Bartonellosis (Cat Scratch Disease)

Bartonellosis is caused by <em>Bartonella henselae</em>, a bacterium carried by a large share of cats worldwide, especially those with fleas. In the cat itself the infection is usually silent: the great majority of carriers look and behave completely normally, which is why the condition is often discovered only through testing or because a person in the household falls ill. When signs do occur they tend to be mild and short-lived — a passing fever, slightly swollen lymph nodes, or occasionally inflammation of the eyes, mouth or, very rarely, the heart. The bacteria are spread between cats chiefly by fleas and the flea dirt they leave behind, so infection clusters where fleas thrive: kittens, strays and outdoor cats carry it most often. The condition matters most as a zoonosis. In people, a scratch or bite from an infected cat can lead to 'cat scratch disease', typically a tender swollen lymph node near the wound along with tiredness and a low fever that usually settles on its own. Because the risk to both cats and people runs through the flea, diligent year-round flea control is the cornerstone of prevention, backed up by prompt washing of any scratch, sensible nail care and gentle play that does not break skin.