What do we know about bird flu? Why should we be afraid of him? Or that this virus is fictitious and the hype around it is just a way for pharmaceutical companies to make money? Or are these the machinations of Western businessmen who want to undermine faith in our domestic hams?
In fact, bird flu poses a real danger to us. Let's try to figure it out. The most pressing questions are answered President of the Russian Academy of Medical Sciences Valentin POKROVSKY, Director of the Influenza Research Institute Oleg KISELEV and Academician of the Russian Academy of Agricultural Sciences Anatoly SMIRNOV.
Why should we be afraid of bird flu if it is not transmitted from person to person, but mainly birds get it?
Because this infection is dangerous primarily because it can gradually begin to circulate among people, infecting person from person to person. According to Oleg Kiselev, director of the Influenza Research Institute, this will take no more than 1-3 years, since the virus is constantly mutating.
Transformations of the avian influenza virus can occur in the body of a person or any animal - for example, a pig (closest to us in physiology). If there is a meeting of two viruses - the human one, which we get sick with every year, and the avian one, both strains will not waste time and will begin to unite in a variety of combinations. One virus will begin to transform into another, a new combination will be formed, and a fresh virus that will “learn” to be transmitted from person to person is ready. It is very important to get vaccinated against the common flu. The body will develop immunity against the currently circulating strain - and then the avian virus simply will not find an ally in it.
When will a bird flu vaccine be available for humans?
Currently, two anti-influenza vaccines are being developed for the H5N1 virus: the Americans and Geneva are doing this together with the WHO. The vaccine trial has already been completed in the United States (G. Bush has allocated $7 billion to fight bird flu and plans to add another $2 billion), and trials in Europe are nearing completion. In Russia, preclinical trials of the vaccine have been carried out, an experimental batch is being released, and the issue of further testing with human participation is being decided. Scientists are faced with the task of being ready for March, when migratory birds that carry the virus will again appear in our country. By this time the vaccine will be ready.
But again there is not enough funding. "We don't have modern technologies for the production of vaccines. All technologies are 10 years old. We need to switch to new methods of genetic engineering to quickly prepare a bank of vaccines against 5-6 strains that have the potential to emerge as leaders,” says Oleg Kiselev, director of the Influenza Research Institute.
There are still no funds in the Russian budget to fight bird flu. Scientists continue to work on the meager funds allocated for current planned work: this year 1.9 billion rubles, next year it will be just over 2 billion rubles. (compare with the USA).
While there is no vaccine, is there anything you can do to protect yourself if necessary?
Bird flu is still a flu, and drugs to treat it can be bought at any pharmacy. Available means are our broad-spectrum drugs such as arbidol, cycloferon; gamma interferons are used to treat advanced forms of influenza infection.
But the main thing you should remember is: at the first sign of the flu, run to the doctor, especially when it comes to children. Many drugs, if not used at the first stage of the disease, are then ineffective.
How to protect poultry if there is no vaccine for it yet?
Today, the only control measure is sanitary treatment of those places where avian influenza was discovered (in the Novosibirsk, Tyumen, Kurgan, Chelyabinsk regions, Altai Territory, the Republic of Kalmykia; recent cases - in the Tula, Tambov region, Stavropol region). “Moreover, disinfection should be carried out without watering the yard from a garden watering can or a fire truck, as shown on TV. This is wrong and absolutely useless!” says Academician of the Russian Academy of Agricultural Sciences Anatoly Smirnov. “Special instructions have been developed, there are disinfectants and equipment with which sanitization is carried out. If the owner of the bird does not have his own funds to purchase them, this must be paid for by the state.
The same goes for cars and people leaving areas where bird flu has been reported. They showed how they use a cylinder to treat the body and trunk of a car. Why? If there is a virus, then it is on wheels, where poultry feces - the main carriers of the virus - can linger. Therefore, the wheels need to be processed first. There is absolutely no point in spraying a person’s coat with something - clothes should be processed only in special formaldehyde chambers.”
It is imperative to burn the corpses of sick birds, and not just bury them. The virus persists in rotting corpses for up to 60 days, and if the burial is dug up by wild dogs or birds fly in, it will spread.
The sooner a vaccine is developed, the better. If bird flu is not resisted, the virus will mutate faster.
When a vaccine appears, it will need to be used only in a threatened area - that is, where the routes of migratory birds lie. This will require 150-200 million rubles.
