Disease Management

Question 0

Give examples of disease management (for different types of infections, zoonosis)

Answer 0

• Acute infections: quarantine stop breeding for 4-6 weeks (with high prevalence), or isolate a few breeding pairs, test, use negative breeding pairs, test off-spring (for low prevalence)
• Beginning infections with slow transmission: test and cull method
• Persistent infections by resistant agent: depopulation, disinfection and repopulation, rederivation by Caesarean or embryo transfer, e.g. most bacteria
• transplacental transmitting agent: rederive and test before breeding, e.g. Parvo
• zoonosis: depopulation, disinfection and repopulation, e.g. LCM

Question 1

Which factors influence disease management?

Answer 1

1) species (large vs small, importance of the strain or of an individual animal)
2) disease
3) therapy
4) experiment (interference, duration)
5) policy of the institute concerning microbiological quality (germfree, gnotobiontic, SPF vs conventional)
6) economical considerations

Question 2

How can you prevent disease?

Answer 2

• use only animals of known origin (SPF)
• quarantine
• adjust housing conditions to needs (separate dirty/clean and quarantine/facility)
• strict management (trained staff)
• evaluation and correction of protocols (SOP)
• regular monitoring of microbial status

Question 3

Why do we need microbiological quality control?

Answer 3

For disease an mortality
Because it might interfere with experimental results
Zoonosis (trichophyty sis, Haverhill-fever, hantavirus)

Question 4

How can we control microbiological quality?

Answer 4

Control the barrier (autoclaves, pressure between rooms)

Control of the animal (health monitoring)

Question 5

Describe direct and indirect methods of health monitoring

Answer 5

Direct: 
isolation/grow the agent
Visualisation of the agent by histology
PCR
Indirect:
Demonstrate antibodies 
Seroconversion: after 3-4 weeks (amount of antibody in blood exceeds amount of antigen)

Question 6

What does health monitoring consist of?

Answer 6

1) pre-necropsy examination
2) necropsy (=autopsy on animal)
Major macroscopic examination
Histopathology of organs that have lesions
3) bacteriology
4) serology
5) parasitology

Question 7

Describe sampling in health monitoring

Answer 7

You can screen:
-animals from the colony
Young: more parasites, better to detect recent viral infections (acute infections), but be aware of maternal antibodies
Older: better to detect history of the colony (chronic infections)
-sentinels - animals that are brought in to the colony to test (Swiss mice)
Must be able to produce antibodies
Housed in open cages
Received bedding material of other cages
4x per year this is tested
But beware of false positive or false negative results

Question 8

What is FELASA?

Answer 8

Federation of European laboratory animal science associations
Gives recommendations for health monitoring of mouse, rat, hamster etc.