A quick fingerprint test designed to show if a person has been infected with SARS-Co-2 is significantly less accurate than the research suggested, scientists say in a new study.
The ABC-19 Rapid Test, developed for use by healthcare professionals in the UK and EU, detects antibodies against the virus in small drops of blood from a finger prick, and can show results in just 20 minutes, without the need for a specialized lab. Tools.
The idea is that healthcare workers can quickly and easily conduct tests in public in care locations, and achieve results on the spot to give an understanding of how many people in the community have antibodies against SARS-Cavi-2 – a strong selling point. Leading the UK government to order one million test devices for 75 million (approximately US 100 100 million).
The order was also guided by the positive results of a “comprehensive accreditation study” provided by the UK-Rapid Test Consortium – an organization representing professional companies, including ABC-19 developed Abingdon Health and Omega Diagnostics.
The study, led by researchers at Ulster University in Northern Ireland, is publicly available, but is still awaiting peer review.
It has been effectively found that the ABC-19 Rapid Test does not give false positive results with 100 percent specificity. Uniqueness is the ability to correctly identify the true negative pattern rather than giving a false negative.
The Ulster study also found that the sensitivity of the test was 97.7 percent. Sensitivity is the ability to correctly identify the true Positive Sample.
Now, however, a new independent study of ABC-19 has found significantly different results in terms of the accuracy of the finger-prick test.
A team of scientists from the universities of Bristol, Cambridge and Warwick analyzed blood samples from 2,847 key workers (healthcare workers and first responders) – 268 of whom previously had a positive PCR result for covid, while 2,579 had an unknown infection condition.
In addition, they tested samples from 1,995 pre-epidemic blood donors (known pre-epidemic coronavirus negative).
The results of the new study indicate that the specificity of ABC-19 is 97.9 percent (not 100 percent, as claimed by the Ulster study), and its sensitivity is 92.5 percent (based on PCR confirmed cases), but in those cases.784. .7 percent. The status of the previous infection is completely unknown.
Probably differences between the two studies. Reflects the differences between how the two groups tested the ABC-19 device, but it is suggested that the Ulster research does not provide a clear picture of the accuracy of the test.
“[The Ulster study] Two other clinical specialists, Depender Gill and Mark J. Ponsford, “two clinical specialists, Dipendra Gill and Mark J. Ponsford,” three clinical specialists who tested positive for antibodies to SARS-CoV-2 proteins in three other ASOS Known as well-known positive people. Write in a commentary article on the findings of the new study.
“Such a relatively extreme selection of reference standards, due to an extraordinary phenomenon known as spectrum bias, exaggerates the accuracy of the ABC environment.”
U.K. An independent study led by Ranya Mulchandani, the first author of a field epidemiology training program – one of the five main workers who tested positive with ABC-19, would be a false positive, in a situation where 10 per cent of the tested population was people. Infected with SARS-CoV-2.
While no test is ever perfect, the reported reduction accuracy of the ABC-19 test is something that people should be aware of, the researchers say.
“These new data are very useful at the public health level,” says Eleanor Riley, an infectious diseases researcher at the University of Edinburgh, who was not involved in the study.
“If we know how many cases are missing in the test, and how many of them are falsely positive, we can adjust our population estimates of pre-infection accordingly.”
For its part, the UK Department for Health and Social Care (DHSC) insists that the new findings are not a problem for the intended use of ABC-19 – which monitors previous infections from the healthcare level in the community, and does not diagnose current ones. Infection in members of COVID-19 people.
“This report shows that these tests have been approved for use in surveillance studies, which were purchased for it,” a statement said.
“They were never intended, and never given for widespread public use, and intentionally ignoring this fact in the report is misleading and unnecessarily irritating.”
Nevertheless, the consequences of these new revelations could be significant. There are allegations that the UK government has delayed the findings of the new study, and legal action has already been taken against the government in connection with the tests.
These findings are reported BMJ.
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