The Comeback of Bird Flu
Srabonti Narmeen Ali and Hana Shams Ahmed
Photo: Zahedul I. Khan
As reports of chickens and other birds dying of bird flu or suspected bird flu keep coming in it is normal for people to respond with fear. But fear, without taking any practical steps, can only spell disaster for a country where thousands of people are dependent on the poultry industry and millions of lives are at risk.
In the context of the dangerously increasing number of avian influenza (more commonly known as bird flu) cases all over Bangladesh, the most threatening piece of information is the possibility of the virus mutating so that it can be transferred from human to human. Bird flu has been a recurring threat in Bangladesh and its neighbouring nations. The problem, however, is that a wave of the disease suddenly hits the nation and then, just as suddenly it goes away, resulting in everyone believing that the problem has either been solved, or has gone away.
Unfortunately for us, the bird flu crisis did not disappear. Like most other types of influenza, bird flu is more common during the winter, when there is less sunlight. According to Zeeshan Hasan, Director of Kazi Farms, “The basic thing is that the disease is naturally destroyed by sunlight. It disappears even if you do nothing as long as it gets warmer. We only see evidence of the outbreaks when it gets cold, but that doesn't mean that the disease is not there when it is warm.”
Hasan, like many more of his counterparts in the poultry industry, does not believe that proper precautions are being taken to prevent outbreaks of bird flu. The government, in order to prevent further outbreaks, is using the culling method, in which they kill the affected birds and destroy the farm in question. According to Dr. Muhammad Salehuddin Khan, Director of Animal Health Administration, “Any poultry farm within a 10 kilometre radius of the affected farm. It is important for everyone, especially all the farmers, to cooperate and comply with the prevention strategy that the government has come up with.”
Until recently, many poultry farmers were not getting ample compensation for the destruction of their farms. Bird flu has caused more than just panic among the people, but has also destroyed the livelihood of thousands of people
Unfortunately most farmers will not cooperate with the government until they are given compensation for their losses. After all, if a farmer's entire livelihood is based on the farm, far be it for them to readily cooperate with the process of destroying it. Until recently, the rule was that any farm with 5000 or less chickens would receive compensation, while the bigger farms would not. However, last week, the government announced that it would provide compensation to all the farmers, regardless of how big or small their farms are.
Even with compensation for their destroyed farms, however, people in the poultry industry does not necessarily agree that culling chickens is the best way to tackle the spreading of the disease.
“First of all, the government is culling chickens based on the assumption that this disease is foreign and that the cases of bird flu are isolated incidents, which have to be contained within the affected areas,” says Hasan. “They are assuming that it is not a domestic disease. The strategy of culling failed in Thailand and Malaysia and it is no longer possible to eliminate this disease.”
Similarly Dr. Rafiqul Haque, Poultry Consultant and Proprietor of the Poultry Consultant and Development Services believes that this “stamping out system is almost nearly impossible to maintain, especially because the plan takes about two to three days to put into action and by that time, the disease has already spread elsewhere.”
Haque goes on to say that the bird flu crisis has become a serious problem for the poultry industry, striking a huge blow which may not be retractable. “About 50 percent of our parent-stock farms have gone out of production. The selling price per chick has gone down from Tk. 20 to Tk 5-6. In addition the government was not, until recently, providing ample compensation for those farmers that have to destroy their farms.”
Hasan agrees that the production of poultry was half of what it was a year ago. “Before, seven million chickens were produced every week, and now the number has gone down to four million and it will keep on reducing,” he says. “This is a big disaster for the industry and the reason that the collapse has happened is that people are consuming less chicken and also that the farmers are not keeping chicken. It's okay for the bigger companies because they are able to invest in other industries, but the smaller farms have no other source of livelihood. The industry and the farmers are terrified because regardless of whether their farms are safe, if the farms in their area are affected there is a high chance that their farms will also be destroyed as well, just because they had the bad luck to be in that area.”
Haque predicts that sooner or later, these small farms and the open houses will no longer be allowed because they cannot be maintained, especially if the government enforces biosecurity regulations for all the poultry farms in the country. “These small farms do not have the facilities and the consultation to be able to realise how to manage disease control,” says Haque.
Biosecurity, or the concept of a controlled environment house, will ensure that a highly protected environment will be maintained, “in which people will have to disinfect themselves by showering and changing before both entering and leaving the farm areas. In addition the farm will have to have dedicated rickshaws and even bags for the sole use of that particular farm,” says Hasan. “It's a very expensive process which the breeders can afford but the smaller farms cannot manage to do.”
