PH14: Zoonoses Flashcards
Define zoonoses
Disease and infections which are naturally transmitted between vertebrate animals and man.
This does not include:
- fish and reptile toxins
- Allergies to invertebrates
- Experimentally transmitted diseases
Define anthropozoonoses
Infections transmitted to humans from animals which act as reservoirs
Define zooantroponoses
Diseases present in humans but could be transmitted to animals
Define amphixenosis
The disease in which both man and animals could act as reservoir hosts
What is the role of the vet in tackling zoonoses?
Raise awareness and promote prevention
Enhance detection (some zoonotic diseases are notifiable and reportable)
What is another name for psittacosis?
Parrot Fever
What causes Psittacosis?
The bacterium Chlamydia psittaci
What are the risk factors to Psittacosis?
- Inadequate ventilation
- Poor cleaning
- Overcrowding
- Long survival in the environment (resistant to drying)
How is Psittacosis transmitted?
Humans: inhalation of dried bird faeces, direct contact with birds, discharges
Bird-to-bird: vertical transmission via egg or trough feeding by regurgitation
Who is most at risk of contracting Psittacosis?
Children, immunocompromised, pregnant women (high mortality of foetuses or new-borns)
How do you prevent psittacosis?
Preventative husbandry: no overcrowding, good ventilation, avoid mixing birds from different sources
Quarantine newly acquired birds
Detain and isolate affected birds followed by C&D
Extra care during PM of infected birds
What causes toxoplasmosis?
Toxoplasma gondii
Who is the reservoir and who is the definitive host?
Reservoir: rodents
Definitive host: cats
How is toxoplasmosis transmitted?
Transmitted by consumption of infectious oocysts in cat faeces
Consumption of tissue cysts in infected meat
Transplacental transfer of tachyzoites from mother to foetus
Who is most at risk of toxoplasmosis?
Pregnant women - might lead to miscarriage, stillbirth, CNS damage to foetus
Immunosuppressed
Sheep - mummified foetus, leathery placenta with multiple white foci of necrosis