Gripe aviar: ¿debemos preocuparnos? – Blog

The aviar flu virus (H5N1) is extended geographically, and infecting new species of birds and several species of moms. At the moment, cases in humans are still few, main people exposed to livestock or infected birds, and no transmission between people has been detected. But this could change at any time.

[Este texto lo han escrito Yvette Moya-Angeler, técnica de comunicación en ISGlobal, y Adelaida Sarukhan, redactora científica en ISGlobal. Se ha actualizado el 21/01/2025.]

What is avian flu?

Aviar flu is infectious cooling that affects birds. It is caused by type A flu viruses, which belong to the family Orthomyxoviridae.

There are several strains of the aviar flu virus, Depend -of the type of protein (H and n) that present on the surface. Those of high pathogenicity (IAAP), including some H5 and H7 strains, have a very praise lethality, especially in domestic birds (Geese and ducks seem to be more resistant to a sickness). Five subtypes (expressing H5, H7 or H9) have shown to be able to infect humans.

Aviar flu is very contagious between birds And it can be expanded from farm to farm by translating animals or infected material (products, vehicles, cages, feed, clothing, etc.). Cooling can also be transmitted by contact between migratory birds and domesic birds.

Why have alarms sounded with avian flu?

The circulation of the Pathogenic Altamete Influenza Virus (IAAP) is not new but, after unique epidemiological stability, since 2020 they have stoed the contagion bulbs.

A mayor geographic distribution

In the last two years, the world has experienced an unprecedented wave of flu avian A (H5N1) that has affected – and killed – to a Large number of domestic and wild birds In many regions, including Antarctica. The propagation of avian flu in wild species could have a devastating effect on the biodiversity of our ecosystems.

To the mayor number of species

In addition, the H5N1 clado that really circulates all over the world has been able to Jump the species barrier and infect various mammals Wild and domestic, including bears, sea lions, seals, great felines, mapaches, dogs, cats, and, more reciete, hundreds of herds from cattle Dairy In the US.

Although it is considered that the transmission of the avian flu between mammals is very little effective, the Avian flu outbreak on a mink farm In Galicia, Spain, in October 2022 is a worrying fact. This is the first outbreak in which transmission of a pathogenic high strain (H5N1) between mammals is documented.

Another worrying fact: in March 2024, H5N1 infections were detected in dairy cows in the US. Since then, the virus has properma to a large number of grief, probably through the machinery used to order them. More than 890 farms in 16 states They have given positive and several tens of infections in workers in the sector have been reported, most of them with mild symptoms a moderate.

Photo: Dattatreya Patra / Unspash

Can people get avian flu?

He Risk for general population is considered, for now, low. People can be infected with an infected withiress contact or their excrement, senic-sanitary measures. Therefore, it is recommended to avoid contact with wild birds and, if any sick or dead, communicate it to the veterinary authorities of the Autonomous Community to withdraw and analyze it.

For the People working on farms And in contact extreme precautions And use personal protective equipment.

Since January 2003 until December 2024, the World Health Organization (WHO) has registered 954 Human infectives By flu virus A (H5N1 subtype) in 24 countriesand 464 deaths. Most cases occurred in Asia and in people in narrow contact with dead or live infected birds, or contaminated environments.

The 2024, USA has reported more than 50 human infections, the vast majority of them on personal exposure to dairy cows. Loss Symptoms in general have been mild (Conjunctivitis on a do) and no nearby contacts have been identified.

What symptoms do aviar flu have in humans? Is it dangerous?

A person infected by the avian flu virus can develop a disease that goes From a mild infectious of the upper respiratory tract (fever and cough) to a Tipa pneumoniaSepsis with shock, acute respiratory distress syndrome and even death.

More than half of the people who have infected with the H5N1 subtype have died (954 infectious reports, 464 deaths). It is possible that the host, the path of transmission and the clado determine viral the severity of the disease. The viral genotype that circulates reality in cattle It seems to cause milder infections (characterized above all by conjunctivitis) compared to the one that circulates in wild birds, which are usually much more serious.

Can an infected person of avian flu transmit the virus another person?

At the moment there are no cases of contagion between people. The real virus circulates between birds and cattle does not have the ability to be transmitted «effectively» between humans. But the fact that it is circulating in an every time mayor of mammals increases the probability of acquiring, Through a few mutationsThe ability to do it. Surveillance, both in animals and humans, is more necessary than ever.

Photo: Dattatreya Patra / Unspash

Should I take causcons if you were meat of birds, eggs or cow’s milk?

There’s no need. So far there is no scientific evidence that aviar flu is transmitted through the food chain. In case of living in a place where there are people of infectious lech cows, raw milk is recommended, it can already contain alive viruses. Pasteurizació, on the other hand, deactivates it.

Why does the virus expand so quickly between countries?

It is believed that the routes of the migratory birds play a role in destrination Virus geographic. Some publications suggest that anatids (ducks, geese or swans), and about migratory, their natural humid son of the virus. It is possible that climate change also plays a role: if migratory routes change, wild birds carrier of the virus reach new territories.

In addition, cooling can perform a country to Otrro Through the illegal international traffic of live birds.

What can we do before avian flu?

Hay that is indicated by working with a perspective of health (a single health), which takes into account that human, animal and planetary health are united. Three quarters of emerging diseases come today from animals: it is about zoonotic cooling in which a pathogen jumps from an animal to the human being. These emerging virus outbreaks are not going to stop, because globalization, aggression to ecosystems, irrupted it in natural habitats and the massive breeding of animals favor its appearance.