2025 FSA Podium and Poster Abstracts

Introduction: Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii, an obligate intracellular protozoan. Infection is usually asymptomatic. Those who develop symptoms may experience flu-like symptoms, swollen lymph nodes, and muscle aches. However, severe symptoms can occur in immunocompromised individuals.

Methods: A 44-year-old male with a past medical history of hypertension and thrombocytopenia presented to the emergency department with one week of progressively worsening left-sided weakness, left facial droop, slurred speech, and altered mental status. After evaluation and workup, MRI ultimately showed a rim-enhancing ovoid lesion in the right parietal lobe measuring 2.2 x 3.2 x 2.3 cm (Figure 1). This was initially believed to be a glioblastoma, and the patient underwent craniotomy for resection. Anesthesia was maintained with TIVA using propofol and remifentanil. The patient was extubated and was transported to the neuro ICU. He was discharged home on the fourth postoperative day. A week after his discharge from the hospital he continued to have headaches and vision changes. On a subsequent visit to the hospital, he was noted to have papilledema and was admitted to the neuro ICU. During admission, the pathology result came back positive for toxoplasmosis. Treatment was initiated with pyrimethamine, sulfadiazine, and Leucovorin. Repeated MRI imaging showed multiple round hyperdense lesions in both cerebral and cerebellar hemispheres (Figure 2). Around this time CD4 count resulted in a value of 5, confirming the diagnosis of AIDS. Combined antiretroviral therapy (ART) was initiated. The patient developed respiratory failure with mechanical ventilation dependency, further complicated by pulmonary embolism and acute intracranial hemorrhage after heparin infusion. The patient’s family opted for palliative care and the patient passed away after a 10-day hospital course.

Fig 1. A rim-enhancing lesion in the right occipital-parietal lobe.

Fig 2. Disseminated toxoplasmosis.

Discussion: Toxoplasmosis is the leading cause of death due to foodborne infections in the United States. Human transmission occurs from the consumption of contaminated meat or unwashed produce, contact with cat feces containing Toxoplasma oocytes, or placental transmission to a fetus.

In immunocompetent individuals, toxoplasmosis infection is often asymptomatic. Neurotoxoplasmosis is the most common manifestation in immunocompromised individuals and can frequently present with a necrotic ring-enhancing lesion on brain imaging. Initial treatment with pyrimethamine and sulfadiazine is preferred.

Conclusion: Immunocompromised individuals who present with fever, lymphadenopathy, encephalitis, and necrotic ring-enhancing lesions on brain imaging should raise suspicion for toxoplasmosis. Treatment should be initiated immediately. Antiretroviral therapy (ART) should be initiated within two weeks of starting anti-toxoplasmosis therapy in individuals with HIV/AIDS. Due to the vague symptoms of toxoplasmosis infection, diagnosis can often be challenging, especially when the immune status of a patient is unknown, as seen in our patient. Although, the incidence of cerebral toxoplasmosis has declined since the introduction of ART and prophylactic treatment in individuals with a CD4 count of <200. However, it is imperative to consider when patients present with cerebral lesions. The unfortunate outcome of our case highlights the importance of early detection and treatment when there is a suspicion of toxoplasmosis infection and regular testing and early diagnosis of HIV infection.