The spread of a new strain of coronavirus was first noticed in 2012, when clusters of pneumonia cases were reported from Qatar, Saudi Arabia, Jordan, Germany and Britain. Cases have now been reported in at least 15 countries across Asia, Africa and Europe. Although many people affected by it are now recovering from their illness, 45% have died – half of them from a complication called acute respiratory distress syndrome (ARDS). ARDS occurs when tiny air sacs in the lungs (alveoli) fill with fluid rather than oxygen; it requires intensive care treatment to save lives. It is not known why some people develop ARDS while others do not. This year's outbreak started with an English patient who had recently flown to Saudi Arabia.
He fell ill in June and then passed on his infection to several family members who he was staying with. Two of them also became seriously ill; one subsequently died. This suggests that while viruses like human coronaviruses often cause mild or no symptoms at all, they can pose serious risks for certain individuals if they make themselves vulnerable through travel or mixing closely with infected persons – particularly hospital staff who treat people coming down with severe illnesses without knowing what has caused them. Other scientists working in labs may be most at risk.
We're starting to understand what these viruses look like: every time we see a coronavirus we know it's going to be closer to SARS, says Ab Osterhaus, a virologist and dean of research at Erasmus University Medical Center Rotterdam in the Netherlands. I hope I'm wrong but I think [another big outbreak] could happen again.