Bird Flu: A Problem for Developing Nations Only?

BEIJING, Feb 20 (Newsmekong) - The alarms over bird flu have repeatedly been going off since the beginning of the New Year. Four Indonesians died in the first two weeks of 2007, Vietnam witnessed outbreaks spreading to eight provinces, Thailand set up a ‘war room’ for a 24-hour operation of monitoring and surveying the spread of the virus, and South Korea even sent out troops for quarantine and culling tasks. Meanwhile, China confirmed a human H5N1 case in the eastern province of Anhui. Hong Kong called for a ban on releasing birds in Buddhist rituals after dead birds in its territory tested positive for H5N1, and Japan says bird flu is back after 13 months.

It seems that the sparks of the bird flu are now becoming a prairie fire. “This H5N1 virus is causing unprecedented damage to the poultry sector, and along the way many people were infected, and more than half of these people died,” warns the director general of the World Health Organisation (WHO), Margaret Chan. “We must not let our guard down. We must maintain our vigilance.

The WHO website (www.who.int) carries weekly updated figures on human cases of bird flu. With a bit of analysis, these numbers suggest that the H5N1 virus is found more in developing countries, especially South-east Asia.

Animal outbreaks and human cases have occurred in more than 50 countries worldwide. Among the 267 human cases reported till Jan. 15, China, Indonesia, Thailand and Vietnam account for 82 percent of these, while Indonesia and Vietnam have reported two-thirds of the deaths.

In contrast, developed countries in Europe and North America are absent from the WHO table of statistics, which could suggest some linkage between bird flu and economic status. If we consider bird flu a development issue, a lot of evidence could be found in prevention and control practices.

SMUGGLING OF VACCINES

Thailand English-language daily ‘Bangkok Post’ reported on Jan. 7 that marine police arrested three Bangkok residents who tried to smuggle Chinese bird-flu vaccines. The police said it was not the first time the group had attempted this, adding that it had tracked the gang a month back. The report also underscored how poultry raisers in Thailand are vaccinating their birds with smuggled vaccines, despite the government’s prohibitions. This is hardly news, especially in the northern provinces, as I found out since I was on assignment in Chiang Mai to cover bird flu stories when the ‘Post’ published the vaccine smuggling story. I asked for a commentary from a senior public health official, but he preferred to be anonymous.

Vaccination itself is a subject of much debate. Some poultry raisers and experts believe that vaccination can prevent their birds from catching bird flu and dying from it. Yet, some virologists argue that vaccination would speed up virus mutations to a point that it triggers a pandemic. In real life, such a situation has happened -- vaccinated poultry do not show symptoms of the disease while carrying and disseminating the virus. According to the Chiang Mai public health official, bird flu vaccines are far from mature, and it is thus very difficult for health departments to trace the origin and routes of infection if vaccinated birds spread the virus. He believes that vaccination makes control and prevention efforts against the H5N1 virus more complicated. Vietnam uses a lot of vaccines, but had new outbreaks in its Mekong Delta region recently, he points out.

A check of Xinhua News Agency’s recent reports on bird flu in Vietnam showed claims by the Vietnamese government that outbreaks took place in poultry farms that did not vaccinate their birds. Xinhua also reports that Vietnam will import some 500 million doses of bird flu vaccines to vaccinate fowl in the 2007-2008 period.

For a better understanding of vaccination as a prevention strategy, I went to Cao Ping, senior veterinarian at Beijing Livestock Husbandry and Veterinary Station. Cao said that vaccination could control and even eliminate bird flu -- if used properly and correctly in the long run. It only takes some 50 days of feeding before chickens reach market size, and hens have to be eliminated after 500 days because of decreasing egg production.

So, even if vaccinated birds carry the virus and spread it, what is the amount of virus that they carry? What is the exact amount of the virus that vaccinated birds discharge? How long could the virus survive in the vaccinated birds? And, will the virus still be harmful after vaccination? All of these questions are very technical, and there are no single and simple answers. There is not much practical significance debating these questions, which will only result in more public fears or panic according to Cao.

International public health experts agree that thorough cooking kills the bird flu virus. According to WHO’s Chinese website, there is no evidence that humans can contract the virus with well-cooked poultry and poultry products, even if these have the H5N1 virus.

Further discussion of the vaccine issue leads to different control and prevention strategies between developing and developed countries. For developed countries, culling is their only choice; they do not use vaccines. But many developing countries, cannot afford the economic cost of culling. For them, a combination of, if not a compromise between, culling and vaccination is a more pragmatic option.

