Clinical Validation of Portable Rapid Testing Kit for Coronavirus

On 20th March, MicrosensDx announced that it had launched its fast and safe molecular test for research use in the detection of RNA from the SARS-Cov-2 virus in sputum, throat and nose swabs.

MicrosensDx has now announced that the test has been assessed for clinical performance using patient samples from 21 residents in a London care home in collaboration with a London University and a major London hospital. Both nose and throat swabs from COVID-19 positive and negative patients were used to assess the performance of the prototype RapiPrep®COVID-19 clinical diagnostic test against the standard laboratory PCR tests run in the London hospital supporting the trial. The study will be reported shortly in the scientific literature but in brief, the new RapiPrep® COVID-19 test was found to be “fast, easy to use and to work equivalently to RT-PCR methods” by the academic and medical staff involved in the trial. These clinical results form part of the validation data that will allow MicrosensDx to complete the CE marking process to allow the company to launch the test as a clinical diagnostic product in April.

Whilst standard laboratory PCR tests for detecting the virus can take about 4 hours from receipt of sample, in practice, the logistics of shipping the swab to a centralized lab and batching the samples means that results are often reported next day. By contrast the new RapiPrep® COVID-19 test takes a maximum of just 30 minutes from swab to result and has been designed to be performed by operators with minimal scientific training.

The advantages of the new RapiPrep® COVID-19 test are:

• Detects active infection: Tests for the presence of the virus in accepted clinical samples (nose or throat swabs).
• Rapid: Test takes a maximum of 30 minutes from receipt of the swab sample, allowing diagnosis of positive patients in very simple laboratory facilities close to the bedside in hospitals, care homes, clinics or at triage in emergency settings.
• Safe: The test contains an integrated virus inactivation step thereby avoiding exposure of the user to potential infection.
• Efficient: The RapiPrep® COVID-19 test uses a magnetic particle viral RNA preparation step optimized to work with the built-in LAMP detection method. This ensures very efficient capture to give the highest possible detection sensitivity. This is in contrast to competing products that do not have this optimized combination of technologies within the same test device
• Accurate: The RapiPrep® COVID-19 test performed well against a very high level “better than gold standard” reference PCR test in the hospital laboratory and the sensitivity was 80% using a single nasal swab
• Easy to operate: three simple manual steps. 
• Automated detection: The instrument has visual representation of the test result and confirmation that the procedure control has run successfully.

A CE marked version of the RapiPrep® COVID-19 test will be available in April in a point of care, ‘patient-side’ cartridge format (intended for small laboratories or clinics carrying out up to 50 samples per day – see image above). MicrosensDx is also now engaged in developing a high throughput version for the larger testing laboratory that will be suitable for automation using standard liquid handling robots.

MicrosensDx CEO, Dr Christopher Stanley, commented: “Our RapiPrep® COVID-19 test kit has been clinically validated as an effective rapid clinical diagnostic test that can be deployed in both patient-side and soon, in high throughput settings. It can detect active infections, where the individual is actually infected with the virus, in 30 minutes or less; even achieving a result in less than 10 minutes  in samples with high viral load. This allows its use in rapid testing of frontline NHS staff and essential workers when placed in a minimally equipped laboratory setting with semi-skilled staff; it will also offer major advantages when used in high throughput laboratories where the speed of the test offers a substantial increase in productivity, this is of critical importance as the testing load in these laboratories is now rising rapidly.”

MicrosensDx is currently scaling up for the manufacture of both versions of the RapiPrep® COVID-19  kits; to supply high throughput UK NHS laboratories and “on demand” testing locations such as clinics, ER, care homes and other locations where simple laboratory capability can be installed.