Toxoplasmosis may also occur in non-AIDS immunocompromised patients suffering from malignancies, most frequently Hodgkin's lymphoma, those on corticosteroids or with systemic lupus erythematosus. Advances in medical technology facilitating organ transplantation, immune suppression due to chemotherapy or disease and the complications of AIDS have highlighted the problems associated with recrudescence of latent Toxoplasma infection. Toxoplasmosis is the commonest cause of focal cerebral lesions in AIDS patients and usually results from secondary reactivation of infection from previously quiescent cysts in the brain tissue. HIV infected patients with some preservation of immune function may present with a chronic toxoplasmosis associated illness of prolonged headache, malaise and low grade fever. Diagnosis is often facilitated by a trial of therapy comprising high-dose sulphadiazine, pyrimethamine and folinic acid for six weeks.
Maintenance therapy is life long to prevent relapse.
Ocular toxoplasmosis associated with HIV infection is a particular challenge to the ophthalmologist. Pyrimethamine, sulphadiazine and clindamycin are most commonly used to treat this high risk group. The potential role of other anti-Toxoplasma drugs including azithromycin and other newer macrolides, and the hydroxynaphthoquinone, atovaquone, with or without concurrent corticosteroid therapy, also need evaluation. Transplant Significant toxoplasmosis associated with organ transplantation is most often seen in a recipient not previously infected with the parasite who is given an organ graft from a donor with chronic, quiescent infection. The graft provides the focus of infection and the recipient is unable to restrict the disease process due to the immune suppressing therapy given to prevent organ rejection.