Necrotizing encephalitis, pneumonitis, and myocarditis are the most common autopsy findings. The most frequent clinical findings reflect involvement of these 3 organ systems. Disseminated toxoplasmosis is being described with increasing frequency. Incidence of toxoplasmic encephalitis in patients with AIDS is directly correlated with the presence of antitoxoplasmal antibodies. In patients with AIDS, CNS involvement is the most common manifestation, ranging from nonspecific, generalized symptoms to focal findings such as headache, altered levels of consciousness, motor impairment, and seizures.
Pulmonary involvement is the second most common manifestation.
Clinically, patients may appear to have tuberculosis or infection with Pneumocystis species. Although a high rate of seropositivity for T gondii exists, clinical manifestation of the disease is relatively rare. The most severe forms of toxoplasmosis occur in patients who are immunocompromised. In adults, multiple organ involvement is extremely serious, but no data on mortality rates exist. In patients with AIDS, untreated toxoplasmic encephalitis is uniformly fatal.