PureInsight | November 28, 2005
Sound of Hope Radio: Our subject today is a very popular topic: the bird flu. For many, when they hear the words "bird flu," they become very fearful. Why is that? Because it is spreading not only in Asia but also in Europe via Russia. Many countries have taken or are contemplating measures to prevent bird flu.
In today's program, we'd first like to ask Dr. Lili Feng to tell us about bird flu. What is it? What is the H5N1 virus?
Dr. Lilli Feng: There are two ways to classify bird flu. This is just a general classification. There are more detailed categories.
The first way to classify it is to differentiate by the nucleoprotein and matrix proteins.
The nucleoprotein and matrix proteins allow influenza viruses to be classified as types: A, B and C. Subtype A can be further divided based on the surface protein: one is hemagglutinin and the other is neuraminidase. H stands for hemagglutinin and N for neuraminidase. These can then be subdivided into other categories. For example, H has 16 subtypes, and N has nine subtypes.
The hemagglutinin (H) is a very important protein that is related to virus proliferation and pathogenic ability. It can be categorized even further, based on whether the protease needed to activate it is distributed so the H can be cleaved in limited or widespread areas of the body, such as the lungs, small intestines or throughout the body. It could also be categorized according to whether the virus will cause regional or whole-body infections. The virus can also be categorized into highly pathogenic or less pathogenic according to its area of infection. Less pathogenic means that the infection is regional. Highly pathogenic viruses include the H5 type that people often hear about. Actually, both H5 and H7 are highly pathogenic viruses.
SOH: So the H5N1 type bird flu we often hear about is a highly pathogenic virus?
Dr. Feng: Yes. It can multiply in any part of the body, because every part of the body has the kind of protease needed to cleave it.
SOH: We have heard of bird flu before, but it didn't seem so scary in the past. For example, in the last century, I think bird flu occurred in Spain and caused a lot of deaths. The most recent research says that the type of flu in Spain was the same bird flu we have now.
Dr. Feng: This is not entirely accurate, although it's easy to make that mistake. In 1918, when the Spanish flu occurred, the lungs of most of those who died were completely destroyed. After very careful research, scientists found three people whose lungs remained relatively well and used a technology called polymerase chain reaction (PCR) to get the virus. Actually, the bird flu in Spain was not H5N1, but H1N1, a less pathogenic type of virus. I will talk about their differences. This was discussed in an article in Nature in 2004. It was very interesting. Its symptoms were similar to today's, but there were differences, too.
SOH: In other words, it was also bird flu, but of a different kind. It wasn't as bad as what we have now.
Dr. Feng: Yes, it was less pathogenic.
SOH: Yet a lot of people died back then.
Dr. Feng: Yes. There is also some confusion about this. A lot of people say that 20 million people died. Actually, the number could have reached 100 million. At that time, the world's population was 1.8 billion. Imagine what 100 million deaths must have felt like! Many magazines and newspaper did not record the details of what happened, but one book was very thorough, and I would recommend it. The book is titled Flu, and the author is Gina Kolata.
SOH: Actually, in China for decades we called bird flu "chicken plague." It was pretty common, especially in rural China. Why is it getting so much attention around the world?
Dr. Feng: Many experts have been studying the cycle of bird flu. Scientific research has found a few factors that can help us better understand the disease. First, the H1N1 virus that spread widely in 1918 was of low pathogenicity. Only enzymes in the lungs and intestines are able to cleave H1N1. But this year's H5N1 virus is of high pathogenicity. Also, the H1N1 virus was transferred from fowls to people through pigs; that's why it wasn't so severe. But the H5N1 virus this year can directly infect people. Although infections between humans have not yet occurred, and the virus has not mutated to spread among people, the situation is still severe. It is much worse than H1N1 from 1918.
The second factor is the history of contagious diseases. It's been almost 100 years since the bird flu pandemic in 1918. Since 1957, flu pandemics happened almost once every ten years: the Asian flu in 1957 by the H2N2 virus, the Hong Kong flu in 1968 by the H3N2 virus and the 1977 Russian flu by H1N1. Since Hong Kong's return to Chinese rule in 1997, the flu has been happening more frequently. In 1997, H5N1 spread in Hong Kong. In 1999, H3N2 spread in Hong Kong. The only case where the H5N1 virus didn't occur in Hong Kong was in 2003, when it appeared in Holland. In 2004, H7N7 was found in Hong Kong. Also in 2004, H5N1 hit Asia. These occurrences have gone far beyond what scientists predicted. That's why scientists are warning the public now.
