Fatal subarachnoid hemorrhage complicating actinomycotic meningitis.

Actinomycosis is caused by Gram-positive Actinomyces species that are part of the normal oral flora with low virulence. We describe a rare case of sudden death of a 48-year-old man with actinomycotic basilar meningitis that was complicated by fatal subarachnoid hemorrhage. Autopsy revealed meningitis at the basilar region of the brain, and histological examination revealed characteristic bacterial aggregates with extensive leukocyte infiltration and severe vasculitis of arteries of this region. Rupture of an artery by severe arteritis was thought to be the cause of the subarachnoid hemorrhage. The probable primary source of infection was found in the left lung. To the best of our knowledge, the complication of subarachnoid hemorrhage has not been reported previously in actinomycotic meningitis.