Forty-two new cases of norovirus were confirmed among personnel working at the Winter Olympics in Pyeongchang on Thursday, taking the total number of people affected to 128, organisers have announced.

The Korean Centre for Disease Control and Prevention on Wednesday said 86 people had been affected, but that number has risen for another day.

POCOG, the organisers of the 2018 Winter Olympic and Paralympic Games, provided an update on the situation in a statement.

Thirty-four of the new cases are among security staff at the Horeb Youth Centre, where the outbreak originated.

Eight are from the Gangneung and Pyeongchang areas.

Nine hundred military personnel were deployed to make up for a shortfall caused by a norovirus outbreak
Nine hundred military personnel were deployed to make up for a shortfall caused by a norovirus outbreak (David Davies/PA Wire)

The Horeb Youth Centre is housing 1,200 security personnel who were quarantined, necessitating in the deployment of 900 military personnel to address a shortfall in security.

However, “those with negative test results at the above location have been released from quarantine and have returned to work,” POCOG said on Thursday.

The unpleasant but rarely serious illness is often caught through close contact or by touching contaminated surfaces or objects.

Norovirus can result in vomiting and diarrhoea, and those affected are encouraged to drink fluids to avoid dehydration.