Toxoplasma gondii Encephalitis
Toxoplasma gondii Encephalitis
Primary Prophylaxis
Start: if CD4 count < 200 cells/μL, or CD4 percentage < 14%, oral thrush, or relevant concomitant immunosuppression, see Primary prophylaxis of OIs
Stop: if CD4 count > 100 cells/μL and HIV-VL undetectable over 3 months
Drug / Dose | Comments | |
---|---|---|
Preferred prophylaxis | TMP-SMX 80/400 mg qd po or 160/800 mg qd po or 160/800 mg x 3/week po |
All regimens are also effective against PcP |
Alternative prophylaxis | atovaquone suspension 1500 mg qd po (with food) |
|
dapsone + pyrimethamine + folinic acid |
Check for G6PD-deficiency | |
atovaquone suspension + pyrimethamine + folinic acid |
Diagnosis and treatment
Diagnosis:
Definitive diagnosis: clinical symptoms, typical focal lesions neuroradiology AND cytological / histological detection of organism in brain tissue. Toxoplasma PCR in CSF has high specificity (95-100%) but low sensitivity (50%)
Presumptive diagnosis: clinical symptoms, serum Ig G toxoplasma Ab, typical focal lesions neuroradiology AND response to empirical treatment. This is the standard in most clinical settings
Notes on treatment:
- Treat 6 weeks, then secondary prophylaxis until CD4 count > 200 cells/μL and HIV-VL undetectable over 6 months
- In patients with cerebral lesions (or surrounding edema) causing mass effect, corticosteroids (dexamethasone) could be used as adjunctive therapy. Corticosteroids should be discontinued as soon as clinically feasible to prevent immunosuppression
- See also anti-infective/ART interaction table for treatment optimization
Drug / Dose | Comments | |
---|---|---|
Preferred therapies |
pyrimethamine + sulfadiazine + folinic acid |
Monitor for myelotoxicity of pyrimethamine, mostly neutropenia Sulfadiazine is associated with crystalluria and may lead to renal failure and urolithiasis. Good hydration is essential. Check renal function and urine sediment for microhematuria and crystalluria |
TMP-SMX |
Preferred intravenous regimen if oral route not possible |
|
Alternative therapies |
pyrimethamine + clindamycin + folinic acid |
Monitor for myelotoxicity of pyrimethamine, mostly neutropenia Additional PcP prophylaxis is necessary |
OR pyrimethamine + atovaquone + folinic acid |
Monitor for myelotoxicity of pyrimethamine, mostly neutropenia | |
OR sulfadiazine + atovaquone |
Sulfadiazine is associated with crystalluria and may lead to renal failure and urolithiasis. Good hydration is essential. Check renal function and urine sediment for microhematuria and crystalluria |
|
OR pyrimethamine + azitromycin + folinic acid |
Monitor for myelotoxicity of pyrimethamine, mostly neutropenia |
Secondary Prophylaxis, Maintenance Therapy
Stop: if CD4 count > 200 cells/μL and HIV-VL undetectable over 6 months
Regimens listed are alternatives
Drug / Dose | Comments |
---|---|
sulfadiazine + pyrimethamine + folinic acid |
|
OR TMP-SMX 160/800 mg bid po |
|
OR clindamycin + pyrimethamine + folinic acid |
Additional PcP prophylaxis is necessary |
OR atovaquone suspension + pyrimethamine + folinic acid |
|
OR atovaquone suspension 750-1500 mg bid po (with food) |