Avian Influenza: A Story About Industrial Fowl Play?

Who really was the source of the 2005 bird flu pandemic? All the evidence points to intensive factory farmed poultry

by GrrlScientist for ScienceBlogs | @GrrlScientist

Intensive Poultry Farming.

Over the weekend, I found this new report [PDF] by GRAIN that shows that the global poultry farming industry is, as I suspected, the primary cause of H5N1 avian influenza, NOT wild birds and backyard free-range poultry farmers as is so widely reported by the media. Further, this report claims that the probable cause for the increased lethality of the avian influenza virus is a direct result of the horrible conditions perpetuated by poultry industry (as I have stated).

This linked report is quite long, but it is important because it claims that the primary source for avian influenza is, and has been, the commercial poultry industry. It discusses the evidence, showing that the virus primarily spreads via shipments of domestic poultry — their chicks, eggs, meat, feathers, manure and feed — from one factory farm to another, along roads and other trade routes, and not along major flyways followed by wild birds, as I and others have noted (Figure 1).

Figure 1. Seasonal migratory flyways followed by wild birds.

Yet, despite the fact that H5N1 outbreak locations are consistent with neither the seasonal timing of migration nor the routes followed by wild birds, many international and governmental agencies stubbornly continue to perpetuate the myth that wild birds are the primary vector for spreading the virus far and wide. However, Richard Thomas from BirdLife International sensibly points out:

“No species migrates from Qinghai, China, west to Eastern Europe. When plotted, the pattern of [H5N1] outbreaks follows major road and rail routes, not flyways. And the absence of outbreaks in Africa, South and Southeast Asia and Australasia this autumn is hard to explain, if wild birds are the primary carriers.”

Fear-mongers counter this evidence with their claim that the die-off of wild geese at Qinghai Lake, China, clearly shows that wild birds are the main culprits in the spread of avian influenza. However, careful studies of the region reveals that Qinghai Lake is surrounded by many large poultry operations, that there is a nearby fish farm (that the FAO helped to build) and that, according to BirdLife International, chicken feces are commonly used as food and fertilizer for fish farms in China.

But certain authorities overlooked these rather important details, and more. For example, many trains and roads connect the Qinghai Lake area to other bird flu outbreak areas, like Lanzhou, which was the source of infected poultry that caused an earlier outbreak of H5N1 in Tibet (1,500 miles away).

But the FAO, among other respected agencies, consistently ignored these little facts until they were finally nailed down on this very issue in November 2005, when a spokesman finally admitted that [PDF]:

“To date, extensive testing of clinically normal migratory birds in the infected countries has not produced any positive results for H5N1 so far.”

Another fact that is often overlooked is that almost all wild birds that tested positive for H5N1 were already dead and most of those were found close to large concentrations of domestic poultry that were known to have avian influenza. If anything, these data indicate that avian influenza is so rapidly lethal among wild birds that most die before they are able to relocate.

“Everyone is focused on migratory birds and backyard chickens as the problem,” says Devlin Kuyek of GRAIN. “But they are not effective vectors of highly pathogenic bird flu. [italics mine] The virus kills them, but is unlikely to be spread by them.”

So if wild birds and free-range poultry are not the primary flu vectors, how is avian influenza spread? The geographic and temporal evidence points directly to the transport of domestic poultry by industry;

“The evidence we see over and over again, from the Netherlands in 2003 to Japan in 2004 to Egypt in 2006, is that lethal bird flu breaks out in large scale industrial chicken farms and then spreads,” says Devlin Kuyek of GRAIN.

For example, earlier this year, the Nigerian outbreak began at a single factory farm owned by a Nigerian Cabinet minister. This particular factory farm is known for importing unregulated hatchable poultry eggs from Turkey where avian influenza outbreaks occurred, and it is located far from any migratory bird “refueling sites”. Therefore, it is much more likely that commercial imports of domestic birds from an already infected area (Turkey, in this case) were the source for the outbreak.

But this isn’t unique: local authorities in India now say that H5N1 emerged and spread from one factory farm owned by that country’s largest poultry company, Venkateshwara Hatcheries.

The fact is that factory farms provide the perfect “viral incubators” where avian influenza can amplify and increase in lethality because of the disgusting conditions of overcrowding and poor hygiene under which domestic poultry are kept, combined with the birds’ lack of genetic diversity. Within these crowded poultry farms, a mild virus rapidly evolves towards more pathogenic and highly transmissible forms, and becomes capable of jumping from one species to another, thereby spreading back into wild birds, which are defenseless against these new strains. These farms also produce polluted air that is thick with viruses that are carried on the breezes throughout the nearby countryside, where wild birds become ill and die, or are slaughtered in mass.

This same scenario is true for small-scale poultry production. Bird flu does not evolve to highly pathogenic forms in free-range poultry operations because the low population densities and the genetic diversity keeps the viral load to low levels. Instead, free-range poultry are the victims of bird flu strains that escape from industrial poultry producers.

The available evidence supports my assertions. For example, in Malaysia, the avian influenza mortality rate among the villagers’ free-range chickens was only 5%, suggesting that the virus is not effectively transmitted among small scale chicken flocks. H5N1 outbreaks in Laos, which is surrounded by infected countries, have only occurred in that nation’s few factory farms, which are supplied by Thai hatcheries, and for years, Thailand has waged an ongoing war against bird flu. Most incriminating of all: the only cases of bird flu that occurred in Laotian backyard poultry, which accounts for over 90% of that country’s total poultry production, were next to the factory farms.

So, based on this evidence, modern intensive farming methods and international shipment of poultry and their products obviously play a strong role in the ongoing H5N1 “problem” in Asia. In my opinion, if the international community was serious about preventing a pandemic of “bird flu”, then it is critical that they take immediate steps to tightly regulate industrialized poultry farming to prevent unrestricted movements of animals and their products from one region to another. Further, it is essential that backyard farming operations are protected from unnecessary mass slaughters so as to preserve the genetic diversity of these domestic animals. And last, but certainly not least, international organizations and governmental agencies should rely on real data and expert help as they develop workable strategies for dealing with health crises, instead of perpetuating the illusion that they are actually accomplishing something by declaring war on the victims. And in this case, the victims are wild birds and backyard poultry farmers.

Who is GRAIN? GRAIN is an international non-governmental organization (NGO) that promotes the sustainable management and use of agricultural biodiversity based on the people’s control over genetic resources and local knowledge. As such, they are not in the back pocket of national and international corporate and industrial giants.

This piece was included with the best science, nature and medical blog writing by the Tangled Bank (issue #49), nominated for Animalcules 1.3 — PZ birthday edition, linking to the best writing in the blogosphere about “wee beasties” — viruses, bacteria and parasites — and included in Grand Rounds, vol. 2, no. 24 (week 76), celebrating the best medical writing in the blogosphere. Also chosen as the co-lead story for the 181st issue of the Carnival of the Vanities.

Originally published at scienceblogs.com on 6 March 2006.