Bone and joint infections caused by Kingella kingae: six cases and review of the literature

Abstract

Six cases of Kingella kingae arthritis, osteomyelitis, and diskitis were studied, and data were reviewed from an additional 23 cases in the English-language literature. K. kingae is a slow-growing, fastidious, gram-negative microorganism that colonizes mucous membranes of the upper respiratory tract. Infections were predominantly seen in infants and young children (86% of cases) and were preceded by an upper respiratory tract infection in 31% of patients. Low-grade fever (38 degrees C-39 degrees C) and pain or swelling involving the affected limb developed insidiously. However, 76% of the infections were diagnosed within 1 week after the onset of symptoms. The knee was involved in 47% and the hip in 33% of cases of arthritis. Osteomyelitis mainly involved the femur (36%); four cases of osteomyelitis (29%) were diagnosed as diskitis. The erythrocyte sedimentation rate was greater than 20 mm/h in all patients. Gram stains of aspiration fluid were positive in 19% of cases, whereas blood cultures yielded growth in only 5%. Radiographic signs indicating the presence of osteomyelitis were observed in 93% of patients. All patients recovered completely. K. kingae is an important causative agent in indolent bone, joint, and intervertebral disk infections.