Fatal influenza A infection with Staphylococcus aureus superinfection in a 49-year-old woman presenting as sudden death

A fatal case of influenza A infection with Staphylococcus aureus superinfection in a previously healthy 49-year-old woman presenting as sudden, unexpected death is reported. Autopsy revealed severe necrotizing tracheobronchitis and hemorrhagic pneumonia. Microscopic examination of the trachea and bronchi showed mucosal necrosis and a dense lympho-monocytic infiltration of all layers. The lungs showed focal hemorrhagic pneumonia. No pathological changes were detectable in the myocardium. Influenza A virus was detected in bronchi and lung samples obtained during autopsy by the polymerase chain reaction (PCR) and bacterial superinfection with Staphylococcus aureus was shown by culturing from tracheal, bronchial and pulmonary swabs obtained during autopsy. PCR assays for the detection of Panton-Valentine leukocidin performed from all samples were negative. This case demonstrates the need for an interdisciplinary approach towards an organism-specific diagnosis of potentially infection-related deaths undergoing a medico-legal autopsy. With improved diagnostic possibilities such as PCR and DNA sequencing, forensic pathologists can, in close association with the field of microbiology, make a significant contribution to the detection of highly infectious agents which must be notified to the authorities. This will increase particularly the knowledge about the influence of these agents on sudden, unexpected deaths in outpatients.