Covid-19 infection rate in Ireland ‘probably not’ plateauing, says Nolan

Nphet member offers explanation for recent trends in coronavirus case numbers

Prof Philip Nolan, chair of the Irish Epidemiological Modelling Advisory Group. File photograph: Paddy Cummins/Collins Dublin

Prof Philip Nolan, chair of the Irish Epidemiological Modelling Advisory Group. File photograph: Paddy Cummins/Collins Dublin

 

The rate of the State’s new Covid-19 infections has slowed but is not plateauing despite appearances, according to Prof Philip Nolan of the National Public Health Emergency Team (Nphet).

New data on transmissions over recent weeks suggests new-case numbers began to grow exponentially at about 4 per cent per day from June 26th. In the space of between July 7th and 12th, counts increased from about 700 new cases per day to 1,200.

However, according to Prof Nolan, head of the Irish Epidemiological Modelling Advisory Group, after a short period of exponential growth, new cases began to slow.

“Case numbers may appear to be plateauing, but are probably not, just growing more slowly than a week ago,” he said on Friday, offering a detailed overview of Covid-19 modelling data on social media.

“If [the] growth rate is slowing, it’s because of our collective caution, and is a signal to keep up the basic public health precautions, not let down our guard.”

He said the latest wave of infection has been unusual compared with previous ones, and that the most likely explanation for the recent trends is that in late June and early July people were catching up on social contacts. As case numbers increased, however, people became more cautious again.

“We do have evidence of behavioural change,” he said. “For instance, we had a spike of travel-related cases. This is not to suggest that travel is driving the growth right now, just to illustrate a sudden shift in what we have been doing.”

Hospital admissions

Prof Nolan also said that while the underlying trend will be unclear for some time, the latest cases have been translating into hospital admissions which have also been growing at between 4 and 5 per cent per day, on average.

“Where we go next is not clear. There are many possible trajectories, depending on our level of contact and how well we reduce the risk of those contacts,” he said, appealing for people who receive vaccines to wait for them to become fully effective.