< Masks

Do I have to wear a mask if I already had COVID-19?

Text updated on 2020-09-24

Yes! Given the uncertainties about the duration of the COVID-19 disease. Because of the risk of infection, the contagious period and the likelihood of reinfection, it is recommended that everyone wear a mask. Everyone must contribute to the SARS-CoV-2 coronavirus barrier!

In a few cases, a second infection with the COVID virus in a cured patient has been demonstrated. In several countries, cases of "cured" patients testing positive for COVID-19 several weeks or months after the symptoms have disappeared and several negative tests have been reported. A hypothesis proposed to explain these results is that the results of these initial tests were false-negatives (i.e., they did not detect the virus while it was present, e.g., the sample was taken incorrectly). It is also possible that the patients may have caught COVID-19 a second time. Another possibility is that the virus remained continuously, at low doses, in these patients before increasing in concentration in the secretions during a second phase. In demonstrated cases of reinfection, the sequence of the virus in the second infection is sufficiently different from that of the first infection to conclude that it is indeed a second infection.

Current data show that it is possible to be infected several times with the SARS-CoV-2 coronavirus, although it is still difficult to estimate the probability of this occurring. It is prudent to wear a mask even if you are cured of a first infection. Moreover, you will set a good example and wearing a mask will reassure the people you meet.

Sources

Four patients became positive for the virus again 5-13 days after their symptoms disappeared and after two consecutive negative tests.

Lan, L., Xu, D., Ye, G., Xia, C., Wang, S., Li, Y., & Xu, H. (2020). Positive RT-PCR test results in patients recovered from COVID-19. Jama.

One case of a patient who tested positive for the virus after two negative tests.

Chen, D., Xu, W., Lei, Z., Huang, Z., Liu, J., Gao, Z., & Peng, L. (2020). Recurrence of positive SARS-CoV-2 RNA in COVID-19: A case report. International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases, 93, 297-299. Advance online publication.

Patients who have been treated have tested positive for the virus after two negative tests.

Xiao, A.T., Tong, Y.X. and Zhang, S. (2020), False-negative of RT-PCR and prolonged nucleic acid conversion in COVID-19: Rather than recurrence. J Med Virol. Accepted Author Manuscript. doi:10.1002/jmv.25855

Study reporting the case of a patient who tested positive for the Sars-CoV-2 virus on his return from Spain, at Hong Kong airport, four and a half months after a first infection. The differences between the viral RNA sequences collected during the two infectious episodes confirm that these are two successive independent infections.

To, K. K. W., Hung, I. F. N., Ip, J. D., Chu, A. W. H., Chan, W. M., Tam, A. R., ... & Lee, L. L. Y. (2020). COVID-19 re-infection by a phylogenetically distinct SARS-coronavirus-2 strain confirmed by whole genome sequencing. Clinical Infectious Diseases.

In this preprint, the authors report the case of a 25-year-old patient from Reno, Nevada, who developed a severe form of COVID-19 one month after the end of symptoms associated with a first infection that did not require hospitalization. Again, the differences in the viral RNA sequences of the two infectious episodes confirm that this was a reinfection and not a resurgence of the first infection.

Tillett, R., Sevinsky, J., Hartley, P., Kerwin, H., Crawford, N., Gorzalski, A., ... & Farrell, M. (2020). Genomic Evidence for a Case of Reinfection with SARS-CoV-2. Available at SSRN 3680955.