Clearly understood. Can you get bird flu from buying food in a store? Biologist Ramn told whether it is possible to eat chicken infected with bird flu. The dangers of meat infected with bird flu.

Among all avian diseases, influenza is still considered the most dangerous. Due to the high mortality rate of the chicken population and the losses caused on the farm, the disease is called plague. How to recognize an insidious enemy, where to expect him from and whether it is possible to save your feathered charges - we will talk about this later in the article.

Chicken flu and its characteristics

According to researchers, chicken flu includes about 10 strains that are fatal to chickens. Of all the types of infection studied, the most dangerous, even for experienced poultry farmers, are H5 and H7.

Did you know? In ancient times, influenza was called "influenza." This name is due to unpleasant symptoms, the occurrence of which was associated with the placement of the planets and the Moon. The level of medicine at that time did not allow us to explain these processes in any other way.

The disease is characterized by a sharp incidence and rapid development of the virus. If no action is taken in a timely manner, you can lose your entire livestock. In addition, in recent years, scientists have begun to talk about the threatening danger of human infection.


The first of these cases was recorded in Hong Kong. Then the H5N1 bird pestilence became fatal for an entire settlement. Note that similar outbreaks, when poultry farm owners became infected with the disease, also occurred in Europe, Asia and Africa.

Infected waterfowl are carriers of the infection. Many of them were able to adapt to it during the period of mutation of the virus and survive, remaining active carriers of the disease. It is typical that avian influenza is asymptomatic in wild animals, but for domesticated birds the virus is lethal.

In order for one chicken to become infected with this disease, a single stay in the environment of wild birds or their environment is sufficient. And to infect the entire herd, it may well be enough:

  • malnutrition;
  • over-compacted poultry house;
  • lack of periodic disinfection of feeders and drinkers;
  • long-term transportation of livestock;
  • contact with recovered and infected individuals, as well as with their eggs and feathers;
  • presence of rodents in the chicken coop.


Swelling of the head is one of the final symptoms of the disease

Did you know? Every year in the modern world, from 250 thousand to half a million people die from influenza.

Young individuals whose immunity has not yet strengthened are at particular risk of infection. According to researchers at the University of Oxford, who devoted a lot of time to studying this topic, the spread of bacteria and mass mortality of poultry begin due to the fact that chickens at home, due to their short life, do not have time to form strong protective functions of the body. It was this factor that influenced the sudden increase in focal outbreaks of influenza in poultry.

Danger of the disease and methods of transmission

Another unpleasant news for chicken farmers is the ability of bird flu to infect other feathered inhabitants of the farm yard. The most vulnerable to infection are turkeys, ducks and geese, which can spread viruses. That is why, when one individual is infected, all living creatures in the poultry house die.


Short-term contact with wild birds is enough for chickens to become sick.

Scientists have identified several ways of becoming infected with bird flu:

  1. The droppings of wild waterfowl and other birds get into the chicken coop and walking areas of the chickens. When dried, its particles, along with dust, can fall into Airways, which also poses a danger to humans.
  2. Consumption of contaminated meat and egg products and water. From the body of an infected bird, the virus spreads into the environment through feces, secretions, and hatching eggs. If you eat poorly cooked meat or soft-boiled eggs, there is a very high risk of infecting people. If there are feathers, excrement and eggs of sick birds in the chicken coop, other birds will also become infected. It is unacceptable for wild birds to enter poultry houses, drink water from drinking bowls and eat food intended for domestic animals.
  3. Contact with cats. This guy is amazing this moment is fraught with mortality due to the fact that cats can bring the infection into the yard by swallowing an infected rodent outside the yard. Therefore, it is better not to allow furry charges into the chicken coop. After all, due to physiological characteristics Mammals have stronger immunity.

Important! The avian influenza virus is sensitive to iodine, 70% alcohol, formalin and Na hydrochloride.


