Ikeda in Cattle, Alabama, USA.

Ikeda genotype, a parasite causing a disease in cattle that leads to significant economic challenges in Asia, New Zealand, and Australia, has been identified in seven U.S. States since 2017. Two previously validated PCR tests for followed by DNA sequencing were performed to test blood samples collected from 219 cattle in Alabama, USA, during the period of 2022-2023. Bidirectional Sanger sequencing revealed that the MPSP gene sequences (639-660 bp) from two cattle in Lee and Mobile Counties of Alabama exhibited a 100% match with those of recognized Ikeda strains, and showed similarities ranging from 76% to 88% with ten other genotypes. A high copy number of Ikeda was detected in the blood of infected cattle (ALP-1: 1.7 × 10 and 1.3 × 10/mL whole blood, six months apart; ALP-2: 7.1 × 10/mL whole blood). Although the confirmed competent vector for Ikeda, tick, has not yet been identified in Alabama, the persistent nature of Ikeda infection and the detection of a high pathogen burden in seemingly healthy cattle in this study suggest that other tick species, as well as shared needles and dehorning procedures, could facilitate pathogen transmission within the herd. Continued investigations are necessary for the surveillance of Ikeda and ticks in Alabama and other U.S. states, along with assessing the pathogenicity of Ikeda infections in cattle.