Bartonella henselae is a gram-negative rod bacterium. It is considered the causative agent of cat scratch disease. This infectious disease, which is actually transmitted by scratch injuries in cats, is usually recognized by lymph node swelling in the armpit, neck or groin region and usually progresses benignly. People with an immune deficiency become ill faster and their sickness will generally last longer.
Recent studies have shown that more and more ticks in endemic areas are infected with Bartonella. It is therefore highly probable that tick bites can lead to Bartonella infections.