microbial foodborne infections and intoxications part 2 W4 Flashcards
norovirus:
site of action?
infective/intoxication?
features?
diarrhoea/fever?
acts on small bowel, infective and intoxication
small round-structured RNA viruses, norwalk-like virus
watery diarrhoea +/- fever
norovirus:
epidemiology?
clinical features?
can be sporadic/small outbreaks (families, workplace) or larger outbreaks (cruise ships, hospitals)
vomiting, diarrhoea, low grade fever
norovirus:
general features?
associated with?
most common viral cause of epidemic gastroenteritis worldwide (winter vomiting disease)
extremely stable (hot & cold)
usually spread directly but some outbreaks associated with shellfish (filter feeders/sewage contamination)
norovirus:
incubation?
duration?
diagnosis?
treatment?
incubation 24-48h
duration 1-2 days
diagnosis: clinical + PCR
treatment: supportive
Escherichia coli:
site of action?
infection/intoxication?
features?
diarrhoea/fever?
small and large bowel
infection and intoxication
gram-negative bacilli, aerobe
watery/bloody diarrhoea +/- fever
Escherichia coli types?
ETEC: enterotoxigenic E. coli (similar to V. cholerae)
EPEC: enteropathogenic E. coli (common in children, small intestine)
EIEC: enterinvasive E. coli (like shigella)
EHEC: enterohaemorrhagic E. coli (colon)
EHEC/EPEC/EIEC - transmission features?
food-borne
faecal-oral
environmental contamination by domestic animals
EHECs highly infectious agents (low infectious load)
EHEC/EPEC/EIEC mechanisms?
attach to microvilli brush borders on enterocytes. type III secretion system - inject toxin and products into cell.
destruction of the microvilli and pedestal formation (due to polymerized actin accumulation.
(secretory and non efficient epithelium)
requires product of its own gene: intimin
seasonality of food-borne disease?
cases peak in late summer - E. coli, salmonella, campylobacter (bit earlier)
cases peak in winter - norovirus
