Septic Polyarthritis Caused by Neisseria meningitidis: A Rare Presentation in Japan.

Neisseria meningitidis is a Gram-negative diplococcus that rarely causes invasive diseases in Japan. We report a case of polyarticular meningococcal septic arthritis in an immunocompetent 62-year-old Japanese man. After 3 days of fever, he developed pain in the dorsum of the right hand and right shoulder. Computed tomography revealed effusions in the right wrist and acromioclavicular joint. Blood cultures grew N. meningitidis serogroup Y, sequence type 1655. A PCR assay detected the 16S rRNA gene of N. meningitidis in culture-negative wrist synovial fluid. Treatment with ceftriaxone followed by oral amoxicillin led to a complete recovery.