Emerging Tests: Progress & Key Developments in the Scramble to Develop a Rapid Coronavirus Detection Test

As coronavirus continues to spread and claim more lives, the development of a quick, safe and effective diagnostic test for detecting the 2019-nCoV virus has become an urgent global priority. Not surprisingly, the most progress has been made in China, Hong Kong and Southeast Asia where the outbreak began and continues to pose the greatest threat. Here is a quick overview of some of the more promising initiatives that have emerged from the region.

The Central Role of RT-PCR Test Technology

Although much remains to be learned about 2019-nCoV, researchers have noted its similarity to coronaviruses found in bats, including the severe acute respiratory syndrome (SARS) virus. Accordingly, test developers have based tests to detect and confirm the virus on rapid real-time reverse transcription polymerase chain reaction (RT-PCR) technology.

The BGI Group Assay

No diagnostic company has played a more direct and active role in 2019-nCoV response than Chinese genome sequencing company, the BGI Group. On Jan. 28, BGI and its MGI Tech subsidiary received emergency clearance from China’s National Medical Products Administration (NMPA) for its real-time fluorescent RT-PCR kit for 2019-nCoV testing. In addition to scaling up production of the assay, BGI donated 230,000 kits and opened a medical test laboratory to support 2019-nCoV response efforts in Wuhan and Hubei Province. It also announced a collaboration with Ares Genetics, a Curetis Group company, to make 2019-nCoV tests available in Europe. Ares will launch a next-generation sequencing testing service for the virus using BGI reagents.

The Hong Kong Assays

On Jan. 31, the journal Clinical Chemistry published the results of a study by investigators from China and Hong Kong claiming to have developed a pair of assays for rapid identification and confirmation of 2019-nCoV. Using publicly available sequencing information about the virus, the researchers focused on viruses in the sarbecovirus subgroup of betacoronaviruses and developed one-step RT-PCR tests targeting two regions of the viral genome—ORF1b and N. They then evaluated the tests in a panel of negative and positive control samples, including respiratory specimens from patients suspected of having 2019-nCoV during different stages after the onset of the illness. Each RT-PCR took about an hour and 15 minutes to run.

The researchers found that the assays were sensitive only to sarbecoviruses, with both suspected patients testing positive. They also determined that the N gene assay was 10 times more sensitive than the ORF1b assay in detecting positive samples. Based on these findings, the researchers recommended:

• Using the N gene assay for initial testing;
• Using the ORF1b assay if the patient tests positive to confirm the result; and
• Follow up testing by a World Health Organization (WHO) reference laboratory if the first test is positive and the second test is negative.
• The PolyU Multiplex Respiratory Screening Panel

Less than a week after publication of the Clinical Chemistry RT-PCR tests study, scientists from The Hong Kong Polytechnic University (PolyU) announced that they have developed a comprehensive panel capable of detecting 30 to 40 respiratory infectious disease pathogens, including 2019-nCoV, in less than an hour via a single test. Incorporating polymerase chain reaction technology into the diagnostic system allows the device to be fully automated from sample nucleic acid extraction and amplification to signal detection and analysis to achieve point-of-care capability. The system does not require manual interaction across the testing process.

Chips and Apps

Response has also extended to mobile point-of-care test lab-on-chip solutions that can diagnose pathogens via an end user’s cell phone. One of the first applications of this technology to 2019-nCoV came on Jan.24 when Singapore biotech firm Veredus Laboratories announced plans for a Feb. 1 commercial launch of a kit capable of detecting the coronavirus with “high specificity and sensitivity.” The VereCoV kit is based on lab-on-chip technology which integrates two molecular biological applications, polymerase chain reaction and microarray. This is the same application that Veredus, which is currently owned by Japanese plastics giant Sekisui Chemicals, has used to create kits for detecting the Mers, Zika, Dengue and H1N1 viruses. The company claims the new kit can detect, differentiate and identify all three coronaviruses in a single test in about two hours.

Takeaway

Although East and Southeast Asia have been the center of activity, scientists, public health laboratories and commercial test makers in the US, Europe and other regions affected by the outbreak are also working furiously to develop and secure expedited emergency regulatory approval for new experimental 2019-nCoV detection tests