Northern Ireland’s chief medical officer has said there is no evidence to suggest there has been a “leakage” of the Covid-19 infection across the border.
Dr Michael McBride was responding to data showing a relatively high prevalence of the disease in a number of border counties in the Irish Republic compared to other rural areas in the state.
“I don’t think that relates to spill over across the border one way or the other,” Dr McBride told Stormont’s Covid-19 briefing on Tuesday.
Outlining his reasoning, Dr McBride said the public across the island had been adhering to social distancing rules and the spread of the epidemic had been “broadly similar” in both jurisdictions.
“So I don’t believe that there is leakage of infection across the border for those reasons, there’s absolutely no evidence to suggest that,” he said.
A regional breakdown of cases earlier this week showed 626 cases of Covid-19 in Co Cavan and 373 in Co Monaghan.
Co Cavan had the highest incidence rate of Covid-19 in the Republic of Ireland per 100,000 of the population, followed by Dublin and Monaghan.
Ireland’s chief medical officer Dr Tony Holohan has already said he does not think that relatively high incidences of the virus in several Irish border counties was linked to people with the infection travelling in from Northern Ireland.
On Tuesday evening, Dr Colm Henry, chief clinical officer at the HSE, said a number of factors could be responsible for the high incidence rate in Co Cavan.
He said there had been an outbreak in a hospital in the area and some other outbreaks in residential care facilities and congregated settings.
“There were certain outbreaks there that led to much bigger numbers and a bigger impact on what is smaller populated county,” he told the daily Covid-19 briefing.
“It doesn’t appear to be directly related to the fact that it is a border county.”
Earlier on Tuesday, a leading epidemiologist said the high number of cases of Covid-19 in the border region may be due to a “super spreader”.
President of the Epidemiology and Public Health section of the Royal Society of Medicine, Dr Gabriel Scally told RTE radio there could be a super spreader in the border region but this could not be confirmed until investigations and comprehensive contact tracing are carried out.
“What we have seen from the outbreaks elsewhere and in other countries is that you can get super spreaders,” he said.
“These are people who may not have all of the symptoms and may not be terribly ill but spread the virus with a very heavy virus load.
“If you get one or two of these people, they can affect a lot of people in a local area so maybe there is a super spreader around – that could be one of the reasons.
“Whatever the reasons, I think it deserves a bit of attention and a bit of investigation and it certainly deserves discussion in a North South forum because I and other people have been saying there is no way out of this without an all island approach.
“That is what we have got to aim for.”
A memorandum of understanding between the departments of health in the Republic and Northern Ireland was signed on April 7 but some differences remain.
Citizens in the Republic are required to restrict their movements to within 2km of home but this does not apply to citizens living in Northern Ireland who cross the border.