Wicomico bird flu scare shows gap in poultry response plan

The poultry sample from a sick flock in Willards, Maryland, was moments away from passing cleanly through a routine bird flu test in December.

Then the data showed something unexpected: the presence of avian influenza.

Salisbury Animal Health Diagnostic Laboratory scientists tested a sample from the same group of birds again.

And again in the last minutes, the test lit up. 

The result was in a category termed "non-negative" or "inconclusive." The poultry community isn't quite sure what to call it.

"It’s the first time that we’ve seen this, at least here on the Eastern Shore," said Maryland state veterinarian Michael Radebaugh. 

The case caused officials to realize there was a gap in their bird flu response plans when it came to results that weren't conclusively positive or negative. They are now working to come up with a systematic response to employ if the situation occurs again.

"It's a possibility we would see more of these cases," Radebaugh said. "We are changing our plans to adapt to that."

Not positive, not negative

Labs on the Delmarva Peninsula use highly sensitive tests to detect avian influenza. If there is a lot of virus present, the test will quickly flag it.

But later in the process, the opposite is true.

"At that level of detection, there is minimal to almost nothing present in the tube," said Brian Ladman, a senior scientist of avian virology at the University of Delaware. "But the science says something is in there."

So the sample wasn't quite fully positive — but it wasn't negative either.

Because of the inconclusive result, the industry voluntarily put down approximately 40,000 chickens on one Willards farm. 

For two weeks, state officials and experts worked to investigate the possible outbreak while waiting to confirm whether the Delmarva commercial poultry industry had its first case of avian influenza in almost 15 years. 

Ultimately, the virus was verified as "not detected" by National Veterinary Services Laboratories. That's the term for a negative test.

Some types of bird flu have occasionally spread to humans, causing sickness and rarely death. In those cases, it is typical for the people to have had direct contact with sick birds.

People infected often have flu symptoms including high fever, cough and difficulty breathing. Complications can include pneumonia, organ dysfunction and septic shock, according to the World Health Organization. 

Even if the disease does not spread to people, bird flu outbreaks can cause cascading results from heavy losses of birds to a shutdown of international trade. 

Officials say they continue to balance response plans that will protect health, guard against the disease's spread and keep the industry from experiencing unnecessary delays in production.

Why is bird flu so scary? 

Sussex County, Delaware, is No. 1 in production of broiler chickens in the U.S, according to the U.S. Department of Agriculture. 

The Delmarva Peninsula includes the Eastern Shore of Maryland and Delaware, along with southern Delaware. Growers on Delmarva raised 605 million chickens with a wholesale value of $3.4 billion in 2017, according to Delmarva Poultry Industry Inc.

The dense population means a contagious poultry disease can quickly escalate into an emergency, Delaware state veterinarian Heather Hirst, said in a public talk.

Avian influenza, commonly known as bird flu, is often present in wild birds. 

The University of Delaware found avian influenza virus in 14 percent of samples from almost 8,000 wild waterfowl and shorebirds on Delmarva between 2007 and 2011, in an early detection program funded by the USDA.

The problem comes when the disease transfers over to domestic bird flocks.

Once bird flu enters a flock, it can spread rapidly among the chickens and to other local farms. 

"It is so important to get ahead of this," Ladman said. "To respect the virus and the possible disaster that can happen."

In 1997, six people in Hong Kong died after confirmed infections of avian influenza.

It was the first time, that scientists know of, where bird flu transferred from poultry to humans from direct contact. 

The outbreak ended only when 1.5 million chickens in the territory were slaughtered. 

“It created such a panic to some people that this would be the next pandemic flu," said Nathaniel Tablante, associate professor at the University of Maryland.

While the Asian bird flu virus has continued to sporadically spread to humans, causing illness and deaths, the North American version has very rarely transferred to people.

Delmarva's most recent confirmed case of avian influenza in a commercial flock was in 2004. 

Although the virus was not highly pathogenic and didn’t spread past a few farms, it had a serious impact on international trade with several countries blocking all U.S. imports of poultry in response.

In 2015, an outbreak of avian influenza flooded through the Midwest, leading to massive depopulations and global effect on trade.  

China still enforces a ban on U.S. poultry imports that's based on this outbreak.

“It’s such a potent virus that it just kills so rapidly,” Tablante said.

He works with area farms through the University of Maryland extension service to increase defenses against the spread of diseases. 

Unfortunately, he said, there's no way to guarantee that there won't be an outbreak of avian influenza in the region. 

Wild flocks of birds will likely continue to carry the virus, Tablante said.

But he advises people to strengthen security on farms to guard against an outbreak. 

That includes not tracking outside feces into poultry houses, building proper housing that protects poultry from wildlife and limiting movements between poultry farms except when necessary.

“It doesn’t happen every day," he said about avian influenza. “Focus on what you can control from your end, practice good biosecurity." 

The good news is, while the disease is still a major concern for poultry producers, it hasn't shown the sustained ability to transfer from human to human.

That means a global pandemic from bird flu is unlikely, said Tablante.

Confusing results led to delay in diagnosis 

The Salisbury lab first detected avian influenza on Dec. 7, after testing deceased chickens from a flock of 18-day-old birds experiencing higher than average mortality. 

It was 19 days later when officials got the "all clear" that the case was not the beginning of a bird flu outbreak on the Eastern Shore. 

