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China Finds Up To 10% Of Recovered COVID-19 Patients Test Positive Again

Updated September 6, 2021

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No nation's researchers have more experience dealing with COVID-19 and its victims than China. With the nation's battle against the disease appearing to start winding down, some interesting findings are coming to light.

One of the more mysterious findings has been that those who have recovered from the virus sometimes test positive again.

As the Los Angeles Times reported, there are many, many unknowns with these cases.

Were some of those patients who were released not fully recovered yet? Can those who have recovered once get sick again? Is there a problem with the testing? And how many patients who appear to have recovered from the illness test positive a second time?

To be sure, hospitals in China were under pressure to free up beds during the thick of the outbreak.

So it's likely that some of the patients who tested positive again never really got all the way past the disease in the first place. Indeed, some discharged patients appeared to be in worse shape than those taking their place, according to reports from Shanghai-based news outlet Paper.

So, anecdotal evidence of patients testing positive a second time and getting sick again are most likely cases in which the patients were actually still sick.

One doctor published a study about a family in Wuhan that called into question the testing process.

Unsplash | Adli Wahid

The family in the study all fell ill with the virus, and were all declared recovered. Five to 13 days after leaving quarantine, all were tested again and tested positive. For the following few days after that they were all re-tested, and once again, they all tested positive.

Experts believe it's most likely that the tests could have been contaminated or that the tests themselves are overly sensitive.

"The test may be positive, but the infection is not there," suggested Hong Kong University's Dr Keiji Fukuda.

The number of people testing positive again also raises questions.

Unsplash | Fusion Medical Animation

Some sources suggests these cases represent as few as 0.2% of China's overall cases. Wang Wei, president of Tongji Hospital, said that about 3% of the patients they studied tested positive again, according to the South China Morning Post.

In Wuhan, quarantine sites reported rates between five and 10% of second positive tests. No national numbers are available, however.

The really important factor is whether any of these recovered patients remain infectious.

Unsplash | Macau Photo Agency

And that's just not clear at this point. Researchers say they haven't seen any evidence of recovered patients testing positive again and infecting others so far. However, they also caution that they simply don't have a large enough sample size to know for certain.

"These are just small samples and not enough to assure us of the validity of our initial findings," Wang said. "We need a large-scale epidemiological study to guide our disease surveillance and prevention works."

Even those who have recovered from the virus are remaining in isolation for two weeks beyond their discharge just to confirm that their bodies have indeed produced antibodies and fought off the virus.

h/t: Los Angeles Times, South China Morning Post

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People & Society