As the third outbreak of coronavirus threatens much of the United States, health experts across the country say there are still not enough tests to keep the virus under control.
Some doctors and hospitals now offer patients quick tests that can give results in minutes. And over the next few weeks, major retailers such as CVS and Walgreens say they will begin offering a type of rapid test called the antigen test, which some people say will give Americans more access to testing.
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“There is a need for testing across the board,”; said Gigi Quick Gronwall, a senior fellow at the Johns Hopkins Health Center, NBC News.
About 30 million Covid-19 tests are performed each month, according to estimates from The Atlantic’s Covid Tracking project. But research has shown that the United States will need another million – 193 million a month, according to one report – to be effective.
One of the main problems was the lack of critical testing materials that has plagued laboratories since the beginning of the pandemic.
“The supply chain has not met demand,” said Dr. Patrick Godby, president of the College of American Pathologists. “We still can’t get enough reagents to run the tests we’d like to run. It’s not just testing reagents, but stocks like tampons. “
In response, the federal government conducts rapid testing or testing as opposed to care, as opposed to the gold standard polymerase chain reaction or PCR test, which requires samples to be sent to a laboratory for analysis, and return may take several days.
Two weeks ago, the Department of Health and Human Services began sending rapid antigen tests to states conducted by Abbott Labs. The test is the simplest to date, as it does not require a car, and the results take about 15 minutes. Some government officials told NBC News that the tests would be used in nursing homes and schools.
“In general, I say it’s a good start,” said Dr. Michael Mina, an epidemiologist at Harvard Health School. “But I am extremely disappointed that the federal government is simply continuing this position, where their only strategy is to acquire what becomes available through industry and corporations in the private market.”
“Different types of tests are needed in different places,” Gronval said. “The most important feature is the speed with which you can achieve accurate results.”
But accuracy was a thorn in the side of rapid testing, as evidenced this month, when nearly 20 members of the Trump administration and campaign, including the president and first lady, contracted the virus. All White House staff and visitors have reportedly been routinely tested for Covid-19.
The problem is that rapid tests are not as sensitive as PCR tests, with approximately 1 in 4 results being false negative.
About a dozen rapid tests have been authorized for emergency use by the Food and Drug Administration. All of them are intended for patients who experience symptoms, because that is when the level of the virus in their body increases.
“Tests at the place of care have their place, and it must be determined by the individual situation,” Godby said. “You are in the doctor’s office and you come in and have a fever, along with symptoms that started five or seven days ago. The express test has a place there. “
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But the fear is that as these tests become more accessible, they could be used as a screening tool similar to what the White House does – a method that has had negative effects after guests at the Rose Garden of the past months said they do not need to wear masks after receiving a negative rapid test result. At least a dozen of these guests eventually contracted the virus.
“Negative results should not be seen as a guarantee of negativity or safety,” said Dr. Christopher Polage, director of the clinical laboratory of microbiology at Duke University’s healthcare system.
A new study looking at the Abbott antigen test, called BinaxNow, found that it could work as an adjunct to PCR testing. Although the study was small and the results have not yet been published or reviewed, researchers at the University of California, San Francisco, found that of the 26 people who tested positive on PCR, 15 were also identified on the test. Abbott. But the researchers note that these 15 were the most infectious because they also had a large amount of virus in their samples. Almost half of these 15 were asymptomatic.
“Disruption of this pandemic could be accelerated if we can deploy and perform a rapid test that will identify people who are most infectious and in need of isolation, many of whom may be asymptomatic,” said study author Dr. Diane Hawler in her release news. “PCR remains the gold standard, but the strategic combination of these tests can help in health facilities where rapid results and knowledge of the risk of transmission on the day of testing are critical.”
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Akshay Sel contributed.