Biosecurity is not the only way to avoid the disease from spreading, according to Hasan. The government could also approve the use of vaccinations for the decrease of the disease. “It's not possible to completely eliminate this virus but we can mitigate it by vaccinating the bird. Most poultry farms already have standard procedures of vaccinating for other diseases for chickens such as Gumbaro and Newcastle disease. It would end up reducing the risk of spreading and also protect our farm workers.”
Haque also agrees that since it is becoming difficult to control the virus by culling chickens that the industry should find an alternative option such as vaccination. “Pakistan has detected four to five strains of the virus and has made four different strains of the vaccine,” he says. “The problem is that it is not a vaccine that you just administer once. Rather there are at least 11-12 shots per bird. If we import this vaccine from abroad it becomes impractical and also expensive. The government should work towards developing a local vaccine which will be sold at a local rate.”
Wastes from infected fowls need to be disposed of properly so that other birds and animals do not contract the views
The government, however, does not agree that vaccination is a viable option for eradicating this dangerous virus. “There are 16 different strains of this virus,” says Khan. “And there have not been any cases where the vaccination of these birds were 100% successful or effective, be it Pakistan or Thailand or Malaysia. Another problem is that we might make the situation even worse. Right now the virus only passes on from bird to bird and sometimes, in the case of the people working in the farms or the wet markets, bird to human. There is a chance that when we vaccinate the birds we may unknowingly create a mutated strain which then makes the virus transferable from human to human.”
Contrary to popular belief deshi (non-farm) chickens may be just as vulnerable to the disease. Many farms are breeding the sonali chicken, which is a farm chicken grown to look like a deshi chicken. In addition, in many cases deshi chickens have a high immunity against the virus, but they can still be carriers. The virus, moreover, has been recently found in other birds such as ducks and crows, which is a dangerous sign. And it's not just one random incident. Over 400 crows have died in Dinajpur in two days, there are reports of crows lying dead in different places in Chittagong and over one hundred of them in the city's Dewanhat area. The reason for their death is unknown but suspected to be bird flu.
One of the deadliest flu epidemics in recent history was the Spanish Flu which killed more than 50 million people around the world from March 1918 to June 1920. It was caused by the unusually severe and deadly Influenza A virus strain of subtype H1N1. Although it was earlier believed that the virus was spread from poultry to humans through swine, some researchers have found evidence that suggests that it jumped directly from birds to humans, without initially travelling through swine. So far no humans have been known to have been affected by it in this part of the region and although 26 people were quarantined in West Bengal, in a state affected by bird flu after they fell sick while culling poultry. They were later released after check ups. So what are the chances of having this virus spread to humans? It's very hard to tell. But nothing should be taken for granted, least of all a potential pandemic in one of the most populated countries in the world.
Dr. Mohammad Manjurul Karim, Associate Professor of the Microbiology Department at Dhaka University has done an extensive research on avian influenza and concludes that there is no reason to panic right now. He points out that chicken are being randomly killed around the country but it's very important to verify whether they have bird flu or any other disease.
Karim explains that the strain or form of the virus in a bird is different from the one in humans. The strain of the virus that is now in circulation can only affect birds and animals. “At the molecular level we have discovered that the properties required to affect poultry are not the same as the properties required to affect humans,” says Karim, “so the question is how the host can break this barrier which can only be brought about through a process of genetic mutation.”
Culling chicken randomly is not the only way to control the spread of bird flu
This, Karim explains, is a completely natural process. If it gains sufficient adaptability then it will affect humans. “We, (scientists), cannot predict it,” says Karim, “but we have not yet reached a stage where we should start panicking.”
Karim points out that although the human strain was found in Cambodia, Thailand, China and Vietnam, in the recent past the total death toll from all these countries was about 180 which does not really qualify it to be called an epidemic. But Intakhar Ahmad, a Masters student of the Microbiology Department of Dhaka University who has also studied extensively on bird flu points out, that Bangladesh is a very densely populated country and the fact that people are very inattentive towards hygiene and most are malnourished with a weak immune system means that if this flu virus were to mutate it will spell disaster for this country.
Whether humans are vulnerable or not in practical terms it will do everyone good in the long run to practice extreme caution. “It is essential that everyone remembers to keep their hands clean at all times,” says Ahmad, “when handling fowls it's very important that masks and goggles are used as the virus can enter through the conjunctiva (the thin, transparent tissue that covers the outer surface of the eye).” This is especially important for those working in the poultry farms. The feed and water provided to the fowls are usually done with machines in other countries but in Bangladesh they are done by hand. The chickens culled out of the suspicion that they have bird flu need to be buried in such a way that they cannot be dug up by other animals and consumed. The flu would just then pass on to other animals. Ahmad also says that salt water is a great neutraliser and everyone handling fowls should wash their hands and the birds with saline water.