To prevent infection with avian disease, people need to:

  1. Wash your hands thoroughly with soap after each visit to the poultry house, as well as before eating food.
  2. Drink only boiled bottled water.
  3. Eat food (especially meat and eggs) that has undergone long-term heat treatment.
  4. Avoid contact with wild waterfowl (swans, ducks, geese, storks, cranes, herons).
  5. Observe personal safety measures during agricultural work. It should be borne in mind that viruses remain viable for a long period. For example, the infection can persist in manure for up to 3 months, and in water bodies for 30 days. Low temperatures contribute to this.
  6. Observe domestic birds and changes in their behavior. After all special meaning have timing for diagnosing the disease and therapeutic measures.

Did you know? According to the World Health Organization, from 2003 to 2005, 112 cases of human infection with the H5N1 avian influenza virus were registered worldwide, of which 57 were fatal. The sick people were mainly residents of Vietnam, Thailand, Cambodia, and Indonesia.

Main forms of bird flu


Modern veterinary science classifies influenza as RNA viruses of the genus Orthomyxoviridae, which, according to serological characteristics, include 3 serotypes:

  • A- its carriers are wild waterfowl. Outbreaks of this infection often cause pandemics among humans and deaths in poultry. The serotype is considered the most virulent and pathogenic for humans and can lead to serious complications. Varieties of influenza A are divided into several strains (H1N1, H2N2, H3N2, H5N1, H7N7, H1N2, H9N2, H7N2, H7N3, H7N5, H10N7 and others);
  • B- the serotype is less common compared to the previous one. It mutates 2-3 times slower and is characterized by genetic diversity. It is characteristic that its mutations lead to changes in circulating strains every 3-5 years, which is the cause of the corresponding epidemics. Note that the insignificant mutagenic potential and the limited number of virus carriers lead to the fact that the influenza B pandemic has not been recorded in nature;
  • WITH— viruses of this serotype infect people and animals, and also provoke severe complications and local outbreaks. The absence of mutations in this form of influenza means that a person gets sick with it only once in his life, and subsequently develops lasting immunity.

Important! In humans, the symptoms of bird flu are no different from those of other viral infections, but the mortality rate is much higher. Patients experience: headaches and muscle pain, general weakness, increased body temperature, nausea, vomiting, diarrhea, bleeding from the nose and gums. On the 5th day of the disease, breathing problems begin.

Today, scientists know about 15 subtypes of type A viruses. The most dangerous of them are considered to be H5N1 and H7N7. Simultaneous circulation of several strains of influenza is possible. In order for an infection to strike a chicken body, it takes very a short time. After just 48 hours of disease development, the entire livestock can be lost.
Pupil damage may be a symptom of bird flu

There are cases when the disease is asymptomatic and mild. Then, in domestic birds, the dynamics of egg laying may decrease and the external characteristics of the feathers may deteriorate. But severe forms of influenza appear within 20 hours after the infection enters the bird’s body. The duration of the incubation period can be from 3 to 5 days.

The course of bird flu can be characterized by the following forms:

  • acute(the most dangerous with a bright clinic);
  • subacute(the illness lasts from 10 to 25 days and is characterized by an unlikely mass death of livestock; recovery occurs in approximately 80 percent of cases);
  • chronic(occurs when infection with a low pathogenic strain occurs and is asymptomatic).

Stages of avian influenza disease

Viral infection, entering the chicken body, multiplies on its mucous membranes. Within 4 hours, the strain infects the blood, adversely affecting its formula, causing a deficiency of red blood cells.


During the entire period of stay in the body of any living creature, the influenza virus goes through 4 stages of development:

  1. It is characterized by the proliferation of infection and the accumulation of toxic substances in the body.
  2. The virus already enters the blood and is easily detected in its composition. This is the period of viremia, when there is a massive mortality of the chicken population. It occurs due to the release of toxins.
  3. The reproduction of viruses has already stopped, and the body produces antibodies.
  4. An accumulation of antibodies occurs in the body of a sick bird, which triggers a mechanism of resistance to the disease.