The third factor was that the 1918 flu killed so many people in spite of being a less pathogenic virus, and occurred in an era with less developed transportation and lower population density. Can you imagine what could happen today, in 2005? International travel and high population density are hotbeds for infections.
The fourth factor is that there is no pharmaceutical medicine that can effectively curb the problem. The pharmaceutical medicines we now have to fight bird flu are somewhat effective, but I don't think they can control the bird flu if it mutates. Tamiflu only inhibits and relieves the symptoms. Nobody knows if it can truly solve the problem.
SOH: I'd like to follow up on your last point. You said that in the last century many died from the Spanish flu. After a century, science and technology are much more advanced, and there are more ways to control diseases. Are you saying that we still can't handle the new bird flu virus?
Dr. Feng: That's correct, because the bird flu viruses can mutate.
SOH: You talked about the different flu pandemics and they all start with H and N, but the numbers that follow differ. Are they different viruses?
Dr. Feng: Yes, the antigenic determinant is different.
SOH: The antigenic determinant is different, meaning they are different types, but they are all called the bird flu.
Dr. Feng: Yes. Another important point is that when we review the history of influenza, much of it was around China. Especially recently, they have been finding the H5N1 virus in ducks exported from China to Japan and Korea. Scientist all know that China is the source for influenza, and people don't feel that they can trust the disease reports issued by the Chinese government. This is another cause of fear.
SOH: The international community has no confidence in the disease status reports issued by China?
Dr. Feng: That's correct. But this information is very important to everyone in the world! People think this pandemic may be worse than the one in 1918. This is another reason.
Another possible factor is that pollution in China has become quite severe. The pollution includes air, water and food. This is terrible for the human and bird immune systems. Birds' immune systems are much less developed than humans'.
SOH: Just now you talked about bird flu's frequent outbreaks in China. The population density in China is very high, and they also raise large numbers of poultry. If bird flu spreads quickly in China, it could be very dangerous.
Dr. Feng: That's right. Now there are over 15 billion fowl in China.
SOH: This reminds me of the spread of SARS two years ago. It was quite frightening when the disease spread in mainland China and to other parts of Asia. Is the Chinese government handling this bird flu problem differently than SARS?
Dr. Feng: No. It's just the same.
SOH: You think it's just the same?
Dr. Feng: Everyone can recall how Zhang Wenkang vowed at the time that China was safe and had no SARS, or only one or two cases. Of course, he was removed from the post in the end.
SOH: So the former Minister of Health, Zhang Wenkang, was dismissed.
Dr. Feng: The Chinese Communist Party (CCP) finally acknowledged [the existence of SARS in China]; this is equivalent to admitting that they had lied. Dismissing the Minister of Health was only to protect themselves, since Zhang alone did not decide this. But now, who is to be removed from his or her position? Perhaps someone from the Department of Agriculture, since they prevented Dr. Yi Guan from speaking the truth? Regrettably, as soon as the bird flu starts being passed from human to human, we will be faced with an even greater death rate than SARS. At that time, it will be too late, even if all CCP leaders are removed.
SOH: You just mentioned Dr. Guan. I read about him in the news, and he was named one of 18 heroes in Asia by Time magazine recently. What contribution did he make in the prevention of bird flu?
Dr. Feng: He is an Associate Professor in the Department of Microbiology at the University of Hong Kong. He is also my classmate from Jiangxi Medical College, but a year junior. He published in the internationally renowned journal Nature the research results he and his team found in the past five years. They collected nearly 100,000 bird specimens, listed more than 250 virus types and plotted how bird flu spreads and mutates in different regions. He did a wonderful job, so Time magazine named him the "bird-flu hunter."
But the CCP closed down his lab in Shantou, China, and accused him of stealing state secrets, mainly because he spoke the truth, revealing how the bird flu originated from southern China.
SOH: So, just because he exposed bird flu, the authorities closed down his laboratory in Shantou?
Dr. Feng: Yes, this story is similar to that of Jiang Yanyong.
