Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction-Based SARS-CoV-2 Tests by Time Since Exposure
2020
This study aimed to determine the false-negative rate of RT-PCR tests for SARS-CoV-2 infection based on the timeline of exposure and symptom onset. Drawing from data in seven studies involving 1,330 upper respiratory tract samples, a Bayesian model was used to estimate these rates.
Findings showed that in the initial four days prior to typical symptom onset, the false-negative rate decreased from 100% on day 1 to 67% on day 4. By the day of symptom appearance, the rate was at 38%, which further dropped to 20% by day 8. However, the rate began increasing after that, reaching 66% by day 21. Due to variances in study designs, there are some uncertainties in these estimates.
The conclusion emphasizes caution when interpreting RT-PCR results, especially early in the infection, and suggests considering the broader clinical and epidemiologic context if test results are negative but clinical suspicion remains high.
Source:
Kurika LM, Lauer SA, Laeyendecker O et al. Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction-Based SARS-CoV-2 Tests by Time Since Exposure. Annals of Internal Medicine 2020; 173 (4): 262-267. https://doi.org/10.7326/m20-1495