Is it true that the bird flu vaccine for humans does not protect against influenza, but only against its complications?
It has been proven that vaccination reduces the incidence of influenza by 1.4-1.7 times. These are not the best results. “But the vaccine is a reserve one and is aimed primarily at occupational risk groups (those who work with poultry). We don’t think that tomorrow half the country will need to be vaccinated with these vaccines,” says Oleg Kiselev.
Is it true that the bird flu strain has the same roots as the Spanish flu, which claimed millions of lives in 1918? Are we facing an epidemic of similar proportions?
The avian flu and Spanish flu viruses are indeed similar. Scientists have found that the Spanish flu genes have a distinct avian origin. But it is unlikely that bird flu will be able to wipe out half of Europe like the Spanish flu. After all, at the beginning of the 20th century there were no antibiotics, and people were actually treated with home remedies. Today, doctors have modern means to combat influenza infection in their arsenal.
Everyone remembers the SARS commotion. And where is this disease now? Maybe everyone will forget about bird flu in a couple of months?
According to the President of the Russian Academy of Medical Sciences, Valentin Pokrovsky, in the case of SARS, it was immediately clear that there would be no greater spread of this disease. Because the only source of infection was rodent meat, which was eaten. In the case of bird flu, there is a massive infection of birds and, most importantly, environment. Hence the speed of spread of influenza and its ability to mutate.
Is it possible to eat meat and eggs from birds with bird flu?
It is possible if you subject them to thorough heat treatment. There were rumors that at 60°C the virus dies. This is wrong! The chicken needs to be thoroughly boiled - boil a young carcass for at least half an hour, and an adult carcass for up to an hour. Eggs must be well-boiled, because the virus is contained in both the white and the yolk - no scrambled or soft-boiled eggs.
In frozen carcasses at -20°C, the influenza virus retains its pathogenicity for 447 days. So, maybe even now someone has an infected carcass stored in their refrigerator and no one knows where it will “go” later.
Why were the corpses of sick birds burned if the carcass could be processed and eaten?
The first cases of bird flu were recorded in private households. How to take, say, 15-20 chickens from an old lady and send them for processing? There are no such technologies and schemes on how to act yet. In addition, the virus can spread during transportation. It is easier and safer to destroy the entire population of sick birds. This practice is used in the event of any dangerous infection. For example, when there was an outbreak of foot-and-mouth disease in England, several million heads of livestock were destroyed, although with proper processing the foot-and-mouth virus does not persist and animal meat can be eaten.
Where did the virus appear?
Bird flu is an acute bacterial infection caused by influenza A viruses (more precisely, their subtypes H5 and H7) belonging to the Orthomyxoviridae family. If hygiene rules are followed correctly, the virus is not dangerous to people.
To avoid infection, it is necessary to avoid contact with birds and heat-treat poultry meat and eggs - the avian influenza virus dies at temperatures above 50 degrees Celsius.
Symptoms of bird flu in humans and animals
Virus incubation period bird flu takes from 3 to 5 days and depends on the age of the bird, its type and strain of the virus. Clinical studies avian influenza not identified characteristic symptoms of this disease. Most are due to environmental factors, co-infections, age and species of bird, and the subtype of virus responsible for the disease.
Bird flu virus...
The main clinical symptoms of HPAI (highly pathogenic avian influenza virus) include:
- appetite disorders, especially lack of appetite;
- depression and others nervous disorders;
- soft shell eggs;
- a sharp decrease in egg production;
- swelling and bruising of the ridge;
- sneezing, swelling of the infraorbital sinuses, lacrimation;
- breathing problems;
The highly pathogenic form of the virus can lead to death, which occurs without prior symptoms. The avian influenza virus sometimes causes infection in humans. But when this happens, the disease is much more severe than the “classic” form of influenza.
Bird flu in humans causes symptoms very similar to those of regular flu, that is, it is characterized by:
- fever;
- cough;
- sore throat;
- pain in muscles and joints;
- ataxia;
- inflammation of the conjunctiva.
Sometimes this can cause breathing problems and pneumonia.
Routes of infection with avian influenza
Contrary to what is commonly thought, the timing and direction of migration of birds living in the wild is different from the timing and direction of avian influenza, and there is no evidence that outbreaks can occur due to transmission of the virus by wild migratory birds.
