Rising cases of common respiratory illnesses in China and elsewhere around the Northern Hemisphere are within the range expected for winter, with no unusual outbreaks reported, the World Health Organization said.

China’s winter illness season is less severe compared to the year before, according to data from its health authority. But the proliferation of a long-standing though little-known pathogen called human metapneumovirus (hMPV) has been raising alarm both at home and in other countries.