Cat Scratch Disease
Picture
Picture
 Cat Scratch
Disease
 FIV
 Lyme’s Disease
 Lepto
 Toxoplasma
Gondii
 Tetanus

QUESTIONS

  1. Okay, what are we currently calling the organism responsible for cat scratch disease?
     
  2. What kind of signs are seen in the human disease?
     
  3. Do cats get sick from this organism?
     
  4. How is the infection diagnosed?
     
  5. Does the organism affect the dog?




     

ANSWERS

  1. The organism causing cat scratch disease is Bartonella henselae.  It is a gram negative pleomorphic rod that lives on or w/i red cells.  It is argyrophilic when it is stained.  It was previously classified in the genus Rochalimaea but it has been re-classified.




     
  2. The usual human disease is a recurrent fever & lymphadenopathy & it is usually self-limiting.  In about 10% of cases it is more serious.  In these cases you can see bacillary (or epitheliod) angiomatosis which is vascular proliferation of blood-filled cysts on the skin.  If the condition involves visceral organs (if you get cysts on your spleen or whatever) it is called bacillary peliosis hepatis.  Other possible forms involved endocarditis, retinitis, pulmonary granulomas, and/or encephalopathy.

    The self-limiting form does not appear to respond to antibiotics but the more serious forms seem to.




     
  3. This is not clear.  When cats are experimentally infected, they seem to get sick; however, the organism can be isolated from many healthy individulas.  Depending on how warm/humid an area is 25-41% of healthy cats can be expected to carry the organism.

    (The organism has been isolated from fleas but it is unknown if fleas may transmit the orgainism.)




     
  4. Diagnosis is made by either 1) culture of organism  2)  histopath using a silver stain (such as Warthin-Starry) 3)  PCR  4)  IFA or ELISA for antibodies is of use only in acute infections.

    *Note it is fairly hard to grow this bug.  It takes 10-56 days to grow on blood agar.




     
  5. This is largely unknown.  The organism has been isolated from a dog w/endocarditits (or at least one of the Bartonella species has).  We have no idea what the K9 story on this is yet.