The poultry industry's focus was on the skies as 2007 got under way, with USDA and other public and private groups around the world monitoring wild bird populations for indications of the spread of the highly pathogenic H5N1 avian influenza virus. After witnessing the spread of H5N1 from Asia into Europe and Africa via wild fowl in the fall of 2006, U.S. poultry producers watched warily as USDA continued to find no suspect virus in its monitoring of the flyways into the United States. But the news coming first from Hungary and then England in January was troubling. In late January, two goose farms in Hungary broke with H5N1, and two weeks later, on February 2, H5N1 was confirmed in a Bernard Matthews turkey flock in Suffolk, England. With the industry's flocks not to mention public health concerns at stake, the hunt was on for how the virus had spread.
Even today, authorities aren't sure how the virus spread to the Bernard Matthews flock, but the details of the epidemiological investigation into the outbreak offer valuable lessons for poultry producers everywhere. Michael Robach, vice president of food safety and regulatory affairs for Cargill, presented a report on the outbreak at the Poultry Processor Workshop. Cargill has poultry operations in the UK, and he was able to monitor the outbreak there as it unfolded.
As the investigation into the UK outbreak unfolded, a number of false leads surfaced, Robach explained, including the fact that four people came down with flu-like symptoms and were tested for the H5N1 virus. While the human illnesses turned out not to be H5N1, this created quite a stir among the public.
The United Kingdom's Department for Environment, Food and Rural Affairs (DEFRA), which was in charge of the epidemiological investigation there, immediately focused on the movement of live birds, in addition to personnel, vehicles and feedstuffs. Authorities also considered the possibility of bioterrorism.
As the investigation proceeded, attention also turned to wild-bird activity around the Bernard Matthews plant in Norfolk. Because the poultry-processing and live-production facilities are on the same site (separated by a fence), the presence of gulls and rooks roosting in the area was a concern.
The question was: How did the H5N1 virus find its way into the Bernard Matthews turkey finishing houses? Like others around the world, the UK investigators already were conducting surveillance of wild bird movements. As in the United States, there had been no H5N1 findings in 2006-07. Within a week, investigators determined that the virus was genetically identical to the one in Hungary meaning that it almost certainly had not passed through another host. This meant it was highly unlikely that transmission from Hungary occurred via migratory birds.
Focus turns to SaGa Foods
At that point, the focus turned to the Hungarian link and the fact that Bernard Matthews operates SaGa Foods in Hungary. Was it possible that the virus was brought from Hungary by Bernard Matthews personnel, equipment or even in raw poultry meat? The Suffolk plant received regular shipments of breast meat from the Hungarian facility. Not only was there ongoing evidence of problems with gulls in the Suffolk plant's waste bins and roosting on the turkey finishing sheds, but the infected sheds had entry points for small birds and rodents. What's more, Robach noted, there was evidence of water leakage into the finishing sheds from the roofs where the gulls were roosting. There was, however, no evidence to implicate the poultry meat transported from Hungary into the UK.
"The link to the Hungarian outbreaks was acknowledged," Robach said, "but it was believed unlikely to be via migratory birds." As authorities continued to evaluate the evidence, suspicion turned more to possible transmission by vehicles, clothing, crates for products and trade links though there continued to be no evidence to implicate transmission via meat from Hungary.
Investigation ends, without closure
By Spring 2007, DEFRA concluded that the exact cause of the outbreak could not be determined. On April 19, Debby Reynolds, director general for animal health and welfare and chief veterinary officer for DEFRA, issued a final report which indicated "the outbreak in Suffolk appears to be the outcome of a series of normally low-probability events and circumstances which cumulatively led to the introduction of the disease."
Robach remarked, "Not a real satisfying conclusion for those trying to figure out what happened."
Reynolds went on to say the findings "illustrated the importance of effective biosecurity for all food business operators, as there is a continuous low-level risk of introduction of avian influenza to the United Kingdom." She concluded, "There are always lessons to be learned, and that process is under way."
Bernard Matthews was compensated approximately $1.2 million (US) for the 160,000 turkeys that were destroyed. The Hungarians are not happy in that half those funds were from the European Commission, while the Hungarian goose farmers received no compensation.
The bottom line
"The bottom line is that we're never really going to know how the outbreak happened," Robach said. Speculation in some European press reports is that the virus was in the meat transported from the plant in Hungary to the one in the UK. "I personally find that to be a rather implausible explanation," he said, "and I think transmission of the virus occurred through human error.
"Someone could have been walking on a farm and laid some equipment down, or maybe didn't practice good biosecurity with some boots. It's not a long plane ride from Budapest to London, and a short enough ride from there to Suffolk," he said.
Robach offered the following observations:
- Companies need to fully understand their supply chains and biosecurity risks.
- Monitoring and surveillance programs need to be in place.
- Disease notification standards need to be harmonized around the world.
- Transparency is important in disease investigations.