Capnocytophaga canimorsus: meningitis and Waterhouse-Friderichsen syndrome in an immunocompetent patient.

Diagnosing sudden, unexplained death in healthy individuals is challenging. This case report details a rare case of fatal Waterhouse-Friderichsen Syndrome (WFS) in a previously healthy 27-year-old man. Post-mortem examination revealed vomit stains, widespread purpura, and haemorrhagic adrenal glands. Microbiological analysis confirmed a systemic infection with Capnocytophaga canimorsus. While C. canimorsus infections are uncommon, their association with WFS is exceedingly rare. To our knowledge, this is the first documented case of fatal C. canimorsus sepsis causing WFS in an immunocompetent patient with no history of a dog bite. This case highlights the critical importance of post-mortem microbiological analyses in sudden, unexplained deaths, even when typical risk factors are absent.