Foot-and-mouth disease - the carrier state in ruminants [Review] [Polish]

摘要

After contact with the foot-and-mouth disease virus (FMDV) ruminants may become chronically infected (i.e. carrier animals). These animals are a potential source of infection and can play a role in the epidemiology of foot-and-mouth disease (FMD). Carrier animals are defined as animals from which FMDV can be isolated from oropharyngeal fluid (OPF) more than 28 days post infection. Chronic infection can occur either after clinical or subclinical FMD infection, and in vaccinated and non-vaccinated animals. The detection of carrier animals has resulted in international trade restrictions. The carrier state is also an important barrier in using prophylactic vaccines against foot-and-mouth disease. This review describes the occurrence of carrier animals and available methods of detection. It also presents the location and properties of the chronic virus as well as the mechanisms of chronic infection and the possible role of carriers in transmitting FMDV.