If there has been one silver lining to the COVID-19 pandemic, it’s been the rise of rapid self-tests, which provide results at home in minutes. Researchers are hard at work at developing similar tests for other diseases—including Lyme.
Lyme disease is transmitted by the black-legged (or deer) tick and infects about 476,000 Americans each year. The faster those people can get treated with the antibiotics doxycycline or amoxicillin, the better their chances of having a short, mild case of the disease.
But despite the clear need, there’s a problem when it comes to speed and ease of testing for the tickborne illness.
How Lyme disease tests are currently done
Most tests are performed in a doctor’s office and require a blood sample to be run through two types of screening. The first, called the enzyme-linked immunosorbent assay (ELISA) test, looks for the presence of antibodies to the Lyme-causing Borrelia burgdorferi and the Borrelia mayonii bacteria. Those antibodies can take several weeks after a bite to rise to detectable levels.
If the ELISA test is positive or inconclusive, a second test—known as the western blot test—is performed. The western blot uses electricity to split antibodies into individual proteins, which lab technicians scrutinize for the telltale pattern of Lyme antibodies. The western blot test is actually less sensitive to antibodies than the ELISA test is (which is why doctors don’t just start with it), but once the ELISA test detects the antibodies, the western blot does a better job of confirming their source.
At-home test kits exist that allow people to collect a few drops of blood with a finger prick, and then send the sample to a lab, which runs the same tests and makes results available, on average, in three to five days. But it still takes weeks after a bite for antibodies to rise to detectable levels, giving the Lyme bacteria time to multiply and spread throughout the body.
A urine test for Lyme disease
What’s long been needed is an at-home rapid test for Lyme disease that can detect the presence of the target pathogen almost immediately. At least two labs in the U.S. are currently working on just those kinds of tests, but they are still years away from being ready for commercial release.
The most promising and farthest along is the at-home urine test being developed at Virginia Tech in partnership with the Department of Defense, which provided a $1.2 million grant for the project. Brandon Jutras, associate professor in the school’s department of biochemistry, is developing a test that looks for infinitesimal fragments of the Lyme disease bacteria and can detect them almost immediately after a person becomes infected.
“Our technique, in theory, would work right after transmission—after you get hit by that bacterium,” Jutras says. “Those [bacterial] molecules should be able to be detected within hours of transmission.”
What Jutras’ work relies on is a portion of the bacterial cell known as the peptidoglycan: a rigid envelope surrounding the cytoplasm, or the gelatinous liquid, within a cell. When most cells grow and divide, the peptidoglycan breaks apart, grows, and then reassembles itself partly from the original pieces.
The Lyme disease bacteria are different. “Instead of reusing those pieces,” Jutras says, “they spit them out into their environment.”
Since those fragments circulate throughout the body, they are ultimately excreted in urine. Jutras is developing a test strip embedded with monoclonal antibodies sensitive to the peptidoglycan fragments, which could be dipped into a urine sample and turn a telltale color if the bacterial material is present. That speed—and the fact that it doesn’t require a blood draw—are central benefits of the test.
“One of the things that is well known and well accepted in the field is that the most critical predictor of patient outcome is how quickly they get treated with antibiotics,” Jutras says. “If you’re waiting a month to know whether you have Lyme disease or not, that’s a critical window.”
While Jutras’ lab is making steady progress, he predicts that it will take at least the next couple of years before his test is ready—which is not all that long by drug or medical-device development standards. Even then, he would have to find an industry partner who could bankroll the production and release of the product commercially. “Hopefully, we’re not too far away from that either,” he says.
A color-changing sticker test
Elsewhere, researchers are developing an entirely different at-home test. At the University of Minnesota, Jon Oliver, assistant professor in the division of environmental health sciences in the school of public health, wants to detect the presence of Borrelia burgdorferi or Borrelia mayonii before they have much of a chance to multiply and spread.
“One thing we’re working on is a direct test that will actually detect the presence of the Lyme disease bacteria at the location of the tick bite,” Oliver says.
The technique he envisions involves developing a sticker treated with a polymerase chain reaction (PCR) assay that is able to detect the DNA of the two Lyme bacteria. As soon as a person notices a tick and removes it, they could apply the sticker to the site of the bite. “The sticker would then turn a certain color if the bacteria was present,” Oliver says.
The technique is a straightforward one, but Oliver and his colleagues are still in the earliest stages of developing it. They are testing different types of stickers to determine their ability to pick up interstitial fluids: those that leak out of capillaries after an injury like a tick bite. The development of the proper PCR assay formulation is still down the line, and the team is still seeking funding for the overall work.
“We’re really at more of a proof-of-concept stage, trying to get it up and running,” Oliver says. “We’ve basically got the bare bones of the technology down; we have an idea of what genes [in the bacteria] to look for, but in terms of testing or even prototyping, we haven’t got to that stage.”
Even once the team does produce a product, Oliver believes it would first be adopted by dermatologists, physicians, and other healthcare professionals, before the U.S. Food and Drug Administration would permit it to be rolled out to the public. But given the simplicity of the product and the ease of use, he believes that approval would not be hard to come by. “It’s just a sticker,” Oliver says. “That would definitely be something that’s publicly accessible.”
More at-home tests could still be coming. Last year, the Steve and Alexandra Cohen Foundation launched the LymeX Diagnostics Prize, with up to $10 million in prize money going to institutions or individuals for successfully developing new and effective Lyme disease detection techniques. So far, 10 teams have made it through the first round of the competition, including Jutras’ group at Virginia Tech. Of the 10 teams, his is the only one developing an all at-home test. But different at-home innovations could yet emerge.
With summers getting longer, winters getting milder, and tick populations spreading and growing, Lyme disease is not going anywhere. Simple, reliable at-home tests might be one of our best weapons to fight the growing scourge.
Write to Jeffrey Kluger at firstname.lastname@example.org.