According to Cao, culling is the only option when bird flu hits poultry farms in the United States and the European Union. Some modern farms go as far as abandoning disease-hit houses and building news ones at different locations. Such strict measures can ensure that contagious animal diseases will not come back for a certain period of time.

Effective culling also depends heavily on compensation policies, which test governments’ financial resources. Cao referred to the British government’s compensation policy when the hoof-and- mouth disease hit the country in 2001. Affected farmers received compensation at rates higher than the market price of their infected livestock, and this led to the rapid and effective containment of the disease in its early stage. However, in the developing world, especially in South-east Asia where backyard poultry is so common and where governments usually face constraints in giving out generous compensation, it is difficult to fully implement culling.

TOUGH MEASURES

What happened in Indonesia recently can illustrate Cao’s arguments. Four people from Jakarta and its surroundings died of bird flu in the first two weeks of 2007. Residents of the Indonesian capital were ordered to get rid of backyard fowl by the end of January, or birds would be confiscated and destroyed. Jakarta’s governor Sutiyoso took these measures to stem a new flare-up in bird flu. Indonesia’s Public Health Minister also announced that such a ban on backyard poultry would gradually expand to the whole country. Yet many doubt the effectiveness of this ban. Compensation would only be paid out for birds confirmed as having bird flu at 12,500 rupiah (1.4 U.S. dollars) each, or about one third of the market price. As for healthy birds, owners could either sell or consume them before the ban comes into effect. Under this scenario, how could poultry owners be expected to cooperate with the government?

Indonesia has reported the highest number of human deaths from bird flu in the world. Most of the human infections come from close contact with sick birds. The ban on backyard poultry aims to change the traditional practice of daily contact between humans and birds. The government also calls for separating the living environments of humans and animals. But a change in lifestyle usually takes time.

Raising poultry, very popular in many developing countries, demands just a little initial investment and delivers relatively fast returns. For backyard poultry raisers, chicken and ducks around the houses is a stable and cheap source of protein and cash. But the bird flu is posing a challenge to many small-scale poultry raisers.

Take China for example. It raises more than 15 billion birds, which makes it the world’s number one poultry and egg producer. Sixty percent of poultry in China falls into the category of backyard and small-scale poultry. “This means more challenges for bird flu control and prevention efforts, which is still very tough at the moment,” said Li Jinxiang, Deputy Director of the Veterinary Bureau of the Ministry of Agriculture. It is very difficult for backyard poultry raisers to implement all the required control and prevention measures. This is why the Ministry of Agriculture is encouraging the establishment of poultry raising communities and large-scale poultry farms across the country. It will not only improve bird flu control and prevention effectiveness but also promote the quality of poultry products, according to Li.

In order to understand why large-scale poultry farms do better in the control and prevention of bird flu, I visited two modern farms near Beijing and Bangkok. The closed environment and strict biosecurity measures left a deep impression on me. I was also surprised at not being allowed to see even a single bird during each visit. Vehicles from outside are not allowed to enter the farms and every visitor has to go through a disinfection process. The Thai duck farm has a disinfection room right beside the entrance. The room is about five metres long, and disinfectant is sprayed all over. As I went through this room, all my clothes got wet. The Beijing chicken farm uses ultraviolet lamp, whose purple hue is really depressing.

BIOSECURITY MEASURES

After visitors underwent the disinfection procedure, the owner of Thai duck farm kept smiling and nodding at me, but did not show any intention of letting me see his birds. He led me to a white line about 30 metres away from where his ducks were housed and said, “Please take pictures”. The Beijing chicken farm owner was even more impressive. He told his staff: “Take the reporter to the monitor room!” It was only through the computer screen that I was able to peep into the chicken house.

The managers of the two farms admit that the threat of bird flu prompted them to implement these biosecurity measures more strictly. Even their own staff go through strict disinfection procedures to keep the virus away from the farm. The biosecurity system requires as few human-poultry contacts as possible, and this is why all the farms refuse visitors’ entry into the poultry houses.

Intensive poultry farming has advantages in animal disease control because disinfection and vaccination measures are easier to implement, according to Du Shousan, the veterinarian who accompanied me during the chicken farm visit near Beijing. Du also said that the closed environment is a natural barrier that keeps the viruses away from the birds inside, and that even fodder has to go through biosecurity checks. From the management and nutrition perspectives, intensive poultry raising means better lighting, ventilation, fodder and drinking facilities, which help improve the poultry quality. Du points out that poultry raised in an open environment is vulnerable for diseases because wild birds, fodder and humans may all be the source of infection. Backyard poultry raisers also may not be able to implement all the necessary measures for disease prevention, according to Du.

