Are COVID-19 Patients Who Test Positive After Recovery Still Infectious?

Patients who have previously tested positive for COVID-19 and then declared to be “recovered” by virtue of a negative test, only to test positive again at a later time, do not appear to be infectious, according to data from the Korean Centers for Disease Control and Prevention. This led the researchers to propose those “re-positive” patients could have developed antibodies that would prevent them from having active illness again. Their conclusions were based on studying 285 people who had recovered from COVID-19. There were no instances of the re-positive patient infecting any contacts. Further, virus samples from those patients could not be grown in culture, indicating the patients were shedding noninfectious or virus particles. It remains to be seen how these results could affect recommendations from the U.S. Centers for Disease Control and Prevention as more regions of the country prepare to “reopen” after social distancing.