Recognition and management of toxoplasmosis.

Toxoplasma gondii is a frequent cause of subclinical latent human infection and an important opportunistic pathogen that may cause severe disease in immunocompromised patients. Patients with AIDS who have antibodies to T. gondii should be considered at high risk for development of clinical disease (toxoplasmosis). Reactivation of latent infection in the central nervous system is a common HIV/AIDS-related complication in these patients. Typical presenting symptoms are headache, confusion, fever, and focal neurologic deficits. Routine serologic tests cannot distinguish active from latent infection. Neuroradiologic studies may be highly suggestive of toxoplasmic encephalitis, but the definitive diagnosis can be made only by demonstration of toxoplasma in brain tissue. The unique pathogenesis of toxoplasmic encephalitis in patients with AIDS necessitates intensive primary therapy followed by life long suppressive therapy. Clinical and radiographic improvement is usually rapid with appropriate treatment.