Symptoms of avian influenza

The fact that pets have become infected with bird flu can only be guessed when the disease progresses in acute form, as well as in cases of highly pathogenic strains that are hazardous to health.

The disease is manifested by the following symptoms:


Important! The H5N1 and H7N7 viruses are transmitted by airborne droplets from an infected bird to humans. So far, there have been no cases of transmission of infection between sick and healthy people.

Diagnosis of influenza

It is important to observe the behavior of the chickens under your care and promptly respond to any deviations in their behavior. There is currently no effective treatment for deadly strains of influenza. Therefore, if you detect the slightest symptom of the disease, it is advisable to inform the veterinary service to check the diagnosis.

The disease is confirmed by histological examination of dead chickens. In such cases, we usually find:


Fresh pathological material from dead chickens (liver, lungs, brain) is also examined in the laboratory. In order to preserve the viral infection, it is permissible to freeze the test samples to 60 degrees Celsius or keep them in a glycerin solution. To confirm the results obtained in infected chickens various stages During the course of the disease, a blood serum test is taken. The data obtained allow us to conclude about the presence or absence of the avian influenza virus.

Experts consider the diagnosis confirmed in the following cases:

  • isolation and identification of a highly pathogenic virus (especially in the presence of signs of subtypes H5 and H7);
  • the presence of identification features of ribonucleic acid;
  • the presence of antibodies to hemagglutinins of viruses of subtypes H5 and H7.
After diagnosing a dangerous disease, to prevent its further progression, all infected individuals are killed. Meat and egg products of such poultry are not suitable for consumption and must be destroyed.


In sick individuals the crest turns blue

In cases where focal outbreaks of avian influenza with fatal outcomes have been recorded in neighboring regions, it is important to completely limit the free range of domestic birds and keep them in complete isolation from the external environment for the next 25 days.

Important! The avian influenza virus is easily destroyed by heat treatment. Infectious agents in meat die when held for ten seconds at a temperature of +85 degrees Celsius.

Is it possible to treat bird flu?

Even if only one chicken in your chicken coop died from an unknown disease, if the diagnosis of bird flu is confirmed, you will have to kill the entire flock in a bloodless manner and burn it. This requirement is justified by the fact that the disease cannot be treated, and the living creatures were in close contact with each other. After slaughter, the poultry house should be disinfected several times.

Despite the development of veterinary medicine, today there is no vaccine against this dangerous virus. Scientists explain this situation by the intensive spread of the strain and its rapid mutation. That is why all attempts to invent an antidote were doomed to failure. So far, researchers have only been able to select compounds that inhibit the development of the virus in the body.


For personal safety reasons, all owners of homestead farms and poultry farms World organization health recommends:

  1. Limit contact between poultry and any wild animals.
  2. Keep children away from wild waterfowl.
  3. Dead animals should be disposed of by burning or in specially designated areas.
  4. If there are sick individuals in the flock, care for poultry, protecting yourself with a respirator, mask and gloves. You should also be sure to wear removable shoes. After work, be sure to wash your face and hands with soap, and treat your clothes with special disinfectants to which influenza viruses are sensitive.
  5. Never eat the meat and eggs of a sick bird or a bird in contact with it.
  6. Immediately report cases of illness to veterinary specialists.
  7. If there are symptoms of viral infections in people developing against the background of chicken death, urgently seek medical help.
  8. Always store meat and egg products in separate containers in the refrigerator.

Did you know? The first mention of bird flu dates back to 1878. The disease was recorded in Italy by the veterinarian Peroncitto. Due to the massive death of livestock, it was initially called “chicken plague”.

Prevention of bird flu

According to experts, no measures guarantee 100% protection of livestock from harm. But still, if you act comprehensively, you can create a reliable barrier that not a single strain can overcome.


