Dynamics of virus excretion and transmissibility of European-type PRRSV isolates of high and low virulence

Porcine reproductive and respiratory syndrome (PRRS) is a disease causing high economic losses worldwide. The etiological agent, PRRS virus (PRRSV), is highly heterogenic. This variability of PRRSV has resulted in the emergence of strains differing in virulence. Previous studies carried out with American-type isolates have demonstrated that the degree of virus transmission and aerosol shedding are related to isolate pathogenicity (1).   However, similar studies have never been done using E