A Look at the Global Bird Flu Outbreak

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The Flu Spreads Rapidly

The current US outbreak of avian influenza(AI) can trace its origins to Asia. In early 2014, a flu strain known as H5N8 was discovered in Korea, China, and Japan. And thanks to the wide migratory scope of wild birds, the disease spread as far as India, Europe, Canada, and the US. Once the virus landed in North America, it began to mix with regional strains to form new varieties of influenza.

All avian influenzas are classified by the combination of two different proteins within the virus. Hemagglutinin, which represents the “H” in flu strain names, seeks out, binds to and attacks cells. Neuraminidase, which represents the “N”, assists in the release of viruses from hosts and the spread of the virus. There are 18 hemagglutinin subtypes and 11 neuraminidase subtypes, and the types of cells that a virus attacks and the severity of the attack will depend on the types of “H” and “N” proteins present as well as the immunities of the target.

Viruses are also classified by their pathogenicity, or their ability to cause severe disease, which is determined by the particular virus’ genetic makeup. Low pathogenicity avian influenza (LPAI), which is usually considered un-harmful to human health, may not cause any symptoms in infected birds and often dies off on its own. Such strains are relatively common around the world, including in North America. High pathogenicity flu (HPAI), however, spreads very quickly and is often fatal to birds. Many of the world’s recent HPAI strains have originated in East Asia.

When H5N8 landed in North America, it spread to several states before its hemagglutinin proteins began to combine with North American neuraminidase proteins, creating two new strains of the virus with mixed origins: H5N1 and H5N2. The effect of H5N1 strain has been minimal and luckily, it differs from the H5N2 strain which has affected large parts of Asia, Europe, and Africa. The new H5N2 strain has been known to cause human fatalities and has caused the vast majority of infections in the current outbreak.

Cracks in the Egg Market

Since the highly pathogenic H5N8 strain of AI was discovered in Oregon on December 19, 2014, 46.7 million chickens and turkeys have died or been culled due to exposure to the virus. Before this, the US’s worst ever AI outbreak occurred in 1983-84 when 17 million birds died, which had a total market cost of more than $975 million. The current outbreak, which has already killed almost three times as many birds as the 1983-84 epidemic, promises to have an even more damaging effect on the US poultry industry.

Egg producers have been hit particularly hard by this year’s plague, as the majority of birds affected by the virus are egg-laying hens. More than 10 percent of all American hens have been killed by the virus. As a result, consumer- grade egg prices have doubled in the past month, reaching their highest levels since records began in 1858.

The effects are being felt both by industry players and household consumers. Manufacturers of processed food products have been unable to source enough eggs from the liquid breaker (pre-broken eggs) sector and instead have sourced their inputs from the “shell” (consumer) sector. Even fast-food giants, such as San Antonio-based Whataburger, are feeling the pinch. Since the chain’s main egg supplier shut operations, the chain has had to restrict its egg-heavy breakfast menu to peak hours at all of its 770-plus locations.

But some market players, have benefitted. Cal-Maine, the country’s largest egg producer, has thus far been able to keep its farms free from infection and as a result, the value of the company’s stock has risen 50 percent over the past three months. For the industry as whole, once the virus has been halted, it will take 18-24 months for the number of laying hens to reach previous levels.

Importers Taking Flight

Industry members are deeply concerned over the potential poultry and poultry-product export losses. Before the outbreak, the US exported more than $5.7 billion worth of poultry and egg products each year, and these exports accounted for 20 percent of total chicken production and 14 percent of turkey production.

But now bans on American poultry, which were instituted the first day after the discovery of AI in December, are ensuring that the quantity and value of poultry product exports will be lower this year. The USA Poultry and Egg Export Council estimates that AI-related trade restrictions have already cost the US close to $600 million in export losses in the first quarter of this year alone. Bans from China, South Korea, and South Africa will be responsible for losses of up to $430 million a year. Limited bans have also been instituted by Mexico and Canada, the two biggest destinations for American poultry.

Protecting these multi-billion dollar trade relationships is one of the primary reasons the US has been reluctant to adopt a potential AI protection strategy: vaccination. The United States Department of Agriculture (USDA) has always viewed vaccinating flocks as a last resort option since many countries, including key trade partners, have threatened to institute complete bans on American poultry if vaccinations are distributed. When vaccinations are administered, antibodies are produced in the poultry which make it difficult to distinguish whether the bird has been vaccinated or infected. There are also concerns that inoculated birds could still carry the virus while appearing to be healthy, and therefore easily pass on the disease to healthy birds.

Due to the severity of the outbreak, the USDA has also considered deploying a vaccine to the areas with particularly high numbers of cases. However, it was determined by early June that current vaccines only provide protection for around 60 percent of chickens, and therefore were not effective enough to be deployed, especially considering the potential trade restrictions that would be instituted as a result.

