Discharged COVID-19 patients fall ill again

A Chinese study finds multiple recurrences of SARS-CoV-2 positivity

One in six patients with COVID-19 discharged from a Chinese hospital have retested positive to the virus, researchers have found in a study that further muddies the issue of immunity.

Their study shows that despite being under strict quarantine conditions, 69 out of 414 patients believed recovered from COVID-19 later tested positive — and 16 required readmission to hospital.

The joint Chinese-US study, published preprint without peer review, followed consecutive patients treated at a hospital in Shenzhen,