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

Norihiko Terada1,2, Tomoaki Shimizu3, Hideyuki Takahashi4,5

  • 1Division of Infectious Diseases, Department of Medicine, Tsukuba Medical Center Hospital, Japan.

Internal Medicine (Tokyo, Japan)
|May 31, 2026
PubMed

Insights

This report details a rare case of invasive meningococcal septic arthritis in Japan. An immunocompetent man fully recovered after treatment with ceftriaxone and amoxicillin.

Area of Science:

  • Infectious Diseases
  • Rheumatology
  • Microbiology

Background:

  • Neisseria meningitidis rarely causes invasive disease in Japan.
  • Meningococcal septic arthritis is an uncommon manifestation of N. meningitidis infection.

Purpose of the Study:

  • To report a rare case of polyarticular meningococcal septic arthritis in an immunocompetent adult in Japan.
  • To highlight the diagnostic methods and successful treatment of this rare condition.

Main Methods:

  • Clinical presentation and imaging (CT scan) were used to diagnose joint effusions.
  • Blood cultures identified Neisseria meningitidis serogroup Y, sequence type 1655.
  • Polymerase chain reaction (PCR) confirmed N. meningitidis in culture-negative synovial fluid.

Main Results:

  • The patient presented with fever and polyarticular joint pain affecting the wrist and shoulder.
  • N. meningitidis serogroup Y was isolated from blood cultures.
  • Synovial fluid PCR confirmed N. meningitidis, despite negative cultures.

Conclusions:

  • Polyarticular meningococcal septic arthritis can occur in immunocompetent individuals.
  • Prompt diagnosis and appropriate antibiotic treatment (ceftriaxone, then amoxicillin) lead to complete recovery.
  • This case underscores the importance of considering N. meningitidis in septic arthritis, even in low-incidence regions.
Keywords:
Invasive meningococcal diseaseNeisseria meningitidisST-1655Septic arthritisSerogroup Y

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