Researchers around the world are working on the next generation of coronavirus tests that give answers in less than an hour, without onerous equipment or highly trained personnel.
The latest so-called point-of-care tests, which could be done in a doctor’s office or even at home, would be a welcome upgrade from today’s status quo: uncomfortable swabs that snake up the nose and can take several days to produce results.
The handful of point-of-care devices now on the market are frequently inaccurate. The up-and-coming tests could yield more reliable results, researchers say, potentially leading to on-the-spot testing nationwide. But most of the new contenders are still in early stages and won’t be available in clinics for months.
Some of the tests in development swap brain-tickling swabs for plastic tubes that collect spit. Others dunk patient samples into chemical cocktails that light up when they detect coronavirus genes.
Another type of test identifies coronavirus proteins in minutes, using a cheap device that’s easy to produce in bulk and deploy in low-resource settings.
“To combat this virus, we need to test widely and frequently, and get the results back quickly,” said Dr. Zev Williams at Columbia University, who is developing a coronavirus spit test that can run in about 30 minutes. “That requires a genuine paradigm shift in the way we go about testing for it.”
The gold-standard method involves funneling a long, absorbent swab a few inches into the nose until it hits the nasopharynx, the part of the airway where the nasal passage meets the throat and a common target of the coronavirus.
“The moment you see the swab, you’re like, ‘Oh no, my face isn’t that deep,’ ” said Fernanda Ferreira, a virologist at Harvard University who took a nasopharyngeal swab test in April. “Turns out it is.”
The virus’ genes must be extracted from the sample with a specific suite of chemicals. The material is then processed through a laboratory technique called polymerase chain reaction, or PCR, in which a machine cycles through several temperature changes to amplify genetic material.
But the process can bog down at multiple points. Swabs and chemicals necessary for processing are often in short supply, and invasive sampling requires trained health care workers who quickly drain precious supplies of gowns, gloves and masks. Additionally, many community testing centers lack PCR machines and must outsource their samples to large laboratories, leading to delays of days or even weeks.
Rachel Coker, the director of research advancement at Binghamton University — one of many institutions nationwide that have begun to reopen — had to wait 10 days for her results after being sampled at a drive-through testing site.
“The good news was it was negative,” she said. But she could have been exposed while waiting for results. “By the time I knew,” Coker said, “it was almost useless.”
Researchers are attempting to streamline every part of the diagnostic pipeline. One timesaving tactic that’s already been rolled out nationwide involves sampling areas other than the nasopharynx, such as swabbing the nostrils or throat, or collecting gobs of saliva.
These tests are painless and avoid putting health care workers in harm’s way. But they aren’t always accurate. “Unfortunately, this virus doesn’t hang around in the nose or throat so much,” said Dr. Ravindra Gupta, a clinical microbiologist at the University of Cambridge.