ANALYSIS - Emerging strains of Porcine Reproductive and Respiratory Syndrome (PRRS) can develop on a regularly basis and every few years a particularly virulent strain will arise and cause waves of disease, reports Sarah Mikesell from the North American PRRS Symposium.
"We do not know exactly how these happen, but the genetic changes have to involve mutation and recombination, and the consequences are bad," said Michael Murtaugh, professor and scientist at the University of Minnesota.
Michael Murtaugh shares insights regarding emerging strains of PRRS in the swine industry and how diagnostics play a role in these developing viruses.
There are two types of diagnostics used in identifying these emerging strains - one is a PCR test which looks at the genetic material of the virus. If the virus changes genetically, the test may not work on the new form of the virus. The second type of diagnostic test is immunological using antibodies, and the antibodies tend to be more conserved or identify more conserved regions.
"The way you identify new strains sometimes is that you know you have a disease but the test is negative. The negative is the clue that you have something new," he said. "Then you work to revise the test so that the new strain will also be detected."