“The job of infectious bronchitis virus is to continue to change so that it can cause disease in chickens,” says Mark Jackwood, research scientist at UGA’s Poultry Diagnostic and Research Center. “Our job is to try to stay one step ahead of this virus which causes big economic problems worldwide.”
Avian infectious bronchitis costs the U.S. poultry industry millions of dollars annually. The American Association of Avian Pathologists continues to list avian infectious bronchitis as the number one research priority for commercial poultry.
Highly contagious, the virus is extremely difficult to control because of its ability to change rapidly and adapt to its host.
But Jackwood and his team of investigators have had a great deal of success battling the Group III coronavirus which affects the upper respiratory tract, causing the equivalent of a common cold in chickens, slowing their growth and diminishing egg production.
There are only a few licensed vaccines available and most of those vaccines have been unsuccessful in controlling the virus.
“Dr. Jackwood’s research contributions have formed the cornerstone for infectious bronchitis control in this country,” says John Glisson, head of the population medicine department. “The U.S. poultry industry looks first to Mark for help whenever this disease enters into our poultry population.”
Jackwood and his colleagues just developed a vaccine due to be released early next year against a new strain of the virus they isolated and identified in 1998. His team also developed diagnostic tests to keep track of where the virus is and what it’s doing.
“These tests can distinguish between the different types of viruses and will show us when new ones start to crop up,” Jackwood says. “We continue to keep upgrading the tests with new technology to make them even more sensitive and more sophisticated-quicker, faster, cheaper.”
His laboratory was one of the first to develop a molecular diagnostic test for viruses in 1993.
But the problem of controlling infectious bronchitis virus is not solved yet because the virus continues to change.
“So what we do is monitor chickens and figure out which strains are out there, which ones are causing the problem,” says Jackwood. “Our diagnostic tests are the key element in surveillance.
“If we have vaccines against the strains we identify, we use them,” he also says. “If we don’t, we examine those viruses more closely and try to develop vaccines.”
Jackwood’s work with infectious bronchitis virus in chickens has had an unexpected bonus.
“We’ve developed a diagnostic test based on our bronchitis diagnostic tests to identify a new coronavirus which showed up in turkeys four years ago,” he says.
This virus has now spread all over the country after first appearing in North Carolina. It results in a huge economic loss for the industry-more than $1 million a year.
What interests Jackwood most about the virus is that it is very similar to the ones they study in chickens.
“Right now we’re trying to find out how it’s transmitted, we’re looking to see how it evolved and we’re trying to see if we can use it as a model for studying SARS,” he says.
SARS-human severe acute respiratory syndrome-is also caused by a coronavirus and has evolutionary ties to other coronaviruses, including chicken and turkey coronaviruses.
“We are also working on a vaccine,” Jackwood says.
