Pig virus costs farmers $800 million a year
U. MISSOURI (US) — Scientists may be a step closer to finding a cure for a virus that inhibits pigs from reproducing and slows the young animals’ growth.
Once pigs are infected with Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the only remedy is for hog farmers to cull their herds.
“Initially, scientists believed that PRRSV bound to a specific molecule, known as CD169, and infected white blood cells in the lungs,” says Randall Prather, professor of reproductive biotechnology at the University of Missouri. “In our study, we’ve found that this is probably not how the virus is infecting pigs.”
For the study, published in the Journal of Virology, researchers genetically modified a litter of pigs so they wouldn’t generate the CD 169 molecule; therefore, the virus would have nothing to bind to and would be killed by the pigs’ natural immune systems.
But after an initial test, the genetically modified pigs did become infected with PRRSV, negating the initial theory.
“While we didn’t find what we were looking for, we did uncover important information about the infection,” Prather says. “This information will help us narrow our search as we continue to fight this virus. We’ll keep searching for answers until we determine how to stop PRRSV.”
When pigs are infected with the disease, farmers must clean everything, Prather says. That means culling the herd, cleaning the barns, and letting the pens sit empty until all viral material is killed. If that doesn’t happen, the virus can continue infecting new groups of hogs.
Farmers have had access to vaccines for the last two decades, but experts warn they are not the best tool to fight the disease.
“Vaccines have been shown to lessen the impact of the disease on farms, but they are not a good tool to control or eradicate the virus,” says Raymond (Bob) Rowland, co-author of the study and professor of virology at the Kansas State University College of Veterinary Medicine.
“With this new information, we understand more about the mechanisms of this virus and how it acts once inside the pig’s body.”
Source: University of Missouri
You are free to share this article under the Creative Commons Attribution-NoDerivs 3.0 Unported license.