Health chiefs are in talks to use British-made coronavirus saliva tests instead of swabs which could hit Boris Johnson’s 24-hour result target time
- The Government is reportedly in talks with epigenetics company Chronomics
- Their saliva test is easier and less painful than swabs used across the UK
- An expert involved said the samples could be read in the lab in one hour
- It comes amid mounting pressure to halve the average waiting time for a result
- Here’s how to help people impacted by Covid-19
A British-made saliva test for the coronavirus could replace swabs and help Boris Johnson meet the 24-hour result target time.
The Government is reportedly in talks with epigenetics company Chronomics about its test – two months after the US approved a similar one.
The kit, which requires someone to spit into a tube, is easier and less painful than swabs currently used at hospitals, drive-in test facilities and in home packs.
Chronomics says it has the ability to significantly increase how many tests are conducted.
An expert involved with the project said the firm was able to turn around test results within one hour of the samples arriving at laboratories.
It comes amid mounting pressure on the Government to halve its average test result waiting time of 48 hours as it moves out of lockdown.
Turning around coronavirus test results within 24 hours is ‘absolutely essential’ for an effective test and trace system, former health minister Jeremy Hunt has said.
The Government is reportedly in talks with epigenetics company Chronomics about its saliva test for coronavirus (pictured)
The kit, which requires someone to spit into a tube, is easier and less painful than swabs currently used at hospitals, drive-in test facilities and in home packs (pictured)
On average, tests are currently taking around 48 hours to come back. Some 90 per cent are coming back within this time frame, Prime Minister Boris Johnson said on Wednesday.
He has pledged that everyone who has a test gets the result 24 hours by the end of this month.
Asked by Mr Hunt what proportion of test results are available in that time frame now, Mr Johnson told parliament: ‘I can undertake to him now to get all tests turned around in 24 hours by the end of June, except for difficulties with postal tests.’
Mr Hunt, the chairman of the Commons Health and Social Care Committee, has been one of many to urge for quicker test results to ensure contact tracing is successful.
WHAT IS THE SWAB TEST FOR CORONAVIRUS?
Nasopharyngeal swabs are used to detect respiratory viruses, such as the flu and the new coronavirus.
It is the preferred choice for SARS-CoV-2 testing, according to the Centers for Disease Control and Prevention (CDC).
It involves inserting a long, flexible cotton bud into the nostril and along the nose ‘floor’. This is supposed to be done slowly so that it is comfortable.
The aim is to reach the posterior nasopharynx, a cavity made up of muscle and connective tissue, covered in cells and mucous that are similar to the nose. It continues down into the throat.
The swab is rotated several times in order to get enough cells.
The sample is then sent to a lab, where it will be tested to determine if the patient’s cells are infected with the virus.
The coronavirus is a RNA virus, which means it uses ribonucleic acid as its genetic material. A process called reverse transcription is needed to transcribe the RNA into readable DNA.
A swab sample doesn’t collect much RNA in one go, therefore a polymerase chain reaction (PCR) is used to rapidly make billions of copies so it can be analysed.
The DNA is dyed a fluorescent colour, which glows if the coronavirus is present, confirming a diagnosis.
The optimal 24 hours has been recommended by the Scientific Advisory Group for Emergencies (SAGE).
The contacts of a person with Covid-19 – traced by Government employed call handlers – are only notified when a positive test result is returned.
If this takes two days or more, it could lead to those contacts infecting more people when they should have been told to self isolate.
The Government is having discussions with London-based Chronomics about rolling out its recently developed Covid-19 saliva test, The Telegraph reports.
Philip Beales, a professor at the University College London Institute of Child Health, who has been helping to coordinate the efforts, said: ‘Our guys are working on a one hour turnaround time from receipt of the sample in the lab, to getting the actual result back.’
A study by Public Health England (PHE) is currently underway to validate the kits for use on masses of people, while Chronomics is talking with NHS bosses.
US Food and Drug Administration (FDA) regulators officially approved the first home saliva test for coronavirus – from Rutgers University – a month ago, on May 8.
In April, the developers RUCDR Infinite Biologics, based at Rutgers University in New Jersey, were given emergency use authorisation which allowed health care workers to begin testing New Jersey residents at select sites throughout the state.
Professor John Newton, the Government’s testing tsar at PHE, has previously said saliva tests are ‘really interesting’ in the diagnosis of Covid-19.
‘So we are actively looking at those and we are engaging with the companies and if they prove to be better then we will use those,’ he said.
Lawrence Young, a virologist and infectious disease expert at Warwick University, who previously told MailOnline Government officials were looking at saliva tests said: ‘I think saliva testing looks very promising and more reliable.’
The Chronomics test would involve patients spitting sputum – a mixture of saliva and phlegm – into a tube.
The collection of the sample can be done anywhere – at home, work or in hospital – by the patient themselves, and the person does not need to have symptoms.
Nasopharyngeal swabs, considered the gold standard, normally require a trained medical professional.
They are invasive and painful because to be accurate, the swab must be pushed deep into the nose until it meets resistance. It can cause someone to gag or suffer a nosebleed.
The sealed tube with saliva is sent to a lab, where technicians read it for RNA – the viruses genetic information.
Nasopharyngeal swabs, considered the gold standard, normally require a trained medical professional. They are invasive and painful because to be accurate, the swab must be pushed deep into the nose (pictured)
The Government will launch a widespread contact tracing scheme to track down people who have been in touch with infected patients. But turning around coronavirus test results within 24 hours is ‘absolutely essential’ for an effective test and trace system, former health minister Jeremy Hunt has said among other experts
Professor Beales said: ‘The saliva test has this inactivation buffer in the bottom, which inactivates the virus, preserves the RNA and then in thousands of [labs] in the country, you can just do a straightforward RNA extraction.’
According to Chronomics, founded by scientists from the Universities of Oxford, Cambridge and UCL, the saliva test is ‘super accurate’.
The website says: ‘Even small errors at high numbers can have dangerous consequences in the context of an infectious disease.
‘Our test… is incredibly sensitive (in a controlled lab environment it can detect a single copy of the virus), it is highly specific to SARS-CoV-2 (and won’t be confounded by other human viruses) and it will detect all strains of the virus that have evolved to date.’
Scientists at Yale found saliva tests had ‘greater sensitivity’ than swab tests and were more consistent in their results.
Writing in their pre-print paper, researchers said saliva was a ‘viable and more sensitive alternative’ to nose and throat swabs because there is less variability in sample collection.
It is still unclear how often swab testing used in the UK produces an incorrect result because PHE has never disclosed this information.
Scientists fear as many as 30 per cent of people who have the virus get a negative result back – known as a false negative – as a result of incorrect swabbing.
There are variances in how medics – and those taking a test at home – do it.
Research by the University of Bristol found between two per cent and 29 per cent of COVID-19 tests produced false negatives.
The number of ‘true positive’ results from swabs taken from the nose was as low as 63 per cent, and 32 per cent taken from the throat, the researchers wrote in the British Medical Journal.
A review of five studies by Public Health Madrid, involving almost 1,000 people, found Covid-19 swabbing produced false negative results the first time round 29 per cent of the time.
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