Background. Streptococcus pneumoniae is an uncommon agent of infective
arthritis. In this report three cases of pneumococcal arthritis are d
escribed. Methods. Retrospective review of synovial fluids processed i
n our laboratory yielding bacteria. The study period was from January
1991 to December 1995. The clinical records of patients with the clini
cal and microbiological diagnosis of septic arthritis were reviewed. R
esults. Twenty-eight out of a total of 43 clinical records had the cli
nical 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 immunosuppres
sion seemed to be the major risk factor involved in the development of
pneumococcal arthritis.