Q&A: When to take an antigen test and symptoms to watch for?

Change in physical wellbeing should be deemed possible Covid symptom, say doctors

Antigen tests, also known as rapid self-tests, can be done regularly. Photograph: Natalia Kolesnikov/AFP via Getty Images

When should I take an antigen test?

Antigen tests, also known as rapid self-tests, can be done regularly if you do not have symptoms of Covid-19 and are regularly in high-risk environment, according to public health advice.

High risk environments include cinemas, theatres or concerts, bars or restaurants, contact sports, multi-household visits and car sharing with people from other households.

Hospital Report

Chief Medical Officer Dr Tony Holohan has said: "You should only consider using an antigen test if you have no symptoms of the disease and only as a further additional tool, along with all of the other public health measures, to effectively combat Covid-19."

If I think I have Covid symptoms, should I do an antigen test?

No. The public health advice is that if you have any symptoms you should get a PCR test.


Why is that the advice?

PCR testing is considered the “gold standard” in testing for this virus due to its increased accuracy.

According to Dr Knut Moe, a general practitioner in Churchtown, Co Dublin, a lot of people are relying on antigen tests when they have symptoms, "but that's not always effective at picking up those cases of Covid".

Dr Mary Favier, Covid adviser to the Irish College of General Practitioners, agreed, adding that she had a patient who had five negative antigen tests, despite having Covid-19.

What are the Covid symptoms?

There has, understandably, been confusion around this in recent weeks as some symptoms for the Delta variant are different to those of the original Wuhan strain while vaccination may result in people having milder symptoms.

Dr Moe said there is a spectrum of symptoms and he has treated patients with only scratchy throats and runny noses, who later tested positive for the virus.

There are also the more widely reported symptoms such as a loss of sense of smell or taste, difficulty breathing and a cough.

“Somebody just getting a head cold or a scratchy throat or just feeling a bit off, they can all be symptoms,” he added.

But that sounds just like the cold I get every year?

Well, the common cold is a coronavirus and Covid is a coronavirus.

“This is the problem, it can mimic so many other illnesses,” Dr Moe added.

So how do I know if I have a cold or Covid-19?

To put it simply, doctors have said you should assume you have Covid-19 until you know otherwise.

If you experience any change in wellbeing, you should contact a GP and get advice, Dr Moe said.

They can then either refer you for a test, allay your fears or bring you in to be examined. An antigen test should not be used at this point in time.

Is that the same for children?

The HSE advice states that children can be sent to school if they only have a sniffle or are sneezing, but feel otherwise well.

A runny nose or sneezing on their own are more likely to be symptoms of a cold or other viral infection, the HSE added.

However, Dr Moe said if the sniffle lasts longer than one day or if it worsens then the child should be kept at home and tested.

“I think really at the moment, with the way the caseload is going, we have to exercise caution,” he said.

“Because the symptoms are overlapping with so many things, we really need to think about getting advice for a GP sooner rather than later or referring for a test.”

But GPs and testing centres are busy and I want an answer straight away?

Unfortunately demand is high due to the high prevalance of virus in the community, which can result in delayed appointments.

Public health advice is for people to continue to isolate while waiting for a test result or until they receive advice from a GP to do otherwise.

Should I do an antigen test if I’m a close contact?

Yes, but only if you are asymptomatic.

Since last month, vaccinated close contacts are being sent out antigen tests; they should take three tests over the course of five days.

Symptomatic close contacts should isolate and undergo a PCR test.

They will also be made available to primary school children from November 29th, if there is a case of Covid-19 in their pod.

What should I do when I get my results?

Antigen tests are supposed to act as a “red light” not a green light, public health officials have said.

That means if you test positive then you should isolate and get a PCR test.

If it is negative,you may still have the virus, and, therefore, should continue to adhere to all other public health measures.