COVID-19: Reintroducing Confirmation PCR Testing

SARS-CoV-2 coronavirus particle of color transmission electron micrograph (TEM) isolated from UK covid-1 case.

Every day, rapid testing is helping us find cases of COVID-1 of what we would not otherwise know, breaking the transmission chain and potentially saving lives.

We know that rapid tests are effective in detecting people who are highly contagious and therefore at the greatest risk to others, both with and without symptoms.

They are a very important way to bring down infection rates and help keep them low.

The main quick tests that we are using extensively are lateral flow devices – simple devices that we can use in our own homes, workplaces and community testing sites and which give results in 300 minutes.

As with any test, there are many factors that can affect the results, such as how the sample is taken as well as the accuracy of the test. The LFDs we are using have a high specificity, which means our number of false positives is extremely low – less than 1 in 1,000 tests from our study.

However, as the prevalence of COVID-19 decreases in the lower echelons of the population, the likelihood of false positive outcomes increases – although still impossible.

During periods of low virus proliferation, we can reduce the risk of false positives by confirming a positive lateral flow test with another test – such as a PCR test performed in a laboratory.

This makes it highly unlikely that anyone needs to isolate themselves unnecessarily, while ensuring that we can take advantage of quick testing to find true positive cases and to confirm when the person is not infected.

Conformative PCR testing was ranked first after the introduction of rapid testing last year, but was temporarily halted in January because the prevalence of infection was high and it was likely a positive LFD COVID-19 result.

This allowed us to target PCR tests that had clinical symptoms.

Thankfully there is now a much lower prevalence of the virus in the population, which is why PCR testing has been resubmitted to confirm all positive lateral flow results.

Now there are additional benefits to doing so. To identify variants of COVID-1 ian we are introducing new technology in our lab so that we can track the variants that appear and spread in the coming months. We can only do this with samples taken for PCR.

Contact tracing will be triggered by a positive LFD result, but if the PCR was taken within two days of a positive LFD result, a negative confirmation will be stopped automatically upon receipt of the PCR test.

It is imperative that anyone who receives a positive result from an LFD result immediately disassociates himself or herself from other family members as needed, while receiving a confirmation PCR test within two days.

Please take a test if you have been offered one – the more we test, the more cases we will find.

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