Sussex hosts regional avian flu summit

By Sam Harvey
Staff Reporter

Avian influenza. While media outlets are paying it a great deal of attention of late, the regular, seasonal flu is actually a far more serious problem. Seasonal, or common, flu claims 36,000 lives – every year – in this country alone, according to the U.S. Department of Health and Human Services, Center for Disease Control (CDC) Web site.

Avian flu, by way of contrast (and not to diminish the tragedy of the deaths), has claimed fewer than 120 lives worldwide since 1996 or 1997, according to the World Health Organization (WHO) Web site.

Perhaps avian flu does deserve some extra play, because there was in fact a pandemic (worldwide) “avianlike” flu outbreak in 1918 and 1919, and that outbreak did claim approximately 50 million lives.

Jeffery Taubenberger and David Morens’ “1918 Influenza: the Mother of All Pandemics,” (referenced on the CDC Web site) indicates that all of the pandemics and most of the epidemics since 1918 have been caused by descendants of the “Influenza A” virus of 1918. (Influenza A can affect not only humans, but dogs, birds, horses, pigs and other animals, and is the most dangerous type.)

The Influenza A category does include the rare-in-humans, but deadly, H5N1 strain of the avian flu presently of most interest around the world. However, as Taubenberger and Morens point out, H5N1 is only distantly related to the 1918 strain.

Further, “The evolutionary path that led to pandemic emergence in 1918 is entirely unknown,” they write, “but it appears to be different in many respects from the current situation with H5N1.

“There are no historical data, either in 1918 or in any other pandemic, for establishing that a pandemic ‘precursor’ virus caused a highly pathogenic (disease-causing) outbreak in domestic poultry,” Taubenberger and Morens continue, “and no highly pathogenic avian influenza (HPAI), including H5N1 and a number of others, has ever been known to cause a major human epidemic, let alone a pandemic.”

However, treating with kid gloves the possibility that H5N1 might spread to North America via wild birds migrating across the Pacific Ocean, America’s federal administration has kicked emergency preparedness planning into high gear.

And Delmarva veterinarians sounded off on those plans at an avian flu preparedness summit on April 18 (at the brand new Carvel Research and Education Center, near Georgetown).

It was quite a christening – U.S. Rep. Mike Castle (R-Del.) led the discussion, joined by Delaware Secretary of Agriculture Michael Scuse, Maryland’s state veterinarian, a veterinarian from the Virginia Department of Agriculture & Consumer Services and poultry industry leaders.

If the group emphasized one thing, it was that people on Delmarva have more experience with avian flu, and are better prepared, than perhaps any other Americans. And, reiterated more than once, even the H5N1 strain did not constitute a human health risk if people follow basic food safety precautions.

H5N1 has been contracted by people who work and/or live in very close proximity to infected birds, or who handle raw chicken guts and innards with their bare hands. It is not easily transmitted to humans, and even more rarely transmitted person-to-person.

Also, the virus is extremely sensitive to heat. From the WHO Web site, “Avian influenza is not transmitted through cooked food. To date, no evidence indicates that anyone has become infected following the consumption of properly cooked poultry or poultry products, even when these foods were contaminated with the H5N1 virus.”

The WHO recommends cooking to 70 C (158 F) “in all parts of the food,” to kill the virus. (But the U.S. Department of Agriculture, the USDA, recommends thorough cooking to 165 F, to get rid of any possible Salmonella bacteria.)

Not that commercial poultry growers in America are letting infected chickens get anywhere near the processing plants, much less the grocery stores. If even one chicken turns up positive for the avian flu in pre-slaughter testing, the entire flock is destroyed.

Often, neighboring flocks may be destroyed for good measure, just to expand the zone of containment.

All this being said, viruses can mutate. The experts noted that it is conceivable that a new strain of the avian flu may materialize at some point – a strain more capable of passing from birds to humans (or worse, more infectious person to person).

Whatever appears over the horizon, Castle noted “prevention and containment at the agricultural level” as the best way to keep avian flu from becoming a human health problem.

But he suggested the administration’s reaction to a possible avian flu pandemic seemed a bit out of proportion with the actual risk. “I agree, basically, with a lot of things that are being done,” he said (stockpiling of vaccines and antivirals, for instance). “However, personally, I’m surprised at the (federal) response.”

Earnestness at the federal level might have been heightened by regret over emergency response in the wake of Hurricane Katrina, he said, “which was less than adequate, at a minimum.”

Others in attendance criticized the draft of the federal avian flu response plan itself.

“This is something I believe the USDA should have done many months ago,” Scuse said. “And I believe their plan is lacking in many areas, because they didn’t get information from the states that have been affected (in the past).”

For instance, Scuse said the USDA had recommended burial of dead chickens as the primary method of disposal (whenever there’s an outbreak, the entire flock is euthanized).

This was off base, he emphasized – people closest to the Delmarva poultry industry had settled on “in-house composting” as a far superior method of disposal, at least among commercial flocks.

University of Delaware’s Dr. Jack Gelb Jr. (chairman of Animal and Food Sciences) had referenced the composting technique earlier in the summit, but George “Bud” Malone, a poultry specialist at the university’s Cooperative Extension, expanded on his and Scuse’s comments.

According to Malone, in-house composting virtually prevented the possibility that the avian flu might spread, by making sure the dead, infected chickens never left the chicken house. He referenced one outbreak in British Columbia (Canada) in 2004, when dust and feathers got away from the farmers trying to dispose of dead chickens, and forced the Canadians to destroy every poultry flock in the Fraser Valley.

And composting solves two problems at a stroke, Malone added, cooking the avian flu out of both the dead birds and their manure. (The two are shoveled into a windrow, down the center of the chicken house. Temperatures inside that pile quickly reach 130 to 140 F, Malone said, sufficient to very quickly destroy the virus.)

The university was also researching methods of “rapid (chicken) depopulation, without putting humans at risk,” Gelb pointed out.

Inducement of anoxia (suffocation) via carbon monoxide is the traditional method, but DuPont’s Phillip Strange (Animal Health Solutions) said there is increasing interest in use of, basically, fire extinguisher foam.

As Malone pointed out, this has several added advantages. Most importantly, he said, foam reduces the number of people needed to do the job and the time involved.

Malone said the foam also suppresses airborne particles that might be carrying the virus, and he felt the foam, being faster than carbon monoxide, was more humane.

Castle said he planned to take the Delmarva-bred ideas back to the USDA, and see if he could get them incorporated into the federal response plan. Although that document is nearing completion, “I’m going to take a run at it,” Castle said.