Expert: Covid-19 false negatives not a failure of the HSE, but rather science catching up with new virus

Clinical Medical Scientist, Sophie Cremen: "Indeterminate results like this happen with new science all the time."

A clinical medical scientist who is shortly to join in the testing process for Covid-19 has said the number of false negatives so far is not a failure of the HSE's but rather science attempting to catch up with a new virus.

It came after it emerged that 100 people had been told the wrong result of their test for the coronavirus.

Sophie Cremen works with Eurofins Biomnis but, speaking in a personal capacity, said the fact that there are some false negatives is more likely because "indeterminate results are common" and that the testing for the virus is relatively new, given that Covid-19 is itself a new disease.

On a Twitter thread she said: "Indeterminate results are common. Especially when we have limited data on a brand new virus and labs are being pushed to the limit."

She said she had been involved in testing for HIV and hepatitis previously and would be involved in the Covid-19 testing in the near future, and that the disease throws up particular challenges.

"These are the problems that happen with new science all the time," she said.

Ms Cremen said there can always be "borderline" results where normally the response would be to repeat the test but in the current circumstances "this not possible".

Let me make this very clear:

The false negative #covid19 results is not the governments or the @HSELive's fault.

Indeterminate results are common. Especially when we have limited data on a brand new virus and labs are being pushed to the limit.

— Saidbh 🏳️‍🌈 (@SCienceSophs) April 13, 2020

Referring to malaria, she said the cyclical nature of that disease means that sometimes someone tested at a certain point in the day may test negative but will have a positive result if checked at a different time.

She said there can be a combination of factors as to why some people receive the wrong result from their test, and added: "it's not as clear cut as it is made out to be."

On Easter Monday the HSE issued a statement in which it said fewer than 100 patients have been wrongly informed that they have tested negative for the virus.

The HSE said this is because some lab tests came back with indeterminate results.

"Unfortunately these indeterminate cases were initially reported as not detected and consequently were notified to people as such in line with the results communication process," the HSE said.

The National Virus Reference Laboratory had then reviewed the data from the original test results and retested the original samples, determining that some of those tests were "weakly positive".

The HSE has been endeavouring to contact all those affected to inform them of the proper test results and to provide any supports they require.

Useful information
• The HSE have developed an information pack on how to protect yourself and others from coronavirus. Read it here
• Anyone with symptoms of coronavirus who has been in close contact with a confirmed case in the last 14 days should isolate themselves from other people - this means going into a different, well-ventilated room alone, with a phone; phone their GP, or emergency department - if this is not possible, phone 112 or 999 and in a medical emergency (if you have severe symptoms) phone 112 or 999