Risk of reactivation or reinfection of novel coronavirus (COVID-19)

I read with great interest the article by Cheng et al.¹ in which they tried to introduce the first confirmed case of novel coronavirus pneumonia (COVID-19) in Taiwan and described her self-recovery process. Joob et al. expressed their concerns about the infection that remains under-detected with self-recovery assumptions in another correspondence paper.² In a letter to the editor paper that later published in the journal of Formosan medical association, Cheng et al.³ confirmed that negative results have been obtained four times from sputum and throat and also urine in this patient. Due to the expansion of the COVID-19 epidemy in different parts of the world, more and more cases are getting infected and of course, many people will be recovering from this viral infection as today April 22 in Taiwan, only 6 deaths have been reported out of 426 cases and 236 patients with confirmed infection have been released from the isolation.⁴ So, it is very important to be sure about the negative cases to be truly negative. Another concern is the reactivation of cases that got the infection, recovered and left isolation. This issue has been brought to the public attention as on April 13, South Korea reported that 116 recovered cases of COVID-19 has been found positive again.⁵ As Korean approach to mark a patient as negative is two negative samples in within 24 h⁶ more precautions seem to be needed to be sure a patient had truly recovered from COVID-19 or may not reactivate again after recovery.

Declaration of Competing Interest

The authors have no conflicts of interest relevant to this article.