
Cat scratch fever is an infection caused by a bacterium spread by fleas. Cats transmit the organisms when they have fleas, scratch themselves, accumulate flea dirt in their claws and then scratch a person or another cat with their contaminated claws.
Healthy people are at low risk of a serious infection, and the disease is usually self limiting. In other people, and especially in those immuno-compromised, the infection can go deeper in the body and cause serious problems. Effective flea control would help reduce the risk of the disease.