Key preventive measures in the fight against insidious avian influenza are:

  1. Complete isolation of poultry from wild counterparts.
  2. Restricting domestic animals from publicly accessible bodies of water, and in cases of focal outbreaks, from possible places of residence of wild birds (this period can last for several months, so reliable and cozy enclosures will be very appropriate).
  3. Strict control of feed consumed by livestock and water quality. It is unacceptable for young animals to feed on eggs of unknown origin. It is better to use homemade products.
  4. Regular disinfection of feeders, drinkers and poultry houses.
  5. Setting up balanced nutrition from the first days of life of chicks, as well as the introduction of vitamin complexes into their daily diet.
  6. In cases of suspected infection, you can give sick animals "Terramycin" (spray the medicine at a 20-centimeter distance from the sick chicken), "Chlortetracycline" (the drug is added to feed mash at the rate of 0.3 g per 1 kg of live weight).
Preventing a disease is always much easier than treating it. And in in this case, when many years of attempts to find a cure for a dangerous virus have not brought the expected result, any preventive measures should be scrupulously followed. Even the most impracticable recommendations at first glance justify the desire to preserve the chicken population.

Video about chicken diseases

Good afternoon, dear readers. What is bird flu and how dangerous is it for humans? Among the problems of infectology left as a legacy XXI century last century, viral infections occupied an exceptional place. They account for more than 80% of all human infectious diseases, the number of which is steadily growing.

Not only is the epidemic process of “classical” infectious diseases intensifying, but new types of pathogens are appearing (prions, virus mutants, etc.), which cause outbreaks and epidemics of often particularly dangerous infections with high rates of mortality and disability among patients (slow infections, avian flu , hemorrhagic fevers, etc.).

Avian influenza was first identified among domestic chickens in Italy almost a hundred years ago, and in 1925 its epidemic was registered in Japan, the Republic of Korea and Vietnam. Since 1959, 21 outbreaks of this infection have been registered in various regions of the world (mainly in Europe and America), 5 epidemics occurred on poultry farms in Australia.

Since mid-December 2003, the global epidemic situation with avian influenza has become more complicated - it was already registered in 8 countries (Republic of Korea - 2003, Vietnam - 2004; Japan - 2004; Thailand - 2004; Cambodia - 2004 .; China - 2004; Laos - 2004;

Since the first report of the appearance of this infection in the 21st century in the Republic of Korea (December 12, 2003), during January-February it spread within the above-mentioned Asian countries, continuing to spread in other regions of the planet.

Everyone knows that influenza is the most common infectious disease in humans, which occurs with severe intoxication and complications, affecting the upper respiratory tract. However, not everyone knows that influenza is a disease not only of humans, but also of animals, including birds.

What virus causes bird flu?

Influenza in animals, birds and influenza in humans is caused by related viruses, which differ only in the composition and aggressiveness of their enzymes, namely the type of hemagglutinin and neuraminidase. It should be noted that the ability of a particular strain of influenza virus to cause diseases in humans or animals depends on the type of hemagglutinin and neuraminidase.

Pathogenic for humans are those strains of the virus that contain hemagglutinin of the first - third (H1 - H3) and neuraminidase of the first and second (N1 - N2) types.

In turn, diseases in animals and birds are caused by influenza viruses that contain hemagglutinin from the fourth to tenth (H4 - H10) and neuraminidase from the third to eighth (N3 - N8) types. It is believed that human infection with animal and bird virus strains is impossible.

Of the 16 currently known influenza strains that infect birds, the most pathogenic for birds are the H5N1 and H7N7 strains. For many bird species, infection with this virus is absolutely fatal.

Bird flu H5N1 and H7N7 poses a particular threat to wild waterfowl and domestic birds - chickens, ducks, geese, turkeys, which generally have no immunity to this disease and quickly die after infection.

Don't people get bird flu?

