I’m writing to you today about a situation that is becoming very serious. Chicken with Bird Flu is becoming a more common subject in mainstream media lately. The big question is when this could become reality for your family. Let’s be honest, it’s coming one day! So, I’ll cover the following areas: the history of it, the science behind it, and what you can do to prepare yourself.
The horrific bird flu that has wiped out 36 million chickens and turkeys, explained
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The final month of Minnesota Timberwolves basketball was livelier than ever this season, and not just because they nearly upset the Memphis Grizzlies in their first-round playoff series.
During one game in mid-April, a woman glued her hand to the court. A few days later, another woman chained herself to the goal post. The following week, a third woman, dressed as a referee, stormed the court before removing her jacket, exposing a shirt underneath that read “Glen Taylor roasts animals alive.”
The protests, coordinated by the animal rights group Direct Action Everywhere, were aimed at the Timberwolves’ majority owner Glen Taylor. Taylor also owns Rembrandt Enterprises, a large Iowa egg producer that has culled — meaning deliberately killed — 5.3 million of its hens in response to a widespread bird flu outbreak (and then laid off nearly all of its staff).
The virus, known as the Eurasian H5N1 avian influenza, began tearing through Europe, Asia, and Africa in late 2021 and is still raging, with Europe experiencing its worst bird flu outbreak on record. It was first detected in the US in January and has since spread to at least 32 states, resulting in the death of more than 36 million chickens and turkeys and triggering a spike in egg prices.
While the virus has a near 100 percet mortality rate among infected poultry — and can spread rapidly among birds, especially in packed industrial farming conditions — it’s currently believed to pose little threat to human beings. It only rarely spills over to people, and only to those who come into close contact with infected birds. Even when there are human infections, “the viruses are unable to efficiently transmit between humans,” notes Michelle Wille, a virus ecologist at the University of SydneyTop ArtcleCT UP veteran on the power of angerin protest
But when certain strains of avian flu do manage to infect humans, it can be deadly. From 2003 to 2021, a little more than half of the 863 people who contracted an earlier strain of H5N1 died. The H5N1 strain currently spreading appears to be less transmissible and less severe to humans than those that infected people in the past, and only two people have tested positive for the strain — a man in the United Kingdom last December, and a man in Colorado last week.
The Colorado man — a prison inmate who had come in direct contact with presumably infected birds while working at a culling operation as part of a pre-release work program — experienced a few days of fatigue and recovered after being treated with an antiviral drug. Around 10 people who came into contact with him are under close observation.
Beyond the occasional one-off case in close human contacts, the bigger worry is that an unchecked flu that spreads among birds has plenty of opportunities to mutate in a way that allows it to transmit efficiently from person to person, thereby kicking off a new influenza pandemic. A widespread bird flu outbreak in 2005 raised alarm bells and prompted the US Senate to allocate $4 billion to prepare for a possible influenza pandemic — though when a new flu pandemic did break out in 2009, the origin was ultimately found in a swine virus.
So far, the bird flu has mostly been a problem for birds. It’s not the disease that’s killing most of them, however — it’s their owners.
When chicken, turkey, and egg companies detect one infected bird, they kill the whole flock in an effort to slow the spread of the virus. And they’re doing so using a variety of excruciating methods, including spraying birds with a suffocating water-based foam or closing off barn vents to raise temperatures so the birds die by heat stroke, a practice called ventilation shutdown, which can take 1.5 to 3.75 hours to kill them.
“It’s horrendous,” says Craig Watts, a former large-scale chicken farmer and currently a director of field operations for the Socially Responsible Agriculture Project, a nonprofit that advocates against industrial livestock operations. “I’ve been in those houses when the power went out and the generator didn’t kick on. In just a few minutes [the heat] is unbearable. … I can’t imagine that going on for hours and hours.”
According to the Storm Lake Times, a newspaper based near Rembrandt’s operation, the company used ventilation shutdown plus, or VSD+, meaning they also pumped heat into their barns to kill the birds faster, a practice being employed in several states. Rembrandt Enterprises did not respond to a request for comment.
The situation is horrific, but given the industrialized nature of the US poultry industry and its response to past bird flu outbreaks, animal advocates say it’s unsurprising. Nearly all birds raised for meat and eggs in the US are raised on factory farms, where producers raise hundreds of thousands to millions of animals per year. And most of these animals are genetically identical, which could make them more vulnerable to bird flu. Some experts say the intensification of animal farming — raising more animals closer together — could also be increasing the virulence and transmission rate of bird flu strains.
