Cryptococcosis

Question 1

What causes cryptococcosis?

Answer 1

it’s an opportunistic systemic fungus

Question 2

How is cryptococcosis transmitted?

Answer 2

through inhalation - from environment or pigeon dropping
- starts with local disease (nasal, paranasal)
- then can go systemic –> CNS (direct extension?), skin, and eyes

Question 3

Do cats or dogs get cryptococcosis?

Answer 3

cats more common than dogs

Question 4

What kind of immune response does cryptococcosis elicit?

Answer 4

• humoral response is not protective
• relies on cell-mediated immunity for recovery
• immunocompetent dogs and cats can get it, vs in people, it’s mostly in the immunocompromised

Question 5

What are the clinical signs of cryptococcosis in a cat? in a dog?

Answer 5

Cats:
- respiratory (50-80%) > skin (40-50%) > eyes (20-25%) > CNS (20%)

Dogs:
- Respiratory/ CNS (50%) > eyes/ periorbital (20-40%) > skin (10-20%)

Question 6

How is cryptococcosis diagnosed?

Answer 6

• easily found in CSF for those with CNS involvement – but could be a risky procedure
• cytology of other affected organ, can be seen 50-70% of the time
• asymptomatic patients can have positive culture
• serology is useful, antibodies not so much as most infected animals don’t mount a humoral immune response
• if no CNS signs, serum = best sample

Question 7

How is cryptococcosis treated?

Answer 7

challenging to treat, protracted treatment
- amphotericin B
- use itraconazole or ketoconazole so consolidate after amphotericin B
- frequent rechecks (monthly) during treatment, and reevaluate 3-6m post treatment

Question 8

What’s the prognosis of cryptococcosis?

Answer 8

Cats: good if externa form; guarded if CNS involved
Dogs: guarded with any form