Laboratory diagnosis of porcine reproductive and respiratory syndrome (PRRS) virus infection

Porcine reproductive and respiratory syndrome (PRRS) is a relatively new, economically important disease of pigs and is characterized by reproductive failure in sows and gilts, pneumonia in young growing pigs, and an increase in preweaning mortality. The PRRS virus (PRRSV) was initially isolated in the Netherlands and the United States and was labeled as the Lelystad and ATCC VR-2332 viruses, respectively. Although these two strains are antigenically similar, some genetic and antigenic differences have been reported. Laboratory diagnosis of PRRSV infection can be made on the basis of virus isolation or viral serology. Recently, a polymerase chain reaction (PCR) test has been developed to detect PRRSV in boar semen and swine sera. The purpose of this diagnostic note is to provide a brief update on the laboratory methods used to diagnose PRRSV infection in swine.