Judges make “wrong” reading of scientific articles and question the reliability...

A judgment signed by two judges from the Lisbon Court of Appeal calls into question the reliability of the PCR tests, which have been used to identify the presence of the SARS-CoV-2 virus (responsible for the covid-19 disease). The appellants are based on two scientific articles that they read “wrong” and “irresponsibly”, defend two experts. At issue is a case that involved four German tourists forced to confinement, during the month of August, in the Azores.

The judgment of Relação maintains that a PCR test is not enough to have a valid diagnosis of covid-19. Only a doctor can diagnose this or another disease. Judges Margarida Ramos de Almeida and Ana Paramés understand that “in view of the current scientific evidence, this test is, in itself, unable to determine, beyond reasonable doubt, that such positivity corresponds, in fact, to the infection of a person ”by the new coronavirus.

“The statement is false”, answers Vasco Barreto, a researcher at the Center for the Study of Chronic Diseases (Cedoc) of the Faculty of Medical Sciences of the Universidade Nova de Lisboa, who considers “irresponsibility” the way two magistrates of a higher court put into practice causes a scientifically validated diagnostic instrument. “PCR tests have a specificity and sensitivity greater than 95%. That is, in the overwhelming majority of cases they detect the virus that causes covid-19 ”.

This is indicated in a scientific article that is cited in the judgment, but that is read “completely wrong” by the magistrates, according to Germano de Sousa, former President of the Ordem dos Médicos and owner of a network of laboratories. At stake is a study (“Correlation between 3790 qPCR positives samples and positive cell cultures including 1941 SARS-CoV-2 isolates”) Whose results were published by Oxford Academic in late September.

PCR tests (“polymerase chain reaction”) are the most widely used diagnostic method in most countries to detect the presence of SARS-CoV-2 precisely because they are the most accurate in identifying the virus. This is a technique that amplifies the virus’s genetic material in successive cycles – with each cycle the material doubles. In the study cited, the relationship between the ability of the samples collected to infect cells and the number of cycles required to obtain a “positive” result was tested.

“The proportion of samples that were no longer able to infect cells maintained in culture in the laboratory increased with the increase in the number of cycles required to obtain a positive signal. This is because after our body controls the infection there are fragments of the virus’s genetic material that persist and decrease over days, when the individual no longer poses a danger to others, ”explains Vasco Barreto. Conclusions like these have helped health authorities in different countries to reduce mandatory quarantine periods for those infected and to dispense with a negative test to “discharge” a patient.

Now, from reading the article, the judges conclude that “the probability of the person receiving a false positive is 97% or higher”. According to the investigation, this only happens if the cycle threshold is higher than 35 “as it happens in most laboratories in the USA and Europe”, reads in the judgment. Again, the information is not accurate. For example, in Cedoc, where Vasco Barreto works, for 42% of the positive tests, only 25 or less cycles were needed and there is scientific evidence of the high capacity for the virus to spread from “positive” cases to less than 25 cycles.

Another “wrong” assessment

There is another scientific article cited in the judgment of Relação de Lisboa (“False-positive COVID-19 results: hidden problems and costs”, Published in the scientific journal The Lancet) which, for Vasco Barreto, does not point in the direction of the reading made by the judges. “This is an appeal for more rigorous criteria to define who are the people to whom tests should be applied”, he says.

Even so, the magistrates rely on this investigation to conclude that “there are so many scientific doubts, expressed by experts in the field, which are the ones that matter here, regarding the reliability of such tests”, “it would never be possible for this court to determine” that the German tourist had the SARS-CoV-2 virus.

This assessment is, once again “wrong” for Germano de Sousa. The German tourist who brought up the case for which the Lisbon Court of Appeal was asked to rule had a positive test after six days in Portugal, after having made a negative test up to 72 hours before entering the country. It was, therefore, “in full swing” when the regional health authority ordered its confinement.

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