THE LAST WEEK of January saw 317 deaths linked to Covid-19, more than 10% of all deaths up to that point.

New data from the Central Statistics Office (CSO) shows that more than 250 people died of the virus every week in the three weeks up to 29 January.

The figures are based on the actual date of death, rather than the date of reported deaths used in daily briefings.

The virus continues to affect older age groups the most, with 64% of all confirmed Covid-19 deaths to date those of people who are 80 or older.

April 2020 remains the worst month for Covid-19 deaths, with a mortality rate of 77 per 1,000 confirmed cases.

In January this year, the mortality rate was 13 per 1,000 cases. However, the CSO has advised this figure may have to be revised, owing to the lag between onset of symptoms and death.

The five weeks leading up to 29 January saw the percentage of weekly cases in the over 80s increase from 2.5% of cases to more than 9.4%.

But the highest number of confirmed Covid-19 cases is in the 25-44 age group, at 66,927.

In the four weeks up to 29 January, there were 8,730 cases linked to an outbreak.

Almost half of these cases, 4,198 (48%), were in nursing homes, 952  (11%) were in residential institutions and 1,178 (13%) were in a hospital or long-term care residence.

The over-80 age group made up 24% of all cases linked to an outbreak over this period.

There were 804 cases (9%) linked to an outbreak in the workplace in the last four weeks.

The number of people being treated in hospital has been decreasing since the week ending 15 January and stood at 539 in the week ending 29 January.

In January the number of people being treated in hospital was 54 per 1,000 confirmed cases, and the admission rate to intensive care units was four per 1,000.

It is possible these figures will be revised upwards owing to the lag between onset of symptoms and being admitted to hospital.

In the week ending 29 January, Dublin accounted for 2,030 cases or 32% of all new cases.

It was the fourth week in a row that weekly cases in Dublin had fallen.

Cork was the county with the second-highest number of new cases (635) for the week ending January 29. No other county had more than 500 weekly cases in that week.

It was the fourth week in a row that Leitrim recorded fewer than 100 new cases.

It was the third week in a row that Longford recorded fewer than 100 new cases and the second such week for Roscommon.

The average number of contacts per positive case per week was two in the week ending 29 January, down from three contacts in early January.