Changes

===Pathogenesis===

===Pathogenesis===

The outcome of primary infection depends on the immune status of the host, as well as the location a''Toxoplasma gondii'' infection may prove fatal. Bradyzoites in tissues cysts may also become activated in immunodeficient states, producing disease. However, primary infection of immunocompetent animals most often causes mild or undetectable clinical signs.

The outcome of primary infection depends on the immune status of the host, as well as the location of and degree of injury caused by tissue cysts. Primary infection normally results in chornic disease, where tissue cysts form but clinical signs are not normally apparent. In immunodeficient animals, or in animals with concurrent illness, chronic infections may become symptomatic as the organism is allowed to proliferate. Acute primary infection in these animals can, rarely, prove fatal.  

 

The mechanism of clinical disease in chronic toxoplasmosis is not fully understood, but may be related to low-level tachyzoite replication, or intermittent antigenaemia and parasitaemia^a have been detected in experimentally

The mechanism of disease in chronic, sublethal toxoplasmosis

is unknown. Disease may be related in part to

low level tachyzoite replication. Intermittent antigenaemia

and parasitaemia have been detected in experimentally

inoculated cats (Burney and others 1999).

inoculated cats (Burney and others 1999).

T gondii-specific antigens and DNA are detected in aqueous

T gondii-specific antigens and DNA are detected in aqueous