• Avian influenza is a disease of birds caused by a type A influenza virus that is capable of infecting virtually all species of birds, whether wild or domestic.
• Between 8 December 2020 and 23 February 2021, Efsa – the European Food Safety Authority – reported around one thousand detections of highly pathogenic avian influenza in 25 European countries and countries belonging to the European Economic Area (EEA), highlighting the "risk of further spread, especially in areas with high poultry density".
• In Italy, more than three hundred outbreaks have occurred since last October, leading to the culling of over 14 million animals in an attempt to halt the disease's advance.
• The responsibility for the spread should not, however, be attributed to the animals themselves, but rather to the ways in which they are farmed, moved and killed, whether in intensive facilities or as victims of hunting.

"Avian influenza: 308 outbreaks in Italy." "18 million animals culled." "Europe's worst epidemic ever." "Avian influenza: even Queen Elizabeth's swans culled." Over recent months, headlines reporting the advance of the avian influenza epidemic have multiplied. Millions of animals have been killed and in the United Kingdom there has even been a case of human infection. But what exactly is it, and how did we get to this point?

What avian influenza is

The Istituto superiore di sanità (Iss) defines avian influenza as "a disease of birds caused by a type A influenza virus […] that is capable of infecting virtually all species of birds", whether wild or domestic. The former, especially those living in aquatic and marshy environments, such as ducks and swans, act as reservoirs for the virus. They harbour it in their intestines, often without becoming ill, and shed it through their faeces, saliva and respiratory secretions. They can, however, be highly contagious to domestic species such as chickens, ducks, turkeys and other poultry.

"The importance of health monitoring for this disease is not solely a matter of animal health but also of public health," states the Istituto zooprofilattico sperimentale delle Venezie. "Type A influenza viruses can, in fact, also infect other animals (pigs, horses, dogs, whales) as well as humans."

Two strains of avian influenza are distinguished: a low pathogenicity strain (identified by the acronym Lpai) and a highly pathogenic one (Hpai), which is more dangerous and capable of causing death in almost all cases. The viruses are further divided into various subtypes identified by the H-N acronym. The best known is H5N1, which has been circulating since 1997 and is considered by the Iss to be the most concerning due to its ability to mutate rapidly and to acquire genes from viruses that infect other animal species.

How avian influenza is transmitted and what are its symptoms?

In animals, symptoms vary both in relation to the pathogenicity of the viral strain and to the bird species affected. In humans, they can range from a mild upper respiratory tract infection (fever and cough) to severe pneumonia, respiratory distress, shock and even death.

The main risk factor for humans is exposure in environments contaminated with a high viral load and in close contact with infected animals, whether alive or dead. Situations that therefore carry a risk include live animal markets (which led to the spread of the virus in Asia), as well as slaughter, plucking, handling of carcasses, or the consumption of dishes containing raw, contaminated poultry blood.

What the current situation of avian influenza in Italy is

It is not entirely clear how this epidemic now striking Europe began or how it spread. The origin of avian influenza is attributed to the migration of wild birds primarily from north-eastern Europe (Russia, Kazakhstan and Mongolia).

Since the beginning of 2003, H5N1 has spread from Asia to Europe and Africa and has become endemic in poultry populations in certain countries. Since then, it has made a series of species jumps, acquiring the ability to infect cats and mice as well, thus becoming a far more concerning public health problem, according to the Iss.

Between 8 December 2020 and 23 February 2021, Efsa – the European Food Safety Authority – reported around one thousand detections of highly pathogenic avian influenza in 25 European countries and countries belonging to the European Economic Area (EEA), highlighting the "risk of further spread, especially in areas with high poultry density".

At the time, cases were primarily linked to certain farms in France, where, shortly afterwards, over 350,000 ducks were culled. That number doubled in December, when over 650,000 animals were killed in a single month. As a precautionary measure, farms in the United Kingdom and France were placed under "lockdown", meaning all birds were moved indoors to avoid any contact whatsoever with wildlife.

But outbreaks soon multiplied in Italy too, particularly in Veneto, which is currently the worst-affected region, along with Lombardia and Lazio. For this reason, since October keeping animals outdoors has also been banned in Italy, though this order is not always observed, as demonstrated by the latest investigation by the association Lav, which documented several violations. According to data reported by the Istituto sperimentale zooprofilattico delle Venezie, more than three hundred outbreaks have struck the peninsula since last October, leading to the culling of 13–14 million animals in an attempt to halt the disease's advance.

