A U.S. Isolate of Ikeda Is Not Transstadially Transmitted to Cattle by .

Ikeda has caused an epidemic of bovine anemia and abortion across several U.S. states. This apicomplexan hemoparasite is transmitted by ticks; however, it is unknown if other North American ticks are competent vectors. Since the disease movement is largely determined by the host tick range(s), the prediction of the spread among U.S. cattle populations requires determination of additional competent tick vectors. Although has mostly been eradicated from the U.S., outbreaks in populations occur frequently, and the U.S. remains at risk for reintroduction. Since is a vector of and DNA has been detected in , the goal of this study was to determine whether is a competent vector of . Larval were applied to a splenectomized, Ikeda-infected calf for parasite acquisition, removed as molted adults, and applied to two naïve, splenectomized calves for transmission. After 60 days, the naïve calves remained negative for by PCR and cytology. Additionally, was not detected in the salivary glands or larval progeny of acquisition-fed adults. These data suggest that is not a competent vector of the U.S. Ikeda isolate.