Conclusion
Patients who have passed an
episode of COVID-19 might test re-positive again, and furthermore,
become ill seriously. A second positive PCR after discharge or negative
PCR is not uncommon, and it is most likely due to disease reactivation
or testing limitations, rather than another exogenous re-infection.
Further prospective studies are needed to provide reliable epidemiologic
data and reveal the mechanisms and risk factors for re-positives.
Although anti-SARS-CoV-2 antibodies do not seem to prevent a second
positive test, they might avert severe illness in re-positive patients.