Toxoplasmosis host response

Acquired immunodeficiency renders a host much more susceptible to secondary infections, including cytomegalovirus, syphilis, herpes zoster, fungi, hepatitis B, tuberculosis, and toxoplasmosis. HIV invades the tissues of the optic nerve and initiates an immune complex-mediated response that results in an optic neittopathy. The primary HIV infection may be responsible for color vision defects, loss of contrast sensitivity, and visual field defects. HIV infection itself may also cause direct degeneration of retinal ganglion cell axons in the optic nerve without a secondary opportunistic infection. 

Innes, E. A. (1997). Toxoplasmosis comparative species susceptibility and host immune response. Comp. Immunol. Microbiol. Infect. Dis. 20,131-138. 

---