This is evidenced by the fact that H5N1 virus actively spread in Kazakhstan, Mongolia and Russia in the summer, when waterfowl molt and are not able to fly. The “attack” of bird flu that took place in Europe in the winter of 2006 also did not coincide with the period of bird migration.
Currently, the greatest danger to humans is the mutation of the H5N1 virus, which can be transmitted from person to person. This could lead to a pandemic, but research shows that only a few such cases have been identified so far.
The virus can be infected from free-living birds, through intermediate sources (drinking water) or direct contact with poultry, through feed. The main source of infection is the feces of infected birds. The virus is also spread by rodents living on farms.
Prevention and treatment of avian influenza infection
In order to avoid infection with avian influenza virus Some precautions should be taken:
- wash with detergents all objects that have come into contact with raw poultry meat;
- ensure that juices from raw meat do not come into contact with other food products;
- avoid contact with bird feces;
- Direct contact with infected birds or their bodies should be avoided - the avian influenza virus is also transmitted through contact with down or feathers;
- avoid eating raw eggs;
- wash hands and tools after each handling of poultry products.
Particularly at risk from the virus are:
- healthy children aged 6 to 23 months;
- children from 6 months to 18 years of age who regularly take aspirin;
- pregnant women;
- people suffering from chronic diseases of the cardiovascular or respiratory systems;
- people suffering from metabolic diseases such as diabetes, kidney failure or immune disorders;
- persons after organ transplantation.
Treatment of bird flu consists of alleviating the symptoms that appear during the course of the disease, as well as the use of antiviral drugs, of which the most common is oseltamivir.
The day before, Rospotrebnadzor reported that bird flu was discovered at a poultry farm in the Moscow region. All chickens must be destroyed, residents are explained how to handle poultry and what are the symptoms of such a virus in humans. TV channel “360” learned from the head of the laboratory of molecular biology of influenza viruses at the Research Institute of Poliomyelitis and Viral Encephalitis of the Russian Academy of Medical Sciences, Alexandra Gambaryan, whether it is possible to become infected through boiled chicken and why outbreaks of the epidemic occur in Russia.
Spread of the virus
The good thing for Russia is that these are only isolated cases. In principle, it [the epidemic] is not circulating in Russia. This means that some birds have flown in from the south, or it happens that someone bought a sick one across the border.<…>For Russia, the trouble is precisely that periodically recent years this has happened many times
Alexandra Gambaryan.
The H5N1 virus primarily circulates in Southeast Asia and Egypt. When there are outbreaks in these regions, the entire population there is destroyed. So, during the outbreak in China, all poultry was eliminated. There were no eggs or chickens throughout the country.
Methods of infection
According to Gambaryan, the most dangerous moment when there is a risk of infection is plucking a chicken. During this process, dust from the sick chicken can enter the lungs, which is likely to lead to death.
Through products - no. Although I’m not sure that anyone would sell sick poultry as a product, if you cook it properly, then there is no longer any danger
Gambaryan about the risk of becoming infected with bird flu through chicken.
She explained that it is necessary to destroy the sick bird, subject the chicken to heat treatment, “either burn it or boil it in boiling water.” In this case, it is better for a person to have less contact with a sick bird.
Symptoms and disease
A person has a week or two [of the incubation period of the virus], depending on the dose. And the distinctive symptoms are very high temperature and almost guaranteed death. It is difficult to take action in advance because the incubation period is quite long, and then everything develops quickly. But intensive therapy is already important here
A biologist from the Russian Academy of Medical Sciences said.
According to her, if a person can hold out for “four days” without dying, then he will quickly recover. But at the very first symptoms, you need to urgently go to the hospital.
When the disease begins, it is high fever, suffocation, defeat internal organs, everything goes on quickly
Gambaryan.
At the same time, it is more difficult for doctors now, since there is a flu epidemic. On the first day it is difficult to distinguish it from a bird, and an accurate diagnosis is made a few days after laboratory testing.
An outbreak of bird flu occurred in early March in the Sergiev Posad district of the Moscow region. for residents and a reminder about the symptoms of the disease. According to open sources, the last time a person died from bird flu was in 2014 in Canada.
Birds, like people, get the flu. Influenza viruses infect birds, including chickens and poultry, as well as wild birds such as ducks.
Most avian influenza viruses only infect birds. However, avian influenza can pose a risk to humans. The first case of human infection with the H5N1 virus occurred in 1997 in Hong Kong. Since then, the bird flu virus has spread to birds in Asia, Africa, the Middle East and Europe.
