and how is it defined?
spontaneous bacterial peritonitis:
ascitic fluid infection without an evident intra-abdominal surgically treatable source
What is the aetiology behind SBP?
bacteria within the lumen cross the intestinal wall into mesenteric lymph nodes. Lymphatics carrying the contaminated lymph ruptures because of the high flow and high pressure associated with portal hypertension. Seeing of ascitic fluid via the blood also occurs
Which bacteraemia can patients with bowel cancer present with?
streptococcus bovis (now called S.gallolyticus)
What is S.bovis/S.gallolyticus bacteraemia also associated with?
endocarditis
What is angular cheilitis?
a mild infection at the side of the mouth caused by S.aureus or candida
What is the name of white lesions on the tougue that can suggest AIDS?
oral hairy leukoplakia