Molecular survey of the seven recognized Eimeria species in chicken farms in Japan

Coccidiosis is an economically important disease of chickens caused by Eimeria species. This study investigated the detection status of the seven recognized chicken Eimeria species in 108 pooled fecal samples from 56 farms in Japan using species-specific real-time PCR. All seven species were detected. E. acervulina was the most frequently detected species at both the sample and farm levels, and multiple Eimeria species were frequently detected in individual samples. Because live vaccines used in several farms contained E. acervulina, E. maxima, E. tenella, E. necatrix, and/or E. mitis, detection of these species could not distinguish vaccine-derived from field strains. Detection of E. brunetti and E. praecox indicated circulation of non-vaccine species.