Epidemiology
- Toxoplasmosis is the most common cause of focal brain lesion in AIDS
- Pulmonary toxoplasmosis is uncommon
- Higher incidence of HIV-related Toxo in Western Europe, Africa than in North America (possibly due to dietary differences)
- About 33% of T. Gondii Ab-positive HIV cases will develop CNS Toxo
- Average CD4 at time of diagnosis of Toxo is 32
Physiology
- Reactivation of chronic, latent infection
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Diagnosis
- Induced sputum: diagnosed no cases
FOB: BAL or TBB may reveal organism
Pleural fluid: may reveal organism
CXR/Chest CT patterns:
1) Diffuse bilateral interstitial/ coarse nodular infiltrates: indistinguishable from PCP
2) Pleural effusion: may be seen
T. Gondii Ab: present in 10-40% of HIV-positive patients in USA
-Positive in 11 of 12 reported cases in one series
Clinical Presentations
- Interstitial Pneumonia (see [[ILD-Etiology]])
-Dyspnea:
-Fever:
-Dry cough:
-Extrapulmonary involvement: present in 7 of 12 reported cases in one series
Treatment
- Pyrimethamine + Sulfadiazine: preferred treatment
- Prevention: one study showed decreased incidence of pulmonary Toxo with Pyrimethamine + Dapsone prophylaxis in cases with positive T. Gondii Ab and CD4 >200
References
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