The virus has affected chickens, turkeys, pheasants, ducks, geese, and swans in over 40 premises across the nation.

More than half a million birds have been culled in the UK due to an unprecedented outbreak of the H5N1 virus, which causes avian influenza or bird flu.

According to the Animal & Plant Health Agency (APHA) over 40 premises have been infected since last October in what is being described as ‘UK’s largest-ever outbreak’. By comparison, there were 26 outbreaks in the UK during the entire winter last year.

The virus has affected chickens, turkeys, pheasants, ducks, geese, and swans.

 The government set up an Avian Influenza Prevention Zone (AIPZ), including strict biosecurity measures, at the start of November in a bid to contain the virus.

Subsequently, a strict order to keep all birds indoors has also been enforced.

What is causing these outbreaks?

According to the poultry industry, migratory birds from Europe have contributed to the local spread of the virus. So far this winter, almost 300 wild birds have been found with the disease at more than 80 locations.

Speaking to the BBC last week, the government’s chief vet Christine Middlemiss said that she was “very concerned about what’s happening.

 “It used to be that we would have a reasonable-sized outbreak and then have two or three quiet years,” she added.

“But that’s not happening now. We’re seeing this across the whole of Europe. We need to understand better why we’re getting these ongoing infections every year.”

Asked if climate change was causing increased outbreaks, Middlemiss said: “We don’t know specifically, but it’s certainly one of the thoughts that our experts are having.

“The birds migrate to the north of Russia over the summer and mix with other birds on other global flight pathways and exchange the viruses. So it’s quite plausible that with climate change and change in pathways that different mixing is going on.”

‘Real problem is factory farming’

While the government is trying to pinpoint plausible causes for these frequent events, Juliet Gellatley, founder and director of Viva! said: “The real problem is factory farming. Whilst wild birds undoubtedly contribute to the local spread of the virus in the wild, it is human commercial activities, particularly those associated with poultry, that are the major factors responsible for the global spread of bird flu.”

She continued: “Large, industrial sized units, housing tens of thousands of birds. provide the ideal environment for infectious diseases to spread and mutate.”

Risk to human health

In her BBC interview, Middlemiss admitted that there was “a lot of virus out there”.

Moreover, avian influenza viruses are among the most dangerous viruses that can affect humans. In people, H5N1 has a case fatality rate of around 50%.

However, H5N1 is not easily caught or spread between humans yet. But scientists writing in the journal Emerging Infectious Diseases said: “If this virus acquires human-to-human transmissibility with its present fatality rate of 50 per cent, the resulting pandemic would be akin to a global tsunami.

“If it killed those infected at even a fraction of this rate, the results would be catastrophic.”

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