Animal reservoirs and primary hosts of Bartonella

Bartonella are hemotropic bacteria that infect numerous wild and domestic mammals, and some are directly responsible for zoonotic infections. There are 27 currently known species or subspecies of Bartonella. Wild and domestic animals represent a large reservoir for Bartonellae, but man is the unique reservoir for two species. Reservoirs are characterized by a long-lasting bacteremia, sometimes with recurrences. Cats have long been considered as an asymptomatic reservoir of Bartonella, but direct and indirect (serological) evidence indicate that they too can be affected by Bartonella infection. Dogs are considered as accidental hosts for Bartonella, and clinical features in this species are very similar to those seen in man. The most frequent signs reported in dogs and man include endocarditis, ocular, neurologic, articular, renal, and even skin disorders, as well as systemic manifestations. Endocarditis has also been described in cattle. In reservoir species, the main vectors of Bartonella are hematophagous arthropods, such as cat flea (Ctenocephalides felis), ticks (genus Nodes), or the louse-fly (Hippoboscidae). Blood culture, serology and PCR are used for the diagnosis of Bartonella infection in reservoir hosts. As no vaccines are available, prevention in carnivores relies mostly on appropriate tick and flea control. The outcome of the treatment of these infections remains uncertain and does not result in complete bacterial eradication.