Control of GI infections Flashcards
What are most GI infections in the community caused/related to?
Cross-contamination of work surfaces/utensils
Undercooking of food
Improper storage of food (not refrigerated)
Poor reheating of food
What is the most common cause of healthcare-associated diarrhoea?
C.Diff
What is the mechanism of action of C.diff?
Produces 2 toxins, toxin A and toxin B (enterotoxin and cytotoxin)
Where is C. Diff usually found and what causes it to become a problem and cause infection?
It is carried in small numbers in the bowel. Infection occurs when antibiotics kill off the norma competitive bowel flora and allow C.diff to overgrow.
What does C.diff produces and what is it resistant to?
C.diff produces spores that survive in the environment and are most resistant to disinfectants and the organism can be transmitted from one patient to the next.
What are the symptoms of having C.diff infection?
Diarrhoea
Bloody +/-
Abdo pain
What can severe C.diff lead to?
Severe causes - progression to pseudomembranous colitis of bowel perforation
What is the management of C.diff?
Depends on severity
Less severe = oral metronidazole
Severe = oral vancomycin
How can people prevent C.diff infections?
Good antimicrobial prescriing (stewardship) - use narrow spec antibiotics where possible
AVOID 4 C’s
Isolation of patients
Hand washing (NOT alcohol gel)
Cleaning of environment
What type of organism is C.diff?
Gram positive spore-bearing bacillus
Spores resistant to disinfectants
What are the different laboratory diagnosis of C.diff?
Screening test for presence of the organism (GDH)
If GDH positive, test for presence of toxin (toxin A&B)
(Culture can be done if strain needs to be typed – not done routinely)
(STOOL TOXIN)
What type of strains of c.diff are hyper-producers?
027 and 078 - increased morality and risk of death
When might c.diff cases increase?
In winter due to increased hospital admissions and asa due to norovirus
What is the most common cause of diarrhoea and vomiting in children under 3 years?
Rotavirus
What is the spread route of rotavirus?
Person to person
Direct or indirect
Describe the diarrhoea in rotavirus?
Diarrhoea with NO BLOOD
How long does rotavirus usually last?
For around 1 week and it is self limiting
When can rotavirus be severe?
In immunocompromised children
Describe the infectious dose of rotavirus?
There is a low infectious dose of around 100-1000 particles
How does rotavirus cause dehydration?
Decreased absorption of fluids and increased secretion in bowel causing dehydration
What might children develop post infection of rotavirus’?
May develop post infection malabsorption causing more diarrhoea
How do you diagnose rotavirus?
PCR test on faeces
How do you manage rotavirus?
Rehydration is key - orally where possible
How can you prevent rotavirus?
Rotavirus vaccine (oral
Live attenuated vaccine, excreted in faces
2 doses, age 2 + 3 months
Describe norovirus?
Commonly known as the winter vomiting bug
What ages does norovirus affect the most?
Affects all ages - IT IS HIGHLY INFECTIOUS
What is the route of spread of norovirus?
Faecal-oral/droplet
Person to person (or on contaminated food/water)
Describe the infectious does of norovirus?
Low infectious doses needed
What is the incubation period of norovirus?
Short often < 24 hours
Describe the symptoms of norovirus?
Sudden onset of explosive diarrhoea and vomiting - lasts 2-4 days
What does vomiting in norovirus lead to?
Widespread contamination of the environment –> outbreaks
How do you diagnose norovirus?
Daces specimen or vomit swab for PCR test
How do you treat norivirus?
Rehydration is key - esp in young and elderly
Are outbreaks common in norovirus?
YEs esp in hospitals, school, cruise ships
When are patients are their most infectious?
When they are symptomatic with diarrhoea
What infections would cause a patient to need a side room (isolation)?
C.diff
Norovirus
What other infections are spread by faecal-oral route?
Hep A and E
Resistant bacteria that are carried in the GI tract e.g vancomycin-resistant enterococci, highly resistant Gram negative organisms (CPEs)
Explain some of the standard infection control precautions of diarrhoea in hospital?
All patients with diarrhoea that might be infectious should be placed in a single room with own toilet/commode
Cohort nursing in bays may be required during outbreaks on wards – all patients with the same infection nursed
together with their own team of nurses
Wards may be closed to new admissions
Increased ward cleaning/disinfection of surfaces required
What contract precautions might be done to control diarrhoea in hospital?
Hand washing Gloves Apron Single use of items Cleaning/disinfection of items with hypochlorite, terminal disinfection of room Report exposure to contaminated material
