Ecological disaster a fact, also risk of pandemic due to bird flu virus

The question is not if, but when, a human pandemic due to the bird flu virus will occur – with the consequences of a corona crisis. Scientists are still reasonably optimistic that things will not progress that quickly. But anyone following the news about the recent outbreaks of bird flu has little reason not to see the increasing number of local infections as harbingers of an ecological and possibly humanitarian disaster. Intensive poultry farming has become a major source of infection.

The bird flu virus continues to amaze scientists. You can read and listen to that in the articles and podcasts about the consequences of new infections. Outbreaks that result in tens of thousands, hundreds of thousands, millions of dead animals. Intensive poultry farming is the main source of infection for the deadly, rapidly mutating virus. One sick wild duck flying over and pooping in the drinking water of a goose or chicken farm can easily infect a few of the thousands of animals. From there, the infection progresses exponentially. It stops when all infected animals are dead, either due to the disease itself or due to the culling of thousands of animals on farms. In the latter case, by appropriate intervention by the veterinary authorities.

The Netherlands has been hit several times by major bird flu crises. Most recently from 2021, more than six million chickens, ducks and turkeys died a pointless death. The ‘avian influenza’ has turned from a centuries-old incidental problem into a structural problem since 1996 after an outbreak in China. The virus has established itself in wild waterfowl populations and can emerge and become active anytime, anywhere. “There is no idea yet how many wild birds now carry the virus. It is also still unknown to what extent infected poultry farms spread the virus in the environment before all animals have been killed,” the statement said. update and map with infections from the Levende Have site.

Mammals also infected with bird flu

This only concerns poultry, but the bird flu virus is also circulating among mammal populations. And especially among production animals in intensive livestock farming, such as goats, sheep and cows. The recent outbreak on American dairy farms has sent shockwaves among consumers. Is it still safe to drink milk from American cows? (yes, if it is pasteurized). Cows on a dairy farm can be kept under control, but what if the virus spreads to wildlife populations? Then large-scale mortality of North American wildlife is not unthinkable.

In uncontrolled outbreaks, the virus rages through populations until there are no living animals left to infect. That produces, for example, a shocking item on Het Jeugdjournaal on, from October 29 last year: “More than 1,300 elephant seals dead due to bird flu.” Three months later the site reported Livescience: “Bird flu wipes out more than 95% of southern elephant seal pups in ‘catastrophic’ mass mortality.” The marine biologists who have been monitoring the population on the southern coast of Argentina for years were crying on the beach, because they had never experienced this before. An entire generation of newborn elephant seals died overnight, an estimated 17,000. The puppies received the virus through their mother’s milk. After reaching southern Argentina, the virus reached the Antarctic mainland and is currently threatening seabirds and penguins there.

The ‘highly pathogenic’ bird flu virus is called H5N1. This has nothing to do with five atoms of hydrogen and one atom of nitrogen, but with the so-called surface proteins hemagglutinin (H) and neuraminidase (N), which occur on viruses. These ensure adhesion to and damage to the tissue cells of the prey animal. There are 18 possible positions of hemagglutinin and 11 of neuraminidase. In principle, dozens of variants can arise from this, not all of which are equally pathogenic. The human flu viruses are of the H1 type.

Waterfowl flu viruses are H5 species. Most cause (mild) flu, upper respiratory tract infections or simply inflamed eyes. But a single one affects all tissue types. The new variant H5N1 emerged in 1996 in China, near Hong Kong, on a gigantic goose farm. A toddler was the first fatality. The fear of large-scale contamination among people did not materialize, partly due to government intervention that contained the virus.

The infection by a wild water bird with the virus from another animal, which has no defense against the virus in question, is a natural course of events. The animal in question is unlucky if the virus is of the H5N1 type. Unlike other types of viruses, H5N1 not only infects the respiratory tract or intestines, but all tissue types. The subvariant H7N7 is also highly pathogenic. The infected animal becomes full of viruses, dies an irrevocable death, and is a source of infection for every animal that comes into contact with it.

