- Olivet Nazarene University in Illinois uses pooled testing to rule out covid cases
- The method involves multiple swabs being tested for the virus simultaneously.
- If the virus is not detected then they are all considered negative for the virus.
- But if the group is positive then each sample is tested again individually
Experts say virus tests should be analyzed in batches at the start of future outbreaks because doing so can lead to early spread of diseases.
When the coronavirus pandemic started last year, technicians checked the swabs in person.
But now scientists at Olivet Nazarene University (ONU) in Illinois have found that the saliva test is just as effective.
This method involves sifting several samples together and analyzing them for traces of the virus.
If it is not detected in the sample, all participants are considered negative.
But should it be picked up, then everyone involved in the sample needs to be individually tested again.
The UK was late in introducing pool testing to accelerate its Covid diagnosis, lagging other countries including the US and Germany.
Experts say virus tests should be analyzed in batches at the start of future outbreaks as it may contain emerging diseases like covid early (stock). Pictured: A woman is tested for Covid at a testing center
A pilot scheme was introduced only in November – at the end of England’s second lockdown – before being rolled out more widely.
In the study — published in the journal Microbiology Spectrum — 3,500-odd university students had saliva samples taken at least once a week throughout the spring term.
The saliva swabs were analyzed in groups of five or ten, with each sample testing positive for the virus individually.
The positive cases were then asked to isolate, and their close contacts were traced by the university.
It detected 83 per cent of Covid cases – similar to the level of accuracy seen for the gold standard nasal swab.
Academics said it only cost the university $0.43 (32p) to process each sample, which they claimed was one of the lowest prices for the test.
The institution decided to bring in the measure after facing an interrupted autumn period where classes were canceled or postponed due to the outbreak.
Other measures in use at the time of the study included wearing face masks indoors, social distancing of two meters and limiting class sizes to 50 students.
Attendees were also asked to self-isolate for 14 days before returning to the campus.
Timeline of UK’s pooled testing regime
August 2020Former Prime Minister Tony Blair and former Health Secretary Jeremy Hunt called on the government to start using pool testing. At this point the strategy is already being deployed in other countries.
September 2020: There are suggestions Boris Johnson’s plan to process 10 million swabs a day could test 50 swabs at a time.
October 2020China, America, Germany and Israel are all using pooled testing. In the UK it has been taken over by some NHS trusts such as the one in Devon.
November 2020At the end of the month the UK launched a pilot pooled testing scheme for students. This came amid revelations of ‘Operation Moonshot’ and plans to conduct 10 million Covid tests a day.
ONU describes itself as a small Christian university in the midwestern United States.
Associate Professor Daniel Sharda, lead author of the study, said: ‘Our study represents an important step towards achieving rapid test results on a large scale, while conserving supplies and reducing costs.
‘Future pandemics should use joint strategies from the outset, when tests are otherwise limited.’
Some NHS trusts, including the North Devon Healthcare NHS Trust, began using pooled testing near the start of the pandemic.
The government faced significant pressure from scientists and politicians, including former Prime Minister Tony Blair, to implement the method widely in Britain.
But the first pilot was launched only on 24 November, clearly intended for student families to use this method.
Concerns were raised last September that 50 swabs could be tested simultaneously as Boris Johnson tried to conduct millions of tests a day.
The researchers say five to ten swabs should be collected for each test, and only among asymptomatic individuals.
Britain struggled to get its testing regime off the ground at the start of the pandemic, leaving ministers battling in the dark to understand how far the virus has spread in the country.
At one time a major component for PCR tests in the country was almost phased out, meaning fewer tests could be done.
But in April last year, former Health Secretary Matt Hancock had set a target of conducting one lakh tests a day by the end of the month.
Boris Johnson has invested more than £1 billion in testing launching sites across the country and providing lateral flow testing for every home.
The UK is currently conducting around one million PCR and lateral flow tests every day.
The UK Health Security Agency – which took over from Public Health England – has been contacted for comment.