Description of a New Clade within Subtype 1 of Betaarterivirus suid 1 Causing Severe Outbreaks in Spain.

This report describes 28 genome sequences from a new clade within subtype 1 of Betaarterivirus suid 1 , formerly known as porcine reproductive and respiratory syndrome virus 1. All share a potential recombinant pattern, with a highly pathogenic Italian strain as the putative major parental sequence and three other possible parents.