Theme 11 L5, L9: GI Infections Flashcards
1
Q
Which sites of the GI tract are sterile?
A
- peritoneal space
- pancreas
- gall bladder
- liver
2
Q
Which sites of the GI tract are non- sterile?
A
- mouth
- oesophagus
- stomach
- small bowel
- large bowel
3
Q
What are 3 types of dentoalveolar infections?
A
- 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
4
Q
What are the signs of peridontal infection?
A
- plaque beneath the gingival margin
- gingivitis (inflammation of gums)
- periodontitis
- periodontal abscess
- acute necrotising ulcerative gingivitis (Vincent’s angina)
5
Q
Name 2 deep neck space infections?
A
- Peri tonsillar/ quinsy abscess
2. Acute suppurative parotitis
6
Q
What is Lemierre’s syndrome?
A
suppurative jugular thrombophlebitis –> bacteria seen in jugular vein
7
Q
What is an iatrogenic cause of mucositis? (inflammation of mucous membranes of the GI tract)
A
-chemotherapy induced
8
Q
What is a risk factor of chemotherapy induced mucositis?
A
caries, peridontal diseases
9
Q
What is Boerhaave syndrome?
A
rupture of the oesophagus –> a sponteanous perforation of the oesophagus that results from an increase in intra oesophageal pressure
10
Q
How can oesophageal rupture lead to infection?
A
-results in contamination of the mediastinal cavity with gastric contents
11
Q
How do you manage oesophageal rupture?
A
- avoidance of all oral intake
- nutritional support
- antibiotics, PPI
- drainage of fluid collections
- debridement of infected and necrotic tissue
12
Q
How is H.pylori transmitted?
A
person-to-person through faecal-oral / oral-oral
13
Q
Explain the pathogenesis of H.pylori infection?
A
bacterial urease hydrolyses gastric luminal urea to form ammonia that helps neutralise gastric acid and form a protective cloud against the organism
14
Q
What is the classical presentation of cholangitis?
A
Charcot’s triad:
fever, abdominal pain, jaundice
15
Q
In a biliary tract infection, what will be elevated in an LFT?
A
- ALP
- GGT
- billirubin (predominately conjucated)
16
Q
Explain the symptoms and clinical findings in cholecysitis?
A
- 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
17
Q
What can an overgrowth of bacteria result from?
A
achlorhydia (e.g after gastric surgery) impaired motility blind loops of bowel surgery radiation damage
18
Q
What is the causative agent of Whipple’s disease?
A
tropheryma whipplei - ubiquitous in environment
19
Q
What is Whipple’s diseased characterised by?
A
rare, multi-system process characterised by four manifestations: joint symptoms (arthralgia), chronic diarrhoea, malabsorption/abdo pain and weight loss
20
Q
Which parasite can cause liver abscesses?
A
entamoeba histolytica
21
Q
What are liver abscesses associated with?
A
an increased risk of colonic malignancy
22
Q
What will be elevated in liver abscesses?
A
serum alkaline phosphatase
23
Q
How is mycobacterium tuberculosis associated with the GI tract?
A
-can affect any of the GI tract (ileo-caecal) is most common site
24
Q
What is pancreatitis mostly associated with?
A
alcohol use
25
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
26
What is the difference between complicated and uncomplicated diverticulitis?
-antibiotics have no proven efficacy for uncomplicated diverticulitis
27
What is the difference between diverticulosis and diverticulitis?
Diverticulosis = mere presence of diverticula
Diverticulitis = inflammation and complications of diverticula
28
What is an intra-peritoneal abscess?
localised area of peritonitis with a build up of pus
29
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
30
How do we treat an intra-abdominal abscess?
drainage combined with therapy
31
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
32
What is SBP and how is it defined?
spontaneous bacterial peritonitis:
| ascitic fluid infection without an evident intra-abdominal surgically treatable source
33
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
34
Which bacteraemia can patients with bowel cancer present with?
streptococcus bovis (now called S.gallolyticus)
35
What is S.bovis/S.gallolyticus bacteraemia also associated with?
endocarditis
36
What is angular cheilitis?
a mild infection at the side of the mouth caused by S.aureus or candida
37
What is the name of white lesions on the tougue that can suggest AIDS?
oral hairy leukoplakia
38
Where is a peridontal infection found and what are the types?
