The flu problem and, in particular, its bird version is widely used in press, and in opinion of some people, it simply became a subject of gamble whether on pharmaceutical, or on poultry-farming markets - on the first making a profit, on the second - ruining...
The head of an infectious diseases department of the Crimean medical university docent P.S. Arshinov and the head of the department of microbiology, virology and immunology professor Y.L.Krivoruchenko took part in the discussion of the problem. Here are their opinions.
Flu viruses
New human flu viruses can cause pandemic - it is a result of mutations and recombinations. In the case of viruses the majority of mutants dies, as they lose, instead of get something useful. However some mutations just allow a flu virus to stay in a human population or in other owners. And the recombination is a regrading of genetic material which has already existed earlier in parental virus variants. Having infected the same cell of the owner, genes from one parental culture mix up with the genes of another, forming posterity with features of both initial viruses. The hybrid individual arises: separate genetic blocks do not undergo changes, but the unusual combination of these blocks creates a new product.
Recombination is considered to be the main tool of new culture creation. When changes are quick, as a result there arises something unprecedented - including, the most dangerous pandemic variants of flu virus. Recombinations make human population immunity, which is adapted to earlier existed cultures, absolutely insolvent. Biological "kitchen" where such virus-murderer is created is located basically in South-East Asia, but gradually there are emissions in other regions of the world - for example, in Russia where the cases of bird flu have already been registered.
Bird flu virus
It is well-known that poultry gets sick more often then wild birds, which are considered to be natural flu viruses reservoir. Viruses spread with feaces. In the places of mass nesting virus can be found in water. It is very important for Crimea. Ornithologists call this peninsular a “bird station” in bird migration. Besides, birds spend the winter on Sivash and Lebjagii islands.
Cultures can come to the Crimea with birds from Asia. Judging from not systematic data, virus variants similar to those, that caused mass animal and people deaths were fixed in Black sea counties.
Virus occurred in the countries that are not far from Ukraine: in Rumania, Turkey, though Turkey has denied it. Anyway, this virus has appeared on the territory of Russia and animals are sick.
The problem is that in many countries still there are no generally adopted test-systems, which would allow to register, if these are the same virus cultures as those found in Asia. Final comparative analysis is not made yet. We still don’t know a lot. And we may not know it till, the mass bird deaths will begin, with the infection of pigs and other mammals.
Swine flu virus
The swine peculiarity is that a lot of its immune reactions and other physiological characteristics are very similar to human. They are more alike than any other animals. Initially virus, including flu, is more easily adopted by swine, then by human. Swine is an intermediate stage, where the virus comes to the state when such variant can occur, that will be able to spread in human population (from man to man). Such was the way of famous “Spaniard” virus, said American and English scientists, who made a retrospective genetic analysis. So the history may recur…. The only difference is that the knowledge about this infection, virus nature and preventive measures approaches has greatly changed. People are waiting for epidemic, they are ready to resist it more deliberately…
And we really should be afraid!
Flu pandemic and epidemic
Majority of scientists accept that pandemic can really occur. The question is when: his year, next year or in few years time? And the main question is – what will be human lethality? Predictions are a bit hypertrophied. For example, Americans believe that if pandemic will occur, then hundred thousand people will die in the USA. Such predictions are made on the results of the latest epidemics and are in some way called to make people and government worry. This is a political and commercial risk.
Of course, when such questions as global epidemic occur, political interests and big sums of money of different countries interact. These money are connected with vaccine production and its purchase at the level of the nation, profits of the firms, producing diagnostic systems and medicine.
Ukraine, as well as any other nation, won’t be able to make a self-isolation. That’s why, as a theorist scientist, I can say that if the whole world will get flu, then Ukraine will also fall ill. If there won’t be any special vaccine, then of course a lot of people will get sick. For today there is no bird influenza vaccine, instead of it some scientists suggest using vaccine against flu viruses’ variants, that people had before. It is logical. Recombinant cultures include part of the parental genes, including human ones (and close ones). Thus, vaccine against human virus with hemagglutin H1 can partially protect, but from what? It can’t protect from being infected, but the level of lethality and complications can be reduced.
Bird flu preventive measures
Chicken can be eatable, but it should be boiled or fried properly. Flu virus dies at 100°C but it stays alive after freezing.