Dena Jones of the Animal Welfare Institute says the 2014-2015 bird flu outbreak in the US, which led to the culling of more than 50 million animals — the largest cull in US history — didn’t prompt any real change in the industry. Instead, mega operations that raise millions of birds per year are continuing to be built across the country, from Oregon to Wisconsin and West Virginia to North Carolina as US chicken and egg consumption rises.
There are culling methods that kill the birds much quicker than ventilation shutdown, such as spraying them with nitrogen-filled foam or gassing them in small enclosures, a method some producers are using to address this outbreak. There’s also a race to create an effective bird flu vaccine that could be used to slow the spread of future outbreaks, a race the USDA is partially funding.
Considering the speed at which bird flu spreads among commercial poultry flocks, and how painful it is for infected birds, the industry has no choice but to mass cull. But the USDA’s approval of ventilation shutdown in 2015 and the rise of its use in recent years, combined with the slow pace of vaccine approval and adoption, mean that for the time being, the birds themselves will continue to receive little consideration in the fight against bird flu. The ongoing expansion and intensification of US animal agriculture, along with a rise in animal disease outbreaks, might also mean that we need to learn how to live with the bird flu and the looming threat it poses.
Bird flu spread, explained
Migratory waterfowl, like ducks, geese, and terns, are the natural hosts of highly pathogenic avian influenza strains, but can largely — though not always — carry and spread the virus without showing symptoms.
Wild birds rarely come into direct contact with farmed chickens and turkeys, most of which are raised in large indoor barns — especially in more developed economies — but instead spread the virus when their fecal droppings, saliva, or nasal secretions contaminate animal feed or land on surfaces like farmworkers’ clothing or farm equipment. Researchers say the global poultry trade also contributes to the worldwide spread of the bird flu through the import and export of infected poultry.
Once any birds test positive for the virus, the whole flock is culled, as the flu can quickly spread to the tens of thousands of other hens, chickens, or turkeys in a single farm. And the flu itself is agonizing for infected poultry. Chickens have trouble breathing and suffer from extreme diarrhea, and sometimes develop swelling around their head, neck, or eyes. Turkeys’ wings can become paralyzed and they might experience tremors.
Bird flu outbreaks have been recorded in commercial poultry flocks since at least the 19th century, but the frequency accelerated — and became a bigger issue in the poultry industry — starting in 1997, when an outbreak of H5N1 in Hong Kong chicken farms led to 18 infections in people, six of whom died. Officials responded by culling all 1.3 million chickens in Hong Kong in the winter of 1997-98. Since then, outbreaks have occurred around the world every few years.
And not much beyond mass culling can be done to slow the spread once it starts. Adel Talaat, a professor of microbiology at the University of Wisconsin-Madison, says we should improve disease surveillance and farm biosecurity to help prevent new outbreaks and slow the spread, but a vaccine that could reliably reduce transmission would go a long way.
At the moment, there aren’t any highly effective vaccines on the market, but Talaat is working to develop one using a database of thousands of avian influenza antigens to create a “composite” vaccine that he hopes will protect against current and future virus strains. “Our job is to try to stop this cycle of transmission,” Talaat says. “Because if you stop the cycle of transmission you will be able to basically stop the mutation and stop the replication of the virus.”
He estimates it could take up to five years until he completes his work and hopefully receives USDA approval, and says a mass vaccination program in the early phase of a bird flu outbreak could be effective at slowing the spread of the virus.
“In a big country [like the US], once we start seeing any one case, we know it’s going to go throughout the states — state by state — so we really should start an aggressive campaign for vaccination right away,” Talaat says.
Aside from the ineffectiveness of currently available bird flu vaccines, they’re also made in such a way that it’s impossible to distinguish vaccinated, non-infected birds from infected birds. And because no country wants to import meat from potentially infected birds, the vaccines have been a non-starter. Talaat hopes his vaccine will solve this long-standing problem.
A spokesperson with the National Turkey Federation told Vox over email that the trade group “supports vaccine development and believes it can be done relatively quickly. However, World Organisation for Animal Health (OIE) rules impose severe trade penalties for vaccine use, and we are encouraging USDA to work aggressively for a change in those rules.”
“Decisions on vaccinations require many data and we’re investigating an avian influenza vaccine that could distinguish from the wild-type virus,” Rick Coker, a USDA spokesperson, said over email. “We do not have a time frame on any potential vaccine or how it would be used.”
There are also efforts underway to create a gene-edited chicken breed immune to bird flu. But for now, the primary way to prevent the flu from killing poultry is by killing poultry.