On Monday 24 January alone, the association Essere Animali, which has been working for months to expose the sharp rise in the spread of avian influenza, filmed the culling of over 300,000 chickens at a farm in the province of Vicenza.

But if viruses are spreading this quickly, the fault does not lie with the animals.

Wild species are always the scapegoat

"Wild birds are often seen as the villains of the situation, but they are in reality the victims of a virus that began to spread because of poultry. We use wild species as a scapegoat to justify poor biosecurity regulation and the fact that we move thousands of chickens all around the globe," Dr Ruth Cromie, a researcher at the Wildfowl & Wetlands Trust — an international charity for the protection of wild birds and wetlands in the United Kingdom — explained in an interview with the British daily the Guardian in November 2020.

In 2017, two billion chickens were transported live around the world, and the number shows no sign of declining. Even countries that are considering adopting restrictions on the transport of live animals could exclude them from the legislation, as in the case of the United Kingdom, which is deciding whether to ban the export of cows and sheep, but is not, for the time being, considering poultry.

However, the problem is not limited to the movement of animals alone. It should instead be traced back to the beginning of the chain, to the moment and place in which they are born.

In intensive farms, animals are clones exposed to viruses

Intensive farms do indeed appear to be one of the factors that allow viruses — not only avian influenza — to spread so rapidly. The Efsa has already stressed that "current biosecurity measures are insufficient to halt the advance of the disease" and that it would be necessary to "reduce farm density." In other words: there are too many animals all together.

In intensive farms, animals are crammed inside sheds in appalling sanitary conditions that create the ideal environment for viruses to spread and mutate. Added to this is the fact that they are stressed, physically weaker and lack the genetic diversity to resist the arrival of external pathogens.

This happens because all the individuals involved in the food supply chain are in effect clones, genetically selected to deliver the greatest profit in the shortest possible time. Broiler chickens, for example, which are reared for their meat, have been selected over the years to reach 4 kilos in under 50 days; laying hens to produce 300 eggs a year, compared with the 30 they would produce in the wild. This, as well as causing them enormous physical problems, makes them genetically identical and potentially more vulnerable to viruses, because they lack the genetic diversity within the group that, in nature, would make them more resilient. As Jonathan Safran Foer writes in his celebrated essay Se niente importa, on farms "Biodiversity has been replaced by genetic uniformity."

The livestock sector is also concerned

In this case, the severity of this avian influenza epidemic is declared not only by animal rights organisations, but also by members of the livestock sector itself. "This is the worst ever, both in terms of spread and in terms of the aggressiveness of the virus, given that it can kill up to one hundred per cent of the animals on a farm," reflected Michele Barbetta, the re-elected president of the poultry farmers' section of Confagricoltura Veneto, who also owns an agricultural and livestock business comprising four poultry farms in Carceri, in the province of Padova.

It should also not be forgotten that viruses can be transmitted from farm to farm via contaminated machinery, tools and equipment, vehicles, feed, cages, or even the clothing of workers.

No one talks about the hunting sector's responsibility

A particularly high risk of spread is also posed by hunting. "The Po Delta is a wet market where every season millions of birds that naturally host avian viruses are killed," journalist Sabrina Giannini notes in a post on Instagram.

It is now a year since the episode of her television programme Indovina chi viene a cena in which she also investigated the issue of avian influenza. In the exceptionally rich wetland of the Po Delta, it is the hunters themselves who attract the birds, since the most important migratory bird route from the north passes through here. "This determines the presence of very large numbers of waterfowl," Lorenzo Serra of the Migratory Avifauna Area at Ispra, the Istituto superiore per la protezione e la ricerca ambientale, specified in the episode. "Numbers that would not be so high if artificial baiting were not carried out."

In wildlife hunting reserves, furthermore, the use of live animal decoys is permitted: animals are kept inside small cages to attract others of their kind, which are then killed by hunters. "They attract wild birds, with which they share everything: water, food and viruses," Giannini concluded. A year on, nothing has changed.

The animal rights association Lav also invites reflection on the risk of avian influenza transmission to humans in these situations, given that hunting represents "the only event in which a human being can legitimately come into contact with the blood and bodily fluids of killed animals, in the absence of any precaution and without these animals having ever undergone a preventive health check."

Even a study carried out by the University of Bologna in 2