Primary meningococcal arthritis as initial presentation in a previously undiagnosed HIV-infected patient.

A 38-year-old African-American male complaining of pain in multiple joints was initially diagnosed with gouty arthritis concurrent with gonococcal septic arthritis. The diagnosis was made based on arthrocentesis results showing Gram-variable cocci and monosodium urate crystals in the synovial fluid. Final blood and synovial fluid cultures confirmed a diagnosis of primary septic arthritis caused by Neisseria meningitidis, serogroup X. Further evaluation revealed a reactive HIV antibody test with enzyme- linked immunoassay (ELISA) confirmed by western blot. His CD4 count was 36 cells/mm and viral load was >500,000 copies/mL. We present a case of primary meningococcal arthritis caused by N meningitidis serogroup X as the initial presentation of a patient with previously undiagnosed HIV.