A former SDLP councillor who has recovered from Covid-19 believes members of his family may have had the virus as far back as December.
Declan Boyle told how he collapsed in his south Belfast home after falling ill in March.
He later tested positive and said the symptoms he displayed - exhaustion and loss of appetite - were identical to those experienced by his wife and one of his sons when they fell ill before Christmas. The first case of Covid-19 was not confirmed here until late February.
In an interview with the Belfast Telegraph, Mr Boyle also revealed he is to donate his blood as part of a scientific trial to help others battling the disease.
He has registered with the Northern Ireland Blood Transfusion Service, which is collecting blood from those who have recovered from the virus and have been symptom-free for a month.
It is hoped that antibodies in their blood can be used to bolster the struggling immune system of infected people. The treatment works using the liquid part of the blood known as convalescent plasma.
Explaining how he fell ill, Mr Boyle said he was disturbed that there appeared to be no system of contact tracing in place as he had never been asked to identify those he could unwittingly have infected.
He said he took the initiative himself and phoned anyone he thought he could have passed the virus on to.
Mr Boyle was elected as an SDLP councillor in 2014 but left the party in 2017 in a row over abortion.
He failed to hold his seat when he stood as an independent in last year's election. He owns and manages student properties in the university area of Belfast.
Mr Boyle (58) said he began to feel unwell on March 20.
"I was sweating a lot yet I was still cold. I lost my appetite but I didn't think it was coronavirus as I had no cough," he said.
"A day or two later, I felt so exhausted that I had to go to bed in the middle of the day. I then developed a slight cough. When I got up to use the toilet the next morning, I felt myself losing consciousness in the bathroom.
"I tried to make it back to the bedroom as I didn't want to hit the toilet basin or shower when I fell. I collapsed on the bedroom floor. I don't know how long I was out for."
The former councillor said he spent the next fortnight in bed.
"I lost my sense of taste and smell. I struggled to eat anything, even a slice of toast. I drank diluted orange juice as I knew I had to keep hydrated," he said.
"I was so tired that I did almost nothing but sleep.
"I watched a bit of TV. I'm normally a news junkie but I stopped watching the news. It became too depressing, and a bit scary, with all the coronavirus deaths in Italy.
"After a week, my cough began to get worse. I remember lying in bed at 4am coughing so violently I almost had no control of it, and thinking, 'Is this the beginning of it getting really, really bad'?
"But thankfully I was always able to breathe and didn't endure the horror of gasping for air that some people have had.
"I took my temperature several times every day but thankfully it never went over 38C."
Mr Boyle, who lives with his wife and four children, said he was lucky to have an en-suite bedroom which meant he could self-isolate easily, and to be well looked after by his family.
His daughter, who is a nurse, administered the coronavirus test on him. A week later it came back positive for Covid-19 and for influenza B. Mr Boyle said he was astounded not to have been asked to list those with whom he had been in contact.
"I didn't expect my GP to do that, but I did think somebody would be in touch. It is illogical not to have contact tracing," he said.
"I contacted people myself and nobody has so far told me that I transmitted the virus to them. But there should be a system in place to do this rather than leaving it up to individuals to take the initiative themselves."
Although the former councillor did not infect his wife or children, he believes that family members may have had coronavirus in mid-December.
The first confirmed case of Covid-19 in Northern Ireland was announced on February 27. It involved a woman who had been on a skiing holiday in northern Italy and returned home via Dublin.
But anecdotal evidence from Mr Boyle and others suggests that coronavirus could have been here before Christmas when people were unaware the disease existed.
Mr Boyle said: "One of my sons, who is a student at Queen's, returned from a skiing trip in December.
"He wasn't ill but, a few days after he came home, my wife and youngest son became sick. Their symptoms were identical to mine. They felt exhausted and they lost their appetite.
"My son is 17 years old. He plays rugby and Gaelic football. He is very fit but this wrecked him for a fortnight.
"I've since spoken to other people who reported falling ill in December but just thought they had the flu. One woman attended a wedding here in December where the bride and her family were from Wuhan. She told me that she and some other guests became sick the following week."
Mr Boyle said that by volunteering for the Northern Ireland Blood Transfusion scheme he hoped to be able to help others suffering.
He warned the public to continue to take coronavirus very seriously.
"I've no underlying health issues. I don't smoke or drink and I train several times a week, but this knocked me for six," he said.
"I lost two stones and even a month on people were still telling me I looked very failed.
"I'd advise anybody who contracts coronavirus not to try to work from home. I think that's the mistake that Boris Johnson made. You just have to rest and conserve your energy.
"I wear a face mask now when I'm in enclosed spaces but I'm not a fan of gloves except for doing something like holding a petrol pump. There's too big a risk of cross-contamination when you wear gloves. People are just better off regularly washing their hands."