Avian Influenza in Poultry
In 1878 a respiratory disease causing high mortality in poultry was first described as Fowl Plague. In 1955 an influenza virus was isolated as the cause of Fowl Plague or avian influenza. This article provides a few fact about Avian Influenza and provides links to more detailed information on this destructive disease.
Avian Influenza in Poultry – In 1878 a respiratory disease causing high mortality in poultry was first described as Fowl Plague. In 1955 an influenza virus was isolated as the cause of Fowl Plague or avian influenza. This article provides a few fact about Avian Influenza and provides links to more detailed information on this destructive disease.
A few facts about Avian Influenza
Avian Influenza (AI) is a contagious viral infection which can affect all species of birds. In intensive poultry rearing systems young fattening turkeys and laying hens are usually the most affected species.
Free-living birds may carry influenza viruses without becoming ill due to a natural resistance. It is known that wild waterfowl present a natural reservoir for these viruses and can be responsible for the primary introduction of infection into domestic poultry.
The virus causing avian influenza is an Influenzavirus A virus of the family Orthomyxoviridae. Several virus subtypes exist, which are divided on the bases of the antigenic relationships in the virus glycoproteins haemoagglutinin (H) and neuraminidase (N). At present 15 H subtypes have been recognised (H1-H15) and nine neuraminidase subtypes (N1- N9).
Influenza A viruses infecting poultry can also be divided on the basis of their pathogenicity (ability to cause disease).
The very virulent viruses cause highly pathogenic avian influenza (HPAI) with mortality in poultry as high as 100%. In the whole world there have been only 19 reported primary isolates of such viruses from domestic poultry since 1959. A severe epidemic occurred in Italy in 1999/2000 causing 413 outbreaks with 16 Million birds affected.
Other AI viruses cause a much milder disease (low pathogenic avian influenza, LPAI). Clinical signs are much less evident or even absent and mortality is much lower.
Sometimes secondary infections or environmental conditions may cause exacerbation of LPAI infections leading to more serious disease. Evidence suggests that certain avian influenza virus subtypes of low pathogenicity may, after circulation for some time in a poultry population, mutate into highly pathogenic virus strains.
To date only viruses of H5 and H7 subtype have been shown to cause HPAI in susceptible species, but not all H5 and H7 viruses are highly pathogenic.
The main symptoms of HPAI in poultry are depression, loss of appetite, cessation of egg laying, nervous signs, swelling and blue discoloration of combs and wattles due to disturbance of blood circulation, coughing, sneezing and diarrhoea. Sudden death can occur without any previous signs. The mortality rate may reach up to 100% depending on the species, their age, the virus type involved and environmental factors like concurrent bacterial infections.
Clinical signs of LPAI consist primarily of mild respiratory disease, depression and drop in egg production in laying birds.
The incubation periods for these viruses range from as short as a few hours to 3 days in individual birds and up to 14 days to spread throughout a flock.
Transmission and spread
All the available evidence suggests that the most common primary introduction of AI viruses into an area is by wild birds, usually waterfowl, but gulls and shorebirds have also been implicated. Direct contact between wild bird and poultry is not always necessary for introduction of virus into poultry farms, as infected waterfowl may spread AI viruses by infective faeces into an area and these may then be introduced to poultry farms by a variety of mechanisms that may transfer the virus mechanically. If contaminated with influenza viruses, surface water used as drinking water may also be a source of infection. Poultry kept in free range or poultry which have access to surface water are at specific risk. AI is transmitted within a farm by direct contact of infected animals with healthy animals, or indirect contacts with contaminated equipment or farm staff.
Spread of AI viruses from farm to farm is mainly by mechanical transfer of infective faeces, in which virus may be present at high concentrations and may survive for considerable periods. Shared water or food may also become contaminated.
However, man is a very important cause of secondary spread of AI for domestic poultry. Caretakers, farmers, workers, trucks and drivers visiting farms, moving birds or delivering food have caused the spread of AI virus both on to and within farms.
Legislation and basic disease control measures
The O.I.E (Office International des Epizooties, the World Organisation for Animal Health) has classified HPAI as a “list A” disease, signifying a rapidly spreading animal disease of major economic importance, such as Foot and mouth disease or classical swine fever.
EU legislation to control avian influenza is laid down in Council Directive 92/40/EEC. All suspected cases of AI must be investigated and appropriate measures taken in case of confirmation of HPAI. To limit the spread, infected poultry must be killed in a humane way and disposed off safely. Feedingstuffs, contaminated equipment and manure must be destroyed or treated to inactivate the virus.
To prevent further spread of disease the veterinary authorities are required to immediately put in place movement restrictions on the affected holdings and on all farms in a radius of at least 10-km around these holdings, the so called surveillance zone. If necessary, stamping-out measures can also be extended to poultry farms in the vicinity of or which have had dangerous contacts with infected farms.
