Meningococcal septic arthritis following Umrah: A sentinel event during a mass gathering–associated outbreak

Mass gatherings such as Umrah are recognized high-risk settings for the transmission of invasive meningococcal disease (IMD). Although meningitis and meningococcemia are the most common clinical manifestations, meningococcal septic arthritis is rare and may represent an early sentinel event during outbreak activity. During Ramadan 2025, clusters of IMD temporally associated with Umrah were reported internationally, with confirmed cases predominantly linked to serogroup W135. We report a 67-year-old man with controlled diabetes mellitus who developed acute monoarticular septic arthritis of the ankle two days after returning from Umrah in Makkah, Saudi Arabia, during the Ramadan 2025 IMD cluster. His illness was preceded by fever, sore throat, and upper respiratory symptoms. Respiratory multiplex PCR using the BioFire FilmArray Respiratory Panel detected Influenza B. Synovial fluid analysis demonstrated marked neutrophilic leukocytosis (159,000 cells/µL) and Gram-negative diplococci, with cultures confirming Neisseria meningitidis susceptible to ceftriaxone and ciprofloxacin. Blood cultures were negative. The patient’s meningococcal vaccination status was uncertain at presentation. He underwent urgent surgical debridement and completed a three-week course of antimicrobial therapy. His clinical course was complicated by Clostridioides difficile colitis, which resolved with fidaxomicin. Full clinical and functional recovery was achieved. This case highlights primary meningococcal septic arthritis as a rare but clinically significant manifestation of IMD occurring in temporal association with Umrah. In the context of mass gatherings, atypical and localized presentations may function as sentinel surveillance signals of broader transmission events. Strengthening vaccination verification, laboratory capacity for serogrouping, and integrated outbreak preparedness strategies remains essential to mitigate transmission risks during Umrah and similar large-scale religious gatherings.