Location: Animal Disease Research
Project Number: 2090-32000-040-000-D
Project Type: In-House Appropriated
Start Date: Oct 1, 2021
End Date: Sep 30, 2026
This project aims to develop a risk mitigation plan to reduce threats associated with bovine babesiosis for the U.S. livestock industry. To develop bovine babesiosis control strategies, there are significant knowledge gaps regarding Babesia-mammalian-tick host interactions that need to be addressed. These gaps include a lack of understanding of Babesia stage-specific protein expression, limited knowledge regarding drug therapy efficacy and safety, and genetic conservation among geographically distinct Babesia isolates. Additionally, little progress has been made on characterizing the mechanisms regulating a protective immune response to bovine babesiosis, understanding the risk of introducing pathogens into disease-free regions by wildlife, and rapidly changing environmental factors. This plan will address these knowledge gaps by developing diagnostic assays for detecting cattle infected with Babesia spp., discovery and testing of potential Babesia antigen targets expressed by the parasite during its development within cattle or tick vectors, development of efficacious and safe treatment regimens to control babesiosis, characterizing the immune response to Babesia and identification of targets that can be used to develop a vaccine, and developing mathematical models to predict the spread of bovine babesiosis parasites into U.S. herds. This project will address the following objectives. Objective 1: Develop intervention strategies to minimize the impact of bovine babesiosis outbreaks, to include vaccine and therapeutic development to prevent clinical disease or block transmission of bovine babesiosis. Sub-objective 1A: Improve molecular and serologic diagnostic assays for bovine babesiosis. Sub-objective 1B: Evaluate the capacity of bovine antibodies against Babesia gamete and kinete surface antigens to minimize the impact of bovine babesiosis outbreaks. Sub-objective 1C: Assess the efficacy of chemotherapeutic approaches to eliminate Babesia pathogens and disrupt transmission. Objective 2: Characterize the immune response to infection with Babesia bovis, to include identifying targets that can be used as correlates of protection and examining age-specific differences. Sub-objective 2A: Investigate age-specific immune response differences to acute Babesia bovis infection between naïve young calves and adult cattle. Sub-objective 2B: Identify Babesia bovis proteins required to induce an immune response that mitigates disease severity. Objective 3: Develop predictive models of potential Babesia disease spread in the United States to assist in mitigating potential future outbreaks. Sub-objective 3A: Develop prediction models of potential Babesia parasite spread into the United States.
Objective 1: Develop intervention strategies to minimize the impact of bovine babesiosis outbreaks, to include vaccine and therapeutic development to prevent clinical disease or block transmission of bovine babesiosis. Goals: The research will focus on developing strategies for mitigating or preventing bovine babesiosis outbreaks. Specifically, 1) develop cost-effective diagnostic assays for detecting cattle infected with B. bovis and/or B. bigemina, which are major threats to the U.S. cattle industry, 2) evaluate bovine antibodies against Babesia tick stage-specific parasites for their capacity to prevent transmission and reduce acute disease, and 3) identify efficient drug(s) to clear infection to minimize the impact of bovine babesiosis outbreaks. Objective 2: Characterize the immune response to infection with Babesia bovis, to include identifying targets that can be used as correlates of protection and examining age-specific differences. Goals: The research will focus on a comprehensive characterization of the immune response of calves to infection with B. bovis and defining cytokines/chemokines associated with reduced disease severity. Also, Babesia surface proteins will be identified and utilized to understand immune mechanisms responsible for controlling Babesia infection within the mammalian host. The outcome will provide a strong foundation for future Babesia subunit vaccine development. Objective 3: Develop predictive models of potential Babesia disease spread in the United States to assist in mitigating potential future outbreaks. Goal: The research focus will be to develop and validate models that better predict areas at risk of Babesia parasite introduction into the United States.