[specify] It is a facultative intracellular microbe that targets red blood cells.

[4] One study showed Bartonella henselae invaded the mature blood cells of humans.

[5] It infects the host cell by sticking to it using trimeric autotransporter adhesins.

Symptoms start with a papule at the site the microbe entered, followed by lymphadenopathy, usually in the axillary node.

[10] Many other complications can arise from this infection beyond the typical fever, lymphadenopathy, and general malaise.

Because of chronic sinus tract formation risks, the nodes should not be incised to be drained.