GI Infections Flashcards
3 main clinical syndromes caused by GI infections
Secretory diarrhoea
Inflammatory diarrhoea
Enteric fever
Mechanism of secretory diarrhoea
Toxin production → Cl- secretion into the lumen
Pathogenic causes of secretory diarrhoea
Cholera, ETEC, EPEC (enteropathogenic E. coli), viruses
Causes of inflammatory diarrhoea
Inflammation and bacteraemia
CHESS organisms
Causes of Enteric fever
Typhoidal salmonella
Yersinia
Brucella
Sources of Clostridium botulinum
Vacuum packed food
Inactivated by cooking
Symptoms of Clostridium botulinum
Cleavage of SNARE proteins prevenitng ACh release → descending paralysis
Mx of Clostridium botulinum
Antitoxin
C. perfringens sources
Reheated meats
C. perfringens incubation
8-16hrs
C. perfringens Sx
24 hrs water diarrhoea and cramps
gas gangrene
Clostridium difficile causes and key complcations
3 Cs ABx
Pseudomembranous colitis
Clostridium difficile management
- Vancomycin
- Fidaxomicin
Bacillus cereus source and incubation
Source - reheated rice
Incubation - short (4hrs), long (18hrs)
Staph aureus toxin and incubation
Enterotoxin
2-4 hrs (STwoFourlococcus)
E. coli forms
ETEC - Traveller’s
EIEC - Invasive dysentery
EHEC - haemorrhagic
EPEC - infantile diarrhoea (Paeds)
What can you treat E. coli with?
Ciprofloxacin
Salmonella typhi and paratyphi symptoms
Enteric fever - constipation, fever, rose spots, splenomegaly
Salmonella typhi and paratyphi treatment
IV ceftriaxone then PO azithromycin
Salmonella enteritidis sources
Poultry, eggs, meat
Salmonella enteritidis incubation
12-48 hrs
Shigella features
Distal ileum and colon → mucosal inflammation, fever, pain and bloody diarrhoea
Vibrio cholerae features
Rice water stool
Comma shaped bacteria
Campylobacter features
Headache, fever prodrome then abdo cramps and bloody diarrhoea
10 days
Campylobacter treatment
Erythromycin and ciprofloxacin for first 5 days
Listeria monocytogenes sources, features and Tx
Monocyto-cheese
perinatal/immunocompromised
Watery diarrhoea
Ampicillin
Yersinia enterocolitica source and Sx
Undercooked pork
terminal ileitis
Appendicitis-like presentation
Entamoeba histolytica features
Flask-shaped ulcer
Dysentery, flatulence, tenesmus
MSM
Liver abscess
Entamoeba histolytica management
Metronidazole
Giardia lamblia microscopy
Pear-shaped trophozoite
Giardia lamblia symptoms
Fat malabsorption → foul smelling stools
Most common intestinal parasite
Giardia lamblia
Giardia lamblia Tx
Metronidazole
Cryptosporidium parvum features
Immunocomp & severe diarrhoea
Kinyoun acid fast +ve
Cryptosporidium parvum Tx
Paromycin
Enteroviruses and age ranges
Noro - adults
Adeno - <2 years
Rota - <6 years, nursery
