Zoonoses & Emerging Diseases

Question 1

Why is the WHO definition of zoonosis limited?

Answer 1

Excludes intoxications e.g. shellfish poisoning (due to toxin not infection) and shellfish are invertebrates

Question 2

How can zoonotic illnesses be transmitted?

Answer 2

DIRECT:
• Contact with infected body fluids, excretions or infected tissues
• Inhalation of infected aerosols
• Ingestion of infected material
• Faecal material: pica
• Food borne zoonoses
• Contamination of water
INDIRECT contact (i.e. physical contact with a previously infected object or surface = fomite)
VECTOR: fleas, mosquitoes, lice, ticks. Prevention bycontrolling the vector

Question 3

What are the 2 risk groups?

Answer 3

1. Those with regular animal contact

2. Those with decreased resistance to infection

Question 4

How do the impact the economy?

Answer 4

• Legislation and mandatory inspection
• Produce loss
• Personnel loss
• Monitoring / surveillance programmes
• Healthcare costs; difficulty in diagnosing

Question 5

How do they impact the public?

Answer 5

• Morbidity and mortality
• Food scares and dietary change
• Increase legislation and consumer / producer cost
• Political change / FSA creation
• Concerns among animal owners/workers
• Disease control costs in animals

Question 6

What are the main zoonotic diseases in birds?

Answer 6

Companion animals
• Mycobacterium avium complex
• Psittacosis (ornithosis)
Farmed birds
• Influenza
• Newcastle disease

Question 7

How is Newcastle disease transmitted and controlled?

Answer 7

1. direct contact with infected birds; Inhalation/ ingestion of faecal matter and fomites
2. • Vaccination
   • Use of adequate PPE (respirators and facemasks) when working with flocks and in housing
   • Cleaning and disinfection of all housing
   • Notifiable disease; stamping out of positive flocks

Question 8

What is Toxoplasmosis and how is transmitted and controlled?

Answer 8

1. A protozoan parasite, cats host, worldwide
2. • Cat faeces
   • Food and water contaminated with faecal matter
   • Undercooked meat with cysts
3. • Daily litter cleaning; remove oocysts prior to sporulation
   • Feed cooked cat food
   • Hand-washing
   • General cat health

Question 9

What is Echinococcosis and how is transmitted and controlled?

Answer 9

1. Tapeworms or cestodes: adult - dogs; larvae - ruminants, humans (cyst)
2. consumption of viable eggs from dogs faeces (contaminated food or water, fomites,
   hand-to-mouth)
3. • Deworming of dogs
   • Control of stray dogs
   • Avoid feeding dogs with sheep offal
   • Abattoir inspection controls
   • Hygienic measures and education

Question 10

What are emerging diseases?

Answer 10

Diseases that are newly recognized in a population or have occurred previously but show an increase in incidence, expansion in geographical, vector or host range