Development of an equine coronavirus-specific enzyme-linked immunosorbent assay to determine serologic responses in naturally infected horses.

The research article describes a study aimed at developing and validating a specific test (ELISA) for detecting antibodies to equine coronavirus in horses in order to study the prevalence of the virus.

Introduction to the Study

• The focus of this study is on equine coronavirus (EqCoV), a viral infection present in most horses, conventionally identified via quantitative qPCR analysis of feces and viral genome sequencing.
• While qPCR helps in detecting the virus during the acute phase of the disease, there is a lack of an equine-specific antibody test to study EqCoV’s prevalence in various horse populations.
• The researchers sought to develop a new, equine-specific enzyme-linked immunosorbent assay (ELISA) to address this gap.

Development of the ELISA Test

• The developed ELISA test was designed to target antibodies to the spike (S) protein of EqCoV.
• This test was validated using acute and convalescent sera collected from 83 adult horses involved in 6 separate outbreaks.

Results and Utility of the ELISA Test

• Results indicated that the EqCoV S protein-based ELISA was able to reliably detect antibodies to EqCoV in naturally infected horses.
• The greatest seroconversion rate (the development of specific antibodies in response to an infection or immunization) was observed in horses showing clinical signs compatible with EqCoV infection and in those with EqCoV qPCR detection in their feces.
• Due to this, the newly developed ELISA test could be effectively used for seroepidemiologic studies, allowing for a richer understanding of the overall infection rate of EqCoV in various horse populations.