Epidemiological aspects of cattle tick fever in Brazil

The present work reviews the epidemiologic situation of Anaplasma marginale and Babesia spp. infections and the occurrence of cattle tick fever outbreaks in Brazil. In areas of tick fever enzootic instability, environmental conditions interfere with the development of Rhipicephalus (Boophilus) microplus: chilly winter in the southern region, floods in the Pantanal, and low humidity in the Caatinga. In contrast, the climatic conditions of stable zones (Cerrado, Amazon and Atlantic Forest biomes) favor tick development. In enzootic areas, tick fever is uncommon because the animals are in frequent contact with the parasite, acquiring immunity naturally during the period of innate resistance; however, outbreaks may occur when calves become infested by considerable numbers of infected ticks during this period or in adults raised in tick-free environments that become infested for the first time when transporting to stable areas. It is necessary to better understand the disease's risk factors under stable conditions and the implications of the mechanical and other vector transmission of A. marginale. To prevent tick fever outbreaks in Brazil, it is important to develop and use anaplasmosis and babesiosis vaccines in cattle from enzootic unstable regions, especially when animals are moved to stable areas.

Automated summary

The present work discusses the epidemiology of Anaplasma marginale and Babesia spp. infections and cattle tick fever outbreaks in Brazil. Environmental conditions in enzootic areas affect tick development, while stable zones provide favorable conditions. In enzootic areas, animals acquire immunity naturally, but outbreaks can occur when calves or tick-free adults become infested with infected ticks. Understanding the disease's risk factors and transmission mechanisms is crucial. Vaccination in enzootic unstable regions can help prevent tick fever outbreaks in Brazil when animals are moved to stable areas.