Toxoplasma gondii

Question 1

Overview

Answer 1

Presents as toxoplasma encephalitis (TE) in people with HIV

Found in raw meat, shellfish, soil, and cat feces

Occurs due to reactivation of latent tissue cysts

Question 2

CD4 count

Answer 2

< 50

Question 3

Presentation

Answer 3

Focal encephalitis

Seizures, tupor, coma

Question 4

Diagnosis

Answer 4

+ anti-toxoplasma immunoglobulin (IgG)

CT/MRI shows lesions in grey matter of cortex or basal ganglia

Question 5

Treatment

Answer 5

Start ART within 2-3 weeks of diagnosis

Preferred:
Acute: pyrimethamine 200 mg PO once then weight-based x 6 weeks
- ≤ 60 kg: pyrimethamine 50 mg PO QD + sulfadiazine 1000 mg PO q6h + leucovorin 10-25 mg PO QD
- > 60 kg: pyrimethamine 75 mg PO QD + sulfadiazine 1500 mg PO q6h + leucovorin 10-25 mg PO QD
OR
Bactrim 5 mg/kg BID x 6 weeks

Chronic:
Pyrimethamine 25-50 mg PO QD + sulfadiazine 2000-4000 mg PO QD + leucovorin 10-25 mg PO QD
Or
TMP-SMZ DS PO BID

Adjunctive Steroids–>mass effect with focal lesions or edema
Anticonvulsants–>patients with history of seizures

Question 6

Primary Prophylaxis

Answer 6

CD4 cell count < 100 + toxoplasma IgG +
- TMP-SMZ DS PO QD

D/C: CD4 cell count > 200 cells/mm3 x 3 months on ART, Or CD4 cell count 100-200 cells/mm3 and HIV undetectable x 3-6 months

Restart: CD4 cell count < 100 cells/mm3 Or CD4 cell count 100-200 cells/mm3 and HIV undetectable

Question 7

Secondary Prophylaxis

Answer 7

Patients after completion of treatment for acute episode

D/C: CD4 count > 200 cells/mm3 x 6 months on ART AND successful completion of initial therapy AND asymptomatic

Restart: CD4 count < 200 cells/mm3