Public health experts have expressed concern over the holding of house parties during the pandemic, saying now is not the time.

Acting Chief Medical Officer Dr Ronan Glynn said: "There are safe environments, there are ways to keep environments safe and then unfortunately in the context of a pandemic, there are less safe environments, one of which is house parties".

He added: "We're pleading with people, particularly in the context of what we are seeing this evening, that now is not the time. Now is actually the time to limit your contacts".

The Chief Clinical Officer at the Health Service Executive warned that young people are not immune even from the most serious effects of the virus.

Dr Colm Henry said "if it runs rampant among younger people, that will lead to uncontrolled transmission".

He said the message is that young people can catch the virus and young people can get very sick.

"We are relying on a society solidarity to protect those who are most vulnerable."

The Chair of the Epidemiological Modelling Advisory Group said a house party is the perfect way to spread the virus out into the community and into people who are vulnerable.

Prof Philip Nolan said: "Some young people who get this [virus] will become severely ill, they are not invincible."

This evening's briefing at the Department of Health heard that the rise in the Covid-19 infection rate here is a "serious concern".

The reproduction rate, or the number of people who become infected from each positive case, has increased to an estimated 1.8 from 1.3 a week ago, Prof Nolan added.

"A reproduction number of almost 2 is a serious concern, and although we have not yet seen a significant increase in community transmission, there is a significant risk this could develop over the coming days and weeks," he said.

He added that a sharp increase in the number of cases has been reported over the last week, and he said "there are a number of causes for concern" in the latest data.

There is a real risk that community transmission could develop over the coming weeks, he said.

"This emphasises the need for each of us to be extraordinarily cautious, so that we don't contribute to any further transmission of the virus."

Dr Glynn said there have been no clusters or outbreaks related to bars serving food and restaurants, but he said there have been a number of cases in people working in restaurants and hotels.

On calls for evidence to be published on how the opening of all pubs would lead to outbreaks, he said "there is nothing magic about this evidence".

He said there are numerous places across the world where pubs have led to significant clusters and outbreaks in cities such as Aberdeen and Sydney.

Dr Glynn said the decision not to open all pubs was taken as part of the overarching aims of protecting public health.

"We have a pandemic here. It has not gone away. This disease is lethal. We have had a very significant number of deaths in this country and we need to do everything we can to ensure we don't go back to where we were earlier this year." 

The Department of Health was today notified of five additional deaths and 69 new Covid-19 cases.

A specific warning has been issued to the people in Kildare, Laois and Offaly to pay particular attention if they have symptoms of Covid-19 and to double down on public health measures, after a significant number of cases and clusters in those three counties.