Table 2

Proposed features for distinguishing SARS-CoV-2 reinfection from prolonged SARS-CoV-2 viral shedding

SARS-CoV-2 reinfectionProlonged SARS-CoV-2 viral shedding
SequencingConfirmed RNA sequencing with evidence of distinct SARS-CoV-2 viral strains at distinct episodes would provide a definitive diagnosis of SARS-CoV-2 reinfectionRNA sequencing showing the same SARS-CoV-2 viral strains at distinct periods could suggest prolonged SARS-CoV-2 viral shedding rather than reinfection; unless clinical suspicion is high for SARS-CoV-2 reinfection, further evaluation would be needed to assess if the patient has been reinfected with the same SARS-CoV-2 strain
Cycle threshold (Ct) valuesVariability in SARS-CoV-2 Ct detection has been documented in cases of SARS-CoV-2 reinfection, with some cases with increased or decreased Ct values on reinfection episode (with Ct varying from 16.6 to 36.85)8 Likely to have high Ct values suggesting low level viral shedding; however, low Ct values may be observed in immunocompromised patients who have decreased ability to clear the virus
Viral cultureLikely to be positiveCould be positive or negative (latter representing non-viable virus detected via SARS-CoV-2 PCR tests)
Timing of repeat positive testingVariable; time between positive SARS-CoV-2 RNA PCR in documented cases of SARS-CoV-2 reinfection ranges from 48 to 142 days8 Variable
Antibody testing in bloodCould be positive or negative*Could be positive or negative
Host characteristicsVariable; the majority of documented cases of SARS-CoV-2 infections noted in immunocompetent hosts (with the exception of one patient taking inhaled corticosteroids)8 Variable; notably, immunocompromised hosts are more likely to have prolonged episodes of SARS-CoV-2 viral shedding
Symptomatic vs. asymptomatic presentationVariable symptoms; may have milder (including asymptomatic presentations) or worsening symptoms as noted in prior cases of SARS-CoV-2 reinfection8 Predicted to have asymptomatic presentation if due to prolonged SARS-CoV-2 viral shedding
  • *SARS-CoV-2 re-infections may occur more commonly in individuals with waning immunity after their first SARS-CoV-2 infection.