Avian influenza is a disease caused by strains of the influenza virus that primarily affects birds.
In the late 1990s, a new strain of avian influenza emerged and was seen to cause severe illness and death, especially in poultry such as ducks, chickens or turkeys. As a result, this strain was called highly pathogenic (that is, very dangerous and contagious) avian influenza and was given the term H5N1.
There are 16 in total various types bird flu. The H5N1 strain is the most concerning because it is the most contagious and the most deadly. Fortunately, this virus is very difficult for people to get infected with.
A relatively new strain of bird flu has been discovered in China. The influenza A virus was named H7N9 (H7N9 Chinese avian influenza). On March 31, 2013, the identification of the H7N9 virus was reported; the new strain differed in antigenic composition from the H5N1 avian influenza virus. Unfortunately, the H7N9 strain of avian flu appears to be genetically unstable.
Since its discovery in 2013, at least 48 different subtypes of H7N9 have been identified. As some H7N9 viruses persist in chicken farms in China, researchers fear that their strains will continue to exchange genes with other influenza viruses, which could start a new pandemic.
Since the discovery of the highly pathogenic influenza, infected birds have been found in Asia, Europe, Africa and the Middle East. Careful control measures, including eradication of infected flocks of birds and vaccination of healthy animals, have reduced the number of cases, but the virus continues to exist among domestic birds in regions of Asia and Africa. In 2007-2008, there was a small outbreak in Bangladesh and Pakistan associated with contamination of domestic chickens.
In March 2015, avian influenza was detected in several turkey flocks in the United States. This has led to a number of countries banning the import of American poultry products.
Similarly, in March 2015, avian influenza was detected in chickens in Holland. Most experts believe that poultry become infected with avian influenza due to contamination from wild bird feces.
As of March 2015, no human cases of avian influenza have been detected in the US population. Although the H1N1 swine flu virus that caused the pandemic contains some avian flu genes, it was not the original H5N1 virus.
The virus spreads among birds due to the fact that infected birds secrete it into their saliva, nasal secretions and droppings. Healthy birds become infected when they come into contact with contaminated secretions or droppings from sick animals.
Contact with contaminated surfaces (such as a cage) can also allow the virus to spread from bird to bird. Symptoms in birds can range from mild (eg, decreased egg production) to multiple critical organ failure and death.
First human case of the disease, which developed from infection with highly pathogenic avian influenza, was discovered in 1997. From then until 2016, according to the World Health Organization, 846 people were infected with the H5N1 virus, of whom 449 died.
Human cases of highly pathogenic avian influenza have most often been observed in Southeast Asia and Africa. Mutations have occurred frequently in the virus, and it is possible that some of these could create a more contagious virus that could cause a regional epidemic or worldwide pandemic of avian influenza in humans.
Fortunately, the mutations that have arisen so far have not made the virus more infectious, although concerns about this remain. The discovery of the H7N9 strain of avian influenza is causing concern.
Four people in China have been infected with the H7N9 virus, two of whom have died. Health officials around the world are concerned about the possibility of a type of avian influenza emerging that could easily spread from birds to humans. Although mild transmission between humans has not yet developed, H7N9 avian influenza infected 707 people, of whom 277 died. Most of these infections were associated with contact with infected birds or their droppings.
Table. Number of confirmed cases of avian influenza A H5N1, according to the World Health Organization, 2003-2015
| Country | Total cases | Died |
| Azerbaijan | 8 | 5 |
| Bangladesh | 8 | 1 |
| Cambodia | 56 | 37 |
| Canada | 1 | 1 |
| China | 53 | 31 |
| Djibouti | 1 | |
| Egypt | 346 | 116 |
| Indonesia | 199 | 167 |
| Iraq | 3 | 2 |
| Lao People's Democratic Republic | 2 | 2 |
| Myanmar | 1 | |
| Nigeria | 1 | 1 |
| Pakistan | 3 | 1 |
| Thailand | 25 | 17 |
| Türkiye | 12 | 4 |
| Vietnam | 127 | 64 |
| TOTAL | 846 | 449 |
What is the cause of bird flu?
Bird flu is caused by strains of the influenza virus that have evolved to be specifically adapted to invade bird cells.
There are three main types of flu:
The virus that causes avian influenza is influenza A, which contains eight strands of RNA that make up its genome.
