A single particle of porcine reproductive and respiratory syndrome virus (PRRSV) is about 1,000 times smaller than the width of a strand of hair. It’s easy for the microscopic germs to move undetected through vast amounts of air, meaning costly viruses that infect swine are exceedingly difficult to detect.
PRRSV alone costs United States producers around $1.2 billion every year. Several swine diseases—including the influenza virus—can also transmit to humans.
“Ultimately, we are creating capacity to respond to animal diseases with the goal to ensure food security and protect animal and human health,” said Montserrat Torremorell, a professor and department chair of the Department of Veterinary Population Medicine (VPM) at the University of Minnesota College of Veterinary Medicine (CVM).
Torremorell and researchers at CVM, in collaboration with the Department of Mechanical Engineering, are developing a tool that would detect swine viruses and stop their spread. The project secured $1 million in new funding from the U.S. Department of Agriculture National Institute of Food and Agriculture (USDA-NIFA)
The project will develop a way to use aerosol samplers—like the ones developed to detect SARS CoV 2 in a crowded room—to catch swine viruses such as PRRSV, even when a herd has very low levels of the virus. Once captured, the virus’ genetic material will be sequenced using Target-Enriched Long-Read Sequencing of Virus (TELSVirus), which is a novel approach and quickly determines what the virus is and identifies new variants.
The novel sampler in combination with the novel way to analyze viruses could be useful “to understand how diseases get transmitted, how far pathogens can travel in the air, and to decipher whether pathogens are airborne or not,” said Torremorell. “The TELSVirus component is key because it allows us to detect multiple viruses at the same time.”
This will allow producers to respond more rapidly and effectively as costly viruses emerge.
A long-lamented problem
Determining whether a virus is airborne has proven to be a tricky task because it’s difficult to sample enough volume of air to find lurking viruses. The new device would remedy that by increasing sensitivity to viruses. By rapidly sequencing the ribonucleic acid (RNA)—he genetic material of any viruses captured from the air—the tool would be able to identify new variants and emerging diseases before the viruses have a chance to spread to other herds. This is particularly important because some variants are more transmissible than others and would require different protocols to stop them, Torremorell said.
Current sequencing tools require that a scientist know exactly what virus they have in a sample. Thanks to TELSVirus and the novel sampler, scientists would be able to identify viruses even when they did not suspect ahead of time they were in a sample.
Screening the air for viruses cuts down on biosecurity concerns. Right now, veterinarians have to take samples from individual animals to determine whether a virus is circulating in a herd, which means bits of virus could be transferred outside of a facility through them. If an air sample shows a virus is present, experts would be able to determine what, exactly that virus is without setting foot in a barn.
“The key is also about finding out how pathogens spread inside and between farms,” Torremorell said.