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  • Writer's pictureElizabeth Dalchand, MD

A Case of Toxoplasmosis

Chief Complaint: Altered Mental Status 

HPI: A 56 year old female, recently immigrated from Haiti, presents with several weeks of slurred speech, altered mentation, unsteady gait, and aphasia. Patient states that she hasn’t been to a doctor in a while. She lived in Haiti as a sex-worker. She came into the ED because a distant family friend made her come due to worsening symptoms. No sick contacts. She lives alone and works as a grocery cashier.

ROS: +chills, weight loss, malaise, back pain, weakness. Denies nausea, vomiting, diarrhea, constipation, abdominal pain, chest pain 

PMH/PSH: None 

Physical Exam: 

  • Vitals: BP 129/73 T 36.8 HR 83 SPO2 99% 

  • General: comfortable, alert, pleasant, thin

  • Skin: No rashes, abrasions, lesions, or erythema 

  • HEENT: EOMI, PERRL, dry oral mucosa, thrush, no oropharyngeal erythema 

  • CV: RRR, no murmur, normal peripheral perfusion, no lower extremity edema  

  • Pulm: CTAB 

  • GI: Soft abdomen, non-tender to palpation 

  • MSK: left hand resting tremor, muscle strength 3/5 on UE/LE 

  • Neuro: A&O x2, right facial droop, negative pronator drift, antalgic gait, unable heel-to-toe, intact sensation, hyperflexia 3+ in UE 

DDx: CVA, neurocysticercosis, intracranial abscess/mass, cancer, TB

Work Up: 

  • Labs – Chem and CBC WNL

  • Blood Cx – negative

  • CXR: no cardiopulmonary process 

  • MRI brain w/wo contrast: Peripherally enhancing lesion in the left frontal operculum with adjacent edema with mild mass effect.

  • Rapid HIV – positive 

  • CD4 – 138 

Clinical Course: Neurology and Neurosurgery were consulted but they deferred to infectious disease once clinical suspicion and imaging pointed to Toxoplasmosis. Infectious disease recommended pyrimethamine, sulfadiazine, and leucovorin, which were started in the ED. Initiation of ART therapy was held for 3 weeks to prevent immune inflammatory syndrome. Patient was lost from follow-up after discharge.


Cerebral toxoplasmosis is caused by Toxoplasma gondii, an obligate intracellular protozoan which multiplies in the intestines of cats. Oocytes are excreted in cat feces, which can invade hosts and form tissue cysts. It can also be found in undercooked meat. Risk factors include undiagnosed HIV, non-compliance with ART, immunosuppression, and pregnancy.  

Take Away #1 

Cerebral Toxoplasmosis is the most common AIDS Defining Infection.

Others include primary lymphoma of brain, invasive cervical cancer, Kaposi sarcoma, disseminated CMV/VZV, cryptosporidium diarrhea, PML, PCP, MAC, and cryptococcus.

Take Away #2 

Diagnosis requires all three for 90% probability that Toxoplasmosis is the etiology of symptoms. 

  1. Clinical symptoms of encephalitis (seizures, AMS, headache, etc.) 

  2. A positive T. gondii IgG antibody

  3. Brain imaging (gold-standard MRI with contrast) showing ring-enhancing lesions

Take Away #3 

Toxoplasmosis Treatment 

  • Sulfadiazine 1-1.5 mg QID (sulfa allergy: clindamycin 600 mg QID)

  • Pyrimethamine 200 mg loading dose then 75 mg QD 

  • Leucovorin 25 mg QD

  • Dexamethasone 4 mg QID if there is midline shift on imaging


Elizabeth Dalchand, MD is a current second year resident at Stony Brook Emergency Medicine. She can be found on Twitter @LizDalchand.


  • Porter SB, Sande MA. Toxoplasmosis of the central nervous system in the acquired immunodeficiency syndrome. N Engl J Med 1992; 327:1643. 

  • Grant IH, Gold JW, Rosenblum M, et al. Toxoplasma gondii serology in HIV-infected patients: the development of central nervous system toxoplasmosis in AIDS. AIDS 1990; 4:519. 

  • Luft BJ, Hafner R, Korzun AH, et al. Toxoplasmic encephalitis in patients with the acquired immunodeficiency syndrome. Members of the ACTG 077p/ANRS 009 Study Team. N Engl J Med 1993; 329:995.


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