Abstract
West Nile virus (WNV) is the leading cause of mosquito-borne disease in the United States. Cases of WNV occur during mosquito season (summer to fall), and an estimated 70-80% of human infections are subclinical. Most symptomatic persons experience an acute systemic febrile illness; 1% of those infected develop neuroinvasive disease—meningitis, encephalitis, or flaccid paralysis. In 2021, 2695 cases of WNV cases were reported by the CDC; 1645 cases (61%) were in Arizona, 1114 (68%) of which presented with neuroinvasive disease. Advanced age, organ transplantation, and immunosuppression are risk factors for neuroinvasive disease. We report a fatal case of non-donor derived WNV meningoencephalitis in a bilateral lung transplant (BLT) recipient.
A 59-year-old woman underwent BLT for interstitial lung disease. She was sensitized before transplant and underwent aggressive induction with anti-thymocyte globulin, plasmapheresis, and intravenous immunoglobulins (IVIG) as well as standard immunosuppression with corticosteroids, mycophenolate mofetil, and tacrolimus. She was discharged 15 days after BLT, but presented 2 weeks later with fever, fatigue, and myalgias. Her symptoms progressed to include visual hallucinations, tremor, and eventually an obtunded mental status requiring intubation. Non-contrast CT and MRI of the brain were unrevealing, an EEG suggested encephalopathy, and a lumbar puncture (LP) showed lymphocytic pleocytosis concerning for viral encephalitis. Three days after the LP, WNV IgM returned positive and another brain MRI, this time with contrast, showed symmetric midbrain and brainstem diffusion restriction consistent with WNV encephalitis. Her immunosuppression was reduced to include corticosteroids and tacrolimus alone; she received IVIG and higher dose corticosteroids. Despite these interventions and supportive care, she never regained consciousness and eventually lost all brainstem reflexes. A repeat brain MRI showed progressive edematous changes in the bilateral brainstem, cerebellum, and thalamus. She died 51 days after admission when care was withdrawn.
WNV infection can cause devastating neuroinvasive disease in immunocompromised transplant recipients. Increased vigilance and patient counseling is warranted, particularly in states like Arizona with a high incidence of WNV disease during mosquito season.