Bear-ly Breathing: What's Causing Respiratory Failure in This Patient?
While Trichinellosis is a rare parasitic infection, it may be misdiagnosed as another type of infection or illness. A case study presented at the CHEST Annual Meeting 2015 describes a patient with worsening respiration due to the migration of Trichinella to the diaphragm in the parenteral phase of infection, traced to the consumption of wild bear meat.
A 47-year-old male without prior medical history presented with symptoms of worsening fever, edema, and myalgia that had persisted for one week. His symptoms continued despite treatment with empiric antimicrobials and supportive care, and no bacterial or viral causes were identified. The patient experienced hypercapnic respiratory failure (pH 7.31 and PaCO2 51) and was transferred to the ICU and non-invasive positive pressure ventilation (NIPPV). Chest x-ray indicated decreasing lung volumes and diaphragmatic ultrasound noted decreased bilateral excursion.
Upon questioning, the patient stated that he was a hunter and had caught and eaten a wild bear three weeks prior. A parasitic evaluation showed Trichinella antibodies so albendazole and prednisone were initiated; after two weeks of treatment, the patient's symptoms slowly improved. Eventually NIPPV was no longer needed and samples of the ingested bear meat were confirmed as T. spirialis.
Animal studies have suggested that Trichinella infection can lead to reduced diaphragmatic function, with recovery of muscular function taking months to years. In patients with respiratory deterioration of unknown origin, a parasitic evaluation should be conducted to rule out Trichinellosis.
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