Septic arthritis caused by Streptococcus pneumoniae

BACKGROUND: Streptococcus pneumoniae is an uncommon agent of infective arthritis. In this report three cases of pneumococcal arthritis are described. METHODS: Retrospective review of synovial fluids processed in our laboratory yielding bacteria. The study period was from January 1991 to December 1995. The clinical records of patients with the clinical and microbiological diagnosis of septic arthritis were reviewed. RESULTS: Twenty-eight out of a total of 43 clinical records had the clinical and microbiological diagnosis of septic arthritis and three (11%) were caused by Streptococcus pneumoniae. The infective source in two of these three cases was probably the respiratory tract, and the most common location was the knee. CONCLUSIONS: In our cases immunosuppression seemed to be the major risk factor involved in the development of pneumococcal arthritis.