About 40% of cats carry the bacteria in their saliva at some point in their lives, cats that carry Bartonella henselae do not themselves show any signs of illness. Most people contract the disease after being scratched or bitten by a cat.
Since these bacteria may also be present on cat fur, it is possible to contract the disease from petting a cat and then rubbing your eyes. Kittens are more likely than older cats to carry the bacteria and to transmit the infection to humans. Sometimes people who get cat scratch disease do not recall ever being scratched or bitten by a cat.
Symptoms
A person who has had contact with an infected cat may show common symptoms, including:
- Bump (papule) or blister (pustule) at site of injury (usually the first sign)
- Fatigue
- Fever (in some patients)
- Headache
- Lymph node swelling (lymphadenopathy) near the site of the scratch or bite
- Overall discomfort (malaise)
- Less common symptoms may include:
- Loss of appetite
- Sore throat
- Weight loss