Bioindustry source of fire

The vehemence of H5N1’s proliferation is frightening enough. It becomes dangerous when fatally infected birds infect fellow birds, such as chickens, ducks or geese, that are closely packed together on a (poultry) farm. H5N1 needs moisture to move, which is why waterfowl are particularly affected, but not exclusively. Things become even worse when mammals ingest the virus: cats, dogs, foxes, bears that grab an infected animal. The scientists were surprised that (American) cows can also be infected. But then again not, given the virus’s previous unpredictable steps.

“The outbreak of the highly pathogenic bird flu virus has spread from birds to cattle in recent weeks, with several farms showing evidence of the virus in milk,” the trade journal writes. Cattle breeding on April 22. “The US Department of Agriculture (USDA) has now confirmed that cow-to-cow transmission also plays a role in the spread of the virus. The USDA is still investigating exactly how this works.”

How exactly could that be? Like any organism, a virus has only one purpose in life (although that is not the case). living organisms in the case of viruses, nor of the purposefulness of evolution): the survival of the species. Don’t believe all that talk about the meaning of life, we are on earth for one reason only: to reproduce to guarantee our continued existence. Viruses are among the oldest organisms and have managed to survive for so long because they adapt to the circumstances. It is now suspected how the virus spreads among cows: via the milking machines. They transmit the virus from udder to udder.

“The Erasmus MC is in the news worldwide because researchers have developed a bird flu virus that spreads through the air among mammals” AD, 2011

Chicken-on-chicken, mink-on-mink, cow-on-cow: that worries virologists the most. If the deadly virus can infect a mammal of the same species in a densely populated stable without the intervention of an infected waterfowl, then it means that the virus has mutated. In the ‘steps’ mentioned above, the virus adapts and becomes better and better at infecting (= surviving itself) another organism.

In 2011 wrote the AD: “The Erasmus MC is in the news worldwide because researchers have developed a bird flu virus that spreads through the air among mammals.” The virologist Ron Fouchier successively infected ferrets with the mutated virus that had mutated in a predecessor and thus obtained, after a small number of intermediate steps, a very highly pathogenic virus, which could even infect people through airborne transmission. The virus was destroyed, such tests are no longer done for safety reasons. It had been shown that such a virus could arise in the lab. And probably also in the wild.

Low chance, high mortality

No one was actually surprised that an employee of an American dairy farm became infected through intensive contact with the cows. Because bird flu is except one zoonosis, an infectious disease that can be transmitted from animals to humans, as well as COVID-19, Lyme disease, Q fever, toxoplasmosis, and salmonellosis, also contagious from person to person. However, there is an important difference with the course of the disease due to other pathogens: the risk of death. Of the more than eight hundred registered cases of human infection with H5N1, almost half have ended in the death of the victim. The other zoonoses don’t even come close to achieving that.

Optimism among scientists about the severity of human-to-human transmission is based on the limited transmission of the H5N1 virus. The fact that there are so few human victims proves that human-to-human contagiousness is low. Unlike human flu viruses, it does not reside in the upper respiratory tract, where it can reach the next victim with each sneeze. H5N1 settles deeper in the lungs.

The contagiousness of the current variants must be mentioned. Human-to-human infection is very possible, but depends on the adaptation of a mutated virus. In order not to give the virus a chance to mutate – we have seen this with the coronavirus – the initial outbreak among animals must be suppressed as quickly as possible. Rapid detection leads to thorough intervention, such as preventive culling of poultry farms. That horror is the risk of intensive factory farming. There are also antivirals and generic vaccines available that can alleviate the severity of an infection.

If large-scale human-to-human infections with a highly pathogenic H5N1 variant occur, it will take several months before a vaccine specific to that variant is developed, as we saw with the corona pandemic. That has shown what it can do in society. Sick and dead, panic everywhere, people forced to shelter in place, economic crisis and major social disruption. Division between anti-vaxers and loyalists who got every shot and major doubts about the current handling of production animals. Let’s start by improving the latter.

Huib Stam