OSLO, Dec 3 (Reuters) - At least 13 people in Oslo have been infected with the Omicron variant of the coronavirus following a corporate Christmas party described as a "super spreader event", and their numbers could rise to over 60 cases, authorities said on Friday. The outbreak took place at a Christmas party on Nov. 26 organised by renewable energy company Scatec , which has operations in South Africa where the variant was first detected. "This party has been a super spreader event," Preben Aavitsland, a senior physician at the Norwegian Institute of Public Health, told Reuters by email. "Our...