A person suspected of having coronavirus was put into isolation at Altnagelvin Hospital in Londonderry on Wednesday, as two other people in Northern Ireland were confirmed to be infected.
It is understood the patient's admission caused considerable disruption after the patient arrived at the Emergency Department, as it had to be deep cleaned afterwards. It is also understood patients in a surgical ward deemed suitable were discharged early in order to help staff manage the situation.
It comes amid calls for consistent advice across all health trusts in Northern Ireland.
Earlier this week, the Western Trust asked members of the public not to come to any of its hospitals or care facilities in a bid to minimise the spread of coronavirus. The Trust has also asked people who have appointments to attend these unaccompanied unless it is absolutely necessary.
On its social media, the Trust said: "We are taking necessary precautions to protect our patients and staff from #COVID19. We are asking the public not to visit patients in our hospitals and community facilities unless absolutely essential.
"Where possible, please attend your appointment on your own."
The Belfast Telegraph contacted other Trusts to see if they too were issuing similar advice.
While a spokesman for the Belfast Trust said it wasn't, the Northern Trust said it understood the Health and Social Care Board was going to give a statement to the media which would apply to all Trusts.
Vice-chairman of Stormont's Health Committee Gary Middleton MLA said inconsistent information was not helpful to the public. He said: "The Western Trust has asked members of the public not to visit loved ones in hospital or in its care facilities
"I think these type of measures are sensible but what is needed is a consistent approach - not just in terms of our Health Trusts but in terms of local authorities on whether or not events should or should not be cancelled."
Mr Middleton's sentiments were shared by SDLP MLA Mark H Durkan who added: "It is vitally important at this stage and it will become even more important as this situation escalates that there is clear, concise information given by the authorities otherwise that space becomes filled with rumour and suspicion that heighten panic and that is where we don't want to be."
The Commissioner for Older People in Northern Ireland Eddie Lynch said his office has been inundated with calls.
He said: "My office is seeing an increasing number of calls from both care providers and concerned relatives of those residing in care homes in relation to Covid-19, many of whom are confused by conflicting messaging and approaches being taken."