Rapid bedside testing ‘faster than standard centralised testing for Covid-19’

Rapid bedside testing is faster than standard centralised tests for coronavirus, and may improve infection control in hospitals, research suggests.

Point-of-care-testing for suspected Covid-19 reduces time to results and may help with infection control, suggesting these tests might have clinical advantages over widely used laboratory PCR methods, researchers say.

A study tracking Sars-CoV-2 testing on admission to a UK hospital found the wait for results was just 1.7 hours using point-of-care testing (POCT) close to the patient’s bedside.

While it was 21.3 hours using the standard process of PCR testing in a centralised lab within the hospital.

The study, published in The Lancet Respiratory Medicine, assessed the real-world impact of POCT, and was conducted between March 20 and April 29.

Dr Tristan William Clark, lead author from Southampton General Hospital, said: “Our findings are the first to suggest the clinical benefits of molecular point-of-care Covid-19 testing in hospitals, demonstrating reduced delays, bed moves, and time in assessment areas, which all lead to better infection control.

“We believe that molecular POCTs should be urgently integrated into care pathways to reduce coronavirus transmission within hospitals to prevent the next wave of the pandemic overwhelming health services around the world.”

Over the recent months, a number of molecular POCT testing platforms have been developed, promising rapid results from testing in the area where the patient is being seen, such as A&E.

Swab samples are placed into test cartridges that take up little physical space and can be operated by health-care staff, unlike the standard laboratory PCR test where samples are sent off to centralised labs and dealt with by specialist staff.

Although there are data to support the speed and accuracy of POCT kits, there remains a lack of insight into their impact on hospital care and transmission, researchers say.

They add that reducing diagnosis time is key to tackling the virus as it allows patients to be quickly isolated and for treatment to be started immediately.

It also allows patients to avoid assessment areas, resulting in less need for decontamination of beds and reduced staff exposure.

The researchers suggest rapid, accurate tests are urgently needed in preparation for the next wave of the pandemic.

The non-randomised trial took place in the acute medical unit and emergency department of Southampton General Hospital and included 1054 adults with Covid-19 symptoms.

Nose and throat swabs were taken from all patients and tested for infection with Sars-CoV-2 virus.

Around half (499) of the patients were tested using POCT in a dedicated hub in the unit, using a kit known as QIAstat-Dx Respiratory Sars-CoV-2 Panel, which detects Sars-CoV-2 and other respiratory viruses, including influenza.

They were also tested using the standard laboratory PCR test.

The remaining control patients were tested only using standard PCR testing.

According to the study, 197 (39%) of 500 patients in the POCT group were found to be PCR-positive for Sars-CoV-2 compared with 155 (28%) of 555 in the control group.

Researchers found the median time to receive results with POCT was 1.7 hours compared with 21.3 hours with the PCR, and the difference remained large after taking into account factors such as disease severity, age, and sex.

Secondary analyses looked at infection control and diagnostic accuracy.

After testing, patients were transferred to definitive Covid-positive or negative wards.

This took eight hours in the POCT group, compared with 28.8 hours in the control group, with 13.7% transferred directly to the correct ward in the POCT group and 0% in the control group.

The mean number of bed moves between admission and final ward arrival was lower in the POCT group at 0.9 moves than in the control group at 1.4 moves, researchers found.

They also found that improvements were seen without compromising diagnostic accuracy.

Most of the Covid-positive patients were recruited into a further clinical trial that took place during the first wave.

Patients in the POCT group were enrolled in clinical trials two days quicker than those in the PCR group.

The authors caution that there are limitations to the study, including that they were unable to randomise the groups due to staffing resources, and there were differences in baseline measures of a number of factors, with the POCT group showing more severe disease.