Cold air in slaughterhouses and meat-packing factories could be behind coronavirus outbreaks, scientists say, suggesting winter could bring a second wave of Covid-19.
The entire Welsh island of Anglesey faces being quarantined after 158 staff at the 2 Sisters chicken factory tested positive for the virus, leading to the plant being closed and 560 staff and their families being sent into self-isolation.
Another plant in West Yorkshire, run by the company Kober, also closed due to an outbreak last week and 38 people caught the virus at a factory in Wrexham, Wales.
More than 1,000 workers at a meat-packing factory in north-western Germany were confirmed to have caught Covid-19 last week, and slaughterhouses and similar meat-processing facilities around the world have suffered major outbreaks of the virus.
Cramped and poorly-ventilated working conditions may be to blame because they make social distancing difficult.
But experts also suggest that the cold and sunless refrigerated buildings can allow the virus to spread and infect people faster than it would outside.
This has added to concerns that the virus could resurge in the winter in Britain, when daylight hours are shorter and the temperature drops outside. Cold and flu viruses are known to thrive in these conditions, and the coronavirus could, too.
One scientist said: ‘The perfect place to keep a virus alive for a long time is a cold place without sunlight’.
The 2 Sisters chicken factory in Anglesey, Wales, has closed after 158 staff tested positive for the coronavirus. Officials are now considering quarantining the whole island
Experts say meat processing plants may be an infection risk because they are cold and without sunlight
A Covid-19 outbreak at the 2 Sisters chicken factory on Anglesey has raised the prospect of the whole island, home to 70,000 people, having to be quarantined to control the virus.
At least 158 people working at the plant, run by a company which supplies KFC, Tesco and M&S, tested positive for Covid-19, causing the whole factory to shut down.
Schools on the island were due to reopen today but that has been cancelled because of the factory outbreak, and a total lockdown is being considered to stop the illness spreading onto the mainland.
Dr Christopher Johnson of Public Health Wales said it was likely there would be further infections in the area spreading from the factory spike.
He said: ‘Testing of employees continues, and it is likely that some additional cases will be identified in the coming days.
‘The increase in cases is as we anticipated when a focused track and trace programme is implemented, and does not mean that the spread of infection is increasing.’
ARE VIRUSES STRONGER IN THE WINTER?
Although the coronavirus hasn’t been around long enough for scientists to study whether it changes in the winter, looking at cold and flu viruses – which are most common in colder months – can shed some light on how viruses are more infectious in winter.
Dry, cold air supports viruses
For a virus that causes infection by piggy-backing on droplets of moisture coming out of someone’s airways, like Covid-19, its ability to float in the air is critical for infecting people.
Warmer air is more humid, meaning it has more moisture and droplets in the air bind to the droplets carrying the virus. This makes them bigger and heavier and causes them to fall to the ground faster, where they are significantly less likely to infect someone.
In cold air, which is naturally drier, they can remain lighter and float for longer, meaning they’re more likely to spread disease.
Flu virus gets physically harder
A study in 2008 found that the outer membrane, or shell, of a flu virus actually gets harder in cold weather.
It turns from a more liquid blob in warm weather to a tough, rubbery coating in the winter. This means the virus is stronger and can survive for longer.
There is no evidence the same thing will happen with the coronavirus, because it is a different type of organism – but it is possible.
Human behaviour changes
Viruses can spread more effectively in winter because people spend more time together indoors, where they are forced into closer contact than they would be in the park in summer.
The closer together people are, the more likely they are to spread the virus between them.
People are also more likely to get too little vitamin D in the winter, because they usually make it from exposing their skin to sunlight.
Shorter daylight hours – and cold weather even when the sun is shining – mean people don’t make as much of the vitamin, which is vital fuel for the immune system and helps the body to fight off viral infections.
Studies have found Covid-19 patients with vitamin D deficiencies appear to be more likely to be hospitalised or die than those with enough of the vitamin.
In a similar situation in the German region of North Rhine-Westphalia, at least 1,029 staff last week tested positive for coronavirus at a slaughterhouse run by the company Tönnies.
And slaughterhouse outbreaks have been reported around the world, including in the US and France, throughout the pandemic.
Experts say they are particularly at risk of virus outbreaks, in part because of the wintery conditions inside them.
Dr Chris Smith, a virologist at the University of Cambridge, said on LBC ‘temperature is going to play a part’.
He explained: ‘When I’m breathing I’m blowing out droplets of moisture from my respiratory tract and the virus which is growing in there would be packaged up in the droplets.
‘Now the droplets will hover for a period of time in the air and then sink to the ground… and if it’s very dry, cold air – and cold air carries less moisture, remember – the droplets will stay smaller and stay airborne for longer.
‘If it’s very humid, moisture joins them, makes them bigger and heavier, and they fall and they drop out of circulation faster – so temperature could be a factor.’
Sunlight is also known to degrade viruses and make them less able to survive on surfaces that are exposed to UV light.
Rays of sunlight are thought to damage the genetic material inside the virus, making it less able to reproduce and killing it faster.
Professor Calum Semple, a disease outbreak expert at the University of Liverpool, told The Telegraph that cold, sunless food factories are ideal conditions.