Usual flu preventive measures and treatment can be useful. Pavel Spiridonovich Arshinov, head of an infectious diseases department of the Crimean medical university, docent, will continue our discussion.
Flu preventive measures
Flu is an infectious disease and its preventive measures need our high attention.
Mankind knows flu for over 1000 years. According to academician V.M. Jdanov, in this period there were 500 epidemics and no less than 13 flu pandemics, mainly caused by the flu virus type A. This type is able not only to change its antigens constantly, but also to replace them. But it is species-specific: usually, bird virus can’t infect a swine or a man and otherwise. Because of low stability in the environment virus is transmitted respiratory and translucently.
It is important to use preventive measures in those age-specific categories that are the most amenable. The most amenable in this case are children under 5 year old and people over 65 years old. Flu lethality level is about 0,01 – 0,2 percent during epidemic, during pandemic it increases. During 1918-1919 according to different data from 20 to 40-50 million people died from flu. Considering that in 2003 in Ukraine 1 million143 thousand people were infected, and in 2004 – about 2 million people, in 2005- 2006 another epidemic is expected. There will be a circulation of new viruses type A and type B.
Except for the human flu virus, in the world there are another types of A virus that often infect birds (H.7N7, H7N2, H5N1 and others). From the December 2003 cases of flu from contact with poultry were recorded. There were different clinical signs: from light in Netherlands to hard with the death of 62-72 people in the region, where about 2,5 million people live (South-Eastern Asia). People get infected in the direct contact with ill birds. There were no reports of bird flu infection from man to man. So bird flu is a serious veterinary problem, but not medical.
There are two theories of flu variability. One of them pays attention to the flu virus recombinations, and another – to recyclic virus onset in human population. This issue is not studied enough.
The basic method of flu preventive maintenance is annual inoculations. Vaccines are developed, and their structure changes depending on antigenic structure of prospective A flu culture, which, probably, will cause epidemic or pandemic.
From all vaccines, considering even small probability of bird flu occurrence in structure of human diseases, the most appropriate are the split vaccines which, unlike subunit, include not 2 antigenes, but 6 antigenes (2 external and 4 internal), that allows immune system to create more quickly and more tensely immunity, that can be important for creation of cross immunity to the bird flu - in case of its possible occurrence.
It is necessary to carry out flu preventive maintenance with split vaccines in November-beginning of December, so that to the beginning of ARD rise (the end of December-January) greater part of the population will generate immunity. According to the French doctors, the split vaccines has reduced the cases of ARD in 2,6 times.
Flu treatment
What flu treatment can be offered? - amantadine and remantadine, oseltamivir. It is necessary to note, that flu A sensitivity to remantadine has decreased recently, and it is forbidden to use for treatment of children under 14 years old as it is can cause changes in CNS. Arbidol has appeared. It is used for flu treatment in a doze of 400 mg/day in 2 intakes within 3-5 days, and for preventive maintenance - 200 mg/day with an interval 3-4 days, duration of a treatment is 3-4 weeks. Arbidol reduces risk of flu and ARD in 2,6-3,2 times, shortens duration of illness for 2-2,5 days and reduces frequency of postinfluenzal complications in 2 times. Others interferon inducers can be used, and also - vitamin complexes, plentiful drink, etc. (and all this – according to the doctor recommendation). Antibiotics should be applied rather cautiously, paying attention on age: to children - only over 6 months, to adult patients – over 65 years.
Walks on air, tempering procedures, observance of sanitary-and-hygienic norms are recommended for immunity strengthening. Try to avoid stresses, to have a proper diet. Use vitamins including vitamin C, but cautiously - a short period and small dozes (there is an opinion of experts, that surplus of vitamins can be more harmful, than their lack). If you have flu don’t take alcohol in the "medical" purposes: a flu is not a cold, it’s an infectious virus disease. Try to limit participation in actions with big congestion of people - someone can be infected and not know about it (as signs are not shown yet) so, he can be a carrier of disease. Constantly working air-conditioner also does not assist health – it is better to air the room more often. Limit use of public transport - whenever possible, at least a part of way to work (study) and from work go by foot. As you notice the first signs of disease - stop contacts with other people, call a doctor, keep confinement to bed.
Take care of your health!