Karim also points out that boiled food is always safe to eat. “In fact the virus cannot withstand a temperature beyond 60 degrees Celsius,” he says. Many consumers have stopped eating eggs for fear of getting afflicted with bird flu. Karim says that it is very unnecessary. “The virus cannot pervade the shell, it works like a barrier,” he says. But if one wants to be extra careful, it is better to eat it boiled during this period of panic. Washing the eggs with salt water is also a sensible precaution.
Extreme caution needs to be maintained by poultry farm workers
as well as buyers so that the disease does not spread to humans
Both Karim and Ahmad are of the opinion that vaccines for birds will be of no use. Each avian influenza type A contains one of the 16 subtypes of haemagglutinin (HA) and nine neuraminidases (NA). So theoretically speaking 144 subtypes may exist although only the H1N1, H2N2 and H3N2 subtypes have been documented for past pandemics in humans. “Although there are vaccines available, its effectiveness is subject to suspicion,” says Karim, “because when it changes its genetic make-up it gets a newer appearance.” That would make the vaccine useless. The other fear, Ahmad points out, is that if the vaccine is pushed into an already affected chicken, then it will just help the virus mutate and the vaccine will become redundant.
“If we are to make a vaccine for humans we need humans to be affected,” says Karim, “after that the strain can be isolated and the haemagglutinin protein targeted. But there have been no human casualties in this region yet, so we can conclude that a threatening strain has not developed yet. And it's only after an affected human being is found that the drugs that are available can be tested and verified as to whether they are effective or not. If it's not then we will have to design a new drug.”
Dead crows are being randomly found in places all over the country creating panic among the public
Ahmad points out that symptoms of Avian Influenza overlap with the symptoms of the common cold. Coughing and fever are the common symptoms. But with bird flu there might be diarrhoea, meningitis, breathing difficulty and conjunctivitis. The bad news is that the drug treatment can only work if it is detected within 48 hours of the virus attacking the body. Influenza is worse in the winter because there is so little sunlight that produces a vitamin D deficiency in human bodies. Activated vitamin D has profound effects on human immunity. Our body's innate immunity, especially the production of natural antibiotics also goes up and down every year with our vitamin D levels.
Dr. Mohammad Manjurul Karim is at the moment working on a developing a new kind of vaccination that will be target the inherent properties of the avian influenza virus. “We are progressing with the idea that no matter how much an organism alters itself it has some basic properties that cannot be altered which is called the conserved region in the genetic sequence,” says Karim. “We want to create a vaccine strain targeting these conserved regions but unfortunately we do not have that infrastructure or financial backing in our country to do that. We have the blueprint of the virus in our hands, from there we have been able to isolate those conserved regions that are not alterable. And targeting those conserved regions we can develop an antibody or a vaccine which can neutralise or cripple the strain no matter what changes the virus brings to itself.”
Epidemics, whether in animals or humans, ultimately boil down to the lack of awareness and hygiene. The crowded conditions that exist in poultry farms in Bangladesh are the perfect condition for any virus to spread. It is very important for the poultry industry to change its practices. Poultry should be raised in smaller scale, under less stressful, less crowded and more hygienic conditions with outdoor access. Deforestation destroys the natural habitat of birds and makes them more likely to come into contact with domestic animals thereby widening its range of hosts. Consumers too, must always practice hygiene in all aspects of their lives.
|The production of chickens per week has been reduced by half -- from seven million to four million. Where the selling price of a chick was originally Tk. 20, it is now Tk. 5
||The government and the poultry industry are both trying to introduce the concept of biosecurity for farms so as to reduce the risk of the virus spreading. Unfortunately it is a very expensive process and many of the smaller farms will not be able to survive as a result.
Bird flu has spread to 13 of West Bengal's 19 districts resulting in the culling of more than 50,000 birds, spelling trouble for parts of India's poultry business. The poultry market in Bangladesh also faces a considerable amount of trouble. Price of chicken has already gone down by more than Tk 10 and many overcautious consumers have simply stopped buying chicken. Awareness and taking precautions will not only save the poultry market from a disaster but also keep consumers safe and avoid a human outbreak.
(R) thedailystar.net 2008