|ORTEGA-S, J. ALFONSO|
Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2007
Publication Date: 7/16/2007
Citation: Cantu, A., Ortega-S, J., Mosqueda, J., Garcia-Vazquez, Z., Henke, S.E., George, J.E. 2007. Immunologic and molecular identification of Babesia bovis and Babesia bigemina in free-ranging white-tailed deer in Northern Mexico. Journal of Wildlife Diseases. 43(3):504-507.
Interpretive Summary: The white-tailed is an important secondary host for Rhipicephalus (Boophilus) annulatus and R. microplus. The deer are important in the Cattle Fever Tick Eradication Program in South Texas because they sustain and disseminate R. microplus and R. annulatus. Whether or not the white-tailed deer are also able to serve as hosts for the agents of Texas fever (Babesia bigemina and Bab. bovis) is an important epidemiological question. In a study done in the states of Nuevo Leon and Tamaulipas in Mexico, blood samples of wild white-tailed deer were collected and analyzed for the presence of antibodies against the bovine Babesia species. Additionally, blood samples from some of the deer were analyzed by a polymerase chain reaction (PCR) method that can detect the DNA of Bab. bovis and Bab. bigemina. Antibodies of both Babesia species were detected in some of the deer and DNA of both species of Babesia was discovered in several deer. It is predictable that ticks infected with Babesia would be present in an area where Texas fever is established and that the infective life stages of the Babesia would be injected along with tick saliva during the feeding of ticks. Antibodies and DNA specific for Texas fever are evidence that deer were exposed to the parasites, but are not evidence that the white-tailed deer is a competent host for either Bab. bovis or Bab. bigemina.
Technical Abstract: The suitability of white-tailed deer (Odocoileus virginianus) as hosts for the cattle ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus (Boophilus) annulatus, has been well documented. These ticks have a wide host range, and both transmit Babesia bovis and Babesia bigemina, the agents responsible for bovine babesiosis. Although this disease and its vectors have been eradicated from the United States and some states in northern Mexico, it still is a problem in other Mexican states. It is not known if wild cervids like white-tailed deer can act as reservoirs for bovine babesiosis. The purpose of this study was to determine if B. bovis and B. bigemina or antibodies against them occur in white-tailed deer in the states of Nuevo Leon and Tamaulipas, Mexico. Twenty blood samples from white-tailed deer from two ranches were collected and tested with a nested polymerase chain reaction (nested PCR) and indirect immunofluorescence antibody test (IFAT) for B. bovis and B. bigemina. Eleven samples were positive for B. bigemina and four for B. bovis by nested PCR; amplicon sequences were identical to those reported in GenBank for B. bovis (Rap 1) and B. bigemina. Results of the IFA test showed the presence of specific antibodies in serum samples. This is the first report of the presence of B. bovis and B. bigemina in white-tailed deer using these techniques and underscores the importance of cervids as possible reservoirs for bovine babesiosis.