Publications – Swine in Minnesota

Pooling udder skin wipes to detect influenza in preweaning pigs

This is a recent publication from the Torremorell’s lab refining the use of udder wipes to detect influenza in preweaning pigs. It is available in the Journal of Veterinary Diagnostic Investigation.

Key points

Pooling of three, five, and ten udder wipes was evaluated.
Sensitivity decreased if the Ct count was above 31.5.
Pooling more than three udder wipes can affect the ability to detect influenza virus.

Evaluation of oral fluid as an aggregate sample for early detection of ASF

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Since ASF has been found in the Dominic Republic last week, swine producers are concerned about it spreading into the United States. Early detection would be essential to ensure a rapid response and containment of the disease. This week, the MSHMP team shares the summary of a Canadian study looking at using oral fluids as a tool to diagnose ASF.

Key Points

Oral fluid samples may be used as a low labor, cost effective alternative sample source for rapid detection of ASFV during ASF surveillance.
ASFv genome was detected in oral fluids at low-to-moderate levels as early as 3-5 days post infection, before clinical symptoms started.
Further research is needed to understand limitations and best practices of oral fluid sampling for ASFv

Phylogenetic Structure and Sequential Dominance of Sub-Lineages of PRRSV Type-2 Lineage 1 in the United States

In a new study by Paploski et al., researchers from the VanderWaal lab delineated the phylogenetic structure within PRRSV Lineage 1, described past dynamics of different viral strains through quantifying viral population sizes across time, and identified antigenically relevant amino acid changes associated with each sub-lineage.

Key points

Lineage 1 of PRRSV-type 2, which is the most prevalent PRRSV lineage in the U.S., can be sub-divided into eight sub-lineages
We documented the cyclic emergence and turnover of different lineages and sub-lineages (about every 3 years) in the commercial pig population based on both sequence count data and estimated past viral population sizes inferred from genetic diversity through time.
The eight sub-lineages differed in key amino acid sites of the GP5 that are thought to be involved in the immune response to the virus. This lends further strength to the hypothesis that immune-mediated competition or selection may drive the emergence of new PRRSV sub-lineages in the U.S.

Histological Lesions and Replication Sites of PCV3 in Naturally-Infected Pigs

A team of researchers led by Dr. Fabio Vannucci investigated the lesions associated with a natural infection by Porcine Circovirus 3. They focused their study on histological lesions as well as replication sites to get a better understanding of this virus’ pathology. The article is available in open access on the journal’s website.

Are mosquitoes a risk for ASF?

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, the MSHMP tip summarized a publication by Qin et al. regarding the risk of mosquitoes carrying and transmitting African Swine Fever virus.

Key Points

African swine fever (ASF) continues to pose a large risk in the absence of safe and effective ASF vaccines
There is evidence indicating that mosquitos may be a possible ASF vector
Mosquitos captured at ASF positive farms had DNA extracted and tested for ASF with no positive results