In accordance with Community legislation, all Member States have AI contingency plans in place to ensure that the most appropriate measures are immediately implemented.
At farm level preventive hygienic measures such as cleaning and disinfection are crucial. Disease awareness amongst farmers and cooperation by all people in the poultry sector must ensure that the strictest biosecurity measures are applied to prevent disease spread.
The existence of a large number of virus subtypes together with the known variation of different strains within a subtype pose serious problems when selecting strains to produce influenza vaccines and to use vaccination as a routine tool for disease prevention.
In accordance with Directive 92/40/EEC, vaccination against AI may be used to supplement the control measures carried out after confirmation of disease. Birds vaccinated against the HA subtype corresponding to the one which is circulating are protected against the worst effects of AI. The decision to introduce vaccination may be taken by the Member State concerned, with or without prior approval by the Commission. Such steps must be accompanied by further disease control measures, including trade restrictions, in accordance with the Standing Committee procedures(1). Following confirmation of LPAI, vaccination against AI is currently being applied in some regions of Italy, pursuant to Commission Decision 2002/975/EC(2). This vaccination strategy developed and applied in Italy makes use of a heterologous vaccine, allowing discrimination between vaccinated and infected poultry(3). This strategy was adopted for the first time in the world in 2001 by Commission Decision 2001/847/EC(4) and allowed certain trade restrictions on the meat of vaccinated poultry to be lifted.
However, the immunity induced by vaccination may not be sufficiently rapid to stop farm-to-farm spread of HPAI. Furthermore, emergency vaccination is also hindered by practical difficulties related to the administration of the vaccine (each single bird must be injected).
|1 Certain specific disease control measures may be taken by the Commission, following a debate in the Standing Committee for the Food Chain and Animal Health, which includes representatives of all Member States.|
2 Commission Decision 2002/975/EC of 12 December 2002 on introducing vaccination to supplement the measures to control infections with low pathogenic avian influenza in Italy and on specific movement control measures, Official Journal L 337, 13.12.2002, p 87.
3 The vaccine is prepared with a virus strain which has the same H type of the field virus circulating in the area, but with a different N type. The vaccinated birds are protected against the field virus but they produce antibodies against a different neuraminidase. A serological test may then allow discrimination.
4 Commission Decision 2001/847/EC amending for the third time Decision 2000/721/EC to modify the Italian avian influenza vaccination programme and current trade restrictions for fresh meat originating from vaccinated turkeys Official Journal L 315, 1.12.2001, p 61.
Potential threat to human health
The human population all over the world is continuously affected by epidemic waves of Influenza due to virus strains of human origin, causing mainly respiratory infections which may be particularly serious in the young and elderly people and in the immuno-depressed individuals. Vaccines are available and their use is recommended for at-risk groups.
However, influenza viruses of avian origin may also be occasionally responsible for disease in humans. In recent years three different subtypes of avian influenza virus have been detected on five occasions in humans, causing disease of varying degrees of seriousness. In all cases the avian influenza viruses have shown a very limited tendency to spread in the human population (the spread was self-limiting).
In 1996, a H7N7 virus of avian origin was isolated in England from the eye of a woman with conjunctivitis who kept ducks. In March 1999 two independent isolations of influenza virus subtype H9N2 were made from girls aged one and four who recovered from flu-like illnesses in Hong Kong. Subsequently, five isolations of H9N2 virus from humans on mainland China in August 1998 were reported.
The most serious case occurred in May 1997 in Hong Kong. A virus of H5N1 subtype was isolated from a young child who died in Hong Kong and by December 1997 the same virus was confirmed by isolation to have infected 18 people, six of whom died. There was evidence of very limited human to human spread of this virus, but the efficiency of transmission amongst humans was extremely low. In February, 2003 a new transmission of avian influenza virus subtype H5N1 to humans was reported in Hong Kong, infecting 4 people of one family, two of whom died. In Europe several cases of avian influenza have been identified, but they have never had any human consequences.
The exact mode of transmission of these viruses to humans is not known. In this context, surveillance for influenza viruses in humans and animals is relevant for both human and animal health. The disease requires a high level of preparedness, both at national and at Community level. The Commission has identified influenza as a priority area within the Community Network for Communicable Diseases. A disease surveillance network is in place under the decision 2119/98/EC (EISS: European Influenza Surveillance Scheme) to monitor virological and clinical data concerning influenza in 18 European countries. These activities are carried out in collaboration with the other existing surveillance networks, including those co-ordinated by WHO.