Through that time, which included Christmas Day, the industry was on a razor's edge.

"This flock could potentially have been a powder keg," Ladman said.

In addition to testing for the presence of any avian influenza, labs also test for two dangerous versions of the disease, known as H5 and H7. The Willards sample came up with a non-negative result for H5.

The 2015 bird flu outbreak that caused close to 50 million birds to be put down across 15 Midwestern states was also the H5 strain.

That added fear, Ladman said.

More:Maryland air quality monitoring plan reignites poultry battle

More:Poultry growers would get incentive to use alternative water source with Virginia bill

The confirmation process took longer than average because tests flip-flopped between negative and inconclusive. 

Initial samples that were inconclusive at the Salisbury laboratory tested negative at the national lab in Iowa. But the national lab flagged inconclusive samples from the same flock that had tested negative in Salisbury. 

"It was very confusing," said Radebaugh.

Because scientists couldn't conclude that there was no avian influenza detected, they had to wait while the lab completed a virus isolation test. 

Sample material was placed into eggs that were then incubated to see if the virus would grow.

The process takes nearly two weeks. 

During that time, officials headed to command center for monitoring bird flu in Georgetown. 

The Willards farm was quarantined. Scientists began testing poultry on the 94 farms in a 6-mile surrounding radius. 

On Dec. 13, the poultry company voluntarily decided to put down the sick flock, killing approximately 40,000 birds.

"It is hard to watch,” said Ladman, who was not present at this event but has seen others in the past. "It impacts the grower. It impacts the people who are there. We all, who are interacting with chickens, do like and respect those birds."

But the decision made sense, he said. The danger to the poultry industry was too high.

"We have to react" 

Previous to December, the department had two sets of plans for addressing outbreaks of avian influenza based on the disease's potential to kill chickens. 

Low pathogenic avian influenza is often found in wild birds. It does not typically cause death or serious disease symptoms. 

But several strains of the low pathogenic virus, H5 and H7, have been known to mutate into the high pathogenic version.

High pathogenic strains of the disease have caused serious outbreaks leading to millions of deaths in chickens around the world and even limited spread to humans.

During the scare last year, they improvised a path based off previously developed response plans, said Radebaugh .

"We just can't rest our laurels and say 'Oh we'll just wait and see,' " he said. "We have to react."

Officials closed movements of high-risk poultry products into and out of the infected zone but didn't institute a complete shutdown.

Chickens were allowed to leave the 6-mile zone to be slaughtered 24 to 72 hours after testing negative for the virus. 

The state didn't mandate a depopulation of the sick flock. That's something that is required on day one when a high pathogenic virus is confirmed. 

In the case of a low pathogenic detection, a presumptive positive would lead to the consideration of depopulation or slaughter based on surveillance. 

Radebaugh said with an inconclusive case, depopulation won't be mandated in all situations. 

"I think we'll take each case as it comes," he said. "Now if it was a positive result or a detected result, then that’s a different story. Then we would really be on top of that."

Radebaugh said the state learned a lot from the event, particularly regarding communication.

Officials moved to the command post in Georgetown, Delaware, — about 28 miles from the Willards farm — four days after the first test. That's the same day when the Maryland governor’s office was notified of the case, according to the Maryland Department of Agriculture.

A day later, Delmarva Poultry Industry and other stakeholders were notified. The next day, the command center shared information with Wicomico County and began answering media inquiries. 

An official press release wasn’t sent until Dec. 27, after the negative test result was confirmed by the national lab. By then, 20 days had passed since the first inconclusive result.

"We certainly learned about notification," said Radebaugh. "Communication is so important in how we should notify both internally and externally."

The Maryland Department of Agriculture is working with its regional counterparts to draft an official response plan in the case of another "non-negative" result. The department aims to complete the plan in September.

Despite the lack of a plan, officials and industry representatives said they are pleased with the response.

"Food safety really comes first," said James Fisher, spokesperson for Delmarva Poultry Industry Inc. "You can’t ignore an inconclusive result but you don’t want to unnecessarily disrupt the livelihoods for growers and profits for the company." 

Although the depopulation was voluntary, Ladman said he thinks the same decision would be made by poultry companies in the future.

He said the region did a good job of addressing a tough situation.

"I don’t think that you can do anything more, I don’t think you should do anything less," he said. 

Parties communicated across state lines, which is a unique challenge on Delmarva, where Delaware, Maryland and Virginia’s poultry markets are intimately connected.

"We worked very well together. That was a good test for us," said Radebaugh. "We are prepared."

But he's also hoping that scientists can uncover more information about this type of inconclusive result. 

Eventually, Radebaugh wants to know whether avian influenza detected that late in the test process has any chance of transmission to other birds.

"We need more research on this," he said.

My stories on Eastern Shore agriculture take time to create. To keep working each day I need your support. If you already subscribe, thank you. If not, and you want to see me unearth more stories, subscribe to Delmarva Now today.

Do you have a story about the poultry industry? Contact reporter Jenna Miller at jmiller@delmarvanow.com, 443-669-4005 or on Twitter @jennamargaretta.

More:Swamp cancer: Chincoteague ponies get hope to stop spread of disease with vaccine

More:Census 2020: Undercount could impact funding for Virginia Shore, says expert