SOH: When exposing SARS, Dr. Jiang Yanyong of Beijing's 301 Hospital was very brave, as he spread the truth overseas through Time magazine. Now, facing the very dangerous bird flu, would China's Department of Agriculture still insist on keeping the information covered up?
Dr. Feng: Yes. It is reported that a little girl in Hunan Province died after eating chicken. The World Health Organization has repeatedly requested that China provide information about the girl's death. But China refused, using the excuse that she was cremated. They said she died of pneumonia. Of course, I do not think cooked chicken would spread the flu virus, but in its preparation, if your hand was in contact with the dead chicken's blood, you may become contaminated. Since China refused to make public the information and keeps it a state secret, I think it is likely she died of bird flu.
SOH: Other than its spread in China, what is the situation of bird flu in other countries right now?
Dr. Feng: Right now, it is not spreading from human to human. But when human-to-human spread starts, I am afraid that will be too late. The U.S. is prepared to close its borders at any moment; Australia is doing the same. The U.S. may restrict travel; a bill to invest 7.1 billion dollars in bird flu is currently before Congress, and the U.S. has given Chiron 62.5 million dollars and Sanofi Pasteur 100 million dollars to develop bird flu vaccines. The U.S. has adopted many measures. However, no country would be spared [in a pandemic], since it would involve everyone. This will be the pandemic of this century, and every scientist will tell you that it will come. The only question is whether it will come sooner or later.
SOH: Didn't you just say that bird flu has not reached the degree of human-to-human contagion?
Dr. Feng: Now it is mainly in poultry. I remember that in the 1997 breakout of the H5N1 virus in Hong Kong, the first casualty was a three-year-old boy, who died of bird flu. Later the H5N1 virus was discovered in his body. Since that year was Hong Kong's return to China, the Hong Kong government was careful in preventing the spread of bird flu and killed 1.2 million chickens. About 80 percent of Hong Kong's chickens came from mainland China.
SOH: Right. What are the symptoms of bird flu? Could you please tell us?
Dr. Feng: There are several symptoms. Fever, coughing and shortness of breath will occur 100 percent of the time; there may or may not be mucus. These symptoms are similar to pneumonia, but they are very severe, and they come much more violently.
SOH: How can one tell if one is infected with bird flu?
Dr. Feng: If one person is infected with bird flu, the case should be reported to the World Health Organization and the medical departments that monitor the bird flu as soon as possible, because they can immediately know whether it has mutated. If we can catch the first mutant, it is certainly a blessing to humanity.
SOH: So, you should call the doctor [if you have a bad flu] and be examined; this can prevent the gene from mutating and threatening humankind?
Dr. Feng: Not only preventing it from mutating; in case it has mutated, they can figure out ways to deal with it. For example, it is easier to make a vaccine. Everything is clear—if we know what kind of virus it has mutated to, it will be relatively easier to control.
SOH: You just talked about the issue of information transparency. For infectious diseases, the information transparency is absolutely important. How does this information transparency affect every individual's health?
Dr. Feng: This will be the first flu of the century and everyone will be involved. Probably no one can escape. But everyone should know the truth and at the same time let others know the truth. This is about life and death, crime and punishment, because everyone's attitude of dealing with it may cause life-threatening danger to himself or herself or other people. Be sure never to ruin one's life or that of others through selfishness or ignorance.
SOH: The information is still blocked in mainland China, therefore, we should let our friends and relatives know about this information so they can prepare.
Dr. Feng: Yes! It is very important!
Why are the United States and European countries so vigilant over this bird flu? They have learned their lesson from the past. In 1918, no official expected that such calamity could happen. In fact, prior to the outbreak of the epidemic, the medical authorities reassured the public based on groundless confidence. Of course, that was during wartime, and they might have thought that the war was the primary concern.
Concealing the state of an illness is absolutely not good; it can only harm people and the country. History has given the Chinese government lessons. From 1918 until now, only two flus have had nothing to do with China—one was the Russian flu and the other one was the Holland flu. But now, the Chinese government is still lying. Also, there was the lesson of SARS, so everyone should be clear about this and tell the truth.
SOH: From the larger perspective, we should allow everyone to know about and understand the seriousness of the bird flu. What specific measures should individuals take?
Dr. Feng: It is not like what people think, "I have strong immunity. I am not afraid of it!" Especially during the 1918 flu, most people who died were young people and people in the prime of life. The army had a very high death rate, and in some places the death rate was 60 percent.
