Cat Scratch Disease: A Zoonosis You Should Know
📝 Summary
Cat scratch disease is a bacterial infection from Bartonella henselae, spread mainly by a cat's scratch or bite. Cats carry it without symptoms, but people may get a red bump, swollen lymph nodes, and fever. Most cases are mild and self-limiting, with antibiotics for severe ones. Wash scratches well and see a doctor if signs appear, especially for children and the immunocompromised.
1 What It Is and How It Spreads
Cat scratch disease is caused by the bacterium Bartonella henselae, also called cat scratch fever. The bug lives in a cat’s mouth, nose, and claws, with kittens and strays carrying it most often—yet the cat itself shows no signs. About 40% of kittens may harbor it.
Spread is mainly through a scratch or bite from an infected cat, or when a cat licks a human wound or mucus membrane such as the eye. Fleas move it between cats, but people don’t catch it from fleas. Reassuringly, it does not pass directly from person to person.
2 Symptoms in People and What to Do
Signs appear 3–14 days after a scratch: a red bump or blister at the site, swollen tender lymph nodes (armpit, neck, or groin), and low-to-mid fever with fatigue, headache, and poor appetite like a cold. Rare but serious forms bring high fever, belly pain, eye inflammation, and in very few cases encephalitis or endocarditis. Children, teens, and the immunocompromised are most at risk.
If you’ve been scratched and show these signs, see a doctor—an infectious disease or emergency clinic—where blood tests confirm it. The disease is usually self-limiting and may clear in 1–2 months, but obvious cases get antibiotics such as azithromycin or doxycycline by prescription. Never self-prescribe. After any scratch, wash the wound with soap and running water for at least 15 minutes and squeeze out dirty blood, then apply iodine. To prevent it, respect the cat’s mood to avoid scratches and keep its claws trimmed.
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