Influenza viruses are classified based on the analysis of two proteins on their surface - hemagglutinin (H) and neuraminidase (N). There are many types of hemagglutinin and neuraminidase proteins.
For example, the recent pathogenic avian influenza virus possessed hemagglutinin type 5 and neuraminidase type 1. Thus, it was named “H5N1” influenza A virus.
The 2013 virus had different surface proteins, H7 and N9, hence the name H7N9. Other types of avian influenza include H7N7, H5N8, H5N2 and H9N2.
There are many types of influenza viruses, most of them prefer to live in a limited number of animals. Thus, swine flu primarily infects pigs, and avian flu primarily infects birds. Human flu strains are best adapted to humans.
A small number of infections can occur through incidental hosts, for example when people come into close contact with infected birds and become infected with avian influenza. In addition to humans and birds, it is known that pigs, tigers, leopards, ferrets, domestic cats and dogs can sometimes be infected with avian influenza viruses.
Influenza viruses mutate frequently and easily. These mutations can occur spontaneously in one virus or can occur when two different strains exchange genetic material. Influenza viruses have two main types of mutations:
- antigenic shift, when large segments of RNA swap places between influenza viruses various types;
- antigenic drift, when small RNA sequences change places.
Antigenic shift is usually responsible for the emergence of new strains.
For example, the 2009 swine flu pandemic was caused by a virus that included genetic material from strains of swine, bird and human flu. New mutations could allow the virus to evade the immune system and render old vaccines ineffective.
In 2011, one strain of a highly pathogenic avian influenza virus mutated in this way, making the existing vaccine used against avian influenza ineffective against the new strain. Sometimes the influenza virus mutates in such a way that it becomes capable of infecting new species of animals.
Serious influenza pandemics occur when a relatively new strain of influenza virus emerges that is highly contagious to people. The deadliest pandemic in modern history was the 1918 flu (also known as the Spanish flu, although it did not originate in Spain).
The 1918 virus quickly spread and killed tens of millions of people around the world. Mortality was particularly high among young, healthy adults. Although the 1918 virus was a human influenza virus, it had many genes that likely came from a strain of avian influenza. One of the reasons why health authorities are closely monitoring and trying to limit human exposure to sick birds is to try to reduce the chances of new strains emerging that may have the ability to thrive in human tissue.
What are the risk factors for developing avian influenza?
People can become infected with avian influenza through contact with infected birds (such as chickens) or their infected droppings or secretions.
Risk factors include caring for sick birds, killing sick birds and preparing them for consumption. Despite the huge number of people who come into contact with birds every day around the world, human cases of avian influenza remain rare.
This highlights how difficult it is for the avian influenza virus to infect human cells, but that difficulty may be reduced by mutations such as antigenic shift. The H1N1 swine flu pandemic that began in Mexico is an example of such a mutation.
Although direct contact with sick birds poses the highest risk of developing avian influenza, indirect exposure to bird droppings or other products (such as eggs) is also dangerous. Contact with unwashed eggs from sick birds or water contaminated with their droppings poses a potential risk of developing the disease.
Transmission of the virus from person to person has occurred in isolated cases. Therefore, caring for a person infected with avian influenza is also a risk factor for developing the disease.
There is a theoretical risk for laboratory workers who work with avian influenza viruses. In one case in 2009, a company inadvertently sent live avian influenza samples to a research laboratory, which were then used to vaccinate ferrets. This contaminated vaccine did not cause human disease.
Is it possible to get infected from another person?
Sometimes, after personal contact, a patient with bird flu can infect another person.
In 2006, 8 members of one family fell ill with bird flu in Indonesia, and 7 of them died. Why this happened is not known exactly. Family members most likely came into contact with infected birds. They also may have shared genes that made them especially susceptible to the virus.
What about bird flu that has been genetically modified in the laboratory?
In the fall of 2011, Dutch scientists made a stunning announcement. They genetically altered the H5N1 virus so that it spreads through the air among ferrets.
Why were ferrets chosen? Almost all human influenza viruses spread easily among these animals, which is why they are often used in scientific research.
Scientists in the US also created a mutant strain of H5N1 that spread among mammals.
These studies showed that the H5N1 virus has the potential to become dangerously transmissible among mammals, including humans.
Scientists have not released important information about creating mutant viruses; these details are available only to qualified researchers.
But these studies have caused very pronounced controversy. Some scientists say that mutant viruses cannot be created, since they can escape beyond the boundaries of laboratories. In 1977, the H1N1 flu broke out on the border between Russia and China and was considered lost. Although officials deny it, many scientists believe the virus spread from a laboratory.
