簡要描述：PRRSV is a small, enveloped RNA virus. It contains a single-stranded, positive-sense, RNA genome with a size of approximately 15 kilobases. The genome contains nine open reading frames. PRRSV is a member of the genus Arterivirus, family Arteriviridae, order Nidovirales. Subclinical infections are common, with clinical signs occurring sporadically in a herd. Clinical signs include reproductive failure in sows such as abortions and giving birth to stillborn or mummified fetuses, and cyanosis of