ARS | Publication request: Challenges for the Control and Eradication of the Tropical Cattle Tick Rhipicephalus microplus and Perspectives of Anti-tick vaccines

Submitted to: Agricultural Research International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 2011
Publication Date: N/A

Technical Abstract: The tropical cattle tick, Rhipicephalus microplus (Canestrini), is a damaging ectoparasite of cattle and a key vector of babesiosis, also known as Cattle Fever. Although R. microplus was eradicated from the United States, it remains endemic in Mexico and a permanent quarantine zone along the Texas-Mexico border has been established to prevent it from re-entering the U.S. This tick pest continues to cause severe economic losses to cattle production in tropical and sub-tropical countries, including Mexico, Brazil, and Australia. Tick control has traditionally relied on chemical acaricides. However, during the past decades resistance to all major classes of chemical acaricides in R. microplus has developed and this hinders the current control efforts. There is an urgent need for developing more efficacious tick control technologies, including new anti-tick vaccines and new acaricides with novel modes of action. The current tick research at the USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory (KBUSLIRL) focuses on the identification of tick genes and proteins that are critical for tick feeding and reproduction. A significant portion of the R. microplus tick genome and transcriptome has been sequenced and assembled by the team and its collaborators. Three novel tick antigens have been discovered, and the initial on-animal trial revealed over 70% efficacy against R. microplus. TickGARDTM and Gavac® are two commercially available anti-tick vaccines that were developed in Australia and Cuba, respectively. Various levels of control by the two vaccine products have been reported in different studies. A new study is currently under way to evaluate the efficacy of Gavac® against local strains of R. microplus and a closely related tick species, R. annulatus, in Texas. The implications of use of anti-tick vaccines in the USDA’s Cattle Fever Tick Eradication Program will be discussed.