Toxoplasmosis:

Presumptive Diagnosis: *usually made to avoid brain biopsy

1. CD4 < 100
2. Lack of effective prophylaxis
3. Clinical syndrome (headache, neuro symptoms, fever, etc.)
4. + T. gondii IgG antibody
5. Imaging consistent with disease (multiple ring-enhancing lesions)

* If present >90% probably of TE.

Definitive Diagnosis:

1. Clinical syndrome (headache, neuro symptoms, fever, etc.)
2. Identification of ≥ 1 mass lesion by brain imaging
3. Detection of organism in biopsy specimen

Treatment:

1. Sulfadiazine
2. Pyrimethamine
3. Leucovorin – to prevent pyrimethamine induced hematologic toxicity

• Measure response to treatment with daily neurological exams and repeat neuroimaging after 2-3 weeks
• 75-80% of patients with TE will show radiographic and/or neurologic improvement
• Treat for 6 weeks followed by maintenance therapy

ART:

• 3 drugs from 2 different classes
• Usually 2 nucleoside RTIs “backbone” and 3rd agent – either  a protease inhibitor or an integrase inhibitor

Post-Exposure Prophylaxis:

• Started immediately after exposure => continued for 4 weeks
• Test immediately, 6 weeks, 12 weeks, and 6 months
• 3 Drug Regimen: Tenofovir-Emtricitabine + Raltegravir

Pre-Exposure Prophylaxis:

• Recommended for certain high-risk populations: heterosexual partners of infected patients, MSM, IVDU
• 2 Drug Regimen: Tenofovir-Emtricitabine