Fatal Encephalopathy Associated with Influenza in a Health Care Professional

Abstract

A 41-year-old nurse was referred to our hospital with a fever and disturbed consciousness. She tested positive for influenza antigen. CT and MRI findings revealed low density and intensity areas in the right occipital and lateral lobes with remarkable brain edema, which led to a diagnosis of influenza encephalopathy. Influenza A antibodies in the serum were below the detection limit despite the patient receiving previous vaccination three months earlier. A PCR analysis revealed that the influenza HA gene was classified into clade 3C.2a, subclass AH3N2. The present case indicates the potential development of encephalopathy in adults under certain conditions.