Friday, September 20

Coronavirus: When does a person sick with COVID-19 stop being contagious (whether or not they have symptoms)?

On day 14 since he announced he had COVID – 19, the president of Mexico, Andrés Manuel López Obrador (AMLO), reappeared in public.

The president reported that last Friday they did a test and it was negative, so this Monday he resumed his activities: “Fortunately I got ahead, we are here to continue fighting,” he said at his morning press conference.

Some journalists, however, questioned him if after this experience he would order the mandatory use of masks in the country or if he himself would use one hereinafter. He firmly answered “no.”

“In Mexico there is no authoritarianism, it is forbidden to prohibit, everything is voluntary, the most important thing is freedom and everyone must assume their responsibility, “he said.

” Also, according to what the doctors suggest, I no longer contagion, “he said.

But how many days does it take for a person to stop transmitting the SARS-CoV-2 virus once they contract it? The 14 Are days of isolation enough?

prueba PCR
PCR tests may continue to be positive for several days or weeks after infection with the virus.

Incubation

Since SARS-Cov-2 was detected in China at the end of 2019, several scientific teams have been investigating the incubation period of the new coronavirus.

One of these studies, conducted by researchers at the Johns Hokpins School of Public Health and published in Annals of Internal Medicine coronavirus in May 2020, found that the average incubation period of the new coronavirus is 5 , 1 days.

And most (97, 5%) of those infected who develop symptoms do so three of a period of 11, 5 days.

“Since a person is exposed to the virus through the nose or mouth, an average of three days until symptoms begin to develop, such as cough and fever ”, explains to BBC Mundo Dr. Vicente Soriano, a doctor specializing in infectious diseases and clinical genetics and former adviser to the World Health Organization.

“But the ability to infect others, to transmit that virus to others lasts from 7 to 10 more days “, explains the expert, who is also a professor at the International University of La Rioja, Spain.

He adds that from that moment on, when the symptoms have already subsided or disappeared, the possibility of infecting others also decreases.

coronavirus
Masks can help reduce the risk of that an infected and asymptomatic person infects other people.

The expert emphasizes, however, that the tests PCR, which are used to detect the virus, can continue to test positive for several days or weeks after the virus is contagious.

But this does not mean say that the person is still contagious.

“The PCR that detects fragments of the virus genome can remain positive after one, two or up to three weeks after the person is cured of covid”, Vicente Soriano points out.

“But that positive CRP does not reflect contagiousness . What the PCR detects are virus fragments, or ‘junk sequences’, which are fragments of the virus genome that are in the respiratory tract and that we expel for several weeks after the disease has been cured ”, explains the expert.

Indeed, the sensitivity of diagnostic tests is a problem that has been known since they began to be applied and illustrates why the statistics of the covid – 19 are far from perfect.

But as Dr. Vicente Soriano underlines, “the contagiousness of the coronavirus is basically 7 to 10 days, one or two days before the symptoms start and while the symptoms occur ”, he adds .


  • 09 days after appearance symptoms and
    • 24 hours without fever and without using fever-reducing medications and
  • When other symptoms of covid are improving – 19
  • Source: CDC


    Coronavirus
    It is believed that until 30% of people infected with coronavirus do not have symptoms.

    But what happens when a person becomes infected with the coronavirus and has no symptoms? How do you know that you will not infect others?

    A study published in August in Journal of the American Medical Association (JAMA) coronavirus found that close to 30% of patients who test positive for coronavirus are asymptomatic.

    And the researchers found that despite not presenting symptoms, patients are carriers of the same amount of virus as patients with symptoms and both remain with that viral load for the same time.

    Therefore, experts point out, the importance of wearing masks and observing social distancing.

    These two measures can help reduce the risk that a person with covid – 19 and asymptomatic infect other people.

    “With asymptomatic patients it is not known for how long they can be contagious,” explains Vicente Soriano.

    “Basically, Asymptomatic people can transmit viruses to others for a week, just like those with symptoms, but unless the person has an antigen test (to detect that they had the disease) or a PCR, that person goes unnoticed “, the expert tells BBC Mundo.

    ” Hence the interest in tracking to identify people who may have been in an area of ​​contagion with people who have not yet tested positive and do the antigen test or PCR, from the 48 event hours. ”

    In this way, says the expert, asymptomatic patients can be identified and kept isolated during 10 days to avoid other infections.

    When a person had symptoms, it is not necessary to perform the screening test again, it is enough that it is maintained 10 days isolated to stop being cont agiosa.

    Severe patients

    These recommendations, however, are not apply to people who had more severe symptoms of covid – 14 and were not hospitalized.

    As indicated by the Centers for Disease Control and Prevention (CDC) of the United States, in In many cases, when a person was seriously ill and was not hospitalized, they must remain at home until 20 days after the initial onset of symptoms.

    Likewise, people with immune system disorders or weakened immune systems who had covid – 19, they should stay longer at home and consult their doctor to know when they can stop isolating themselves.


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