Carriers of foot-and-mouth disease virus: A review

This review describes current knowledge about persistent foot-and-mouth dis ease virus (FMDV) infections, the available methods to detect carrier anima ls, the properties of persisting virus, the immunological mechanisms, and t he risk of transmission. In particular, knowledge about the carrier state, the period in which virus can be isolated from animals 28 days or longer po st infection, is important, because the risk that animals may carry the vir us will influence the diagnostic and preventive measures that need to be ta ken. Although many years of research have led to much knowledge about foot- and-mouth disease and its causative agent, there are still numerous aspects of the virus and the disease that are not yet fully understood. Areas for further research on persistence of FMDV are discussed.