What are the symptoms and signs of bird flu?
Symptoms appear approximately 2-8 days after infection. Infected people suffer from common flu symptoms, which may include:
- Increased temperature (above 38° C).
- Cough (usually dry, without sputum production).
- Sore throat.
- Muscle pain.
- Nausea.
- Vomit.
- Diarrhea.
- Headache.
- Joint pain.
- Lethargy.
- Nasal discharge (runny nose).
- Insomnia.
- Eye infections.
In children, the symptoms are similar. This viral infection may progress to the development of pneumonia and respiratory failure. Bird flu causes a very aggressive form of pneumonia (acute respiratory distress syndrome or ARDS) that is often fatal.
How do doctors diagnose bird flu?
Routine tests for human influenza A will be positive in patients with avian influenza, but they are nonspecific. To establish an accurate diagnosis of avian influenza, specialized tests must be performed. The virus can be detected in sputum using several methods, including cell culture or polymerase chain reaction (PCR). The growth of the virus in cell culture is carried out in laboratories that have the appropriate biosafety certification. PCR detects influenza A virus nucleic acid. Specialized PCR detects avian strains.
During and after infection with bird flu, the body produces antibodies against the virus. Blood tests can detect these antibodies, but this requires one blood draw early in the disease and a second one several weeks later. Therefore, results are usually available after the patient has recovered or died.
How to treat bird flu?
Due to the small number of human cases, scientific research on the treatment of avian influenza has not been possible.
It is believed that best way To prevent the development of bird flu is to avoid contact with sick birds and their droppings. People are advised not to touch any sick or dead bird. The World Health Organization currently recommends oseltamivir (Tamiflu) and zanamivir (Relenza) for the treatment and prevention of avian influenza. These drugs can suppress viral replication and improve patient outcomes, especially survival rates.
For best results, Tamiflu should be taken within 48 hours of the onset of symptoms. But, since the mortality rate from bird flu is very high, doctors should prescribe oseltamivir to patients who were diagnosed later.
For patients in serious condition, doctors can increase the recommended daily dose or extend treatment. It should be borne in mind that drug absorption may be severely impaired in patients with severe symptoms. gastrointestinal tract.
Patients with known or suspected avian influenza should remain at home or be hospitalized (isolated from other people).
Although Tamiflu and Relenza can be effective drugs in treating influenza caused by the H5N1 avian influenza virus. However, more research is needed to demonstrate their effectiveness.
Scientists from the United States and China have reported cases of drug resistance in human H5N1 viruses.
Patients should:
- rest;
- drink enough fluids;
- eat well;
- take medications for pain and fever (prescribed by a doctor).
Patients infected with the H5N1 virus often develop complications such as bacterial pneumonia. They require antibiotics and some need supplemental oxygen.
What are the complications of bird flu?
Complications of bird flu include:
- shortness of breath;
- pneumonia;
- acute respiratory distress syndrome (ARDS);
- lung collapse;
- mental state disorders;
- convulsions;
- failure of organs and systems;
- death.
Unfortunately, patients infected with avian influenza often have one or more of the complications listed above. Mortality rates for the H5N1 strain are approximately 55% and for the H7N9 strain approximately 37%.
What is the prognosis for bird flu?
In human cases of avian influenza, the prognosis remains poor. Many cases of the disease developed in poor people living in rural areas of underdeveloped countries who did not have access to modern intensive care units or antiviral treatment.
Approximately 55% of people diagnosed with H5N1 avian influenza died from the disease; the H7N9 strain has similar mortality rates - 37%. Survivors may have long-term health problems if organs and their systems are severely damaged.
Prevention of bird flu
There is currently no way to stop the spread of bird flu - it is a virus carried by birds, including wild birds that migrate. Understanding bird migration and monitoring their movements is provided by health authorities and agriculture necessary data to protect people and pets.
Vaccination– There is a vaccine for human seasonal influenza, but not for avian influenza. Various laboratories around the world, as well as pharmaceutical companies, are working on a bird flu vaccine.
In 2007, the first human vaccine against the highly pathogenic avian influenza virus was approved in the United States. This vaccine was made from inactivated viruses and did not contain live ones.
