As an easy and rapid method to diagnose coronavirus virus, including SARS-CoV-2, SARS and so on, Reverse Transcription Polymerase Chain Reaction (RT-PCR) was commonly used to confirm COVID-19 infections worldwide. Some institutes or universities provided several RT-PCR assays to diagnose 2019-nCoV (previous name of COVID-19) and the protocols.
Because of occurrence of abnormal results, several articles from Chinese research groups had referred to the RT-PCR diagnoses for COVID-19 infections according to China CDC guideline.
False-negative RT-PCR test results had been reported by a previous study. 5 in 167 patients had presented negative results in first RT-PCR detection for 2019 novel coronavirus with positive chest CT finding. All of them were finally confirmed with COVID-19 infection by second, third or multiple repeated RT-PCR detections.
A correspondence on viral load in upper respiratory samples showed that some patients received negative or positive results alternately and repeatedly by using the primers targeted the ORF1ab region of novel coronavirus genome, and similar situation was also described in another correspondence.
A recent letter discussed positive RT-PCR test results after two consecutively negative results in four patients recovered from COVID-19, and could not rule out false-negative results.
The investigation had paid attention to the above phenomenon and tried to understand the extent of false-negative results from changes of new cases of the COVID-19 infections in China. Based on the primers provided by research institutes from different countries, especially primers from China, detailed analysis of non-specificity of primer sequences had been conducted, and interference of human mRNA targeted by the primer was discussed deeply for RT-PCR detection of COVID-19 infections.
Link to the paper: https://doi.org/10.1101/2020.04.07.20056804
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.