Salmonella septic arthritis following total knee arthroplasty for rheumatoid arthritis in a patient receiving etanercept

The treatment of rheumatoid arthritis (RA) has recently seen a paradigm shift with the introduction of biological therapy, but there is concern that this will result in an increased incidence of infection. Postoperative infection is always a potentially problematic complication, even though a large review by the British Society for Rheumatology has shown that anti-tumor necrosis factor (TNF) therapy is not associated with an increased risk of overall serious infection in comparison with disease-modifying antirheumatic drugs [1]. It is well known that Staphylococcus aureus and Staphylococcus epidermidis are common pathogens of postoperative infection, although Salmonella infection after joint replacement is quite rare in the English literature [2-19], accounting for <0.3% of cases of septic arthritis [20]. Furthermore, there have been no reports of Salmonella infection following etanercept and few reports discussing the source of Salmonella infection.