Pathology
Toxoplasma gondii, an intracellular protozoan parasite, is the definitivehost of felines.
Aetiology
Cysts present in cat feces can cause infection through contact with soils and plants, when coming into contact with contaminated cat litter, or through grazing in herbivores.
Symptoms
- Primary infection: fever, lymphadenopathy, and mild hepatitis.
- Congenital infection: miscarriage, and a triad of hydrocephalus, cerebral calcification, and chorioretinitis in around 60% of cases.
Signs
- Old or active chorioretinitis detected on fundoscopy.
- Painless lymphadenopathy.
Investigations
- Bloods: testing for IgM antibodies.
- Microbiology: Toxoplasma dye test as well as viral PCR.
- Histology.
Treatment
- Conservative: Supportive.
- Medical: If immunosuppressed, pyrimethamine with sulfadiazine or clindamycin.
Complications
- Congenital infection.
- Pneumonitis.
- Myocarditis.
- Blindness.
- Encephalitis.
- Brain abscess.
- Disseminated infection.
Prognosis
Generally good, however in immunocompromised individuals, discontinuation of treatment can result in relapse or even death.
