Fact review. Did Covid-19 Test Positive in an Apple Juice Sample? – observer

The increase in tests for Covid-19 in the population has generated many doubts, especially on social networks. In this sense, a post appeared on Facebook on November 5, where, through a video, a person, who appears to be a health professional from a country to be identified, demonstrated a supposedly low degree of reliability of a test to Covid-19: The individual drank apple juice and placed a sample on two test instruments. One was positive for the new coronavirus, the second was not. However, it is a post misleading.

“It is a very fast test and we do not know if it is validated or commercialized. Or even if it is a fraud. We do not know what the manufacturer is, the sensitivity, the specificity, what is inside the juice bottle. “This is how Filipe Froes, pulmonologist and coordinator of the Covid-19 crisis office of the Ordem dos Médicos, reacts before the Observer before the video.

The doctor raises a number of doubts about the video, admitting that there can even be cross-reactions, as happens when, for example, one drug interacts with another, which would weaken the test result shown in the video. But Filipe Fores emphasizes that, in this case, it is not possible to know with what type of components the supposed health professional is operating or, even, in what dose. The pulmonologist admits, however, that this may be a rapid antigen test (commonly known as rapid tests), noting that it is not good practice. “It is bad for everyone that scientific knowledge is the result of this type of uncontrolled and not validated experiences,” he concludes.

In addition to not being able to identify with 100% certainty which manufacturer or what type of test it is, the video also does not respect the time necessary to be able to make an accurate and careful reading of the result. “It takes 10 to 30 minutes to read. It is also important to note that one of the tests is already installed, it was not removed from the packaging and it was the one that was positive ”, says João Júlio Cerqueira, specialist doctor and author of the page Scimed – Science Based on Evidence.

João Júlio Cerqueira also gives the example of a rapid test, the Panbio Covid-19 Ag, developed by Abbot and which has already been launched in Portugal – and this type of test has already arrived in the country, to allow expanding the universe of tests that are done daily. , as reported by the Observer on October 28. In his description you can read that “presents results in 15 minutes”, time that is not respected in the video. This information was also released by the Directorate General of Health, together with Infarmed, in a joint informative circular, on October 14. “The tests can be carried out in small series, with low complexity of technical execution and allow obtaining results in a short period of time (between 10 to 30 minutes), being, in most cases, visual reading or optical reading in equipment. . portable, ”the document reads.

João Cerqueira, unlike Filipe Froes, hypothesizes that it is a serological test, but adds that the antigen tests “are identical.” These types of tests have already been approved in other countries, with the results arriving in 10 minutes, and they cannot be interpreted in 15 minutes, as they are not reliable. This is what happens with the tests of Healgen, a company that develops, manufactures and markets diagnostics in vitro, approved by the Food and Drug Administration, the US federal agency that regulates this matter, which seem to be precisely the ones used in the video, analyzing the first picture. The company logo is visible in the first seconds. However, without confirmation from the author of the video, this information cannot be considered completely valid.

It is necessary to emphasize that there are two types of rapid tests: serological tests, which detect antibodies to evaluate the immunity of the population, requiring only one drop of blood. And the tests that complement the PCR’s, which are antigens, that use a nasopharyngeal product collected with swabs, which, as mentioned above, need between 10 and 30 minutes to detect the presence of viral antigens. “Both can only be read after a certain time and cannot be read after a certain time. Both reading before and after can give false positives or negatives. The liquid may react with the product on the test strip as the placed sample diffuses into the cassette. But this “reactivity” can disappear because it is not specific “, concludes João Cerqueira. At no point in the video are these standards respected.

A viral video argues that a supposed Covid-19 rapid test came back positive for an apple juice sample. Specialists heard by the Observer, such as Filipe Froes, pulmonologist and coordinator of the Covid-19 crisis office of the Ordem dos Médicos and João Cerqueira, specialist doctor and author of the page Scimed – evidence-based science, deny the author. The waiting time to obtain credible results (10 to 30 minutes) in the video was not followed, nor is it possible to know, with complete certainty, what type of test, its sensitivity and specificity, but also the manufacturer. Also, it is also not possible to know if apple juice has other components or if it became contaminated after the person drank it. There are too many doubts for the video to be considered credible.

Thus, according to the Observer’s classification system, this content is:

Note: this content was selected by the observer as part of an association of fact check like Facebook.