Control of GI Infections Flashcards
common organisms of GI infections in the hospital settings
clostridium difficile (C diff)
describe C diff
common cause of healthcare-associated diarrhoea
carried as part of normal bacterial flora in elder (and infants)
mechanism of action of C diff
organism produces 2 toxins;
A - enterotoxin
B - cytotoxin
how does C diff cause infection
antibiotics kill of normal competitive bowel flora - allowing for C diff to overgrow and produce spores = making it resistant to disinfectants
spread of C diff infection
transmitted from patient to another via hands and also surfaces
symptoms of C diff
diarrhoea +/- blood
abdominal pain
severe cases of C diff - symptoms
pseudomembranous colitis
bowel perforation
treatment for less severe C diff
oral metronidazole
treatment for severe C diff
oral vancomycin
prevention of C diff
isolation of patients
hand washing
clean environment
good antimicrobial prescribing (narrow spectrum)
describe features of C diff
gram positive
spore-bearing
bacillus
laboratory tests for C diff
screening for presence of organism (GDH)
organism positive - presence of toxin (A and B)
culture (if strain needs to be typed) - not done routinely
laboratory results for C diff - positive result
screening test positive
toxin test positive
laboratory results for C diff - indeterminate result
screening test positive
toxin test negative
management of indeterminate result of C diff
send repeat specimen for testing
clinical decision is required if next set of results is also indeterminate
outbreaks of C diff
more cases in winter due to increase number of admissions and to norovirus - this is where strains need to be typed
hyper-producer of toxin strains of C diff
cause an increase in morbidity and death
viruses causing diarrhoea
rotavirus
norovirus
describe rotavirus
commenest cause of diarrhoea and vomiting in children <3 years - severe in immunocompromised children
commoner in winter months
lasts about a week
how is rotavirus spread
person-person - direct or indirect
symptoms of rotavirus
mild to severe diarrhoea (no blood)
dehydration
may develop post-infection malabsorption - causing more diarrhoea
how does rotavirus cause dehydration
decreases absorption of fluids and increases secretion in bowel
lifecycle of rotavirus
billions of particles are shed in faeces when diarrhoea
they then survive in the environment until spread to another patient
laboratory tests for rotavirus
PCR on faeces
treatment for rotavirus
rehydration
oral rotavirus vaccine
describe vaccine for rotavirus
live attenuated vaccine
execrated in faeces
children aged 2-3months
describe the norovirus
‘winter vomiting disease’
affects all ages
community circulation is the reservoir
how is norovirus spread
highly contagious
faecal-oral or droplet route of spread
person to person (or on contaminated food/water)
symptoms of norovirus
sudden onset diarrhoea and vomiting - leading to widespread contamination
laboratory tests for norovirus
PCR test - faeces specimen or vomit swab
treatment for norovirus
rehydration
infections spread via faecal-oral route
hepatitis A and E
resistant bacteria in GI tract - vancomycin-resistant enterococci, highly resistant gram negative organisms
