Experts keeping a close watch on Mers coronavirus. Excerpt from a long article:
So far, the virus – a so-called coronavirus similar to the one that causes Severe Acute Respiratory Syndrome (Sars), which killed hundreds of people in Asia in the early 2000s – has not been spreading particularly quickly. But the fear is that the recent upswing in cases could indicate that something has changed to make it more easily transmissable. That, combined with its current high kill rate, could make a nightmarish combination.
“We’ve seen a really sharp turn in the trajectory … [and] we’re seeing much more spillover to other parts of the world,” said Dr Kamran Khan, an associate professor at the University of Toronto and a specialist in infectious diseases at St Michael’s Hospital in Toronto.
Last year he published a study on the international spread of Mers, and describes the recent rise as “very concerning on a number of fronts”. It appears though, that the feared tipping point, when the virus mutates to become more easily passed from person to person, has not yet been reached.
A recent University of Bonn study compared the RNA (ribonucleic acid, the virus equivalent of DNA) from the viruses in 30 recent Saudi cases to the genetic sequences from earlier cases. It found the virus was not, thus far, evolving genetically. So the current surge in cases can’t be attributed to a new mutation that helps the virus spread more easily.
So what is behind the upsurge? It could be the weather, or an increase in the circulation of the virus at this time of year because more camels are being born. Some of the problem could be poor hygiene control in Saudi hospitals. Part of the explanation could simply be that now the authorities are actively looking for the disease, they’re finding more of it.
Finding a definitive reason is difficult without a better understanding of where infections are coming from. We know that people have caught the virus directly from camels, with the nasal discharges of infected animals capable of transmitting the Mers virus. However, it is unclear what proportion of infections camel-to-person transmissions account for.
“The ideal would be to address the risks at their source but … there’s a lot we don’t know about how the virus is getting into human populations. Is it directly from camels? It’s very difficult to say because there are a lot of unknowns,” said Dr Khan.