New foot-and-mouth disease test determines infected vs vaccinated pigs
A newly developed foot-and-mouth disease assay can distinguish between the antibodies caused by immunisation and those caused by actual disease.On behalf of the Swine Health Information Center Iowa State University has developed a foot-and-mouth disease virus enzyme-linked immunosorbent assay for swine oral fluid specimens.
Swine Health Information Center Executive Director Dr Paul Sundberg says one of the most important distinctions of this test is its ability to differentiate between vaccine antibodies and antibodies that come from exposure to wild type virus.
"There are FMD vaccines that are available and should we get FMD in North America those vaccines will be probably be deployed to help control and prevent the spread of the virus," said Dr Sundberg, speaking to Farmscape.
"That would lead to a conundrum if the blood from those vaccinated animals were to be tested for antibodies because the antibodies that will show up from the vaccine could look like the antibodies that could show up from a natural infection.
"The natural infection might result in animals carrying the virus long term.
"The vaccine would not and it's going to be important to be able to differentiate those two.
"This test has a real advantage in that it can tell the difference between the antibodies that would be caused by vaccine and the antibodies that would be caused by natural exposure.
"Thus we would be able to differentiate those animals and we'd know which animals are at higher risk of being further sources of virus to other animals, a real important distinction that we'll need to have should we need to respond to an outbreak."
Dr Sundberg says, based on testing in the field, there is a high level of confidence that we've got a very usable test that could be deployed in the face of an outbreak. He says it will still need USDA approval for use but it represents a big step forward in being prepared for FMD should it get here.