SOH: Why were most of the deceased young and middle-aged adults?
Dr. Feng: Because the immune system is actually very much controlled by the nervous system. Of course, the nervous system controls the entire body and is not limited to special cells like T cells and B cells, which have specific functions. Other cells, such as the endothelial cells that are distributed throughout the body, also belong to the immune system. A disease such as the bird flu that attacks the entire body tests the integrity of one's entire immune system.
The balance and harmony of the immune system is very important. When there is no attack from any disease, the immune system is in a relatively relaxed state. It is elastic, like a rubber ball. It can jump high when hit, and can stop immediately when needed, so that it wouldn't cause death.
They did an experiment on the bird virus of the 1918 flu and found that what was truly lethal was not the virus, but the subsequent immune hypersensitivity induced by the virus, in which the cytokines and chemokines, which are two of my research subjects, were twice or three times more than that in ordinary viruses. This indicates that you must take care of your immune system. When your body and mind are in harmony, your immune system will be in a harmonized state.
SOH: The immune system you just mentioned would be stronger when a person is at ease, in harmony and happy; hence his immunity is stronger.
Dr. Feng: Having a strong immune system alone is not enough. I remember an interesting example, which is the 1918 phenomenon. Few children contracted the disease and died from it. An Eskimo village only had three adult and fifty child survivors. This violates a fundamental principle of immunology regarding the immaturity of children's immune systems. However, children have pure hearts. We should learn from them, they are so pure minded. Hence, try your best to maintain a mental balance. However, at this time, one must pay attention and remind everyone that if the bird flu indeed comes, everyone needs to be mentally prepared; one must be calm and adjust one's breath. Methods like Tai Chi and yoga are good for achieving that.
SOH: Because the Chinese government did not release detailed information on the epidemic of bird flu in China, the seriousness of its nature is unknown. Because of this uncertainty, one should be very aware of the situation.
Dr. Feng: Of course. Another issue is pollution. Chief engineer Liu Ning from the Ministry of Water Conservation said that fast economic development intensified the water quality problem in China. Currently, 25 percent of the water is contaminated, 35 percent of underground water is below standard, 54 percent of the domestic water in the plains is also below standard and over half of the cities have severe pollution of their underground water. Hence, what you drink is toxic for the immune system and can damage it. Besides the typical cells in the immune system, like the T cells and the B cells, there are also other cells in the immune system. For example, the integrity of the endothelial cells is important to the immune system during flu epidemics.
SOH: Has environmental pollution already damaged humans' immune systems and caused their immunity to deteriorate?
Dr. Feng: There has definitely been deterioration. Earlier this year, many people had doubt about the Streptococcus suis outbreak then. Everyone was puzzled by how the bacteria Streptococcus suis could cause such damage.
SOH: Do you mean the Streptococcus suis outbreak in Sichuan this year?
Dr. Feng: Yes, it caused 38 deaths. Many scientists thought it to be a lie initially, but to their surprise, their research results proved it true. Streptococcus suis normally exists in pigs. It is common for a pig farmer to carry Streptococcus suis. How can it cause death? First, modern people's immunity is incredibly low; secondly, Streptococcus suis may have mutated, though there is no proof of it. Some people suspect it is due to drug resistance. Regardless of the cause, it is giving people a warning: Environmental pollution may damage the immune system, so we must be on high alert!
In 2003, China had 65 billion tons of sewage discharge; about one third of industrial wastewater and two thirds of sanitary sewage had never been treated and was poured directly into rivers. Think about it. What kind of damage would this cause to people living there, and to their immune systems and the entire biological system? That includes the birds, and the immune system of birds is extremely weak.
SOH: So it is no surprise that there continue to be large-scale infectious disease breakouts in China.
Dr. Feng: In the beginning, they thought the cause of the infection was raising chickens, ducks and pigs together. Now this bad custom is still practiced, and there are other complicating factors. In one word, if the bird flu indeed breaks out in China, the outlook will be bleak. So everyone should inform others of this truth and tell them to be prepared. Good preparation always brings hope.
Compiled from a Sound of Hope interview by reporter Wang Yang. Lili Feng, M.D. is an Associate Professor of Medicine at Baylor College of Medicine in Houston, Texas. She has authored and co-authored several papers on immunology.