ORF5 – Swine in Minnesota

Infection dynamics and incidence of wild-type PRRS virus in growing pigs

This new publication from the Torremorell’s lab is focusing on growing pig herds in the Midwest and how wild-type PRRS virus can spread among them. The full publication is available on the journal’s website.

Highlights

Wild-type PRRSV infections in growing pigs are common and more prevalent towards the middle to end of the growing phase.
Site-level surveillance is useful to understand PRRSV infections in vaccinated pigs.
Biosecurity practices in growing pig sites are key to prevent lateral infections.

Understanding whether PRRS viruses in a neighborhood are closely related

This week, the MSHMP team is sharing results from a study looking at how related PRRSv ORF5 sequences from a same area are.

Key Points

28 space-time clustering of PRRSv based on producers’ routine molecular surveillance were identified in the course of 2010-2019.
Being inside or outside a space-time cluster significantly explains the genetic variability of most, but not all cases.
Assessing space, time, and genetic relatedness relationships in PRRSV transmission is complex, and overall trends might miss important case information.

PRRSv ORF5 difference from VR2332 by herd type

This week, the MSHMP team assessed differences in ORF5 sequences compared to VR2332 based on the type of farm, the sequence was collected at.

Key points

Breeding herd sequences differ 8%-16% while in other herd types they differ 1%-15% from VR2332 at the ORF5 level.
The larger nucleotide identity (%) range compared to VR2332 in growing pigs suggests a higher viral diversity within this group.