What is it?

Bartonellosis is a group of infectious caused by bacteria belonging to the Bartonella genus. Bartonella mainly transmitted by carriers like fleas, lice, or sandflies. Of these zoonotic species, several may be transmitted to humans by companion animals (dogs and cats), typically through a bite or scratch.
Bartonella infection does not always cause overt illness. Studies have detected clinically healthy people that have tested positive for Bartonella but have no known history of typical Bartonella symptoms. Those who do become ill usually develop mild disease that tends to end without treatment. However, Bartonella can cause severe infection in some people. Immunocompromised patients, and people with HIV/AIDS, are more likely to develop severe, life-threatening disease.