A rapid COVID-19 test is useful, but too little to hit the pandemic.

Since September, the Food and Drug Administration has Approved 7 COVID-19 tests The result is results within 30 minutes, which can significantly improve access and efficiency of testing across the United States. Antigen test You can look for viral proteins and process them on your portable machine or card.

The idea behind these rapid tests is to detect symptomatic, presymptomatic, and asymptomatic infected individuals before spreading the coronavirus. However, despite the massive distribution of these tests by federal authorities More than 40 million people to date of 150 million rapid tests ordered by medical company Abbott – COVID-19 infections have surged in all states since early November.

This raises the question of whether the current influx of rapid tests can actually delay the spread of COVID-19.

In some targeted applications, and if people are taking other precautions, including wearing masks and social distance, rapid testing can be a valuable tool. However, the current availability and accuracy of these tests significantly limits their effectiveness in slowing the spread of the virus in the community.

Speed ​​rather than accuracy

Rapid antigen testing, in addition to its speed Cheap and easy to make Therefore, it is more widely available The more commonly used gold standard PCR test Theoretically. However, there are trade-offs between these attributes. Diagnostic accuracy is low..This makes them good candidates Used as a screening toolHowever, it is not very useful in accurately diagnosing SARS-CoV-2 infection.

A one-time test does not mean that a person can do it Travel or interact safely without precautions.. There is no completely accurate test, but there are real questions about the performance of the new rapid test.

Some test makers Reported accuracy Between 84.0% and 97.6% of individuals tested within 5 days of developing COVID-19 symptoms. However, there is a clear gap between the reported performance of these tests. What will be achieved in the real world..Anecdotally, these tests Missing recent mild and asymptomatic infections – In fact, rapid testing is only approved by the US Centers for Disease Control and Prevention. Use in patients with symptomatological COVID-19.. And, of course, people can get infected right after they are tested.

For rapid testing to effectively limit the spread of the coronavirus, experts Conducted at high frequency – You may miss some cases, but if everyone is constantly tested, you will catch many. But even frequent tests are not a panacea. This is only part of the approach that must include social distance, wearing masks, and other precautions.

When President Trump and many of his inner circles were infected with COVID-19, a highly publicized example of how rapid testing strategies failed occurred. This is probably due to a single superspreader event. Everyone reportedly had a quick test every day, but largely ignored other means such as face masks and social distance.Someone may have been Infected, asymptomatic, test negative, then started to develop..

Extensive repetitive testing

To control the coronavirus, it is important to detect infectious presymptomatic and asymptomatic individuals. Rapid inspection can do this, But only if people are screened repeatedly according to schedule – as before What’s happening with some experts Inter-university sports.

The idea is by testing people early and often-perhaps even As much as every day – Rapid inspection You can catch the infected person before spreading the coronavirus to others.. But on a national scale, it’s a huge number of tests.

Researchers estimate that the United States needs to perform at least 20 million rapid tests per day. Reduce infection.. The 150 million rapid tests ordered by the government in late August were assigned to high-risk populations, but the population as a whole rarely covered a week. Also, keep in mind that you need to have all the logistics capabilities, compliance with frequent tests, and the infrastructure to respond quickly to results.

Targeted approach

The federal government said it wasn’t tested fast enough for the general public to be repeatedly tested. Priority deployment of rapid inspection to high-risk nursing homes.. The federal guidelines for the use of rapid testing in nursing homes are a good example of what a testing program looks like, Current challenges in using rapid testing..

If even one of the nursing homes is positive, all staff and residents Test every 3-7 days Until the facility is released from COVID-19 for 14 days.If the facility does not have a case, all staff must take the test According to their county test positive rate – – The higher the rate, the more tests will be needed..

[The Conversation’s science, health and technology editors pick their favorite stories. Weekly on Wednesdays.]

Still, nursing homes have problems Accuracy, staffing, cost Find yourself while using these tests Again at stake during the current surge..Rapid testing certainly helps to catch many cases and should be used in these settings, but cannot be overcome alone The bigger problem that contributes to the spread in these settings..

Rapid testing is effective in highly controlled settings where people are frequently tested and other mitigation measures are in place.please look Successful NBA bubble As proof. However, in other environments where isolation, wearing masks, and increasing social distance were difficult or non-compliant (such as nursing homes and the White House), rapid testing kept the virus away.

Current testing capabilities are far from the hundreds of millions of tests required per week to protect the general public. To date, the promise of cheap and convenient COVID-19 testing, which is the only means of controlling disease transmission, has not been fulfilled.