Prevalence of <i>Anaplasma</i> spp. and <i>Theileria</i> spp. Antigens and Antibodies in Housed and Grazing Korean Indigenous Cattle

<b><i>Background:</i></b> Infection with tick-borne pathogens (TBPs) causes anemia, jaundice, and growth retardation in cattle. Many studies have conducted antigen (Ag) tests for major TBPs, such as <i>Anaplasma</i> spp. and <i>Theileria</i> spp., in Korean indigenous cattle (KIC); however, few studies have analyzed antibodies (Ab) against these pathogens. <b><i>Materials and Methods:</i></b> This study simultaneously tested 15 housed cattle raised indoor for over a year and 67 grazing cattle for <i>Anaplasma</i> spp. and <i>Theileria</i> spp. Ag using polymerase chain reaction analysis and Ab using enzyme-linked immunosorbent assay. <b><i>Results:</i></b> The <i>A. phagocytophilum</i> was detected in 3 housed cattle (20.0%) and 30 grazing cattle (44.8%), whereas the <i>T. orientalis</i> was detected in 3 housed cattle (20.0%) and 54 grazing cattle (80.6%). The positivity rates for <i>Anaplasma</i> spp. Ab did not differ significantly between housed and grazing cattle (4 out of 15 [93.3%] and 55 out of 67 [80.0%], respectively). The positivity rates for <i>Theileria</i> spp. Ab were higher in grazing cattle than in housed cattle (21 of 67 [31.3%] and 0 out of 15 [0.0%], respectively) (<i>P</i> < 0.01). No difference was observed between the frequency of grazing and the abundance of Ab against either pathogen. Meanwhile, as a result of comparing the detection of pathogen Ag and Ab, <i>Anaplasma</i> spp. showed the highest proportions of 73.3% and 47.8% in Ag (-)/Ab (+) for housed cattle and grazing cattle, respectively. <i>Theileria</i> spp. showed the highest rates of 80.0% in Ag (-)/Ab (-) for housed cattle and 52.2% in Ag (+)/Ab (-) for grazing cattle. <b><i>Conclusions:</i></b> This is the first study to determine the impact of antibody abundance against <i>Anaplasma</i> spp. and <i>Theileria</i> spp. on antigen prevalence in KIC.