High level of Covid-19 positives in antigen tests confirmed by PCR result

Taoiseach says he is ‘strong believer’ in the value of antigen testing

Four in every five who reported a positive Covid-19 antigen test result to the Health Service Executive went on to test positive for the virus in an official PCR test, new HSE figures show.

For the past month, the HSE has been asking people signing up for PCR tests – the standard test used by the HSE – whether they had carried out an antigen test at home beforehand.

Of 10,258 people who said that they had tested positive on an antigen test, 79 per cent were confirmed positive under the PCR test results when they were returned. The high confirmation rate on the PCR test is in line with international data.

Some 87 per cent of people who tested positive on their antigen tests at home reported showing symptoms of Covid-19, while 63 per cent said that they were fully vaccinated.


The HSE encourages people with symptoms to seek a PCR test.

Taoiseach Micheál Martin said that he was a “strong believer” in antigen tests and that their use would be considered by the Government as part of considerations on its response to the rising number of cases of Covid-19 when the Cabinet meets on Tuesday.

‘Moderate perspective’

“The public health officials have a more moderate perspective on the value of antigen testing, but some sectors have rolled out antigen testing and that’s something that the Government will be considering as well over the next 24 hours,” said Mr Martin.

He said the continued use of Covid-19 certs showing that people have been fully vaccinated was “certainly an item on the agenda, as is mask-wearing and so on”.

The measures are being considered in response to an increase in Covid-19 cases.

New figures on HSE test results showed that Covid-19 cases have been increasing across all age groups with the 55-64-year-old age group recording the highest positivity rate of 11.7 per cent for the week to October 17th, an increase from 10.5 per cent a week earlier.

The second-highest positivity rate was among the 65-74-year-old age group, at a rate of 11.4 per cent.

‘Extra layer’

The Government's chief scientific adviser Prof Mark Ferguson said on Monday that antigen testing was "really useful" as it provided "an extra layer of protection". He said that while antigen had a role combating Covid-19, it was not a solution in itself.

The HSE has been carrying out a pilot scheme of antigen testing to screen people without symptoms across third-level colleges, creches and residential care facilities.

Initial data shows that between July and October, there were 916 antigen tests carried out on teachers and students at third-level facilities and two positive cases were returned.

At creches, there were 1,242 tests carried out and one positive case confirmed.

Under the programme, people agree to be tested twice a week. In the third-level colleges and creches, they can carry out the tests at home, while in residential care facilities they have to be supervised by a nursing manager due to the risk associated with that setting from Covid-19.

Early data from the screening in the residential care facilities shows there have been about 3,500 negative antigen test results and just two positive tests.

The programme is being carried out on a pilot basis for operational reasons to assess the distribution of the tests to the participants and the reporting of the results.

The Department of Agriculture has been facilitating the rollout of rapid antigen detection tests at meat plans and food production factories since the start of the year.

Simon Carswell

Simon Carswell

Simon Carswell is The Irish Times’s Public Affairs Editor and former Washington correspondent