A precision medicine approach to managing 2019 novel coronavirus pneumonia

Wang, Minjin; Zhou, Yanbing; Zong, Zhiyong; Liang, Zongan; Cao, Yu; Tang, Hong; Song, Bin; Huang, Zixing; Kang, Yan; Feng, Ping; Ying, Binwu; Li, Weimin

(ii) The diagnosis is 'Highly Suspected' in patients with an RT-PCR result positive for ORF1ab and negative for N gene/E gene. The analyses should be repeated with a different RT-PCR kit or replicated with a nucleic acid test kit based on a different methodology (Fig. 4b) or further genomic sequencing should determine whether the virus has a potential mutation. (iii) The diagnosis is 'Uncertain' when ORF1ab gene amplification is negative. In this case, regardless of the N gene/E gene result, a replicate test should be done with another kit, or the process of sampling and testing should be repeated (Fig. 4c) . (iv) The interpretations of 2019-nCoV RT-PCR results (Fig. 4d) : a positive nucleic acid test result includes a cycle threshold (Ct) value less than 35 and a standard S-shaped amplification curve of ORF1ab, N gene/E gene, and internal control (IC) on RT-PCR. A negative RT-PCR result is one with absence of amplification curve for ORF1ab and N gene/E gene and, at the same time, presence of an S-shaped amplification curve for IC (Fig. 4e) . When the Ct value is between 35 and 40, the result is a suspected positive and should be reviewed before a diagnosis is done.