Racing Towards the Development of Diagnostics for a Novel Coronavirus (2019-nCoV) (2020/02/07)

In December 2019, a mysterious viral illness causing pneumonia broke out in the city of
Wuhan, in Hubei Province in China. A proportion of the earlier cases were associated with a
seafood market in the city, where exotic animals were also sold for food (1). Since then, this
illness has been shown to be caused by a novel coronavirus (nCoV) that is provisionally
named 2019-nCoV. As of February 1, 2020, the disease has been confirmed in over 12,000
cases, with 259 deaths. Geographically, the disease has spread beyond China to over 20
other countries.

The sensitive and specific detection of this virus is an important part of the global healthcare
response to this outbreak. In this issue of the Journal, Chu et al reported the development
of two one-step real-time reverse transcription polymerase chain reaction (PCR) assays for
detecting 2019-nCoV (2). The two assays target the Orf1b and the N region of the viral
genome. Due to the relative paucity of positive control materials when the authors
developed these assays, the authors had designed the primers and probes such that they
would also cross-react with the Severe Acute Respiratory Syndrome (SARS)-CoV. The
authors then use SARS-CoV as one of their positive controls. The authors argued that this
cross-reactivity would not cause any diagnostic ambiguity as SARS-CoV was no longer seen
clinically following the resolution of the SARS epidemic in 2004.

Author: Y M Dennis Lo, Rossa W K Chiu