Some residents in Wuhan, China, who contracted COVID-19 and recovered have tested positive for the new coronavirus again, according to NPR.
Wuhan is the city in mainland China where the new coronavirus originated. In all, COVID-19 has infected more than 80,000 people in China, since the first outbreak in Wuhan in December 2019. From March 18-22, the city has reported no new coronavirus cases caused by direct transmission, viewed as a significant achievement.
But data from quarantine facilities in Wuhan, where patients who were hospitalized for COVID-19 are sent after being treated and discharged from the hospital, shows that about 5 percent to 10 percent of the patients deemed "recovered" have tested positive for the virus a second time.
Some of the recovered patients who were found to be positive again appear to be asymptomatic.
Four of the people who retested positive spoke with NPR said that they were released from the hospital after they were treated and had tested negative for the virus. All four are being isolated and observed. It is unclear why they retested positive.
One theory for the positive retest is that the first negative test may have been false. Another is that the test may be inaccurate. A director at the Chinese Academy of Medical Sciences estimated in February that the nucleic acid tests used in China accurately identified positive coronavirus cases only about 30 percent to 50 percent of the time, NPR reports.
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