homepage logo

SDSU lab responds quickly to PEDv

By Staff | Nov 12, 2014

-Contributed photo RESEARCH ASSOCIATE Aaron Singrey dilutes PED virus to a working concentration so it can be used to inoculate samples to test for PEDv neutralizing antibodies.

BROOKINGS, S.D. (SDSU) – An emerging virus demands quick action, said Jane Christopher-Hennings, director of the Animal Disease Research and Diagnostic Lab at South Dakota State University.

One week after the diagnostic lab at Iowa State University confirmed that porcine epidemic diarrhea virus had spread to the United States, Christopher-Hennings said, researchers at the ADRDL released a diagnostic test to differentiate PEDv genetic material from that of other viruses.

According to Eric Nelson, an ADRDL researcher, the first-generation, gel-based polymerase chain reaction test by the lab’s molecular diagnostics group improved the test’s sensitivity and cut the testing time in half, making it possible to get same-day results.

The second-generation test was commercially available within a few months.

Quick diagnosis

ADRDL’s quick turn-around time for diagnostic testing provides a real value to producers, said Glenn Muller, executive director of the South Dakota Pork Producers. “The diagnostic lab is the primary source of determining a true, confirmed case of PEDv.”

The PCR-based test can also be used on environmental samples to detect whether items brought onto the farm are contaminated, Hennings said.

In addition, the test results fulfill the U.S. Department of Agriculture reporting mandate, which requires producers whose herds test positive to review their biosecurity measures with their veterinarians to pinpoint any changes that may be necessary.

Detecting antibodies

Once an animal is exposed to the virus, it develops antibodies, Nelson said. ADRDL scientists produced several tests to detect the animal’s immune response to PEDv.

These tests are important, not only to identify animals previously exposed to PEDv, but also to evaluate an animal’s antibody response to vaccines, said Travis Clement, a research associate.

Neutralizing antibodies, in particular, are important indicators of protective immunity to the virus, Clement said. If pigs with these antibodies have negative PCR results, meaning they have stopped shedding the virus, they might be safely integrated into the operation.

Within four to six months, ADRDL had developed monoclonal antibody reagents used to detect PEDv in tissues from infected animals and to detect viable virus in cell cultures.

Though ADRDL does vaccine research, Nelson said, “We’ve had our hands full on the diagnostic side.”

ADRDL does antibody testing on candidate vaccines to determine whether the antibody levels measured are high enough to provide clinical protection against the virus and therefore predict their effectiveness, Hennings said.

ADRDL monoclonal antibodies became commercially available this spring and are used in multiple research laboratories developing vaccines.

“With an emerging disease, research, diagnostics and control measures are critical in limiting the damage and extent of the disease,” said Hennings.

Networking among diagnostic labs, especially in the Midwest with regard to swine diseases, helps researchers quickly identify new diseases and develop diagnostic tools.

Please Enter Your Facebook App ID. Required for FB Comments. Click here for FB Comments Settings page