Serological surveillance for FMDV antibodies serotypes O and A in cattle in Tongliao, Inner Mongolia, China

Abstract

Foot-and-mouth disease (FMD) is an acute, febrile and highly contagious disease caused by foot-and-mouth disease virus (FMDV), mainly affecting cloven-hoofed animals. FMDV antibody detection can provide a timely understanding of the immune level after vaccination. In this study, 22,902 cattle blood samples from free-range households and large-scale farms were collected from eight districts in Tongliao city, Inner Mongolia Autonomous Region, China, from January to December 2020. Serum antibodies against serotypes O and A FMDV were detected by liquid-phase blocking ELISA. The results showed that the positive rates of serotypes O and A FMDV antibodies in Tongliao were 91.21% and 90.18%, respectively. The positive rates of serotypes O and A FMDV antibodies in 8 regions ranged from 85.80% to 98.41% and 84.48% to 96.77%, respectively. The positive rates of serotypes O antibodies in cattle from households and farms were 82.15% to 97.41%, and 90.51% to 99.32%, respectively. The positive rates of serotypes A FMDV antibodies in cattle from households and farms ranged from 83.47% to 96.77% and 84.98% to 97.30%, respectively. The positive rates of serotype O FMDV antibody in spring, summer, autumn and winter were 92.68%, 94.40%, 88.84% and 84.32%, respectively, and those of serotype A FMDV antibody were 93.50%, 92.19%, 87.26% and 88.86%, respectively. The results indicated that the immunization level of FMD was high in Tongliao city, and all positive rates exceeded the requirement that the qualified rate of immune antibody should be kept above 70% all year long according to the National Compulsory Immunization Plan of Animal Epidemic Diseases in 2020. However, vaccination and antibody detection of cattle raised by households in autumn and winter should be strengthened. The results of this study can provide a basis for authorities to formulate FMD prevention and control plans.