A New COVID-19 Lamp Test Could Save Lives

As the virus continues to spread, experts are trying to find ways to quickly identify the patients most likely to need treatment. One potential new test is a colorimetric loop-mediated isothermal amplification (LAMP) kit that detects the virus by looking for a specific gene. The system uses a swab, a small tube of purple chemicals and a battery-operated base station to perform the test. It takes only 20 minutes and has the potential to save lives by identifying those patients who should be given antiviral drugs.

The test works by converting RNA into DNA using reverse transcription. Then it adds 6 primers that bind to the target gene. When the reaction is performed at the correct temperature, these primers form a circular construct with each loop opening up to let in more primers, amplifying the target gene. Each of these steps is accompanied by a visible change in the reaction that can be detected by a special detector. This is an isothermal reaction, meaning that it is heated only once and then cooled down again. This allows for a much faster reaction than traditional RT-PCR, which requires repeated heating and cooling and can be difficult to operate outside laboratories.

Using this technology, the test can identify COVID-19 viral load in respiratory secretions from patients with a high or low clinical score. The results can then be used to provide a recommendation for patients to start taking remdesivir, the vaccine approved by the Food and Drug Administration. This system is intended to provide a quick and reliable diagnostic tool for doctors in the field who need to make an informed diagnosis based on real-time data.

A study analyzing the performance of the LAMP test found that it had a higher sensitivity than RT-qPCR when tested on purified RNA. It is also able to detect lower viral loads than RT-qPCR in respiratory samples, including saliva and nasal swabs. It also has a lower error rate and higher specificity than other point-of-care tests for the virus.

However, the authors of that study warn against comparing the performance of different molecular tests as they may be biased by their choice of reference method. Using an established suboptimal molecular detection method for comparison with a new one may exaggerate the sensitivity and diagnostic value of the new test.

Another company, OptiGene, has developed a similar colorimetric test that can detect the virus in swabs taken from the nose. This system is more advanced than the Abbott test, and it has embedded optics that read a fluorescent result. It also looks for a protein that is produced by the body and can help differentiate the results of a positive or negative test. It is currently being used to screen NHS staff and in asymptomatic testing pilots in Southampton.

This test is being offered in some areas of the UK as part of a national plan to prevent the spread of the virus. Patients who have a history of shingles or other conditions should avoid these tests.