PH14: Zoonoses

Question 1

Define zoonoses

Answer 1

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

Question 2

Define anthropozoonoses

Answer 2

Infections transmitted to humans from animals which act as reservoirs

Question 3

Define zooantroponoses

Answer 3

Diseases present in humans but could be transmitted to animals

Question 4

Define amphixenosis

Answer 4

The disease in which both man and animals could act as reservoir hosts

Question 5

What is the role of the vet in tackling zoonoses?

Answer 5

Raise awareness and promote prevention

Enhance detection (some zoonotic diseases are notifiable and reportable)

Question 6

What is another name for psittacosis?

Answer 6

Parrot Fever

Question 7

What causes Psittacosis?

Answer 7

The bacterium Chlamydia psittaci

Question 8

What are the risk factors to Psittacosis?

Answer 8

• Inadequate ventilation
• Poor cleaning
• Overcrowding
• Long survival in the environment (resistant to drying)

Question 9

How is Psittacosis transmitted?

Answer 9

Humans: inhalation of dried bird faeces, direct contact with birds, discharges

Bird-to-bird: vertical transmission via egg or trough feeding by regurgitation

Question 10

Who is most at risk of contracting Psittacosis?

Answer 10

Children, immunocompromised, pregnant women (high mortality of foetuses or new-borns)

Question 11

How do you prevent psittacosis?

Answer 11

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

Question 12

What causes toxoplasmosis?

Answer 12

Toxoplasma gondii

Question 13

Who is the reservoir and who is the definitive host?

Answer 13

Reservoir: rodents

Definitive host: cats

Question 14

How is toxoplasmosis transmitted?

Answer 14

Transmitted by consumption of infectious oocysts in cat faeces

Consumption of tissue cysts in infected meat

Transplacental transfer of tachyzoites from mother to foetus

Question 15

Who is most at risk of toxoplasmosis?

Answer 15

Pregnant women - might lead to miscarriage, stillbirth, CNS damage to foetus

Immunosuppressed

Sheep - mummified foetus, leathery placenta with multiple white foci of necrosis

Question 16

How do you prevent toxoplasmosis?

Answer 16

Humans

• Cook food thoroughly
• Wash veggies
• Hand washing
• Correct kitchen hygiene
• Pregnant women to avoid all contact with cat, pregnant animals, raw meat, or soil
• PPR when handling soil, cat faeces, aborted materials

Cat

• Do not feed raw meat
• Clean litter daily
• Discourage hunting

Sheep

• Keep aborted ewes (they can pass down immunity)
• Vaccination
• Medicated feed
• Keep only adult, neutered cats on farm

Question 17

What causes toxocariasis?

Answer 17

Dogs: toxocra canis

Cats: toxocara cati/mystax

Question 18

How is toxocariasis transmitted?

Answer 18

Animals: transplacental infection

HumansL by accidnetal ingestion of oocytes

Question 19

How do you prevent toxocariasis?

Answer 19

• Deworming
• Sourcing animals from approved breeders
• Older animals are more immune
• Clean your pet’s living area (safe disposal of faeces
• Do not allow children to play in areas that are soiled with faeces
• Wash hands with soap and warm water
• Teach children that it is dangerous to eat dirt or soil

Question 20

What are the two types of toxocariasis?

Answer 20

Visceral larva migrans

Ocular larva migrans

Question 21

What causes Q Fever?

Answer 21

Coxiella burnetti

Question 22

What are the risk factors of Q Fever?

Answer 22

• Close contact with ruminants
• Environmentally resistant spores
• Occupational disease: vets, house workers, farmers

Question 23

How is Q fever transmitted?

Answer 23

Animals: direct contact with infected birth fluids, milk, urine, mother to foetus or indirectly via vectors

Humans: aerosol, mucosa/skin abrasion in contact with infected material, drinking unpasteurized milk/dairy products, ticks and fleas

Question 24

How do you control against Q Fever?

Answer 24

• Identify, segregate, eliminate infected animals
• Disinfection of abortion area
• Vaccine
• Control of ectoparasites on livestock
• Good personal hygiene
• PPE when handling abortion
• Reduce exposure to infected tissues and fluids
• Pasteurization of milk

Question 25

What causes Glanders?

Answer 25

Burkholderia mallei

Question 26

Where does Glanders occur?

Answer 26

Middle-east, South America, India

Question 27

How is glanders transmitted?

Answer 27

Horses: ingestion of contaminated food and water

Humans: via discharges from infected horses via skin abrasions, mucous membranes, or aerosols

Question 28

Who is the reservoir of glanders?

Answer 28

equidae

Question 29

Who is at particular risk of glanders?

Answer 29

Vets, horse-workers, butchers

Question 30

Where are the lesions for glanders? for farcy?

Answer 30

Glanders: lesions seen in the nostrils, submaxillary lymph nodes and lungs

Farcy: located on the surface of limbs or body

• Acute: nasal discharge, coughing, high fever, and ulceration o the nasal mucous
• Chronic: nodules develop subQ and ulcerate

Question 31

How do you prevent glanders?

Answer 31

• Banning imports from countries where the disease has been reported
• Cull affected animals
• Use adequate PPE