Infection of the soft tissue around the mouth
1. Mild (gingivitis)
2. Moderate (periodontitis)
3. Severe (necrotising gingitivitis)
39
If parotitis is caused by bacteria i.e not mumps, what is the causative agent?
S.aureus
40
What are the two types of food borne GI diseases?
intoxication and infection
41
What are the differences between intoxication and infection in terms of:
1. Transmission
2. Incubation period
Intoxication:
- ingestion of pre-formed toxin
- rapid incubation period
- not communicable
Infection:
- ingestion of bacteria, virus or parasite
- slower incubation period
- person to person (faecal-oral)
42
What are the symptoms of an intoxication with a food bourne GI disease?
```
vomiting
nausea
diarrhoea
weakness
respiratory failure
numbness
sensory/motor dysfunction
```
43
Which factors contribute to intoxication with a food bourne GI disease?
inadequate cooking, improper handling temperatures
44
What are the symptoms of an infection with a food bourne GI disease?
```
diarrhoea
nauseau
vomiting
abdo cramps
fever
```
45
Which factors contribute to infection with a food bourne GI disease?
inadequate cooking, cross contamination, poor hygiene and handwashing procedures
46
What does intoxication food poisoning with S.aureus result in?
- it is a heat stable enterotoxin
- projectile vomiting and nausea
- no diarrhoea
47
How fast is the onset of S.aureus food poisoning?
4hrs after eating - fast
48
S.aureus food poisoning can result from eating what?
mayonnaise, meat, dairy products
49
Explain the features of food poisoning with B cereus?
Bacillus cereus I:
- vomiting
- no diarrhoea
- quick onset
Baccilus cereus II:
- little vomiting
- profuse diarrhoea
- 12-14 hours after eating
50
Eating what can result in B cereus food poisoning?
B cereus I:
-cooked rice and other starchy foods
B cereus II:
-wide variety of foods
51
What are the features of clostridium perfringes food poisoning and what foods is it associated with?
- abdominal cramps
- watery diarrhoea
- 1-4 hours after eating
- meat, meat products
52
What are the features of intoxication with clostridium botulinum?
- neurotoxin / botulism
- blurred vision, respiratory failure
- flaccid paralysis
- slow (1/2 days after eating)
53
Consuming what is associated with clostridium botulinum?
improperly canned food
54
What is infant botulism?
C.botulinum spores in honey can colonise infant (<1 yr) GI tract and produce toxin
-causes constipation, neurological symptoms but is a milder disease than in adults
55
Is salmonella toxin mediated?
no it is an infection
56
What are the effects of infection with salmonella food poisoning?
- cramps, diarrhoea, fever, myalgia
- nausea and vomiting
- onset 6-8 hours after eating
57
What is salmonella ssp found in?
poultry, birds and some reptiles
58
What is the most common type of salmonella?
S.enteritidis
59
How do you treat gastroenteritis caused by salmonella?
- antibiotic treatment is not recommended for health people with gastroenteritis due to salmonella infection
- consider antibiotic treatment if older than 50, immunocompromised or have vascular/valve disease
- if so, prescribe ciprofloxacin
60
What does dysentery mean?
an infection of the GI tract that causes diarrhoea containing blood or mucus
61
What are the effects of being infected with Shigella spp (dysentery)?
- watery, bloody, mucoid stool, abdo pain
- fluid, electrolyte loss
- 36-72hr incubation period
62
How can infection with Shigella spp occur?
guts of humans, primates, faecal oral route
63
What are the 3 types of shigellae on DCA?
S. dysenteriae - most severe
S.flexneri
S. sonei - most mild, common in UK
64
How do you treat gastroenteritis caused by Shigella?
Antibiotic treatment is not recommended for health people with mild shigellosis
Consider antibiotic treatment for people:
- With severe disease
- Who are immunocompromised
- With bloody diarrhoea
if so, ciprofloxacin
65
Explain the features of infection with campylobacter spp?