It seems that the threat of bird flu has had good effects when it comes to improving biosecurity measures in intensive poultry enterprises. However, small-scale farming and backyard poultry raising will continue in the foreseeable future, and this is the weak link in prevention and control efforts. China’s Ministry of Agriculture launches intensive vaccination campaigns every winter and spring in order to make sure that poultry raised in the traditional small-scale way are safe from animal diseases.

PREVENTION, CONTROL NOT SO EASY

I talked to a number of experts in order to better understand how difficult the bird flu control and prevention efforts may be. The senior public health official in Chiang Mai believes that it should have been very easy. The key, he says, lies in educating the farmers who should understand the basics of transmission routes and prevention knowledge. For example, these include knowledge about the separation of humans and poultry, wearing gloves when in contact with the poultry and washing hands afterwards, as well as the deep burial of infected birds. However, educating farmers scattered in the vast countryside turns out to be an arduous task. Some farmers deliberately flout the rule of burying infected poultry, and the chances of contracting the virus when slaughtering and preparing the birds for meals are still high. In Thailand, the government plans to educate primary schools pupils on how to live with bird flu.

The senior veterinarian at Beijing Livestock Husbandry and Veterinary Station, Cao Ping, agrees in theory with his Thai counterpart. He believes that the usually lower education levels of farmers prevents them from effectively implementing control and prevention measures – such as disinfection measures that should, if used properly, be the simplest and most effective method. But in practice, the farmers get confused about the exact dilution amount, and too little means futile work, while too much harms both humans and poultry. Cao also points out that some farmers think that spraying disinfectants randomly could do everything when this actually achieves nothing.

Cao also explained in theory why control and prevention proves to be very challenging. There are three key links in infectious animal diseases: the source, routes and vulnerable animals. Effective control of any of the three means elimination of the disease, but the reality is always very tough, if not impossible. The source is sometimes invisible, so how do you locate it? The transmission route is more troublesome. How can you control when the virus spreads in the air? Human can also host the virus. Poultry farms can say no to visitors, but their own workers are not 100 percent safe. This is why some farms demand that their staff not keep any birds at home. Finally, there is the vulnerable animal. Cao joked that you cannot ask poultry farms to get rid of all birds and raise horses to prevent bird flu.

Li Jinxiang, Deputy Director of the Veterinary Bureau of the Ministry of Agriculture, points out that it is tough to deal with wild birds that spread the virus. Migratory birds are a major source of bird flu infection, according to epidemiological research projects conducted by the Ministry of Agriculture and the Chinese Academy of Sciences. Li said that measures can be taken to ensure the separation of humans and poultry, but no one can guarantee that wild birds are virus-free. As long as wild birds carry the virus, they can have opportunities to infect poultry. When outbreaks in poultry take place, birds will excrete large amounts of the virus, and this will be very harmful to public health.

The recent outbreaks in Japan may provide some evidence for the argument that migratory birds are to blame for bird flu. Japan confirmed on Jan.13 that the H5N1 virus hit a poultry farm in the country’s south. A lot of wild ducks were near the farm, and the farm manager said that curtains were used to cover the chicken houses to prevent contact with wild birds. Japanese government officials told the press that wild birds carrying the virus might have dropped their excrement into the chicken houses through the seams of the curtains. If this proves to be true, it only illustrates how difficult bird flu control and prevention effort could be.

FEARS OF A HUMAN PANDEMIC

Fears that the H5N1 bird flu virus may mutate into a pandemic influenza strain that reaches humans have constantly haunted the world since the virus re-emerged in South-east Asia late 2003. How real is this possibility? Will humankind be caught off guard and suffer great casualty tolls if such possibility becomes real?

Influenza is a common infectious disease, so common that people ignore the horrible side of it. It kills 250,000 people worldwide every year. The influenza virus mutates every 20 years into a form that causes a wider pandemic and more damages. It is reasonable that U.N. bird flu coordinator David Nabarro always warns the international press that an animal and human flu pandemic will break out one day, although no one can predict the exact time. Some public health experts refer to the 1918-1919 Spanish flu to describe the severity of a global flu pandemic. The Spanish flu went through three waves, lasted two years and claimed the lives of tens of millions. What is even more horrible is that the virus that triggered the 1918 pandemic came from animals. This gives public health experts sufficient reason to worry that the current H5N1 virus might also mutate into a form that easily spreads among humans.

