Zoonotic Diseases Flashcards
Describe the lifecycle of Echinococcus granulosus?
Adult tapeworm produces eggs within a proglottid, which are passed in the faeces of the dog.
Eggs are then ingested by an intermediate host (e.g. sheep or pig), travel to their tissues and develop a cyst.
Humans then eat the intermediate host
What are the signs of Echinococcus granulosus?
Hyatid cysts develop
May not observe any signs for years
If cyst develops on liver - can cause abdo pain, nausea, vomiting
If cyst develops in lungs - can cause chronic cough, chest pain, shortness of breath
How is echinococcus granulosus treated?
Anthelmintics
Surgical removal or drainage of cyst
What causes Toxoplasmosis?
A parasitic protozoa called toxoplasma gondii
What is the definitive host of T gondii?
Cat
Describe the life cycle of T gondii
Infected cat sheds oocysts for 2-3 weeks - sporulated oocysts are aerosols in the environment. The intermediate hosts become infected (e.g. sheep, cows)
Human inhale the oocysts or ingest the infected intermediate host.
What are the signs of Toxoplasma gondii?
Incubation period of 1-2 weeks
Mild flu-like symptoms
In immuno-suppressed humans, tissue cysts can multiply rapidly - can cause neurological signs or respiratory and heart disease.
What can happen if T gondii infects a pregnant human?
Can cause abortion, congenital toxoplasmosis causing CNS and ocular disorders
What causes Leptospirosis?
And hosts
Leptospira icterohaemorrhagia (host dogs and rats) and causes liver failure or Weil's disease) Leptospira canicola (host dogs) causes kidney failure Leptospira hardjo - host cows
What are the signs of Leptospirosis (incl incubation period)
Incubation 2-4 days
Mild form causes flu-like symptoms
Severe form causes liver or kidney failure. Can also cause spontaneous abortion if contracted during pregnancy
What agents cause Toxocariasis?
Toxocara canis and Toxocara cati (nematodes)
What are the signs of Toxocariasis?
Visceral, ocular or neural larval migrants
What causes Mange? Hosts
Mites
host dogs and cats
How is mange transmitted?
Passed through close contact
What are the signs of mange?
Found commonly in areas with skin folds, feet, behind knees, under arms etc Intense pruritis (itchy skin) red blisters inflammation Mite burrowing tracks
What causes salmonellosis? Host?
Various salmonella species. Host dogs cats rabbits etc
How is salmonellosis transmitted?
Excreted in faeces. Ingestion of milk eggs meat etc or contact with the contaminated environment
What are the signs of salmonellosis? Including incubation period
Incubation 12-72 hours
Young, old and immunosuppressed at greater risk
Haemorrhagic diarrhoea, fever, headaches and muscle cramps
Recovery usually in one week
What causes campylobacteriosis? Hosts?
Campylobacter jejuni (pathogenic bacterium). Host dogs cats cattle etc
How is Campylobacter jejuni transmitted?
Excreted in faeces.
Ingestion, close contact with contaminated animal products or environment. Poultry are healthy carriers of the bacteria
What are the signs of campylobacter?
Incubation 2-5 days
Vomiting and diarrhoea
Abdominal cramps
What causes Psittacosis? Host
Chlamydophila psittaci (bacterium). Host birds
What are the signs of psittacosis?
incubation 4-15 days
Flu like symptoms developing into sever pneumonia
Can be fatal without treatment
What causes Leishmaniasis?
Intracellular protozoan parasite Leshmania
What transmits Leishmaniasis?
Phlebotomine Sand Fly
What are the life stages of the Phlebotomine sand fly?
Egg, larva, pupa, adult
Describe the life cycle of Leishmaniasis?
Sandfly consumes a blood meal from an infected dog, protozoa develop a flagella and swim to the mouth of the fly. They are then transmitted in the saliva when the sand fly takes another blood meal.
What are the signs of a dog with Leishmaniasis?
Weight loss Poor appetite Ocular lesions Epistaxis lameness anaemia diarrhoea wounds that don't heal
How would you diagnose Leishmaniasis?
Blood test for PCR
Bone marrow samples
Skin biopsies