He said: ‘If I wanted to preserve a virus I would put it in a cold, dark environment or a cool environment that doesn’t have any ultraviolet light – essentially a fridge or a meat processing facility…
‘The perfect place to keep a virus alive for a long time is a cold place without sunlight.’
This suggests winter could bring the perfect environment for the coronavirus to start spreading rapidly again and producing a second wave of infections in Britain.
The average temperature in January is 4.9°C (41°F) and there are eight hours of daylight, compared to an average 15°C (59°F) and 16 hours of daylight in June.
Dr Simon Clarke, a cellular microbiologist at the University of Reading, said if it really is the cold, dark conditions in food factories accelerating the spread of the coronavirus, it could mean the disease will return to the population at large in winter.
He told Sky News: ‘If these places are refrigerated, do you get an increased susceptibility to infection like you get during the winter with the cold?
‘The truth is, we don’t really know. But my suspicion is it’s got something to do with the cold, refrigerated environment in food factories.’
Experts and officials have repeatedly warned about the prospect of a second wave of the coronavirus in the winter.
And there are fears a resurgence could coincide with flu season, which is the busiest time of the year for the NHS and puts it under immense stress in normal times.
Dr Hans Kluge, the World Health Organization’s chief for Europe, told a briefing last week: ‘It’s well possible that when the autumn starts and we have also the seasonal influenza, there is the possibility of a seasonal effect on the virus – but we’re not sure yet – that then we will see a second wave.
‘So the lesson is that we have to implement what we know works.
‘At the core of the strategy is to find as early as possible, isolate, test suspected people from Covid, and if needs be treat them without any stigma or discrimination.
‘At the same time (governments need) to track and quarantine contacts – contact tracing is an essential element of this strategy. But there is no single solution.’
British authorities are now considering offering free flu jabs to everyone across the country, not just those in vulnerable groups, to avoid a double outbreak.
Scientists fear that Covid-19 could return in winter when lockdown restrictions have been eased and viral illnesses in general are more common.
If that happens and there is another major outbreak, the NHS will once again be at risk of getting overwhelmed.
Vaccinating everyone against influenza could minimise this risk and mean hospitals are under less pressure to begin with and better able to cope with Covid-19 patients.
Currently, the free jabs are mostly saved for over-65s, primary school and nursery children, pregnant women, people with serious health conditions such as heart, kidney or liver disease, and people who live in care homes.
A flu jab is not expected to give people any protection from the coronavirus but to ease pressure on the health service.
But the UK is not alone in its thinking – other countries are planning to do the same and there are already reports of a global supply shortage of the flu vaccines.
Manufacturers in the UK say demand for the doses is rising but companies may not have enough time to develop and manufacture them and get them out to clinics before the cold weather hits.
GERMANY’S R RATE SOARS TO 2.88 AMID SLAUGHTERHOUSE OUTBREAK
Germany’s coronavirus reproduction rate has jumped to 2.88, taking infections above the level needed to contain it over the longer term.
It comes as more than 1,000 staff at a slaughterhouse in the country’s north-west have been diagnosed with the virus in the past week.
The figure on Sunday marks an increase from 1.79 a day earlier, the Robert Koch Institute (RKI) for public health said.
A reproduction rate, or ‘R’, of 2.88 means that out of 100 people who contracted the virus, a further 288 other people will get infected. A rate of less than one is needed to gradually contain the disease.
The number, a sharp increase from 1.06 on Friday, is based on RKI’s moving 4-day average data, which reflects infection rates one to two weeks ago.
RKI said outbreaks have been reported in nursing homes and hospitals, institutions for asylum seekers and refugees, in meat processing plants and logistics companies, among seasonal harvest workers and in connection with religious events and family gatherings.
Police vans are pictured outside the headquarters of Tönnies in Germany – hundreds of staff working for the meat-packing company have caught the coronavirus last week
The German military has had to set up a coronavirus testing facility at the Tönnies meat factory in Rheda-Wiedenbrueck, western Germany, where more than 1,000 staff have now tested positive for Covid-19
Germany’s coronavirus reproduction rate has jumped to 2.88, taking infections above the level needed to contain it over the longer term
Germany has been hailed for getting its Covid-19 epidemic under control faster and with fewer deaths than many comparable countries, but suffered a disaster last week when more than 1,000 employees at a slaughterhouse caught the virus.
The country also recorded its highest rise in cases for more than a month on Friday, with 770 people testing positive, taking the total to almost 190,000.
The most high-profile local outbreak has been a surge in cases at a slaughterhouse run by the company Tönnies in Rheda-Wiedenbrück in the northwest, near Dortmund.
At least 1,029 staff there have now tested positive for Covid-19, Deutsche-Welle reported, and the military has had to set up a testing facility on-site.
Officials in the North Rhine-Westphalia region said they have also seen outbreaks in logistics centres, refugee centres, church communities and after family parties.
Scientists have reassured, however, that the R value becomes less important when overall numbers of cases are low.
If there are fewer people infected it is more likely that a sudden outburst of cases will make the R look higher than it is because of one ‘super-spreading’ event.