09 - Toxoplasma Gondii Flashcards
1
Q
- how many hosts?
A
- facultative two host system (can be one or two hosts)
2
Q
- what is the primary definitive host?
- what is the intermediate host?
A
- (predator) all felines
- (prey) most domesticated animals, mammals, and birds
3
Q
A
tachyzoites - becase they are dividing rapidly
once they form cysts they divide much more slowly - now called bradyzoites
4
Q
A
5
Q
(Life Cycle in a cat)
- ingest oocysts - how many days to oocyst?
- ingest tissue cysts - how many days to oocyst?
- What are sources of feline infection?
A
- 21
- 3
- oocysts (cat feces), tissue cysts (birds and rodents)
6
Q
(Life cycle in a cat)
(oocyst shedding)
- what percent of cat population?
- occurs for how long?
HOWEVER
- 1 bradyzoite or cyst consumed can result in how many oocysts?
- How is this important for cat to human transmission?
A
- 1%
- 1-2 weeks (huge number of oocysts shed)
- millions
7
Q
(Feline infections)
- what clinical signs do you see in cat?
A
8
Q
- What diagnostic method do you rely on?
- What does IgM tell you?
IgE?
A
- serology
2.
9
Q
(Human infections)
- by age 12 what percentage of US population is seropositive?
- What are the sources of infection (look at pic)
A
- 50%
10
Q
(Human infections)
(Congenital Infection)
- in utero can get transplacental transmission of what?
A
- tachyzoites
11
Q
A
12
Q
(Human infection)
- in humans located primarily where?
- new infections are often fatal
(AIDS)
- what percentage of patients acquire Toxoplasma encephalitis?
- what is the big problem here?
A
- CNS
- 25%
- loss of immune control of previous infections
13
Q
(Human Infection)
(Transplation)
- what makes this a problem?
(cancer)
- what is the problem here?
A
- immunosuppressed, organs could possibly contain tissue cysts
- immunosuppression as a result of chemotherapy
14
Q
A
