Published online Jul 9, 2021. doi: 10.5492/wjccm.v10.i4.132
Peer-review started: February 5, 2021
First decision: March 17, 2021
Revised: March 21, 2021
Accepted: June 15, 2021
Article in press: June 15, 2021
Published online: July 9, 2021
Processing time: 151 Days and 22.7 Hours
High viral load has an implication in the clinical outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. At present there is no Food and Drug Administration Emergency Use Authorization for quantitative viral load assay in the current pandemic. Currently the coronavirus disease 2019 (COVID-19) tests are reported as a binary assessment of either positive or negative test.
The intent of this research is to identify whether quantitative SARS-CoV-2 viral load assay correlates with severity of infection and mortality?
To assess high viral load and its association with the severity, mortality, infectiousness in COVID-19 infections.
A systematic literature search was undertaken for a period between December 30, 2019 to December 31, 2020 in PubMed/MEDLINE using combination of terms “COVID-19, SARS-CoV-2, Ct values, Log10 copies, quantitative viral load, viral dynamics, kinetics, association with severity, sepsis, mortality and infectiousness’’. Data on age, number of patients, sample sites, real time reverse transcriptase polymerase chain reaction (RT-PCR) targets, disease severity, intensive care unit admission, mortality and conclusions of the studies was extracted, organized and is analyzed.
High SARS-CoV-2 viral load was found to be an independent predictor of disease severity and mortality in high proportion of studies, and may be useful in predicting the clinical course and prognosis of patients with COVID-19.
There is a wide heterogeneity in fluid samples and different phases of the disease and these data should be interpreted with caution and only considered as trends. In aggregate, these observations support the hypothesis of checking and reporting viral load by quantitative RT-PCR, instead of binary assessment of a test being positive or negative.
In future, longitudinal studies with viral load should be monitored and analyzed, so it can be considered in interpretation of outcome data. It may also be a guiding principle for therapy and infection control policies for current and future pandemics.