According to a preliminary study, a New York fertility doctor has developed a rapid, non-invasive test for coronavirus that can provide accurate results in 30 minutes or less.
The test, developed by Dr. Zev Williams, a reproductive endocrinologist who runs the Columbia University Fertility Center, uses a person’s saliva to detect COVID-19.
A small sample of saliva is placed in a tube containing enzymes and a compound that causes a chemical reaction before the tube is heated with a heat block. The liquid in the tube turns yellow when it is positive for the virus or red when it is negative.
“We wanted to design a one-step test where all the work would be done by enzymes and chemicals rather than by cartridges and components,” Williams said, adding that enzymes and chemicals are easy to scale and distribute.
The rapid one-step test was able to detect as little as one or two copies of the SARs-CoV-2 virus in a microliter of saliva, according to a preliminary study published by Williams on MedRxiv, which means it can detect whether a person is infected even if you only have a low concentration of the virus.
“Low detection limits help ensure that you can detect the virus in infected people, even if they are asymptomatic,” Williams explained.
The study, which has not been peer-reviewed, also recorded a sensitivity of 97 percent and a specificity of 100 percent.
Sensitivity refers to the ability of a test to correctly identify infected patients, while specificity is the ability of a test to correctly identify those who are not ill. In this case, when the sample was negative, the saliva test did not give a false positive result, while when the sample was positive, 97 percent of the time it was detected correctly.
“This test is very, very simple, very fast and extremely accurate,” said Dr. Henry Ji, president and CEO of Sorrento Therapeutics, which has partnered with Columbia University and is authorizing the test.
“Currently the accuracy of other tests is not there.”
If the test is successful in more tests, Williams hopes it can help curb the spread of the contagion by helping to track the contract.
“When you retrieve the results quickly, it allows you to have the individual quarantined so they don’t spread it, and it also allows you to track contacts,” Williams said.
“If you get the results a week later, good luck trying to keep track of contacts if they took the subway system once you’ve lost.”
Current COVID-19 testing involves a nasal swab and specialized laboratories and machinery, slowing down testing and resulting in delays of days, or even weeks, in delivering results.
“The problem is the delay between the time the test is done and the time the results are obtained,” said Dr. Alexis Nahama, Sorrento’s senior vice president for regulatory affairs.
“We need to take the tests to people instead of taking samples from people and taking them to the lab because that is where it breaks today.”
Sorrento is conducting a larger study of the saliva test before applying for FDA emergency authorization next month.
The cost per test is expected to be less than $ 15, Williams said.
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