It stimulates the immune system to produce antibodies against avian influenza, which presumably can protect humans from this disease. The vaccine was purchased by the US government and included in the Strategic National Stockpile. It has not been made available to the general public because the United States does not currently have problems with the highly pathogenic avian influenza virus.
Side effects of the vaccine include arm pain, fatigue, and temporary muscle pain. The vaccine has not been tested for large quantities people, so there may be others, not yet discovered, side effects. The vaccine is effective against the strain that caused large outbreaks of bird flu, but it does not work against the newly mutated strain discovered in 2011. It is unlikely to provide protection against the new H7N9 avian influenza.
Scientific research into influenza vaccines continues. New developments targeting relatively immutable influenza virus antigens may lead to a vaccine that protects against most (if not all) influenza viruses. If these studies are successful, potential future outbreaks of influenza, including avian influenza, could be reduced or prevented.
Each person can minimize the spread of influenza, bird flu and many other infections:
- Hand hygiene - you should regularly wash your hands with warm water and soap, before and after using the toilet, and before preparing food. It is necessary to wash your hands after coughing.
- When coughing, you should cover it with the inside of your elbow, not your hand. When you cough into your hand and then touch some things, the virus can remain on their surface and other people can become infected from them. If possible, it is better to use a tissue when coughing and then carefully dispose of it.
- Sick people should stay away from public places and avoid contact with people.
- When visiting a doctor, the patient must immediately be told in the emergency department that he needs to be isolated from other people. In some institutions, the patient may be given a surgical mask.
- It is necessary to adhere to recommendations regarding vaccination against seasonal influenza and pneumococcal infection.
When cooking, do not use the same utensils for raw and cooked meat. Before touching raw poultry, you should wash your hands with soap and water. The same must be done after this.
Cooked poultry is safe to eat.
Do not go close to dead or sick birds.
What are the experts afraid of?
Currently, it is very difficult for a person to become infected with bird flu, and it is even rarer for one person to transmit this disease to another. Experts fear that if a person already sick with seasonal flu contracts bird flu, the H5N1 virus could exchange genetic information with the human H1N1 flu virus and gain its ability to spread from person to person. An easily transmitted strain of avian influenza virus between people can have devastating consequences.
Bird flu has a very high mortality rate, and if it becomes a pandemic, millions of people could die.
To infect humans, the H5N1 strain must penetrate deep into the lungs. This feature makes it more deadly, but also less infectious. People with an infection deep in the lungs cough and sneeze less than those with an upper respiratory tract infection.
A mutated virus can, for example, infect the upper respiratory tract, as well as the deep ones. Sick people will then shed more viruses through their coughs and sneezes, making it easier to infect others. People nearby will become infected more easily, since the virus will not need to penetrate deep into the lungs to cause illness.
Controlling avian influenza outbreaks helps reduce the chance that an avian influenza virus will come into contact with a human influenza virus and mutate. It is also important to monitor seasonal human influenza rates. The World Health Organization says quickly eliminating avian influenza outbreaks is a top public and global health priority.
For several years now, news of outbreaks of bird flu, a hitherto unknown to us, has been exciting the world. But recently, individual cases have grown into a real epidemic. How to protect yourself and your child from infection? How dangerous is this H5N1? We asked these and other questions that concern every parent to Elena Petrovna KOVALEVA, professor, doctor of medical sciences, leading researcher at the Central Research Institute of Epidemiology of Rospotrebnadzor of the Ministry of Health and Social Economic Development...
- Elena Petrovna, so what is bird flu, the news about which is now more like reports from the fronts? How is it different from other forms? Why is it so dangerous?
- Avian influenza (AI) differs from ordinary human influenza in its severe course and damage to the respiratory tract; Pneumonia develops quickly, and diarrhea and kidney damage are often observed. Mortality reaches 50-70%. Human avian influenza disease was first registered in 1997 in Hong Kong, then in other countries of Southeast Asia, and in 2006 in Turkey. The most common causative agent of AI is virus A (H5N1). Group A virus causes influenza in humans and birds, whales, pigs and other animals. Virus A differs from “human” and avian influenza in the surface structures of H (hemagglutinin) and N (neuraminidase). There are 15 known subtypes H and 9 subtypes N. Diseases in humans are caused by virus A (H3N2, H1N1, H2N2). The most dangerous of the AI viruses for humans is virus A (H5N1). In the Netherlands, there was an outbreak of AI in humans caused by the H7N7 virus, but it was milder.
