By Graeme Murray A virus you’ve most likely never heard of is poised to spike this spring – bringing with it a host of wheezing and breathing problems. Health experts insist we should not assume the common contenders of flu, RSV or Covid are responsible for having a runny nose. A hugely common bug called human metapneumovirus (hMPV) is a cause of severe respiratory infections – but few people know it even exists. The virus, which brings a snotty nose, can spark a fever and cough and even breathing problems such as wheezing, is causing havoc in the US. It has now risen to record levels and one …