Eradication and Prevention Measures

With vaccinations largely ruled out, the USDA has boiled down its AI response into five steps: quarantine, eradicate, monitor, disinfect, and test. In this approach, as soon as a new outbreak of AI is identified the infected premises are quarantined, and movement controls and surveillance activities are carried out in an area designated as the infected zone (three kilometers beyond the infected premises) and the buffer zone (seven kilometers beyond the infected zone). Then all affected birds are culled, which is how the vast majority of birds died in this present outbreak. After identified flocks have been eradicated, domestic and wild birds around the quarantine zone are tested for the virus. If these results come back positive, then the USDA will disinfect areas where the affected flocks were identified. Finally, facilities are thoroughly tested to ensure the virus is no longer present.

In addition to these immediate, reactive steps, the USDA also regularly conducts surveillance of live bird markets, commercial and backyard flocks, slaughter plants, and migratory bird populations. Globally, the USDA works with the World Organization for Animal Health (OIE), the United Nations (UN) Food and Agriculture Organization (FAO), and the World Health Organization (WHO) to assist in preventing the global spread of the virus.

The USDA has also paid more than $160 million in indemnity payments for producers that have been affected by the current outbreak.

The US response to avian influenza is somewhat fragmented and involves multiple players at the industry, federal, and state levels. While the USDA’s guidelines instruct how to properly respond to a potential outbreak, it is not the USDA alone that responds. For example, in Minnesota, after flock owners recognizes signs of illness, he or she will first notify their veterinarians or health officials. Samples will then be collected and sent to the state laboratory. If samples test positive for H5 or H7 AI, the samples will be sent to the National Veterinary Services Laboratory (NVSL) in Iowa. The NVSL is the only laboratory in the US that is allowed to officially confirm the presence of HPAI. If the NVSL confirms the presence of HPAI, only then will the USDA inform the public with an online announcement.

Iowa is the state hardest hit by the current outbreak to date. The USDA has had to send in staff from out of state, but many argue that the resources are inadequate. There have been shortages of the necessary equipment required to humanely kill all of the potentially infected birds, and producers have to wait days to cull flocks while the infection continues to spread. Even after the birds have been eradicated, many producers complain that the USDA is not clear in its guidelines on how long farmers must wait before production can resume.

The private sector has also been stepping up biosecurity measures in response to the outbreak, especially after the culling of 3.8 million laying hens at an Iowan egg facility that had relatively robust measures in place. Many poultry operations now require employees to shower before and after entering a farm, intensively sanitize vehicles and equipment, and bar the entry of postal workers and other unnecessary visitors. These are extreme but necessary measures, as the virus can spread easily. Infected wild birds can spread the virus as they drop their feces while flying over farms and even pieces of dust containing the flu could infect a flock if blown in by a gust of wind.

And while many farms are seriously and successfully ramping up their security, others are failing to do so with the thoroughness and precision necessary. A Reuters investigative team, through spot checks it carried out, claimed to have found that some Iowan farms where failing to enact and perform all of the necessary measures to prevent further spread of the disease. According to the Reuters team, those performing security procedures at the state’s farms failed to give workers protective gear, to disinfect vehicle wheels, and to adequately restrict outsider access.

AI Around the World

The ongoing outbreak in the US is not the first instance of widespread damage to poultry flocks from influenza. Highly pathogenic AI has been noted as far back as the 1870s. The most devastating outbreak of AI occurred in 2003-2005 when the disease spread to more than 50 countries across Asia, Africa, and Europe. Asia was the hardest hit by the outbreak and more than 220 million birds died at a cost of more than $11 billion.

H5N1, the strain of flu that caused that outbreak, spread far more quickly and widely quickly and widely than the current outbreak in the US. The first case of H5N1 in poultry was reported in Korea on December 12, 2003. Within a month and a half, the virus had been identified in Thailand, Vietnam, Japan, Cambodia, Laos, Indonesia, and China. By March 2004, over 100 million birds had already died or been culled. In response to the $11 billion loss that Asian farmers suffered, over $3.6 billion dollars were raised by the end of 2006 from a variety of international donors to help the fight the spread of H5N1.

In addition to the massive economic and industrial damage that H5N1 wrought, that particular strain of influenza was even more troubling because it was transmissible to humans. By August 2006, at least 238 cases of H5N1 had been detected in people, resulting in 139 deaths. If the strain had been capable of spreading to and infecting humans at a pandemic level, the cost would have been close to $2 trillion.

Luckily H5N1 did not cause a global human pandemic, and the spread of the disease eventually slowed. By looking at the experiences of countries that suffered from the outbreak of H5N1, it is possible to develop a frame of reference for the current situation in the US as well as identify what may help prevent and limit future outbreaks.

Vietnam: Culling and Vaccinating

H5N1 hit Vietnam hard. At the peak of the outbreak, the virus was present in 60 percent of towns and required the culling of more than 50 million birds. The country also suffered from the highest number of human cases, as 93 infections caused 42 deaths by mid-2006. The outbreak eventually slowed and then halted for almost a full year. Vietnam did not report a single new case of H5N1 in domestic poultry from December 2005 until one year later.

