A bug passed from camels may trigger the next deadly pandemic, scientists warn.
Known as MERS, it causes a harmless cold in the ‘ships of the desert’ but leads to severe lung disease in patients – killing more than a third.
And it is about to become even more contagious because it is developing mutations, scientists fear.
The next may fuel its spread across the world – with one infected traveller able to start an unstoppable chain of infections.
Biologist Dr Markus Hoffmann, of the German Primate Centre, Gottingen, said: “We must develop systems that help us to predict whether a new mutation will have an impact on transmissibility.
“That is, whether the virus has an increased pandemic potential.
“As with any other viruses with a pandemic potential, it is important to assess the risk of the MERS virus.”
Humans have used camels as a means of transport for thousands of years.
They can carry about 375 to 600 lbs on their backs.
The hump backed animals provide zoo visitors with rides – and take tourists to the Great Pyramids of Giza.
MERS (Middle East respiratory syndrome) is what is known as a coronavirus – a family of bugs behind respiratory illnesses.
These range from the common cold to the dreaded SARS virus which has killed hundreds of people and infected over 8,000 since it surfaced in China in 2002.
MERS was first reported in Saudi Arabia in 2012, since when it has been detected in about 2,000 patients.
More than one in three (36%) have not survived.
Symptoms are those of a severe, acute, chest infection – similar to pneumonia.
All known cases so far have been linked to travel or residence in and around the Arabian Peninsula.
In 2015, the virus affected 186 people in South Korea – killing 38. This was after just one person brought the virus from the Middle East.
It was the largest outbreak so far.
Exactly where MERS came from remains a mystery, but it probably started in an animal.
It has been found in camels and a bat.
There is currently no vaccine or cure. As coronaviruses tend to mutate, there are growing concerns surrounding its pandemic potential.
Until now, patients have mainly been infected through contact with camels. Human-to-human transmissions are rare.
Now the first analysis of its kind has found this may be about to change – owing to MERS acquiring mutations.
It found these made the virus more resistant against the human immune system. The investigation is essential for predicting the risk of a pandemic, said the researchers.
What is more, it may serve as a blueprint for other ‘zoonotic’ viruses that can be passed from animals to humans.
The study published in the Journal of Virology said MERS causes only a mild cold in dromedary, or one humped, camels kept by Arabs for food or racing.
Domestic camels are often the main source of meat, milk and even leather or wool products.
In contrast, human infection is often fatal. The South Korea outbreak was associated with the emergence of a previously unknown mutation.
Dr Hoffmann and colleagues searched specifically for its advantageous effect. The gene variant made it more resistant to antibodies produced by the infection.
Lead author Hannah Kleine-Weber, a doctoral student, explained: “In South Korea, a mutant of the MERS virus arose that showed increased resistance against the antibody response.
“This finding shows the planned use of antibodies for MERS therapy could lead to the development of resistant viruses.”
In August a patient was treated for MERS at the Royal Liverpool University Hospital. It was just the fifth case reported in England.
The unnamed person was from the Middle East, where the infection was understood to have been contracted.
Professor Stefan Pohlmann, head of the Infection Biology Unit lab, said the German government funded lab aims to predict the risk of MERS variants and advise on diagnosis, vaccines and behaviours.
By Mark Waghorn
