WHO predicts risk of bird flu pandemic. What you need to know

The avian flu virus could cause a future pandemic, WHO says. People are infected with highly pathogenic avian influenza very rarely, but such cases occur every year. In 2023, there were 12 human cases in the world, and in 2024 already 76. There were also two fatal cases - children from Cambodia died from the disease. How the virus evolves and whether we should fear a new pandemic - in the material "Izvestia".

Bird flu in the U.S. and Canada

- According to the UN, during the year in the United Statesthere were 61 cases of human infection with bird flu. At the same time, not all of the sick were in contact with birds: in some cases, the virus was transmitted from animals.

- Since 2022, the H5N1 virus strain, which is called avian flu, has overcome the interspecies barrier and began to infect not only birds, but also wild animals, and in March 2024 the disease began to spread among dairy cows: they began to eat less and give discolored milk. At the same time, a case of human infection from a diseased cow was recorded in Texas. A study published in the journal Science in December showed that the version of the virus circulating among cows can bind to human receptors after a single mutation.

The case of the virus: winter flu surge expected in late December

Swine and Hong Kong subtypes of infection are spreading in Russia

- Experts cite the situation of a sick teenager from British Columbia, a province of Canada, as the most alarming case. Doctors were unable to establish his contact with farm or wild animals that could have carried avian influenza. Because of the long and severe disease, the virus mutated directly in the host's body.

How dangerous is the virus

- A characteristic symptom of bird flu epidemiologists call the rapid development of pneumonia. The virus does not simply penetrate the upper respiratory tract: it finds cells in the lower respiratory tract, which are easily affected by bird flu. Therefore, pneumonia develops quickly, within two to three days, making bird flu particularly dangerous.

- The bird flu virus can also provoke other complications, affecting different organs (heart, kidneys, brain). The virus mutates, so a person can get sick again.

- Specialists assume that in the case of mutation of the virus A (H5N1) and its transmission from person to person by airborne droplets, patients will have a clinical picture of influenza: fever, cough, runny nose, intoxication. At first, these symptoms will be pronounced and can cause severe forms of the disease, and only over time, when the virus will adapt to the human body, and the proportion of people with immunity to avian influenza will increase, the severity of the disease will decrease.

- The cold season is the most dangerous period for the spread of the virus. If a person is simultaneously infected with seasonal flu and bird flu, the viruses can exchange fragments of the genetic code, and then bird flu will be able to be transmitted from person to person. Annual flu vaccination helps prevent this scenario.

Avian flu in Russia

- Russian epidemiologists are constantly monitoring the situation with bird flu. There have been cases of the virus crossing the interspecies barrier in the country: in 2021, the world's first case of human infection with the A(H5N8) virus occurred in southern Russia. Seven female workers of a poultry farm were infected from sick birds, all of them got over the disease in a mild form.

- In Russia, as in the USA, H5N1 is most common. In 2024, human illnesses with avian flu in Russia have not been recorded, but epidemiologists are preparing for the fact that the virus may change and cause a noticeable outbreak. Existing flu vaccines do not protect humans from avian influenza, but Russia and other countries have candidate vaccines in their arsenal that target this particular virus.

- If public health authorities decide that it is necessary to vaccinate people against avian influenza, this vaccine will be put into production and will become available as soon as possible. Test systems to detect bird flu in Russia have already been developed, but it is too early to talk about their use, as well as about the release of vaccines. This will happen after the virus evolves and begins to be transmitted from person to person.

- Despite the complicated geopolitical situation, Russian doctors and epidemiologists are not excluded from international cooperation and have access to the most up-to-date information on the spread of avian influenza in the world.

How to prevent infection

- Most often, bird flu is contracted by immunocompromised people who have been in close contact with infected birds. Therefore, experts recommend taking care of your own health, avoid contact with sick animals and remember that even a dead bird can become a source of infection.

- Properly cooked poultry and egg dishes cannot become a source of infection. In the USA, against the background of cases of dairy cow disease, restrictions on the use of unpasteurized milk and cheese have been introduced. No cases of avian influenza in farm animals have been reported in Russia.

- Private poultry houses, zoos and sanctuaries are working to prevent the spread of the avian influenza virus by monitoring animal welfare, vaccinating and treating birds, and having employees use personal protective equipment. It is expected that soon vaccination of livestock against avian influenza will begin at poultry farms - with such an initiative Rosselkhoznadzor came up in 2023.

In preparing the material "Izvestia" talked to:

• Elena Malinnikova, Professor, Head of the Department of Virology of the Russian Ministry of Health of the Russian Federation, leading researcher of the I.I. Mechnikov FGBNU NIIVS, Doctor of Medical Sciences;
• Sergey Voznesensky, Infectious Diseases Doctor, Candidate of Medical Sciences, Associate Professor at the Infectious Diseases Department of Peoples' Friendship University of Russia (PFUR).