Impact case study database

Since its emergence in late 2019, SARS-CoV-2 infection led to 4,144,577 confirmed cases of COVID-19 and 121,747 deaths in the UK alone, with worldwide cases over 83,000,000 and deaths over 1,800,000 by the end of 2020. Rapid and reliable testing is a key tool for controlling the pandemic. Initially this relied on existing testing resources in secondary care settings while centralised laboratories and lateral flow testing programmes were being commissioned. During the first peak of infections in the UK (March-April 2020) national viral PCR testing capacity was rapidly exceeded. Critically, conventional PCR testing requires samples to be sent to a central laboratory that often takes over 24 hours to return results. These slow turnaround times delayed important clinical decisions, such as appropriate therapy and prioritisation for isolation facilities.

The collaboration between the research teams in the Faculty of Engineering and the Faculty of Medicine at Imperial led to the development of a rapid and accurate, true sample-to-answer multiplex RT-PCR diagnosis of SARS-CoV-2 in just over an hour, without the need for any laboratory facilities and trained personnel.

The clinical validation conducted with NHS partners demonstrated high sensitivity (94%) and specificity (100%). Following this trial, the MHRA approved CovidNudge for clinical use in April 2020 [ A]. COVID-19 test machines (“Nudgeboxes”) were first deployed for routine use in NHS settings in late April 2020 and were initially prioritised for cancer wards, A&E and maternity departments to protect those most at risk in eight London hospitals; St Mary’s Hospital in Paddington, Charing Cross Hospital, West Middlesex University Hospital, Chelsea and Westminster Hospital, Royal Hospital Chelsea, Queen Charlotte’s and Chelsea Maternity Hospital, the Renal Transplant Centre at Hammersmith Hospital, and the Tower Hamlets Centre for Mental Health at Mile End Hospital.

From 27 April 2020, the NHS required PCR based testing for all unscheduled admissions to hospital [ B] and the CovidNudge testing platform was able to provide this. The primary impact was in supporting the management of patients in busy acute hospitals, with Chelsea and Westminster Hospital performing up to 200 test per day [ C]. However, an important additional role was the testing of patients admitted by psychiatric services preventing any unnecessary isolation that may exacerbate a patient’s illness. In addition to directly benefitting patients admitted to hospital, rapid CovidNudge testing allowed relatives access to hospitals (e.g. partners of women going into labour were able to attend following a negative test) [ C].

At the beginning of July 2020, the device obtained a CE Mark enabling its additional use in non-clinical locations including care homes and other public emergency services where access to PCR remained limited [ D]. DnaNudge Ltd was indicated on the list of approved coronavirus test providers [ E] and an application for FDA approval began in November 2020. In August 2020 the UK Government placed a £161,000,000 order for DNA Nudgeboxes, to roll out the test UK-wide in urgent NHS patient care and elective surgery settings, plus out-of-hospital locations [ F] at a time when there was very limited availability of rapid viral detection diagnostics.

The lab-free sample-to-answer RT-PCR CovidNudge test, provided the medical community with the means to rapidly diagnose, monitor, and treat disease with high confidence and at a low cost. The rapid deployment of the test continued during the 4^th quarter of 2020, with increasing volumes month on month as more sites adopted the technology with 12,339 point-of-care tests performed in December 2020.

As of the end of December 2020, the system was in use at 87 sites, with over 320 machines deployed and more than 62,000 tests run, complementing other programmes focussed on community settings. The test was designed to detect the emergent B.1.1.7 variant and with the second wave of hospitalised infections, positivity rates rose from 1.1% in September 2020 to 13.7% in December 2020. In December 2020 alone the test identified over 1,600 positive cases allowing rapid and accurate point-of-care clinical decision making.