Which statement best describes cat-scratch disease (bartonellosis)?

Which statement best describes cat-scratch disease (bartonellosis)?

• A. Fungal infection of skin; transmitted by sexual contact.
• B. Viral infection causing pneumonia; transmitted by aerosols.
• C. Bacteria hide in red blood cells and endothelial cells; transmitted by insect vectors after contact with cats; presents with regional lymphadenopathy.
• D. Bacteria cause a generalized rash and fever; transmitted by contaminated water.

Answer: (C)

Cat-scratch disease is caused by Bartonella henselae, a bacterium that can persist inside red blood cells and invade endothelial cells. Transmission occurs when a cat scratch or bite introduces the bacteria, with fleas acting as vectors that contaminate the wound with infected flea feces. The typical presentation is tender, regional lymphadenopathy near the site of inoculation, often with a papule or pustule at the scratch. In otherwise healthy individuals, the illness is usually self-limited, though azithromycin can help if symptoms are bothersome. In contrast, the other scenarios describe fungal, viral, or waterborne illnesses that do not fit the cat exposure and localized lymph node pattern seen with this infection.

Cat-scratch disease is caused by Bartonella henselae, a bacterium that can persist inside red blood cells and invade endothelial cells. Transmission occurs when a cat scratch or bite introduces the bacteria, with fleas acting as vectors that contaminate the wound with infected flea feces. The typical presentation is tender, regional lymphadenopathy near the site of inoculation, often with a papule or pustule at the scratch. In otherwise healthy individuals, the illness is usually self-limited, though azithromycin can help if symptoms are bothersome. In contrast, the other scenarios describe fungal, viral, or waterborne illnesses that do not fit the cat exposure and localized lymph node pattern seen with this infection.