PYEONGCHANG (Reuters) - The number of people struck down by a virus causing vomiting and diarrhoea at the Pyeongchang Winter Olympics has more than doubled to 86, though athletes remain unaffected, the Korean Centers for Disease Control and Prevention (KCDC) said.

The PyeongChang 2018 Winter Olympic Games logo is seen at the the Alpensia Ski Jumping Centre in Pyeongchang, South Korea, September 27, 2017. REUTERS/Pawel Kopczynski

After an initial 32 cases were reported on Tuesday, 54 new cases have been confirmed as of late Wednesday, with police officers, security personnel and food preparation staff among those affected, KCDC Director Kim Hyun-jun told reporters.

The virus broke out ahead of Friday’s opening ceremony and led to some 1,200 security staff being quarantined. Organizers have had to call in military personnel to replace them.

“In order to stop the further outbreak of the virus we’re quarantining patients beginning from the diagnosis to the treatment. We’re going to minimize this outbreak,” Kim said on Wednesday night.

He added that January and February were “peak season” for the virus but fortunately athletes remained unaffected.

“There’s no confirmed cases and that’s the most important thing here, that when the athletes come to Korea they demonstrate their performance after a few years of training,” said Kim.

“In order to prevent any kind of accident that will prevent them from competing well and enjoying the Games we’re doing our best.”

An outbreak of the highly contagious virus at last year’s world athletics championships in London forced athletes from several countries to miss events.

Kim said anyone confirmed to have contracted the virus could be out of action for up to three days.

“After the diagnosis you’re removed from your accommodation facility if you have the virus. The quarantine usually ends in 48 or 72 hours.”