- watery diarrhoea
- nausea, vomiting, malaise, headache
- 2-5 day onset - slow
- toxin and infection
66
How do you become infected with campylobacter?
poultry, birds, faecal-oral route
67
How do you treat gastroenteritis caused by campylobacter?
- antibiotic not needed for mild symptoms
- fluid and electrolyte replacement may be needed
- antibiotics for: severe symptoms, immunocompromised, long course
- if so, erythromycin
68
What are the features of infection with E.coli 0157?
- watery diarrhoea, then bloody diarrhoea
- haemorrhagic colitis/ haemolytic uraemic syndrome in 10%
- 2-5 days onset - slow
- can acquire shigella toxin and produce haemorrhagic diarhoea
69
Infection with E.coli 0157 is associated with eating what?
cattle and meat
70
What are some complications of infection with E.coli 0157?
Acute renal failure, thrombocytopenia, microangiopathic haemolytic anaemia
71
How do you treat gastroenteritis caused by E.Coli 0157?
- all E.colis are self-limiting - don't prescribe antibiotics
- treatment is supportive
72
What are some other less common causes of bacterial gastoenteritis?
- Yersinia enterocolitica
- Listeria monocytogenes – dangerous in pregnant women
- Vibrio parahaemolyticus – associated with shellfish
- Plesiomonas shigelloides
73
Name the 5 viruses that can cause gastroenteritis?
1. Rotavirus
2. Adenovirus
3. Norwark/ norovirus
4. Astrovirus
5. Calicivirus
all effect children, norovirus, astrovirus and calicivirus can effects adults too
74
Amoebic dysentery: What are the effects of infection with entamoeba histolytica?
- watery then bloody diarrhoea
- N&V, tenesmus, malaise
- extra intestinal symptoms e.g liver abscesses
- very slow onset: 15 days
75
How is infection with entamoeba histolytica acquired?
contaminated food and water
76
How do you treat amoebic dysentry?
-antibiotics
77
What are the effects of infection with cryptosporidium parvus?
Cryptosporidiosis:
- watery diarrhoea, weight loss, fever
- severe chronic diarrhoea in immunocompromised
- v slow: 2-10 days
78
How is cryptosporidium parvum acquired?
found in fish, reptiles, animals and common water contaminant
79
How do you treat cryptosporidiosis?
no antibiotics unless immunocompromised
80
What are the features of giardia intestinalis?
Giardiasis:
- foul smelling, watery diarrhoea, cramps
- steatorrhoea, flatulence
- chronic relapsing diarrhoea in some
- 1-4 weeks but sudden onset
81
How do you become infected with giardia intestinalis?
common water contaminant
82
How do you treat gastroenteritis caused by Giardia intestinalis?
-antibiotics - metronidazole
83
What are the effects of infection with vibrio cholerae?
- abrupt, "rice water" stool
- significant fluid loss, hypervolemic shock
- 12hrs-5 days - slow
84
How is infection with vibrio cholerae acquired?
water or food borne (esp shellfish)
85
What are the different serotypes of cholera?
01 - classic cholera
| Non-01 (0139) - milder disease
86
How do you treat cholera?
replacement of fluid loss
87
What are two organisms that cause enteric fevers?
1. Salmonella typhi
| 2. Salmonella paratyphi
88
What are the features of enteric fever from salmonella?
-fever, headache, malaise, anorexia
-diarrhoea, splenomegaly, high fever, rose spots
slow onset
-high fatality if not treated
-can become a chronic carrier - "typhoid mary"
89
How do you treat enteric fever?
immediate antibiotic treatment - azithromycin
90
What are the effects of Clostridioides difficile, an antibiotic associated diarrhoea?
- foul smelling, watery diarrhoea, cramps, low grade fever
| - can lead to PMC (pseumembranous collitis), toxic megacolon and death
91
What type of inflammation is C.diff?
toxin mediated - spores aid transmission
92
What are the risk factors for C.diff?
antibiotics, age> 65 yrs, hospital stay
93
How should you treat antibiotic associated diarrhoea?
stop predisposing antibiotic and start treatment with vancomycin
94
what complications can arise from streptococcus gallolyticus ?
infective endocarditis and septicaemia in elderly
| strongly associated with colorectal cancer