The exception is avian influenza caused by the H5N1 strain. Cases of the disease have been registered among people since 1997. As a rule, this is extremely atypical and is an isolated case of the disease, since the susceptibility of people to this strain of the influenza virus is also not high.

Infection mainly occurs through direct contact with infected birds during and at poultry farms, cutting their carcasses, collecting and packaging eggs.

Much less often, infection occurs through eating raw or undercooked eggs.

Recently, there have been reports of the possibility of airborne transmission of the H5N1 influenza virus from birds to humans.

There is no proven evidence of human-to-human transmission of bird flu. However, the concern is that due to mutations and the exchange of genetic material with human influenza viruses, avian influenza viruses can acquire new properties and be transmitted from person to person, including by airborne droplets.

In such a situation, bird flu can turn into a monster that will pose a serious danger to humanity!

The clinical symptoms of avian and “regular” influenza in humans are similar.

Symptoms of bird flu in humans

With bird flu from infection to the first clinical manifestations takes on average 2-4 days. Characteristic symptoms are high fever, dry cough, sore throat, muscle pain, migraine. In many cases, diarrhea, nausea, and vomiting are observed.

If the course is favorable, recovery occurs after seven to ten days. However, more often, avian influenza in humans becomes severe with the development of atypical (viral) pneumonia, acute pulmonary failure and ends in the death of the patient.

Treatment of avian influenza in humans

Treatment of avian influenza in humans is carried out in the same way as treatment of “regular” influenza.

The same drugs are used: antiviral, antipyretic, anti-inflammatory, expectorant, desensitizing, and the like.

In case of severe course or development of complications, treatment is carried out in intensive care and resuscitation departments.

Prevention

To prevent bird flu, you must adhere to the following recommendations:

  • avoid contact with droppings, secretions, corpses of wild and domestic birds, even if these are isolated cases of their death;
  • when in places where birds die, use cotton-gauze bandages and do not touch the mucous membranes of the eyes, mouth and nose with your hands;
  • buy poultry meat in specialized departments of stores and markets;
  • Consume poultry meat and eggs only after proper heat treatment.

Important to remember! If symptoms of an acute respiratory disease appear within 5 days of being in the place where the birds died, you should definitely seek the help of a doctor.

Antiviral therapy started in the first days of illness with avian influenza significantly increases the chances of recovery.


Join us on VKontakte, read about chickens!

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 that was noted to have the ability to cause serious illnesses 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 of greatest concern 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, mutations occurring 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 strain of bird flu 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

A 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.

Not a large number of cases of infection can occur in an accidental host, 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 incorporated genetic material from swine, bird and human flu strains. New mutations could allow the virus to evade 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 there 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 modified the H5N1 virus to spread it through airborne transmission 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).
  • A 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 can progress to 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 into the treatment of avian influenza has not been possible.

It is believed that The 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 better effect, Tamiflu should be started 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 severely ill patients, doctors may increase the recommended daily dose or prolong treatment. It should be borne in mind that drug absorption may be severely impaired in patients with severe gastrointestinal symptoms.

Patients with known or suspected avian influenza should remain at home or be hospitalized (isolated from other people).

Although Tamiflu and Relenza may be effective drugs in the treatment of 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;
  • to 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 provides health and agricultural authorities with the data they need 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 was not made available to ordinary people, as the US currently has no problems with highly pathogenic avian influenza virus.

Side effects of the vaccine include arm pain, fatigue, and temporary muscle pain. The vaccine has not been tested on large numbers of 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 result in 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.
  • Patients 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, 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 that quick fix Avian influenza outbreaks are a top public and global health priority.

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 researches avian influenza did not reveal characteristic symptoms of this disease. Most of them are due to factors environment, associated 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 other 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 juice from raw meat does 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 chronic diseases 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.

Avian influenza is a viral disease of birds that may not manifest itself in any way or may lead to their death. The viral infection is very contagious, so during an outbreak of bird flu, a large number of birds were always infected. Over time, the disease became dangerous for the human body. As a rule, people became infected from wild birds, which acted as carriers of infection. Bird flu can be classified as a deadly disease, so infection with this virus does not promise anything good man. More details about the symptoms of bird flu in humans will be discussed in this article.

