A sudden death due to acute necrotizing encephalopathy associated with influenza A virus infection: An autopsy case report.

• We report an extremely rare case of sudden death due to acute necrotizing encephalopathy(ANE) caused by influena A infection. • The expression of influenza A virus antigen in the brain by immuno-histochemistry is helpful for diagnosis of ANE due to influenza virus A virus. • The present case emphasizes the neuropathological features of ANE. Influenza occasionally causes central nervous system disorders. Acute necrotizing encephalopathy (ANE) is one of the most severe influenza-associated complications, predominantly affecting infants and young children under 5 years of age. We present this case as it involves a very rare complication of influenza infection that is known to have a high rate of mortality. A 5-year-old girl presented with a high fever and convulsions. Her condition deteriorated rapidly, and she died within 24 h. Autopsy revealed extensive brain edema, multifocal perivascular hemorrhage, and necrosis of neurons without inflammatory cell infiltration in the pons and bilateral thalamus. Tests for influenza virus A and antibodies to it were positive. The girl's death was attributed to ANE associated with influenza A infection based on the clinical presentation, the postmortem neuropathology, and identification of the virus. The goal of this report is to draw attention to the potentially serious complications of influenza A infection. We hope that the lethal outcome of this disease will be fully recognized by medical personnel. [ABSTRACT FROM AUTHOR]