Toxoplasmosis
(Redirected from Toxoplasma gondii)
Background
- Most common cause of focal encephalitis in patients with AIDS
- Risk at CD4 < 100 and not on prophylaxis
Clinical Features
Differential Diagnosis
- Lymphoma
- More commonly single lesion in the periventricular white matter or corpus callosum
- Cerebral TB
- Characteristic inflammatory appearance with isodense exudate filling basal cisterns
- Fungal infection
HIV associated conditions
- HIV neurologic complications
- HIV pulmonary complications
- Ophthalmologic complications
- Other
- HAART medication side effects[1]
- HAART-induced lactic acidosis
- Neuropyschiatric effects
- Hepatic toxicity
- Renal toxicity
- Steven-Johnson's
- Cytopenias
- GI symptoms
- Endocrine abnormalities
Evaluation
- Head CT without contrast
- Shows multiple subcortical lesions with predilection for basal ganglia
- Contrast usually not needed; if obtained, will show ring enhancing lesions
- CSF
- Helpful but high rate of false negatives
- Serology not generally helpful since antibodies common in general population
Management
Antibiotics
Immunocompetent
Antibiotics only needed if patient has severe symptoms
- Pyrimethamine 200mg PO one dose (for loading) THEN 50mg PO q24hrs x4wks AND
- Leucovorin 10mg PO q24hrs AND
- Sulfadiazine 1g PO q6hrs
Immunosprepressed
- TMP/SMX 5mg/kg IV q12hrs OR
- Pyrimethamine 200mg PO one dose (for loading) THEN 75mg PO q24hrs x4-8wks AND Leucovorin 25mg PO q24hrs PLUS
- Sulfadiazine 1500mg PO q6hrs OR
- Clindamycin 600mg PO or IV q6hrs OR
- Azithromycin 12000mg PO q24hrs OR
- Atovaquone 1500mg PO q12hrs
Pregnant
- Spiramycin 1 g orally every 8 hours[2]
- If amniotic fluid is positive treat with 3 weeks of pyrimethamine (50 mg/day orally) + sulfadiazine (3 g/day orally in 2-3 divided doses)
- Alternate with a 3-week course of Spiramycin 1 g 3 times daily OR
- Pyrimethamine (25 mg/day orally) and sulfadiazine (4 g/day orally) divided 2 or 4 times daily until delivery AND
- Leucovorin 10-25 mg/day orally to prevent bone marrow suppression
Steroids
- Consider dexamethasone 4mg IV q6hr for significant edema or mass effect
Folinic Acid
Administer if the treatment regimen includes Leucovorin
- Folinic acid 10mg PO QD x6–8wk
Disposition
- Admit
References
- ↑ Gutteridge, David L MD, MPH, Egan, Daniel J. MD. The HIV-Infected Adult Patient in The Emergency Department: The Changing Landscape of the Disease. Emergency Medicine Practice: An Evidence-Based Approach to Emergency Medicine. Vol 18, Num 2. Feb 2016.
- ↑ Paquet C, Yudin MH. Toxoplasmosis in pregnancy: prevention, screening, and treatment. J Obstet Gynaecol Can. Jan 2013;35(1):78-9.