Human flu is transmitted from person to person by airborne droplets, but the AI virus is not yet transmitted from person to person.
- Did you say bye?
- Yes, I think that the threat of a pandemic (a pandemic is an epidemic that covers most of population of a country or an entire continent) there really are GHGs.
If the “human” flu combines with the avian flu (and this is possible if a person is simultaneously infected with these viruses), then a mutant virus may appear. Its peculiarity will be the inherited severity of the course from the AI virus and “volatility” - the ability to be easily transmitted from person to person, characteristic of the “human” influenza virus.
- How dangerous is bird flu on a global scale?
- This global problem, which is being addressed by the World Health Organization and a number of other international organizations. The GHG problem is a real problem and should not be underestimated. But, on the other hand, one should not exaggerate it and sow panic.
Let me remind you that at the beginning of this century, world health services under the auspices of WHO dealt with another new infection - SARS, or atypical pneumonia - in less than a year. So there is hope to defeat bird flu too.
- Why do they destroy birds? What effect do they want to achieve?
- Let's start with the fact that only poultry - sick and infected - are destroyed. If diseases appear in chickens, the entire population in a homestead or on a poultry farm is destroyed. Chickens get seriously ill and die quickly. All people who became ill with AI were infected from poultry.
The main reservoir of AI in nature is waterfowl; they often suffer an asymptomatic form of infection, but shed the virus for quite a long time (up to 20-40 days).
Wild birds are not destroyed. It is important to protect poultry from contact with them. Shooting of wild birds is carried out in exceptional cases, by decision local authorities, in areas immediately adjacent to large poultry complexes.
- Summer is coming. And almost every mother thinks about whether it is worth going to the village to visit her grandmother or to the dacha in the world latest news about bird flu. What should mom need to provide?
- Of course, you need to go to nature, to the country, to the village with your child. But the mother must comply with a number of requirements:
- do not allow the child to play with poultry and chickens, chicks that have fallen from a nest in a tree, do not kiss chickens or birds;
- no need to feed children warm, freshly laid eggs! Be sure to heat treat them;
- keep the birds in a fenced poultry house;
- do not allow children to play where there is bird droppings;
- ask your child to wash their hands as often as possible;
- do not allow swimming in small bodies of water where there are waterfowl.
- How can you get infected with bird flu?
Several main routes of infection have been identified:
- when eating insufficiently heat-treated poultry meat, raw eggs;
- upon contact or playing with sick birds (chickens, ornamental birds, etc.);
- when fluff or feathers infected with droppings get on a person’s hands and then into a person’s mouth;
- when trying to take the beak of an ornamental bird or a wild chick into the mouth, poultry;
- when swimming in a small pond where birds swim;
- when playing on an area contaminated with bird droppings.
- Is it possible to eat poultry meat? And if so, how to prepare it so as not to fear for your health or the health of your small child?
- Poultry meat can and should be eaten. Just don’t need to buy it secondhand. Certain requirements must be observed: poultry meat should be stewed for at least 30 minutes; it is better not to bake the whole chicken carcass.
Remember that heat treatment kills the avian influenza virus.
- What about eggs?
- Should not be eaten raw eggs. Those that are hard-boiled are safe.
- What are the signs of bird flu in humans?
- The main signs of PG in humans are conjunctivitis, rhinitis, lacrimation, as well as general symptoms that are observed with the flu. But for some time the disease can be asymptomatic. Since the main victims of this virus are children, you need to carefully monitor their well-being, especially if the child has had contact with domestic or wild birds. If you suspect PG, you should immediately consult a doctor.
- Are there any methods of treating bird flu today?
- If a child or adult falls ill, you must call a doctor. Antiviral drugs are recommended for the treatment of PG: arbidol, algirem, oseltamivir or Tamiflu, zanamivir, remantadine. The sooner treatment begins, the better.
- Is it possible to get vaccinated and forget about this threat?
- So far, vaccines have been developed only to protect birds from AI. Birds in households are actively vaccinated. There are no vaccinations that protect humans from AI; they are under development. However, during the pre-epidemic influenza season, it is recommended to be vaccinated against human influenza. First of all, such vaccination is aimed at protecting children and elderly people suffering from chronic diseases from influenza, who usually experience the disease more severely. Domestic and licensed foreign inactivated vaccines are used, the influenza vaccine, which protects against influenza and increases the body's nonspecific defenses.
Prepared by Anastasia BUYANOVA