PREPARATIONS NEEDED

This is the largest infectious disease outbreak amongst animals we have ever experienced, unprecedented in the history of influenza,” Asia-Pacific Advisory Committee on Influenza (APACI) chairman Dr Lance Jennings said in an interview, explaining the relationship between bird flu outbreaks and a human influenza epidemic. “As long as this virus circulates amongst poultry populations globally and exposes humans, we will see ongoing human infections occurring.

Dr Jennings also said that the closeness between humans and animals in South-east Asia has facilitated the conditions that allow the merger of viruses, and that it is of particular importance that people, especially in the Asia-Pacific region, realise the seriousness of influenza. As for when a possible global pandemic will happen, Jennings’ words echoed Nabarro: “We can safely say that we will have a human influenza pandemic. We don’t know when and we don’t know how severe it is. ” Jennings also points out that there are a number of other human influenza viruses circulating that could become the next human pandemic virus, and that no one can predict whether the H5N1 virus will indeed turn out to be this. (APACI) met in Beijing a few months ago.)

Vaccines are the primary medical intervention for protecting people against pandemic influenza, but a human vaccine against H5N1 is not yet available at the moment. Vaccination is also a tricky issue and WHO does not yet have an official position on pre-pandemic vaccination.

First, vaccines work well when they match the circulating strain of flu. But the H5N1 strain has not evolved into a form that passes easily between humans. So there are questions on the effectiveness of the vaccines in research. Second, following this appoach everybody in the world should be vaccinated -- and this is obviously not practical. Even if there are enough financial resources, policymakers have to weigh the risk of immunising against a pandemic that may not happen. A similar lesson is provided by the 1976 swine flu scare in the United States. That year, millions of Americans were vaccinated against swine flu after an outbreak at a U.S. army base, but this never occurred -- and the vaccine was blamed for a rise in cases of a rare neurological illness.

Despite these shortcomings, vaccines remain the final solution to the problem. WHO gathered 120 public health experts and launched a plan in October 2006 to increase global flu vaccine capacity, which is expected to rise to 780 million doses by 2009. Even if the goal is met, the production capacity is still far short of what would be needed to fight a global pandemic. The plan could cost three to 10 billion U.S. dollars over the next decade. Preparations for a possible pandemic could lead to a huge waste of money and production facilities. Who will pay for the bills? For sure, the most vulnerable developing countries cannot afford this huge cost.

TREATMENT

Treatment is another option if vaccines fail. An Oxford research team studied the H5N1 virus in Ho Chi Minh City, Vietnam. Its study suggests that immediate treatment with antiviral drugs is crucial because the H5N1 virus reproduces so quickly that, if not suppressed within the first 48 hours, it tends to push victims to death. “The paradigm ‘hit hard and hit early’ probably is very true for H5N1”, said Menno de Jong, who leads the research.

However, similar questions with the vaccine issue emerge. Where are the anti-viral drugs? How would they be distributed in a pandemic? WHO warned the world of the possible pandemic three years ago, and urged every country to make emergency plans and stockpile drugs. But most antiviral manufacturers are in western Europe, and international donations may reduce sharply in case of an actual pandemic. It will be the developing countries that will not be able to get sufficient vaccines and antiviral drugs.

LOOKING AHEAD

Fortunately, the global influenza pandemic is still a possibility, instead of a reality. There is no evidence that the H5N1 virus has mutated into a form that could pass easily among humans. In the meantime, alarm bells are again sounding for the developing world. A study published in the renowned British medical journal ‘Lancet’ at the end of 2006 says that an influenza pandemic of the 1918 type would kill 62 million people today, with 96 percent of deaths occurring in developing countries. These findings do not surprise WHO’s key influenza expert Keiji Fukuda: “The countries most likely to be adversely affected are the ones with the least resources. This happened then, and is what is likely to happen now.”

(*Zhu Yan of CCTV wrote this story, published by ‘Nanfengchuang’ magazine in its Feb. 1, 2007 issue, under the Imaging Our Mekong media fellowship programme. The programme is coordinated by IPS Asia-Pacific and Probe Media Foundation Inc, with the support of the Rockefeller Foundation. Zhu Yan

(blog.cctv.com/zhuyan) translated this article from his Chinese version.)