Fatal dog bite in the absence of significant trauma: Capnocytophaga canimorsus infection and unexpected death

Abstract

Sudden and unexpected nontraumatic death in individuals with asplenia or hyposplenia is usually due to fulminant bacterial sepsis, most often involving Streptococcus pneumoniae, Neisseria meningitidis, and Hemophilus influenzae. We report a case of a previously well 40-year-old man who died 5 hours after hospital admission. At autopsy Waterhouse-Friderichsen syndrome was identified and Capnocytophaga canimorsus was subsequently isolated on antemortem blood cultures. Infection of humans with this organism is most often due to dog bite or contact. Upon specific inquiry it was ascertained that 2 days before admission the deceased had suffered a superficial bite to his hand by his pet Staffordshire Bullterrier dog. His relevant history included a previous splenectomy following blunt abdominal trauma. Asplenia and hyposplenia at autopsy should prompt microbiological testing with consideration of unusual organisms such as C. canimorsus. Although histories of animal contact or injury are often not available at the time of autopsy, this should also be considered in cases of apparent fulminant sepsis. In individuals with asplenia or hyposplenia, dog bites do not have to involve excessive tissue trauma, vascular compromise, or blood loss to be lethal.