According to a new study released today by the University of Colorado, if half of the population is tested weekly with the cheap and rapid COVID-19 test, the virus could be eliminated within a few weeks. Researchers at the University of Colorado at Boulder and Harvard University.
The authors said such a strategy could lead to a “personal curfew” without closing restaurants, bars, retail stores and schools.
Our big picture is that when it comes to public health, less sensitive tests with today’s results are better than more sensitive tests with tomorrow’s results. Rather than telling everyone to stay home so that no one sick person spreads it, it is possible for others to live their lives by ordering only infectious people to stay home. You can be able to. “
Daniel Laremore, lead author, assistant professor of computer science at CU Boulder
Published in the journal for research Science Advances, Larremore collaborates with CU’s BioFrontiers Institute and Harvard THChan School of Public Health to investigate whether test sensitivity, frequency, or turnaround time is paramount to controlling the spread of COVID-19. Did.
Researchers have scrutinized the available literature on how viral load rises and falls in the body during infection, when people tend to experience symptoms, and when they become infectious.
We then used mathematical modeling to predict the impact of screening by different types of tests on the three virtual scenarios. In a college-type setting of 20,000 people; and in 8.4 million cities.
When it comes to curbing spread, they find frequency and turnaround time far more important than test sensitivity.
For example, in one scenario in a large city, extensive testing twice a week, with rapid and insensitive testing, reduced virus infection (R0 (“R naught”)) by 80%. However, a twice-weekly test using a more sensitive PCR (polymerase chain reaction) test, which took up to 48 hours to return results, reduced infectivity by only 58%. For the same amount of tests, rapid tests were always less infectious than slower, more sensitive PCR tests.
This is because about two-thirds of infected people are asymptomatic and continue to spread the virus while waiting for results.
“This treatise is one of the first to show that we need to prioritize frequency and turnaround when it comes to public health, without having to worry about test sensitivity,” said Senior Director, BioFrontiers Institute and Howard Hughes Medical. Co-author Roy Parker said. Researcher at the institute.
This study also demonstrates the power of frequent testing to shorten pandemics and save lives.
In a scenario where 4% of individuals in a city are already infected, a rapid test of 3 out of 4 people every 3 days reduces the final number of infections by 88%, “outbreak within 6 weeks. Enough to drive it to extinction. “
The study was conducted when companies and academic research centers were developing low-cost, rapid turnaround tests that could be deployed in large public places or commercialized for personal use. I will.
Sensitivity levels vary greatly. Antigen testing requires a relatively high viral load (about 1,000 times more virus than PCR testing) to detect infection. Another test, known as the RT lamp (isothermal amplification via the reverse transcription loop), can detect about 100 times more virus than PCR. Benchmark PCR tests require 5,000 to 10,000 viral RNA copies per milliliter of sample. That is, you can catch the virus very quickly or very late.
In the past, federal regulators and the general public have hesitated to accept prompt testing, fearing that cases may be missed early in the infection. But in reality, infected individuals can transfer from 5,000 particles to one million viral RNA copies in 18 to 24 hours, Parker said.
“In the early stages of infection, there is a very short window where PCR detects the virus, but not antigens or things like the LAMP test,” Parker said.
And in the meantime, he said, the person is often not contagious.
“These rapid tests are infectious tests,” said senior co-author Dr. Michael Mina, an assistant professor of epidemiology at Harvard School of Public Health. “When people are infected, they are very effective in detecting COVID-19.”
He added that they are also affordable. The cost of a quick test is only $ 1 each and the results are returned in 15 minutes. Some PCR tests may take several days.
Mina envisions a day when the government will send easy and cheap DIY tests to every home. He said the results are profound, even if half of Americans test themselves weekly and self-quarantine if positive.
“Within a few weeks, we were able to see this outbreak change from a huge number of cases to a very manageable level,” Mina said.
Rapid testing can also be the key to bringing back the threat of previous Superspreaders such as soccer stadiums, concert venues and airports. Regular customers test themselves along the way and wear masks as a precautionary measure.
“If it’s less than 0.1% of the current cost of the virus, it will allow us to test the entire US population frequently for a year,” Mina said, referring to a recent Harvard economic analysis.
The authors are reassured to know that some countries have already begun testing all citizens and hope that the new U.S. government has designated rapid testing as a priority. It states.
“It’s time to change the way we think about testing, from thinking of COVID testing as what we get when we think we’re sick, to thinking of it as an important tool for breaking the transmission chain and keeping the economy open.” Said Laremore.
University of Colorado Boulder
Larremore, DB, et al. (2020) Test sensitivity is second only to COVID-19 screening frequency and turnaround time. Science Advances. doi.org/10.1126/sciadv.abd5393.
Inexpensive and fast COVID-19 testing can eliminate the virus within a few weeks
Source link Inexpensive and fast COVID-19 testing can eliminate the virus within a few weeks