SESSION TYPE: Infectious Disease Case Report Posters I
PRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PM
INTRODUCTION: Capnocytophaga species are known commensals of the oral cavity of humans and animals (mainly dogs and cats). They are a known cause of skin and soft tissue infections after canine bites but systemic infections are rare in a normal host.
CASE PRESENTATION: We present the case of a 51-year-old male with degenerative arthritis who presented with symptoms of productive cough and exertional dyspnea. He had a 35 pack year history of smoking but had quit about 6 months ago. He had about a quarter cup of mucopurulent sputum production through the day. He denied any associated hemoptysis, chest pain, wheezing, weight loss, fevers or night sweats. Sputum cultures were negative. CT thorax revealed multiple, small, irregular nodular densities in both lung bases, left greater than right, likely representing an inflammatory process. The patient underwent a bronchoscopy with biopsy. Bronchoscopy revealed vidence of mild respiratory bronchiolitis with focal peribronchial fibrosis and alveolar macrophage aggregates possibly related to smoking. Cultures, however, grew out capnocytophaga in both tissue cultures and BAL. He was started on a 2 week course of amoxicillin/clavulanate. Further history revealed that he has 2 dogs at home. He denied any recent dog bite. He did not have evidence of significant dental disease or history of dysphagia. His symptoms improved significantly over the next few weeks and repeat sputum cultures were negative. Repeat CT thorax shows improvement in the bibasilar nodular infiltrate.
DISCUSSION: Capnocytophaga related systemic infections have been reported in the immunocompromised host. The source of infections in these patients is either nosocomial exposure or associated with dental/periodontal disease. In a retrospective review of 31 patients with infection due to capnocytophaga, 16 occurred in immunocompetent patients. The spectrum of disease includes empyema, lung abscess, sinusitis, conjunctivitis, subphrenic abscess, wound infection, bacteremia and osteomyelitis. Bacteremia is more common in the immunocompromised and the infection is frequently polymicrobial. There were 5 deaths in the immunocompromised versus only one death in the immunocompetent patients. Our patient had an unusual presentation of micronodular pattern in both lower lobes. He has responded well to the antibiotic therapy with improvement in CT findings. Whether frequent dog exposure, without a dog bite, contributed to lung infection in this patient is still questionable.
CONCLUSIONS: Capnocytophaga species is a new emerging pathogen in both immunocompromised and immunocompetent hosts.
1) Bonatti H, et al. A series of infections due to Capnocytophaga spp in immunosuppressed and immunocompetent patients. Clin Microbiol Infect. 2003;9(5):380-7.
2) Parenti DM, Snydman DR. Capnocytophaga species: infections in nonimmunocompromised and immunocompromised hosts. J Infect Dis. 1985;151(1):140-7.
DISCLOSURE: The following authors have nothing to disclose: Pankaj Mehta, Pratibha Kaul
No Product/Research Disclosure InformationSUNY Upstate Medical University, Syracuse, NY