April 27, 2021

SARS-Cov2 Infection Detection by Polymerase Chain Reaction and Serologic Testing in Clinical Practice

Category: Article Summary

Topic: Testing and Treatment

Keywords (Tags): testing

• A retrospective study found that 7% participants (271 of 3,075) who underwent both PCR and serologic testing had discordant test results (i.e. negative PCR result and seropositive or vice-versa). These participants either sought PCR testing after viral shedding would be expected to have ended (PCR- but seropositive) or sought serology tests before a detectable antibody response would be expected (PCR+ but seronegative). Cycle threshold (Ct) values for PCR tests was positively correlated with days since symptom onset, indicating that viral load decreased with increasing time. However, no relationship was observed between Ct values and antibody titers from serology tests.

Murad et al. (Apr 26, 2021). SARS-Cov2 Infection Detection by Polymerase Chain Reaction and Serologic Testing in Clinical Practice. Journal of Clinical Microbiology. https://doi.org/10.1128/JCM.00431-21