The outbreak was stopped in large part by resorting to conventional control methods like those that are currently being deployed in the US. Infected and at-risk flocks were culled, farm-level biosecurity measures were increased, and the movement of poultry was strictly controlled. Reporting sick birds could result in the culling of flocks, a massive and usually unbearable cost to farmers. In order to increase the likelihood that farmers would report illness in their flocks, the government increased the compensation that farmers would receive for culled animals from 10 to 50 percent of market value between 2004 and 2005.

Another drastic step that Vietnam took to curb the outbreak was a nationwide vaccination campaign. Between October 2005 and January 2006, roughly 170 million chickens and 76 million ducks were inoculated against the virus. The decision to use vaccines was much easier for Vietnam, as the country exports almost no poultry products and is therefore unaffected by international bans. While the US has close to $6 billion in international poultry and egg trade annually, Vietnam only registered $1.42 million of chicken meat exports between 2000 and 2012. All of these measures contributed to Vietnam’s successful halt of AI.

But while the Southeast Asian country was able to stop the spread of H5N1 for an entire year, the virus made a comeback in December 2006 and outbreaks became widespread in the southern parts of the country. Vietnam has reported presence of H5N1 in domestic poultry every year since.

These subsequent outbreaks have been smaller in scale. Vietnam is at a particularly high risk for HPAI because 60-70 percent of poultry are raised in backyard family farms and in close proximity to other birds. There are also lax farm management practices, live bird shows, and a poor understanding of the disease. In its hopes to stop the spread of the disease, Vietnam has continued to routinely administer vaccinations, especially to smallholder and village poultry producers. This has likely reduced the number of birds which are susceptible to the disease while also minimizing the costs of an outbreak.

Japan: Swift Action and Strong Monitoring

Japan reported its first case of H5N1 in domestic poultry flocks on January 12, 2004, just four days after Vietnam’s. This was the first of four cases to be identified in Japan at the beginning of 2004 and was the first occurrence of HPAI in the country since 1925. At the time, Japan had a much larger stock of live chickens than Vietnam—283 million compared to 178 million. But while HPAI went on to devastate Vietnam for almost two years, Japan eradicated the outbreak within three and a half months.

A key factor to Japan’s rapid success was just that: speed. Japan has 178 Livestock Hygiene Service Centers (LHSC) spread over its 47 prefectures (provinces), and as soon as one of these centers received a report about a possible outbreak veterinary officers were immediately deployed to assess the situation. If an outbreak of H5 or H7 AI was suspected, the process of eradicating infected poultry was carried out as quickly as possible. This applied to H5 and H7 strains regardless of their pathogenicity. This process is still in place today.

In addition to identification, the LHSCs are responsible for eradicating, restricting poultry movement, and conducting surveillance. This infrastructure allows for a quick response time regardless of where in the country an outbreak might occur.

In addition to effective and rapid implementation of culling, containment, and movement control measures, Japanese authorities also carried out epidemiological tracing to identify the movement of infected poultry so they could shut down slaughterhouses where infected birds had been sent. Information sharing with farmers also allowed the private sector to implement their own controls. To further increase cooperation with farmers, Japan increased penalties for delays in reporting incidents of disease, and reimburses farmers 80 percent of the value of culled poultry.

Following the 2004 outbreak, HPAI did not make an appearance in Japan until 2007, and infrequent appearances of the virus have been reported since, including a large HPAI-free period from early 2011 until late 2014.


Other countries are unlikely to afford such a highly technical, nationwide network of disease control centers like Japan. Many recognize that if another influenza pandemic is to occur, it is likely to begin in developing countries as their public health and veterinary services tend to be poorer, vaccines and drugs less accessible, and disease control systems limited. But still, all nations can recognize the need to eradicate, control, and monitor outbreaks as quickly as possible.

Even countries that don’t have the same resources as Japan can follow the East Asian country’s example by taking other disease-prevention measures, such as banning or limiting the extent of live-bird shows. During outbreaks of AI in Hong Kong, the US, and Southeast Asia over the past 30 years, live-bird markets have acted as a distribution point for the disease. Japan does not have any commercial live-bird markets, and this has been recognized as an excellent disease prevention method.

But not just developing countries can stand to learn from Japan’s successes. The US has a similarly large budget available to handle the disease, making it apparent that its failures at containment were rooted in inefficiency and disorganization rather than a lack of funds. Changes to the system responsible for reporting and handling the disease could make the US more like Japan in its ability to quickly halt outbreaks. Avian influenza is unfortunately not a threat that will just go away. Influenza is a living virus that is constantly adapting and mixing with other strains all around the world. And wild birds that can spread AI to domestic flocks can be found in the skies in almost every corner of the globe.

The approach for preventing and limiting future outbreaks must take into account the best practices of countries such as Japan and the US. Identification, eradication, restriction of movements, disinfection, and monitoring are all essential, and emphasis must be placed on carrying out these steps with maximum speed and efficiency.

All countries would benefit from improved cooperation and a free flow of information with farmers. The quicker sick birds can be identified and farmers warned about possible contagion, the safer poultry flocks – and humans – will be.

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