Hygiene

Question 0

What is medical prophylaxis?

Answer 0

-vaccination
for caretakers and researchers –> tetanus and Hep B, only;
for animals, less with rodents, more with larger animals, such as rabbits –> myxomatosis (skin tumours), Rabbit Haemorrhagic Disease Virus
-preventive antibiotics
But can interfere with experiments

Question 1

What is prophylaxis?

And which types are there?

Answer 1

-decreasing infection pressure (=concentration MO per surface or volume)
-protection from pathogenic MO
-prevent spreading of disease
Types:
Medical - vaccination, preventive antibiotics
Sanitary - limiting sources of infection

Question 2

What is sanitary prophylaxis and what are infection sources?

Answer 2

• animals
• personnel and researchers
• biological material
• insects and vermin
• other material

Question 3

How can we prevent animals to be a source of infection?

Answer 3

1) Only use animals that are free from pathogens
Germ-free = completely free from pathogens
Gnotobionts = harbour a fully know microflora
SPF = free from a number of specified pathogenic MO
Conventional animals = microbiological status is unknown and uncontrolled
2) quarantine
40 days isolation, also to acclimatise
3) clinical investigation upon arrival
4) do not keep pets of same species

Question 4

Give some recommendations for quarantine

Answer 4

Physically isolate animal from other animal rooms
Completely separate feed- and garbage ways
All in all out
Personnel only for quarantine area
Strict hygiene measures
Screening (sentinel mice)

Question 5

What a sentinel mouse?

Answer 5

These are animals used to detect risks to humans???

Question 6

How can we prevent personnel and researchers to be a source of infection?

Answer 6

-use strict protocols for entering barriers
-personnel hygiene
Showering, clothing, washing hands and disinfect with Alcogel when entering or leaving or using bathroom, no jewellery or watch

Question 7

How can we prevent biological material (sera, ascites, cells, tissue, tumours) to be a source of infection?

Answer 7

MAP test: mouse antibody production, inoculation of virus-antibody-free animal –> after 4weeks serum sampling and identification (600 to 1200 euro per cell line)
RAP test: rat antibody production
PCR

Question 8

How can we prevent insects and vermin to be a source of infection?

Answer 8

Good design of building

Air lock and fly catcher

Question 9

How can we prevent other materials to be a source of infection?

Answer 9

Sterilising material and control of delivered material
Think of the following:
Before starting disinfection or sterilisation, clean to remove organic material, rinse and dry.
Use correct concentration
Contact time
Disinfect or replace brushes, cleaning towels, floor cloth ate regular basis
Feed and bedding: autoclaving and irradiation
Water: autoclaving, filtration, chlorinating, UV radiation
Air in room: formaline, hydrogen peroxide, Peracetic acid aerosol
Supplied air: filtration (HEPA)
Equipment: autoclaving, formaline, ethylene oxide gas, UV radiation, liquids

Question 10

Which disinfection methods are there?

Answer 10

-physical methods:
Heat - flame, dry heat, humid heat
Radiation - UV, gamma radiation
Filtration - 0.2 mu
-chemical methods
Liquids - phenols (Dettol), halogens (Halamid), quaternary ammonium salts, aldehydes (formaldehyde), alcohol, alkaline products, acids, mixtures (iodine tincture)
Gasses - ethylene oxide (if heat cannot be used, toxic and very explosive), formaline gas (toxic and very irritating, contact time 6-8 hrs, temp > 20 degrees, RH 60-80%
Hydrogen peroxide - release of oxygen radicals H2O2 –> H2O + O2, inactives membrane proteins and enzymes