[Chronic brucellosis: a rare cause of septic loosening of arthroplasties with high risk of laboratory-acquired infections]

Brucella spp. are a main contributor to morbidity in endemic countries, especially in the Near and Middle East and the Mediterranean. However, in most western industrialised countries, cases are rare. Here, we report the case of a previously unrecognised chronic brucellosis with subsequent laboratory-acquired infection. A 64-year-old female presented to the orthopaedic department with loosening of her knee prosthesis after total knee arthroplasty five years earlier. Bacterial cultures were obtained in a preoperative puncture of the affected joint. About two weeks after replacement of the prosthesis bacterial growth was detected by chance in the preoperative culture and Brucella melitensis was diagnosed, whereas the intraoperative swab was negative. Serology revealed a chronic brucellosis while blood cultures were negative. Antibiotic treatment with rifampin and doxycycline was initiated. Two months later, a 32-year-old male physician who was involved in identifying the bacterial pathogen began to suffer from night sweats, weight loss and elevated temperatures. Another 4 weeks later, he developed hip pain and synovialitis. At that time, blood cultures and urine specimens were positive for Brucella melitensis. The serological results were consistent with acute brucellosis. In many European and North American countries, especially Germany, Brucella spp. are rarely isolated from clinical microbiological specimens and present a considerable risk for laboratory-acquired infections.