View source for Capnocytophaga canimorsus

== Background ==

=== Microbiology ===

* [[Stain::Gram-negative]] [[Shape::bacillus]] in the genus [[Genus::Capnocytophaga]]
* May be fusiform and curved
* Grows slowly on standard media
* Capnophilic, preferring high CO<sub>2</sub>
* Oral flora of dogs (60-70%) and cats (15-55%)

=== Risk Factors ===

* Risk factors for severe disease include [[asplenia]] and [[alcoholism]]

== Clinical Manifestations ==

* Infections usually occur after penetrative inoculation from a dog bite or by exposure of membranes or wounds to saliva
** Exposures include close petting, kissing, minor scratches, licking of abrasions, licking of intact skin

=== Bacteremia ===

* Symptoms associated with [[bacteremia]] include fever, diarrhea, abdominal pain, vomiting, headache, and confusion
* A rash is present in 20 to 40%, which can vary from macular or maculopapular rash on trunk and extremities, to [[purpura fulminans]]
* Mortality with bacteremia is 15 to 30%

=== Meningitis ===

* Headache, fever, neck stiffness, and altered mental status

=== Other Sites ===

* Endocarditis is rare, but high mortality around 25%
* Case reports of brain abscess, spinal epidural abscess, eye infections, bone and joint infections, cellulitis, glomerulonephritis, and pneumonia

== Management ==

* Highly susceptible to [[meropenem]], [[imipenem]], [[piperacillin-tazobactam]], [[amoxicillin-clavulanic acid]], and [[tigecycline]]
* May be susceptible to [[ciprofloxacin]], [[clindamycin]], [[erythromycin]], [[tetracycline]], [[aztreonam]]
* Often resistant to [[gentamicin]], [[vancomycin]], [[polymyxin B]], [[trimethoprim]], [[ceftazidime]], [[cefotaxime]], and [[amoxicillin]]

[[Category:Gram-negative bacilli]]