‘Little chance of a bird flu pandemic’
The bad news, according to distinguished epidemiologist Dimitris Trichopoulos, is that children are more susceptible to bird flu since they have not developed antibodies to viruses related to H5N1, as older people have. The good news is that the bird flu virus might infect more people but is causing fewer deaths. In short, the problem is serious but the chances of a pandemic occurring are about one in 10. The global effort must focus on prevention, dealing with the problem at its source in Southeast Asia, and in creating a vaccine, maintains the Harvard and University of Athens professor in this interview. What are the chances of a bird flu pandemic? In my view a pandemic is unlikely, but because there is about a 10 percent chance, quite a serious likelihood; we are right to be concerned and to take precautionary measures. But a pandemic, if once should occur, will not be the end of the world. People are talking about a mutation, which will allow the virus to spread from one human to another. Mutations are very likely and and could even reduce the virus’s pathogenic strength; in a way that is what is happening already. In Turkey, we have seen people more easily infected by birds because over a short period of time more cases were found than in Southeast Asian countries. However, we are looking at an epidemic which is not so deadly. Out of the 18 cases there have been three deaths. If there are 30 or more cases, as has been estimated, the mortality rate is 10 percent or less, compared to 65-70 percent in the beginning. We are already talking about asymptomatic cases… This mutation of the virus is likely to mean that it is more infectious but that the disease it causes is not as serious. So I don’t think the nightmare scenario of the entire population of the earth getting sick and half of us dying will ever come about. Is it possible that bird flu might not have spread to Greece? It is possible, because the migratory season for birds is over and no cases have been reported. However, I think that at some point the bird flu epidemic will enter Greece. That is why more measures should be taken. I think the authorities should tell everyone who has chicken coops that they will be compensated for destroying flocks of birds suspected of being sick, so that no one will want to keep a sick chicken and in fact preserve the infectious source. The bird flu epidemic spread to Turkey as quickly as it did because poultry is the livelihood of the poor, who did everything they could to save their birds. Are you saying that the virus will slowly become less of a threat to birds? Yes, because the virus itself must survive. It cannot destroy everything in its path. Can we eat chicken and eggs? We can continue to eat them if we cook them carefully. Because of the disease we have an increased incentive to do what we should in the kitchen to protect ourselves from any kind of food poisoning. We should handle food very carefully. What we must bear in mind is that while the virus is destroyed when cooking at temperatures of 70-80 degrees Celsius, viruses and microbes survive in the environment for a short period and can reinfect food if we do not wash our hands carefully, as well as all utensils and surfaces that the raw chicken has been in contact with. Would a pandemic have dramatic consequences? Not the kind of consequences people first talked about, that is one in two people dying. The problem is that the flu, according to the model of the 1918 influenza epidemic, has a very rapid infection rate. One person infects an average of two-and-a-half other people. The length of the intervening period, a combination of the incubation and the infection rates, is very short. For SARS it was eight to nine days, for the flu it is three to four days. That means that the time between one case and the next is so short it is not easy to take quarantine measures such as with SARS, which raised a barrier to the epidemic. There just isn’t enough time. For example, if a person comes to the border, he could be infected and infectious but present no symptoms. He could enter Greece and within three days there would be cases of flu around him. There would be no time to isolate him, as there was with SARS. That is why we believe that if there is an epidemic, it will be a pandemic. How long would such a crisis last? We now know more about how a virus is transmitted, we can wear masks, gloves and avoid crowded places, reduce our activities. You can’t do that because it would paralyze life and create a major economic crisis. Don’t forget that despite the relatively restricted extent of the SARS epidemic, it halted economic growth in Southeast Asia. How long would a pandemic last? It depends, a year or two, until it reached around the world, until everyone got sick and many died, only to die out when people acquire antibodies. But as I said, I don’t think such a nightmare scenario is likely. Is there a chance of a milder epidemic? You mean a virus that would infect people but that would not be very aggressive? Perhaps. If there had been smaller epidemics around 1950, older people might have antibodies from infections by similar viruses. Perhaps that explains why in Turkey and the other countries a lot of people get sick but it is the young people who do not have antibodies who die. There is concern over the lack of drugs. Neither Tamiflu nor any other drug would be able to stop an epidemic of this scale. Antiviral drugs can reduce the percentage of fatalities but cannot stop the spread of the infection. Only a vaccination would be able to do that. But in order to produce vaccines we have to know the new version of the virus that is transmitted from one person to another. So for the moment we cannot proceed. However, an interesting proposal was published in The New York Times and adopted by serious scientists, that is to incorporate into the ordinary anti-flu vaccine a fourth version of the H5N1 virus that causes bird flu, a mutation of which would cause the pandemic. That vaccine would not provide complete protection, but would reduce the infection rate and the gravity of the disease. How are initiatives taken to produce a vaccine? By the industry, of its own accord? Yes, of its own accord. If the industry sees no commercial value in it? The state will buy the interest, it will pay. On the condition that the Disease Prevention Centers decide that the flu vaccine produced every year will include a fourth version in addition to the three chosen by the World Health Organization, that for bird flu. The bird flu epidemic might last two years or 20 years. The question is whether pharmaceutical companies should be persuaded to produce the vaccine over several years so as to cover the cost. How often have we talked about the threat of epidemics over the past 20 years? Very often, and the older we get, we also hear about threats that never came about. So we become more confident. There is no doubt that this is a serious problem and concern is justified, necessary, I should say, because it is an incentive to take measures. But I must reiterate that I don’t think a pandemic means the end of the world; there is a 10 percent chance of it happening and it will be milder than we at first might expect. I also think that within a few months there will be vaccines that will be even partly effective. Will the pandemic get ahead of us? No, it won’t. So both we and birds will survive? Yes, we will. But the most important preventative measure is to put down millions of birds around the world. However, it is often done in a barbaric, unacceptable way. Let us not forget that a painless death is the least we can offer them in our efforts to protect our own health. This interview first appeared in the January 22 edition of K, Kathimerini’s color supplement.
