Background: Meningitis and septicemia are the most common clinical manifestations of infections caused by Neisseria meningitidis. This pathogen can be also responsible for septic arthritis occurring as sequelae of meningococcemia or for its rare form, a primary meningococcal arthritis.
Case Report: The report describes a 70-year-old woman with a primary meningococcal arthritis due to serogroup W-135 meningococci. The case did not develop into a more serious form of infection (meningitis or septicemia), despite a significant delay in the introduction of antimicrobial therapy.
Conclusions: The identification of the etiologic agent of arthritis is crucial for the patient, whose infection can progress into invasive disease and whose joints can be rapidly destroyed if proper antibiotic treatment and drainage are not received. It is also very important from a public health perspective, since meningococcal cases require the immediate intervention of antibiotic prophylaxis to reduce the risk of secondary cases.

Keywords: primary meningococcal arthritis, Neisseria meningitidis, Arthritis