There are several Bartonella subspecies that can infect humans. Bartonella organisms cause a wide range of clinical diseases in people including the following:

Bartonella henselae is the causative agent of cat-scratch disease in humans.

Bartonella vinsonii, Bartonella elizabethae, Bartonella washoensis may cause endocarditis in humans.

Bartonella clarridgeiae may cause cat scratch disease in humans.

Bartonella bacilliformis may cause Carrion's disease, Oroya fever and/or verruca peruana in humans.

Bartonella quintana may cause endocardistis, bacillary angiomatosis and or trench fever in humans.

Children and immunocompromised people may suffer severe disease when infected by these bacteria. Cats are considered the major reservoir for these bacteria, although fleas and some other mammals have also been shown to play a role in the disease.

For more information on cat scratch disease in cats – go to Bartonellosis (Cat-scratch Disease)