Bartonellosis: One Health Perspectives for an Emerging Infectious Disease

In recent years, an increasing number of Bartonella species have been identified as zoonotic pathogens, transmitted by animal bites, scratches, arthropods and even by needle sticks. Considering the diversity of newly discovered Bartonella species and subspecies and the large number and ecologically diverse animal reservoir hosts and the evolving spectrum of arthropod vectors that can transmit these bacteria among animals and humans, the clinical and diagnostic challenges posed by Bartonella transmission in nature are presumably much more complex than is currently appreciated by diagnosticians, vector biologists, ecologists, physicians, or veterinarians. Historically the term "bartonellosis" was attributed to infections with Bartonella bacilliformis, transmitted by sandflies in the Peruvian Andes. Currently, however, bartonellosis now includes infections caused by any Bartonella sp. anywhere in the world. Potentially, because Bartonella spp. can infect erythrocytes, endothelial cells, pericytes, CD34(+) progenitor cells, and various macrophage-type cells, including microglial cells, dendritic cells, and circulating monocytes in vitro, the clinical and pathological manifestations of bartonellosis appear to be very diverse in both sick animals and human patients. Because 75% of emerging infectious diseases are zoonoses, many of which are vector-transmitted by an arthropod, a One Health approach to bartonellosis and other zoonotic infections is needed to properly address animal health, public health, and environmental factors that influence the distribution and transmission of these bacteria. The One Health concept encourages a spirit of cooperation among animal, environmental, and human health professionals and promotes developing integrated solutions for complex problems that impact the health of animals, humans, and the planet. Importantly, substantial research is needed to define the medical importance of this genus as a cause of animal and human illnesses.