NHS Greater Glasgow and Clyde confirmed that another 18 members of the athletes' village security workforce have become ill. They have all been told to remain at home until they have been clear of symptoms for 48 hours.
Two cases reported yesterday have now been discounted. It has been reported that no athletes or team officials have been affected.
The Public Health Protection Unit of NHSGGC, Health Protection Scotland and environmental health officers of Glasgow City Council are working together with Games organisers and contractors to investigate, monitor and contain this incident.
Dr Gillian Penrice, consultant in public health medicine for NHSGGC, said: “It is important to remember that norovirus is extremely common and the numbers are consistent with what is happening in the wider community.
“It is the most common stomach bug in the UK and is usually mild and generally lasts for 24 hours.
“The symptoms being experienced by these individuals are mild and none are giving any cause for concern as a result of the virus.
“Village residents and workforce have been informed and issued with health information. There have been no reports from athletes or team officials and the Village is open and operating as normal.”
Games organisers announced today that the source of the suspected has now been traced.
Speaking after the final meeting of the Glasgow 2014 strategic group today, First Minister Alex Salmond said they are confident the probable source of the outbreak has been identified.
It has been traced to a temporary facility that was in use during construction work in the security area.
Mr Salmond said: "We're confident we've identified the cause of the outbreak, a temporary facility which was not as it should be.
"We've taken the measures necessary. We've got a terrific health service and they are on the job.
"We are confident that we're getting to grips with the cause. We will see more cases but it will tail off over the next few days."
Norovirus is the most common stomach bug in the UK, affecting between 600,000 and one million people of all ages every year.
The Athletes' Village is said to be "operating as normal" but infection control measures have been put in place and Health Protection Scotland is working with the health board and Games organisers to minimise risk.
The 700-house Dalmarnock facility was officially opened last Sunday and will host 4,500 competitors and another 2,300 support staff during the Games.
Mr Salmond said the Games will be within the budget of £576 million, plus £90 million for security.
He also announced a £3.5 million investment from the special reserve fund to increase transport services.
The strategic group held their final meeting at the SSE Hydro, where final preparations are taking place ahead of the rhythmic gymnastics competitions which start next Thursday.
Mr Salmond said: "I don't think there has ever been a better facility built in the history of the Games as the Hydro.
"It's going to be a warm, friendly Games that will portray Glasgow and Scotland to billions of people across the world in the best possible fashion."
Lord Smith of Kelvin, chairman of the Glasgow 2014 Organising Committee, said: "The Commonwealth Games are known as the friendly games and I think Glasgow is going to be especially friendly.
"Glasgow people are very warm and welcoming, full of chat, and it's going to be a very warm Games."
Police will be working with the military, Prison Service and private sector to provide security during the event, which runs from July 23 to August 3.
Deputy Chief Constable Steve Allen said: "Preparations have gone according to plan and I've reported to the meeting that all looks good with our security workforce.
"We've got more than 1,300 security staff deployed today and that builds as the Games come closer.
"We are proud to be part of the team delivering a Games experience that will resonate around the country long after the athletes have gone home and the security fences have come down."
Gordon Matheson, leader of Glasgow City Council, said there is a great atmosphere in the city with just five days to go until the Games start.
He said: "The excitement is mounting by the hour. We've had the final meeting of the strategic group and it's with great confidence that we can say we are going to deliver the best Games that have ever been, and they will be within budget."