People first encountered this problem back in 1997, when a bird flu epidemic broke out in Hong Kong (China). Over the next few years, the disease spread to other countries, and during this time many millions of birds, both wild and those living with humans, became infected. People also suffered from the virus, but much less frequently. By that time in the territory Russian Federation No cases of avian influenza have been found in humans.

Since the disease poses a serious threat to human health, all infected poultry must be destroyed. The avian influenza virus is very aggressive, as 7 out of 10 people infected die. The seriousness of the disease has forced representatives of many countries to actively fight its spread.

Causes

Numerous studies by scientists have made it possible to study the 2 most dangerous types of avian influenza virus: H5N1 And H7N7. Experts call them subtypes. Such viruses can easily destroy all infected birds in just 48 hours, but there are also strains that do not lead to the death of the virus carrier. In this case, infected birds suffer from a milder form of the disease.

All viruses undergo mutation over time. This also applies to influenza, thanks to the mutation of which a danger to human health has arisen. The mutated virus differs from the usual form in its dangerous properties - it began to spread not only to birds, but also to domestic animals and, as a result, people. Currently, people go to the hospital with a severe form of the disease, which can lead to fatal outcome within 10-14 days.

Characteristic symptoms

The clinical picture of bird flu can easily be confused with the symptoms of a seasonal cold. The incubation period lasts 2-3 days, although in rare cases it can last up to 14 days.

The most common symptoms of this disease include:

  • temperature increase;
  • the appearance of muscle pain or headache;
  • severe body chills;
  • development of pharyngitis and rhinitis;
  • bleeding gums, and blood may also come from the patient’s nose;
  • discomfort in the abdominal area;
  • attacks of nausea and vomiting;
  • diarrhea (occurs in every second infected person);
  • renal failure.

The development of respiratory syndrome occurs on the second day after infection with bird flu. In this case, the patient may experience viral pneumonia, accompanied by a cough and clear discharge. Hemoptysis, cyanosis and shortness of breath may also occur (the patient begins to choke even after little physical activity).

When infected with the flu child's body meningoencephalitis may also be added to the above symptoms, and with it other accompanying symptoms: confusion, vomiting, severe headaches.

Death occurs as a result of swelling of the lung tissue, which occurs during respiratory failure. When infected with avian influenza, the patient's health may also be at risk from a fungal or bacterial infection. This disease is extremely dangerous, so if you have the slightest suspicion of bird flu, you should immediately consult a doctor.

Diagnostics

The peculiarity of this pathology is also that it is almost impossible to determine it immediately after the first symptoms appear. Bird flu can be mistakenly mistaken for ordinary flu, so timely treatment may be difficult. But these two diseases are very different from each other. First of all, the common form of influenza cannot be fatal and is easily cured. There may be exceptions when the flu is accompanied by more serious illnesses. Fortunately, it is possible to predict the appearance of those infected with bird flu, because it is a “nomadic” disease and not a seasonal one.

You need to start checking each person for signs of infection in the following cases:

  • if a flu epidemic has been declared in the city;
  • domestic or wild birds begin to die en masse;
  • upon contact with a patient infected with an unknown ARVI, especially if suspicious symptoms appear a week later;
  • visiting a country or continent where outbreaks of bird flu have previously been observed;
  • the appearance of suspicious symptoms by a veterinarian or poultry farm worker.

Diagnosis of avian influenza involves medical tests and visual examination of the patient. Doctors recommend going to the hospital at the first manifestation of suspicious symptoms. Such efficiency will increase the chances of quickly and effective treatment illness.

Features of treatment

First of all, it is worth noting that self-medication of bird flu is a sure way to the grave. The disease is truly serious and extremely dangerous, so you cannot rely on the medicinal herbs that your grandmother advised you. Therapy should be carried out inpatiently, and depending on its initiation, the chances of a full recovery increase.

