The PyeongChang Olympic Organization Committee has pulled 1,200 guards from duty after 41 were struck down with the sickness bug.
Officials quickly drafted in a further 900 people to replace the guards, including some from the military, as Norovirus, also known as the winter vomiting bug, is very contagious.
South Korea Olympic Games chief Lee Hee-beom said they are on schedule for Friday’s opening ceremony, despite having to battle the spread of the virus among staff alongside the bitterly cold weather.
Lee said preparations for the first Winter Olympics in Asia outside Japan were complete with athletes arriving in the South Korean town.
He said: “We are fully operational with many of our athletes and officials here and settling into their life in the villages and training is underway at all venues.
“As a president of POCOG (organising committee), I would like to apologise for this.
“Our disease control centre other related government agencies here are now discussing countermeasures and will come up with proper measures and will be announced soon.”
However, Lee said this would have no effect on security arrangements at the Games, held about 50 miles south of the border to North Korea, which South Korea has been technically at war since 1953.
The cold weather, however, could be an issue for organisers with the opening ceremony in the open-air Olympic stadium expected to be freezing.
Temperatures are currently below freezing throughout the day, dropping to as low as -21C at night.
Lee said some fans will not attend the opening ceremony despite having bought tickets, while some competitions could be affected.
He said: “Some have cancelled their ticket for the opening ceremony.
“Regarding the potential of the delay due to the weather, the International Olympic Committee and the international federation have strict rules, for example, ski jumping can not take place if there’s a strong wind.
“We are now installing wind screens at the venue. Despite our efforts and if there is a strong wind, the event can be delayed but the decision won’t be made by me, it will be made by IOC and the federation.”
Lee said a special bag with hot packs, seatwarmers, a blanket, a hat and a windbreaker would be distributed to spectators in an effort to keep them warm at the start of what could turn out to be the coldest winter Olympics in decades.
Athletes from several countries were taken ill and some were forced to miss competitions at last year’s World Athletics Championships in London when the virus was found to have spread through one hotel.