BACKGROUND: Mycobacterium xenopi is a nontuberculous mycobacterium responsible for opportunistic and nosocomial infections, chiefly of the lung; few cases of bone and joint infection have been reported. From July 1989 through May 1993, an outbreak of 58 cases of nosocomial discitis due to M. xenopi infection following percutaneous nucleotomy occurred in a French hospital. Peripheral M. xenopi arthritis seems exceedingly rare. We conducted a study to assess the epidemiological and clinical patterns of M. xenopi arthritis. METHODS: We retrospectively reviewed cases of M. xenopi arthritis reported from May 1993 through October 2004. RESULTS: We identified 7 cases, all of which occurred after invasive surgical procedures were performed on the affected joint, suggesting a nosocomial pattern of infection. Two patients may have been contaminated at the hospital where the M. xenopi discitis outbreak occurred. No source was identified in the other 5 patients. Despite the probable nosocomial nature of the infections, the diagnosis was delayed (mean time until diagnosis, 50 months). Repeated collection of deep tissue specimens for bacteriological analysis seemed crucial to the diagnosis. The treatment relied on combination antimicrobial therapy and surgery. Among 11 cases of M. xenopi osteoarticular infection reported in the literature from 1975 to 2005, (arthritis in 9 cases and osteitis in 2), none were nosocomial. CONCLUSION: A high index of suspicion should be maintained to ensure the diagnosis of M. xenopi arthritis before chronic monoarthritis and before the development of irreversible joint damage.
BACKGROUND:Mycobacterium xenopi is a nontuberculous mycobacterium responsible for opportunistic and nosocomial infections, chiefly of the lung; few cases of bone and joint infection have been reported. From July 1989 through May 1993, an outbreak of 58 cases of nosocomial discitis due to M. xenopiinfection following percutaneous nucleotomy occurred in a French hospital. Peripheral M. xenopiarthritis seems exceedingly rare. We conducted a study to assess the epidemiological and clinical patterns of M. xenopiarthritis. METHODS: We retrospectively reviewed cases of M. xenopiarthritis reported from May 1993 through October 2004. RESULTS: We identified 7 cases, all of which occurred after invasive surgical procedures were performed on the affected joint, suggesting a nosocomial pattern of infection. Two patients may have been contaminated at the hospital where the M. xenopidiscitis outbreak occurred. No source was identified in the other 5 patients. Despite the probable nosocomial nature of the infections, the diagnosis was delayed (mean time until diagnosis, 50 months). Repeated collection of deep tissue specimens for bacteriological analysis seemed crucial to the diagnosis. The treatment relied on combination antimicrobial therapy and surgery. Among 11 cases of M. xenopiosteoarticular infection reported in the literature from 1975 to 2005, (arthritis in 9 cases and osteitis in 2), none were nosocomial. CONCLUSION: A high index of suspicion should be maintained to ensure the diagnosis of M. xenopiarthritis before chronic monoarthritis and before the development of irreversible joint damage.