Up to 500,000 people may have been infected with Covid-19 last week, the Chief Medical Officer has said.
In a letter to Health Minister Stephen Donnelly that was sent last Thursday, Dr Tony Holohan said that the likely population prevalence of active Covid-19 infection was between 5.7% and 9.6%, with this meaning between one in 10 and one in 20 of the population were likely to have been infected.
It comes as 19,290 new cases of Covid have been confirmed by the Department of Health today.
There are 1,062 patients with the virus in hospital, with 92 are in intensive care.
Meanwhile, the letter from Dr Holohan also states that the 14-day incidence rate is at the highest level since the pandemic began.
As of January 5, the incidence rate per 100,000 population is 4,450, which compares to 2,342 a week earlier.
The letter followed a Nphet meeting where the latest epidemiological data was reviewed.
The CMO said that the average daily case count has increased five-fold since mid-December 2021.
The majority of cases were in those aged under-45, but Dr Holohan said that incidence is high across all ages.
“Of the 124,682 cases notified in the 14 days to midnight 4 January 2021, 79% have occurred in people under 45 years of age; and 4% were aged 65 years and older,” he said.
He added that incidence is “lower and rising more slowly in older age groups” but “incidence exceeds that seen in December 2020, and in most age groups is higher than at any time in the pandemic”.
Test positivity is also increasing across all age groups, Dr Holohan said, with test positivity rates greater than 50% in those aged 5-54 years.
The number of Covid cases amongst hospital staff has also seen a “significant increase”.
There were 704 “laboratory-confirmed” Covid-19 infections in hospital staff in the week ending December 26, 2021, compared to 269 in the week ending December 19.
The letter adds that the number of cases of “hospital-acquired infection remains a concern”.
Dr Holohan said that as of January 4, there were over 6,300 staff across acute hospitals and the National Ambulance Service absent due to Covid-19.
The test and trace system is operating at surge capacity and is under “severe pressure”, Dr Holohan warned.
“The demand for testing has been particularly high amongst those aged 19-44 years,” he said.
“Clinical prioritisation is in place to ensure that those most in need receive access first. The HSE has increased testing capacity to 650,000 tests per week. PCR testing capacity is at 300,000 per week and antigen testing capacity has increased to 350,000 per week.” Meanwhile, the number of close contacts also saw a huge increase.
Citing the Contact Management Programme, Dr Holohan said that from December 27 to January 2, the total number of close contacts was 229,113, an increase of 123% on the previous week.
Dr Holohan also said that Nphet has “further reviewed its advice on facemasks within the context of the Omicron variant”.
He said that “all types of masks, including cloth masks, can significantly reduce community transmission if properly constructed, well fitted, and appropriately worn”.
He also added that “medical grade and respirator masks, if properly worn, offer greater protection than cloth masks”.