ARS | Publication request: Evolving translational research to keep the U.S. free of cattle fever ticks

Submitted to: United States Animal Health Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 15, 2011
Publication Date: N/A

Technical Abstract: Cattle fever ticks and bovine babesiosis were the subject in the late 19th century of research efforts exemplifying what we call now the One Health concept. Animal, and human health are inextricably linked under that concept. Theobald Smith, a physician, and Frederick L. Kilborne, a veterinarian, formed the scientific team that in 1893 documented elegantly for the first time that pathogens can be transmitted by arthropods. Cooper Curtice, a veterinarian, contributed pioneering work on the life history of the ticks about that same time. Bovine babesiosis, also known as cattle tick fever, caused by the apicomplexan protozoa Babesia bovis and B. bigemina transmitted by the cattle fever ticks Rhipicephalus (Boophilus) annulatus and R. (B.) microplus had devastating health effects on livestock, and prevented the development of the cattle industry when these tick-borne protozoa and vectors were endemic in the U.S. Cattle fever ticks (CFT) and bovine babesiosis were officially declared eradicated from the U.S. in 1943 after a successful cooperative state-federal program that started in 1907. A permanent quarantine zone is maintained in south Texas to buffer CFT incursions from Mexico where the ticks are established. Major operational components of the CFT Eradication Program (CFTEP) include: surveillance, inspection, quarantine, compulsory dipping of cattle, and/or pasture vacation. Previous estimates adjusted to current values show that the U.S. livestock industry saves at least $3 billion annually by not having bovine babesiosis. Keeping the U.S. free of CFT is an agricultural biosecurity issue of national prominence. A major component of the USDA-ARS KBUSLIRL mission is to provide the CFTEP science-based solutions to keep the U.S. CFT-free in a sustainable manner. This contribution to the USDA-ARS Animal Health Research Review at the USAHA Annual Meeting provides an update on research conducted to meet needs identified during a public workshop held in 2009 where the One Health concept was applied to bovine and human babesioses. An ivermectin-medicated protein feed supplement block for cattle was tested as a free-access, passive, self-treatment technology at the Cattle Fever Tick Research Laboratory. Preliminary results indicate this would be a useful technology for the CFTEP. Efforts are underway to conduct pilot testing of this technology under field conditions. Stall tests revealed that an anti-tick vaccine based on the Bm86 antigen commercially available outside the U.S. was highly (>95%) efficacious against a Texas outbreak strain of R. annulatus. However, the level of efficacy reached against an outbreak strain of R. microplus was statistically insignificant. Our anti-tick vaccine discovery research program is addressing this technology gap. Our lab continued to contribute to the project funded by the National Institute for Food and Agriculture (project no.: TEXR-2009-05759) integrating ecologically-based approaches to re-eradicate CFT from the U.S. Studies revealed that dynamic processes underlie visitation and access to field stations, established using the Thunder Valley Deer Feeder with ARS ‘2-Poster’ treatment adapter, by the white-tailed deer population. A correlation was found between the use of remote sensing technology to identify favorable white-tailed deer habitat and the ability to sample R. microplus larvae in the field. It is expected that outcomes from these research efforts will provide the basis for integrated strategies to mitigate the risk of CFT re-invasion so the national cattle herd remains free of bovine babesiosis. USDA is an equal opportunity provider and employer.