About one third of people with cat scratch disease have other, more generalized symptoms. Very rarely, people with cat scratch disease have symptoms that may include seizures . These symptoms usually begin 1 to 6 weeks after swollen lymph nodes appear and are severe for 1 to 2 weeks. People usually recover slowly, but completely. Bartonella henselae is the bacterium that causes cat scratch disease.
Most cases occur in fall and winter.
In the United States, about 22,000 cases occur annually. Worldwide, the disease affects nine out of every 100,000 persons each year, and multiple cases within families are common, especially among those who have the same cat. A cat with Bartonella henselae infection does not look sick. Lymph node swelling usually begins about 2 weeks after the cat scratch, with a range of 7 to 60 days. Swollen lymph nodes usually disappear within 2 to 6 months in nearly all cases.