A video advocating for an airline promising to resist future COVID-19 restrictions, such as the requirements to be vaccinated, wear a face mask or pass a negative COVID-19 test, contains false information on PCR tests for COVID-19.
The video was shared on Facebook (here) and YouTube (here) and between these platforms was viewed more than 250,000 times. The woman who speaks in the video, prof. Dr. Dolores Cahill (people.ucd.ie/dolores.cahill), has previously spread false and misleading allegations about COVID-19 (here and here). Cahill was not available for comment when Reuters asked him about the information presented in the video.
After expressing her ambitions to offer international travel without restrictions, Cahill goes on to talk about a secondary plan. “I’ve launched a project to follow PCR tests in the last few weeks,” she says (timestamp 14.40).
She continues: ‘Because this whole exclusion is based on positive PCR tests, but actually in the diagnostic world, in PCR, you would never just make a positive or a negative diagnosis, you have to measure the order of the test . 1500 PCR tests were followed up in October 2020, and all were influenza A and B. None were SARS-CoV-2. ”
Later she says she intends to follow ‘PCR’ of people who consent in Ireland and the UK, and will challenge COVID-19 restrictions by taking an order in Ireland to the High Court if the series resumes as Flu return ‘(Timestamp) 15.30).
DIAGNOSIS WITH PCR
Reuters could not find credible sources to claim that PCR tests should not be used to diagnose diseases without sequencing each sample.
“PCR testing and sequencing are completely different things,” Stephanie Brickman told Reuters in an email to the World Health Organization: “It’s not that one is more accurate than the other. PCR tells you if the SARS-COV-2 virus is in someone’s body. By sequencing the virus, you will tell more about the specific strain of the virus with which the person was infected.
‘Sequence order is not used for diagnosis. PCR tests are specifically developed to diagnose a disease, for example COVID-19. During the development process, specificity is checked to make sure that they do not accidentally contract other diseases.
‘It has no benefit to patients who need a diagnosis to follow up on PCR tests, and it would waste time and resources. Sequencing is important to detect variants of the virus, but not for the diagnosis of individuals. ”
Dr Louise O’Connor (here), a researcher at the National University of Ireland, Galway, School of Medicine, also said by email that PCR tests can be used to diagnose diseases and explain how to sequence with the test related: “The first step in designing any PCR test is to track the target (the thing you want to detect),” she wrote. “Usually you will order a whole bunch of viruses or bacteria to make sure you have the order correctly.”
Patterns from this series are then selected and tested on other similar organisms and “if there is a signal from anything other than the target, it is returned to the drawing board,” O’Connor said. “Most developers will try to ensure full or 100% specificity.”
The Irish Health Service Manager (HSE) also said that it was ‘standard practice’ to diagnose many viral infections with a positive PCT test, and although it was ‘considered good practice to sequence some samples for observation purposes’ ‘, it was not necessary to sequence all samples before making a diagnosis.
A Public Health England spokesman told Reuters earlier: “Molecular diagnostic tests, such as real-time PCR, are the gold standard methods for identifying individuals with an active viral infection, such as SARS-CoV-2 (the cause of COVID-19). disease), in their airways.These tests are rapid and yield real-time results.
‘It is important to note that the detection of viral material by PCR does not indicate that the virus is completely intact and contagious, that is, can cause infection in other people. Isolating infectious viruses from positive individuals requires methods of virus culture. These methods can only be performed in laboratories with specialist inclusion facilities and are time consuming and complicated. ”
INFLUENZA
Cahill’s theory that PCR tests for COVID-19 may be inaccurate and show positive results for influenza is not supported by evidence (studies here and here, a previous Reuters fact check on this allegation here).
O’Connor, the HSE, the WHO and the European Center for Disease Prevention and Control (ECDC), all told Reuters in an email that they were unaware of Cahill’s allegations about 1,500 PCR tests performed in October for flu could follow, could not refer. and indicated that such an event would be incredibly unlikely.
The HSE told Reuters: ‘1500 PCR tests were not followed up in October. Despite a significant number of tests, so far no flu has been detected in Ireland in the current winter season “and” there is no evidence of cross-reactivity with the flu test. “
Alexandru Niculae sent an email to Reuters on behalf of the ECDC saying that there could be ‘opportunities for misclassification, mainly due to laboratory or manufacturing errors’, but that one of their experts in applied molecular epidemiology considered it ‘extremely unlikely’. ‘described.
Brickman wrote on behalf of the WHO to say that problems with PCR tests were “rare” and said that “any widespread accuracy problems can be detected quickly”.
O’Connor told Reuters that the ranges for flu viruses and the virus that causes COVID-19 were different enough to ensure that tests were specific to a specific disease. She wrote: ‘I looked at the performance data for most PCRs on the market – it varies depending on the different companies that include their specificity, but in almost all cases flu was checked without cross-reaction. So no, you do not have to sequence every PCR test, otherwise no one uses PCR and they go directly to the sequence. ‘
An allegation that 1,500 COVID-19 samples were tested in Southern California, showing no SARS-CoV-2 but rather flu, spread earlier on social media. The fact-checkers of USA Today have shown that this allegation is unfounded (here).
VERDICT
Untrue. Genetic sequencing is not necessary to diagnose COVID-19, but to detect its strains. There is no evidence that 1500 PCR tests were followed up, and that the flu was wrong with SARS-Cov-2. PCR tests to detect COVID-19 have been developed to ensure that it does not produce positive results for other viruses such as influenza viruses that are genetically differentiated.
This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.