(ORDO NEWS) — According to experts, we are witnessing the sixth mass extinction of wildlife. More than a million species are threatened with extinction, according to a report by the International Panel on Climate Change (IPCC).
The number of bird species, for example, is rapidly declining, as a recent report by BirdLife International confirms – the existence of at least 40% of bird species are threatened with extinction. Among the reasons, researchers name the exploitation of natural resources and climate change.
The spread of viral diseases also poses a danger – for example, in 2022, an outbreak of bird flu led to the death of about four million chickens and turkeys (and this is only in the United States). Outbreaks of the H5N1 strain have also been reported in Canada, Mexico, China, Albania, Latvia.
In Britain, there was an outbreak of a paramyxovirus that turned pigeons into zombies: birds with twisted necks walk in circles.
What is Newcastle disease?
Pseudoplague of birds or Newcastle disease is characterized by damage to the digestive, respiratory and central nervous systems with high mortality and is a particularly dangerous infection.
Birds infected with this virus die within a few days, which does not stop the spread of the disease. Outbreaks of Newcastle are observed annually in poultry farms in Africa, Asia and South America.
The causative agent of infection is an RNA virus of the Paramyxoviridae family, which is most often recorded not only in chickens, turkeys, guinea fowls, pheasants and peacocks, but also in pigeons.
Recently, residents of the island of Jersey in the UK reported a strange and frightening behavior of birds that walk in circles, cannot fly and twist their necks badly.
Newcastle disease is a zoonotic infection, various variants of which can lead to pneumonia, encephalitis and hemorrhagic lesions of the internal organs, and mortality varies from 15% to 30%.
And although this disease is not dangerous for humans, it is still capable of causing trouble – those who often come into contact with sick birds develop conjunctivitis and mild malaise.
The first reports of strange bird behavior appeared in October, when the people of Jersey drew attention to the fall of the pigeons and their inability to balance during the flight.
Due to the severely twisted neck, the spectacle turned out to be so creepy that the media instantly dubbed the paramyxovirus PPMV-1 strain “zombie disease.” The incubation period varies from 4-6 days to a month, and there is no cure for the disease.
Symptoms of the disease
- Intense thirst
- Loss of appetite and exhaustion
- Watery litter of green color
- Paralysis of one or both legs
- Loss of coordination in head movements, neck twisting, convulsions
- A number of vague neurological symptoms
As a rule, the infection is transmitted not only through contaminated food and water, but also by airborne droplets (up to 1.5 km!).
In the wild, the main route of transmission of the disease between birds is fecal-oral (eating food contaminated with bird droppings), and among young individuals, mortality reaches 90%. Fortunately, infection can be prevented by vaccination 6 weeks after hatching.
Newcastle disease in humans
Paramyxoviruses have been discovered recently – today science knows about 12 different strains. The PPMV-1 variant infects captive birds, including waterfowl, birds of prey and songbirds.
The disease was first identified in pigeons in the Middle East in the late 1970s, and over the next decade, the infection spread to Europe, Japan, North America, and South Africa.
According to representatives of the Research Institute of Viral Infections of the FBSI SRC VB “Vector” of Rospotrebnadzor, the new version of Newcastle disease is not dangerous for humans and most often leads to mild conjunctivitis, which quickly resolves without treatment.
To date, human infection with pigeon paramyxovirus has not been described, nor has it been reported in dogs, cats, and other species that have come into contact with infected pigeons.
Other symptoms include respiratory illnesses, and people’s susceptibility to the virus is low. However, not everyone agrees with this statement and experts advise avoiding contact with infected individuals (which primarily concerns poultry farm workers), calling for universal vaccination.
Since Newcastle disease is a zoonotic disease, some researchers assume that a number of mutations can occur that can affect humans. So, according to the head of the department of the Research Institute of Epidemiology and Microbiology.
Gamaleya Alexander Butenko, paramyxovirus can follow the example of coronavirus, posing a serious threat to bats, horses and even humans and can be severe. Another problem is that even dead birds are contagious, causing them to be humanely euthanized.
How to deal with Newcastle disease?
Since there is no cure for Newcastle disease, the single most effective way to beat the infection is through vaccination. Experts also recommend keeping birds clean and regularly disinfecting equipment for keeping, transporting and feeding pigeons on farms.
People who often have to come into contact with sick birds are advised to disinfect their shoes and clothes and wash their hands thoroughly after contact with pigeons, experts advise.
To date, there are several types of vaccines, for the production of which well-known strains of paramyxovirus are used. Vaccination not only reduces the mortality and severity of the disease in birds, but also reduces the spread of the virus.
However, despite the effectiveness of vaccination, some individuals remain susceptible to the “zombie pigeon” virus. There are also known cases of complications after vaccination in the form of granulomas and abscesses, which scientists have not yet been able to explain.
And yet different variants of paramyxoviruses can be transmitted to humans – the same thing happens with other zoonoses. The state of the environment and rapid climate change have already led to an increased incidence of disease transmission between wild and domestic animals.
This means that in the future the world will inevitably face another pandemic, the causative agent of which can be a variety of infectious viral diseases.
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