Lessons learned from the H5N1 outbreak

Canada’s poultry sector has seen relatively minor repercussions from an ongoing global outbreak of highly pathogenic Avian Influenza (AI) but panelists at the recent Health Day hosted by the Poultry Industry Council (PIC) agreed that changes to disease response must be considered if the industry wants to avoid future harm.

That’s largely because this strain of H5N1 AI is unlike any strain the world has experienced before, numerous studies indicate.

Why it matters: The recent AI outbreak in Ontario and North America showed the virus is evolving, and strategies to prevent its spread need re-evaluating.

Canadian poultry producers who collectively lost more than two million birds in this year’s outbreak were obviously affected but evidence from Europe and Asia, where the strain first appeared, shows it could have been far worse.

PIC panel moderator Al Dam, poultry specialist at the Ontario Ministry of Agriculture Food and Rural Affairs (OMAFRA), said there’s no guarantee it won’t worsen if the strain resurfaces in fall.

“I think we’re in a lull (this summer) but there’s a lot that we can learn and there’s a lot that we need to prepare for the next coming months,” he said.

Climate change contributed to the uniqueness of the virus, panelists agreed. Canadian Wildlife Services population management biologist Christopher Sharp said one route taken by this virus from Europe to North America was in a species of wild duck that arrived in Newfoundland for the first time ever due to climate-altered migration patterns.

During a North American AI outbreak in 2015, no wild birds tested positive. This time, various species of wild birds – both migratory and resident – have been affected.

Dr. Jean-Pierre Vaillancourt, professor of avian medicine at the University of Montreal, delivered a presentation about highly pathogenic AI just before the panel discussion. He noted this outbreak’s first five domestic bird cases in Ontario happened in the first two weeks of April when few migratory birds are usually in the province.

“But with climate change, we have a change in the biology of these wild birds” and they often arrive earlier on their northward journey and linger later during their southward return.

In addition, some species including Canada geese have decreased or possibly even curtailed their migration away from Ontario.

Mitchell’s Bay on Lake St. Clair and Long Point on Lake Erie used to be popular among ice fishers, Sharp noted, but are now only frozen for short spans every few years. Otherwise, there is open water in winter and usually Canada geese stay instead of migrating further south.

Vaillancourt said a recent study suggests there are two variants of this strain in Europe, one from migratory birds and another circulating in resident wild birds. This could explain an anomaly first observed during a 2016-18 outbreak when a traditionally out-of-season flare-up in Italy confounded poultry health experts.

Normally, AI runs its course in domestic flocks by late spring. That pattern has so far been true in Canada’s current outbreak. The most recent positive domestic bird test was May 18. In Italy, with H5N8, there was an outbreak from June to December.

“Obviously, there seems to be a change in the biology of the vectors for the virus,” Vaillancourt said. “If that happens here, we may be stuck with highly pathogenic AI year after year, on a cycle.”

With the current H5N1 strain, the pathogens move faster than the incubation period, said Vaillancourt. Birds shed the virus a few days before showing clinical signs of disease.

In France last year, birds were tested five to seven days before being shipped in an effort to limit the virus’s spread. But 10 to 15 per cent of those shipped birds ended up positive.

Tests on birds or the dust within the barn environment are accurate, he said, but they need to be done on the day of shipping or the day before.

These evolving characteristics – moving with climate change and re-infecting faster than the incubation period – mean the current outbreak “is spreading much longer than expected, and it’s everywhere,” Vaillancourt said. Several previous outbreaks were confined to Europe and Asia but this strain had no trouble moving into North America and Africa.

The big risk is that this H5N1 strain develops the ability to make humans sick. It has already jumped to other species of bird as well as mammals including seals, skunks, mink and foxes. “Once mammals start getting sick, you want to take it seriously,” said Vaillancourt.

On the positive side, he noted, strategies to limit the spread remain the same. Separation of sick birds and proper cleaning of facilities and equipment have been practiced for decades and they still work.

Restricting visitors, limiting cross-contamination between production facilities and communicating the progression of outbreaks are also useful.

However, Vaillancourt warned of the need to rethink various strategies. Instead of each producer setting up their own on-farm biosecurity, they may need to accept direction from officials to establish a regional biosecurity approach.

Technology can track feed truck movement, service personnel in barns, security breaches and even wildlife interactions. But the owners of that data must be willing to share it to benefit the whole sector.

“Compliance is a big deal,” he said. “I’ve done consulting in 32 countries. I can tell you you’re not worse than most other countries. But you’re not that much better.”

So far, the Canadian poultry sector has the freedom to euthanize flocks in an efficient and humane manner. That’s not the case in France, where last year H5N1 spread was exacerbated when animal welfare advocates pushed to transport large numbers of live and dead birds to specialized rendering facilities.

Urban-influenced approaches to wildlife management have removed an option to simply destroy any wild geese on a property. As Vaillancourt noted, “society is playing an increasing role” in animal welfare-related decision-making and Canada’s poultry sector should prepare for that.

Sharp cautioned that the Canadian Wildlife Service “is not in the business of allowing the mass killing of wild birds.” He acknowledged that the federal agency recognizes the evolving risk of highly pathogenic AI and will be open to approving permits for removal if, in collaboration with the poultry industry, they are deemed necessary.

Panelists were uncertain about the ability of another federal agency, the Canadian Food Inspection Agency (CFIA), to adequately adjust to the new H5N1 reality.

Vaillancourt told of his experience earlier this year in getting the media involved when he learned a testing lab in Quebec would close for the Easter long weekend in the middle of the active outbreak. The lab eventually changed its plans after media backlash but Vaillancourt said it showed the lack of priority given to something farmers knew should be taken seriously.

He also called on the CFIA to work with United States officials to make available an H5N1 vaccine. Vaillancourt learned from the manufacturer that Canada represents too small of a market for the vaccine to be put through the approval process and offered here. He wants the CFIA to help clear that roadblock.

McKinley Hatchery poultry veterinarian Dr. Mike Petrik said the CFIA must find a way to allow non-government vets to assist with CFIA-designated duties when emergency situations arise. Petrik expressed frustration that, as with a previous AI outbreak in 2015, industry vets jumped to assist with communication but were prevented from visiting active facilities to help. CFIA personnel quickly became overwhelmed, he observed.

“We need to find a way to make the expertise that’s in the industry available to help when it’s needed,” Petrik said.