Toxoplasma gondii

Question 1

Classification

Answer 1

Protozoa

Question 2

Indirect or direct

Hosts

Answer 2

Indirect life cycle

Cat is final host
Human is intermediate host.

Question 3

Transmission and life cycle

Answer 3

Oocysts are shed by feces of an infected cat. Intermediate hosts such as birds and rodents become infected after ingesting soil, water of plant material containing oocysts.

These oocysts transform into tachyzoites after ingestion. These tachyzoites localize in muscle tissue and develop into bradyzoites.

Cats become infected after consuming intermediate hosts that harbor these cysts.

Cats may also become infected directly by ingestion of oocysts.

Humans can become infected by:
Eating undercooked meat of animals harbouring tissue cysts.
Consuming food or water containing these cysts for example while changing the litter box.
Blood transfusion or organ transplantation.
Trans placentally form mother to fetus.

Question 4

Diagnosis

Answer 4

Serology testing
For antibodies

Molecular:
PCR

Observation of parasites in patient specimens such as bronchoalveolar lavage material form immunocompromised patients or lymph node biopsy