The Delta variant with the K417N mutation, also known as the “Mountaineers” variant, has cropped up 14 times in Japan, and 13 of those samples were in travellers from Nepal – mostly climbers from Everest expeditions. At least 100 cases were reported at the Everest base camp, it is believed that the variant could have been spread by climbers ascending the mountain despite widespread national lockdowns across the globe. Cases have also been identified in India, Japan, Portugal, and the UK.
According to Dr Jeff Barrett, director of the COVID-19 Genomics Initiative at the Wellcome Sanger Institute in the UK, at least one case has been found in the US.
The mountaineers variant B.1.617.2 + K417N has also been blamed for the axing of Portugal from the UK’s green travel list. See this report