Infected subdural hematoma caused by Edwardsiella tarda

Objective: Both infected subdural hematoma (ISH) and Edwardsiella tarda infections are rare in humans. E. tarda is a motile, facultative anaerobic, gram-negative rod bacterium, which is isolated from fresh or brackish water, but not usually from humans. Extra-intestinal E. tarda infections are rare and might cause severe clinical symptoms. However, ISH caused by E. tarda has not been reported previously. We report the first case of ISH due to E. tarda. Patient: A 76-year-old man was admitted to our hospital with a headache, loss of appetite, and nausea. Computed tomography revealed bilateral subdural hematoma. Results: We performed burr hole drainage. A hematoma with pus was found on the left side and chronic hematoma was found on the right side. Consequently, we diagnosed him with ISH on the left side and chronic subdural hematoma on the right side. E. tarda was detected in a culture from the hematoma with pus on the left side. As postoperative antibiotic therapy, we administered ceftriaxone and metronidazole for 47 days. The patient was discharged with no residual neurological deficit. Conclusion: Our case implied that favorable outcomes can be obtained by drainage and appropriate antibiotic therapy for ISH caused by E. tarda.