ABSTRACT
Capnocytophaga canimorsus is a commensal organism commonly found in the oral cavity of cats and dogs. Infections with this organism are rare and can affect both immunocompetent and immunocompromised individuals. The authors present a case of Ccanimorsus causing indolent prosthetic hip joint infection in a healthy 66-year-old woman following a history of being scratched by her pet dog. The patient had an atypical history of chronic, low-grade infection which is unusual, as this organism is more frequently associated with acute presentations and fulminant sepsis. This patient was treated successfully with a two-stage exchange of her hip prosthesis and broad-spectrum antibiotics.C. canimorsus is a very rare cause of prosthetic joint infection but an important pathogen to consider, particularly in culture-negative joint infections and a history of animal exposure.
Subject(s)
Bites and Stings/microbiology , Capnocytophaga/isolation & purification , Gram-Negative Bacterial Infections/diagnosis , Hip Joint/microbiology , Hip Prosthesis/microbiology , Joint Diseases/microbiology , Aged , Animals , Anti-Bacterial Agents/therapeutic use , Arthroplasty, Replacement, Hip , Biopsy , Dogs , Female , Gram-Negative Bacterial Infections/pathology , Gram-Negative Bacterial Infections/therapy , Hip Joint/pathology , Humans , Joint Diseases/pathology , Joint Diseases/therapy , ReoperationABSTRACT
A 54-year-old female patient presented to her local district general hospital with a painful, swollen left arm. Imaging revealed an ulnar artery aneurysm. The aetiology was embolic, with an echocardiogram revealing vegetations on the aortic valve. The patient was treated empirically for 6 weeks with amoxicillin and gentamicin for endocarditis. Eight months later, she had an elective aortic valve replacement for symptomatic aortic regurgitation. The valve was culture negative but analysis by 16S rDNA PCR was positive for Tropheryma whipplei In retrospect, the ulnar artery aneurysm and a history of arthralgia were attributed to an underlying diagnosis of Whipple's endocarditis. She continues on antibiotic treatment with resolution of her arthralgia and no clinical signs of infection. Once thought to be rare entity, molecular assays have revolutionised the diagnosis of Whipple's endocarditis, but this case highlights the difficulties and pitfalls in diagnosis.
