The doctors of the FNOMCeO explain why there are more and more false Covid negatives: often, even if in the presence of symptoms, the positivity results after a long time or even when they have already disappeared. Here are the three hypotheses of the experts.
Turn on notifications to receive updates on
“Because despite the symptoms I result negative at swab Covid? “. This is one of the questions that more and more Italians are asking themselves in recent days, when the rate of positivity jumped over 25% and the i curve contagion continues to grow. Many, in fact, even if they have fever and cough, are positive only after a long time from the onset of symptoms and often even when these have now disappeared.
The doctors of the FNOMCeO: in the web directory “Doctor, but is that true?“the Federation has put forward at least three hypotheses.
The first “is linked to our behavior immune system: Symptoms are thought to precede a positive test result because the immune system now activates much faster against the virus. At the beginning of the pandemic, in fact, the infections occurred between people who had never taken Sars-CoV-2 before and who were not vaccinated, and therefore the virus could act undisturbed for several days before the infection was such as to be detected. by the immune system. Today, however, with the majority of the population vaccinated or already exposed to the virus, the immune reaction is faster and can lead to cases in which you have symptoms, but you are not positive, because the viral load is not yet sufficient compared to the sensitivity of the test “, reads the article.
9-year-old girl rushed by plane to Rome: she has Covid and is in danger of life
The second hypothesis, on the other hand, concerns the variants and the way in which the virus circulates in the organism: recent studies have in fact found that the new variants, we are therefore talking about Omicron, which is currently predominant in Italy with the sub-variant Omicron5, procure a smaller accumulation of viral particles in the cells of the nose compared to what happened previously and therefore this makes the effectiveness of the tampon difficult.
Finally, there would also be an increase in the number of tamponi fai da te: it is possible that with the home test do not carefully collect the right biological material that is needed for a result as correct as possible, resulting in a higher number of false negatives.
But, the experts conclude, we must not worry: “For now it is not necessary, but it may be useful to take a few more precautions”. For example, Emily Martin, an infectious disease epidemiologist at the University of Michigan, remembers that “people forget that as soon as they become symptomatic, we should behave differently. A negative test for symptoms should not be a pass to exit. And this is true in the presence of all types of viruses, not just Sars-CoV-2 ″.