Health chiefs have confirmed that 21 people have so far been tested for the coronavirus in Northern Ireland.
However, none of these cases tested positive.
While health authorities will not comment publicly on individual tests for suspected coronavirus and will only confirm diagnosed cases, tests to date are believed to include one on a patient who presented to a Co Down hospital last Friday.
Daisy Hill Hospital in Newry was deep-cleaned after the adult was assessed in an isolation unit.
The previous evening a full quarantine operation was launched at Altnagelvin Hospital in Londonderry after a woman and her infant son also presented with symptoms similar to the virus.
The health service is continuing to make comprehensive arrangements for dealing with the problem.
The total number of cases of Covid-19, the name of this strain of coronavirus, is around 45,000 globally, with the number of deaths in mainland China reaching 1,113.
Almost 1,400 people have been tested for coronavirus in the UK, the Department of Health said.
Eight people have so far been diagnosed in the UK, including two GPs.
The Public Health Agency (PHA) said it was working with partners across the UK, including Public Health England, the Department of Health and local health trusts, and the health service in the Republic of Ireland over the response to the virus.
Health Minister Robin Swann previously said Northern Ireland was likely "at some point in time" to have a case, but the region is prepared for it.
That message was echoed yesterday by Northern Ireland's Chief Medical Officer, Dr Michael McBride, who said the arrival of coronavirus was "inevitable".
"I think we will see cases in Northern Ireland at some stage, which is why we are preparing for a range of eventualities - and will be ready to respond to those," he said.
PHA head of health protection Dr Gerry Waldron added that the health service was monitoring for any potential cases of Covid-19 in Northern Ireland.
Dr Waldron confirmed that the Belfast Trust's regional viral laboratory was one of 12 centres in the UK testing for the virus.
"Until this week, all samples taken from people suspected of having the virus here were sent to England for testing, but the new local facility will speed up results," he said.
A helpline has also been established for anyone in Northern Ireland who has travelled to China, Thailand, Japan, the Republic of Korea, Hong Kong, Taiwan, Singapore, Malaysia or Macau in the past 14 days.
Those with concerns that they may have caught coronavirus are being advised not to attend their GP surgery or turn up to emergency departments.
Dr Adrian Mairs, the PHA's acting director of public health, said: "For anyone who feels that they may have the virus by having been in contact with a proven case, (who has) travelled from one of the affected countries or who feels symptomatic, the advice is to remain at home, self-isolate and contact our helpline number."
The PHA's helpline number is 0300 200 7885. It is open 24 hours a day, seven days a week.
To help reduce any potential spread of coronavirus, people are also being urged to follow the recommended steps for similar illnesses such as cold and flu - catch, bin it, kill it.
Always carry tissues to catch your cough or sneeze, dispose of the tissue as soon as possible after using it, and clean your hands as soon as you can because germs can spread to every surface you touch.
Earlier this week the Government announced new powers in England to keep people in quarantine to stop the virus spreading.
The local Department of Health said it would be "a matter for the Executive to consider if they wish to introduce similar regulations here".
A spokesperson added: "The department is keeping the situation in Northern Ireland under constant review."
Further information is available at www.pha.site/coronavirus.