Epidemiological survey of Babesia gibsoni infection in dogs in Japan by enzyme-linked immunosorbent assay using B. gibsoni thrombospondin-related adhesive protein antigen.

A nationwide epidemiological survey of Babesia gibsoni infection in non-fighting dogs was conducted using an improved ELISA with recombinant B. gibsoni thrombospondin-related adhesive protein (BgTRAP). A total of 1206 dogs from 27 prefectures were examined and 128 (10.6%) tested positive. In the eastern part of Japan, 39 dogs out of the 559 (7.0%) examined were positive, while 89 dogs out of 647 (13.8%) tested positive in the western part of Japan. Although the percentage of dogs that tested positive was significantly (p=0.0001) lower in the eastern part compared to the western part of Japan, overall these results indicate that B. gibsoni infection of dogs has a widespread geographic distribution throughout the country. A history of tick infestation was identified as a significant risk factor for B. gibsoni infection (p=0.0091), while sex (p=0.9411), age (p=0.0920) and breed (p=0.0549) of dogs were not statistically significant risk factors. These results indicate that tick infestation is the most dominant risk factor for B. gibsoni infection of non-fighting dogs in Japan and suggest that other B. gibsoni transmission routes, such as fighting and transplacental transmission, may be less important.