More than 1,200 security guards have been withdrawn from the Pyeongchang Winter Olympics because of a norovirus outbreak. Organisers today said, out of the group, 41 suffered a sudden onset of vomiting and diarrhoea on Sunday. They were transferred to hospital and most were diagnosed with a norovirus infection. <br/><br/>The official said the 1,200-odd people were pulled out from their duties and replaced by 900 military soldiers. Health authorities were investigating the origin of the virus.Norovirus is highly contagious and can also be spread through food or water contamination.