After the patient consults a doctor with suspicious symptoms, the doctor, after conducting certain tests, will send the patient to the hospital. If the symptoms disappear after 5-7 days from the start of treatment, the patient is discharged. But if there are no changes in the condition, doctors are forced to resort to more drastic measures. As a rule, antiviral drugs are used in combination with vitamin complexes and immunomodulators to treat avian influenza. This activates the body's defenses against the virus. Below are the most effective antiviral drugs used to treat avian influenza.

Oseltamivir is one of the the best drugs for bird flu

Table. Antiviral drugs for avian influenza.

Name of the drug, photoDescription

An effective antiviral agent, the active component of which is sodium alginate. The drug has detoxification and absorption properties, due to which it is used in medicine to treat many viral diseases. Algirem is also effective against bird flu.

An inhibitory antiviral drug that affects various viruses. Regular use of Arbidol improves the production of interferon in the patient’s body, thereby stimulating the cellular and humoral reactions of the immune system. This strengthens the body's resistance to the effects of viral infections.

Unlike previous antiviral drugs, Relenza has a selective effect on viruses. The product has regenerative and antibacterial properties, which contributes to the rapid recovery of the body after suffering from the disease.

The active component of this antiviral drug is oseltamivir carboxylate - it has an antiviral effect on the patient's body. The drug is actively used not only to treat bird flu, but also for other viral diseases.

An effective antiviral agent that can help prevent the development of viral diseases. The active ingredient in Tamiflu is oseltamivir carboxylate. It helps reduce the pathogenicity of the virus and inhibit its replication. The drug should be taken only under the supervision of the attending physician.

Another antiviral drug prescribed by doctors to treat avian influenza. The active components of the drug penetrate deep into the cells, where the proliferation of various viruses is inhibited. Zanamivir can be prescribed to both adults and children.

On a note! In parallel with antiviral drugs, doctors prescribe other drugs, the main task of which is to eliminate the clinical manifestations of avian influenza. These could be various immunomodulators, cold medications, and so on. It all depends on the specific case and the characteristics of the patient’s body.

Along with many medications prescribed by doctors, there are also those that are strictly not recommended to be taken when treating bird flu or other viral diseases. Otherwise, the patient may not only not relieve the symptoms, but also radically worsen the already difficult situation.

Reception of such medicines in this case it is strictly prohibited:

  • Antigrippin;
  • Analgin;
  • Aspirin.
  • hormonal drugs(doctors prescribe them for the development of an inflammatory process in the lungs);
  • antibacterial drugs(if a bacterial form of pneumonia has been diagnosed).

All of them are potent drugs, so their independent use is dangerous to health. All actions must be agreed upon with a doctor. This will prevent unpleasant consequences.

Prevention measures

Despite the development of modern medicine, a vaccine against bird flu, unfortunately, has not yet been invented. Many scientists from all over the world are working on its creation, but so far to no avail. Therefore, every effort must be made to avoid the occurrence of this disease.

Preventive measures include the following.

  1. Avoid contact with wild birds, especially if they are suspected of developing the disease. You should also supervise your children so that they do not play with birds.
  2. You should not buy fresh meat from unverified sources. It is not a fact that these are unscrupulous people trying to sell the meat of infected poultry.
  3. In case of suspicious death of poultry, it is not recommended to touch the corpses, especially if the bird died unexpectedly.
  4. After destroying a sick bird, you should wash your hands with antibacterial soap and wash all your clothing.
  5. At the slightest suspicion of infection with bird flu, you should immediately seek help from a doctor. The examination should be carried out by a general practitioner.

Fortunately, bird flu is very rare in Russia. But this does not mean that you need to neglect preventive measures and not follow certain rules. Only a responsible approach will protect your body from this unpleasant disease.

Video - What is bird flu