A total of 141 people who had apparently recovered from Covid-19 have tested positive again, South Korea’s Centers for Disease Control and Prevention (KCDC) said on Thursday.
KCDC deputy director Kwon Joon-wook said the agency did not know what caused the people to retest positive and was investigating.
Most experts think it’s unlikely that somebody will be re-infected for the coronavirus soon after recovering. It’s possible that issues with testing – or varying amounts of viral RNA in the body, which the tests look for – could explain why people tested positive after testing negative.
Kwon also said that the government is studying cultivated samples from the patients to determine whether the cases could be contagious. Kwon said the study will take about two weeks from today.
Earlier, it was reported that about 5-10% of recovered patients in Wuhan, China re-tested positive for the virus at the end of March, according to data NPR obtained from Wuhan quarantine facilities that house COVID-19 patients after hospital discharge.
Constant coronavirus updates, a climbing death toll, lockdown everywhere notwithstanding, the reality is that the vast majority of people who come down with COVID-19 survive it.
In a study published in The American Journal of Respiratory and Critical Care Medicine, researchers found that “half of the patients they treated for mild Covid-19 infection still had coronavirus for up to eight days after symptoms disappeared.”
At a bare minimum, the current guidelines from the Centers for Disease Control and Prevention advise people who are recovering to continue self-isolation for at least seven days after symptoms appear and at least three days after symptoms disappear, and to continue to wear a nonmedical mask when in public.
Just as the number of cases grows, so does another number: those who have recovered.
In mid-March, the number of patients in the US who had officially recovered from the virus was close to zero. That number is now in the tens of thousands and is climbing every day.
But recovering from COVID-19 is more complicated than simply feeling better. Recovery involves biology, epidemiology and a little bit of bureaucracy too.
Once a person is exposed the coronavirus, the body starts producing proteins called antibodies to fight the infection. As these antibodies start to successfully contain the virus and keep it from replicating in the body, symptoms usually begin to lessen and you start to feel better.
Eventually, if all goes well, your immune system will completely destroy all of the virus in your system. A person who was infected with and survived a virus with no long-term health effects or disabilities has “recovered”.
Unfortunately, immunity isn’t perfect. For many viruses, like mumps, immunity can wane over time, leaving you susceptible to the virus in the future.
This is why you need to get revaccinated – those “booster shots” – occasionally: to prompt your immune system to make more antibodies and memory cells.
Since this coronavirus is so new, scientists still don’t know whether people who recover from COVID-19 are immune to future infections of the virus. Doctors are finding antibodies in ill and recovered patients, and that indicates the development of immunity.