Prevalence of redetectable positive SARS-CoV-2 nucleic acid in recovered
COVID-19 patients: a systematic review and meta-analysis
Abstract
Background: The prevalence of positive SARS-CoV-2 nucleic acid in
recovered COVID-19 patients has attracted attention. We aimed to
investigate the repositive rate of SARS-CoV-2 and the clinical features
of discharged COVID-19 patients. Methods: In this systematic review and
meta-analysis, we searched PubMed, Embase, Web of Science, China
National Knowledge Internet, Wanfang Data, China BioMedical Literature,
VIP, and Google Scholar. Fixed or random-effect models were used to
determine effect estimates. Results: Eleven studies were included. The
pooled positive rate of viral RNA in discharged patients was 11% (95%
CI 7-15; I2=90.4%). The median days from discharge to repositivity were
7 to 8 days. Coughing was the most common clinical symptom, occurring in
16% (95% CI 11-20; I2=0%) of patients at readmission. Chest CT and
laboratory indicators of positive retest (PR) patients showed
significant recovery trends. The prevalence of comorbidities between the
PR patients and the negative retest patients were not significant (OR
0.86 [95% CI 0.38–1.95]; p=0.002; I2=76.5%). No close contacts
were positive for SARS-CoV-2 RNA. Conclusion: PR patients were uncommon.
The repositive result was likely due to the incomplete clearance of
virus from a previous disease course. PR patients were less likely to be
contagious. However, close monitoring and quarantine after discharge
from the hospital are necessary. Registration: The protocol has been
registered on PROSPERO, registration ID: CRD42021239650 Keywords:
COVID-19, SARS-CoV-2, discharged patients, positive retest rate