Illustration: Sarah Grillo/Axios
From biosensor chips to wastewater epidemiology, the COVID-19 pandemic is accelerating the development of next-generation disease diagnostics.
Why it matters: If we're going to stop a disease, we first have to know who has it and where. New technologies promise to provide doctors with more reliable intelligence about who in a community has a disease — and who is likely to get seriously ill.
What's new: In response to COVID-19, a number of researchers and startups are pushing new diagnostic technologies that take advantage of cheaper and quicker genetic sequencing to provide far more accurate and rapid intelligence on just where COVID-19 is, and where it might be going.
- "With the coronavirus, we are being catapulted into a new era," says Milan Patel, the CEO of the DNA-based diagnostic company PathogenDx.
Some of the most promising new technologies involve what are called molecular electronics biosensor chips.
- While the RT-PCR tests used for diagnosing active infections repeatedly copy specific viral sequences in a sample before they reach detectable levels, biosensors can detect the presence of viral genes in a sample as it is, producing results much more rapidly.
- As it becomes cheaper, such technology holds the promise of being able to test an entire population for specific viruses, or even scan the physical environment for signs of viral contamination.
- "Imagine an active surveillance system that pings offices, shops, airplanes, train stations to see if you have hot spots for a given pathogen or infectious disease," says Barry Merriman, the co-founder of Roswell Biotechnologies, a startup leading the way on developing commercial biosensors for disease surveillance.
A cruder form of environmental surveillance is already under way — underground. Researchers in several cities have begun testing city sewage for the presence of SARS-CoV-2 viral RNA.
- Sewage is unique as a diagnostic source in that it represents a near-universal sample of what is in — or coming out of — the community. As Mariana Matus, co-founder of the startup Biobot Analytics, told NPR: "Every person that is using the toilet has a voice."
What to watch: Next-generation diagnostics can go beyond simply determining who is and isn't infected. A number of researchers are working on tests that can identify biomarkers that might predict just how sick a COVID-19 patient will become.
- Scientists at the New York University College of Dentistry have developed a mobile app that takes four biomarkers found in blood tests that were significantly elevated in COVID-19 patients — along with known risk factors like age and sex — and uses a machine-learning algorithm to produce a predicted severity score that runs from 0 to 100.
- Quanterix has developed a highly sensitive antibody test capable of indicating early in a COVID-19 infection whether a patient is likely to develop an immune overreaction — called a cytokine storm — that can lead to a more severe case. "That allows for an entirely different insight on disease severity and treatment options," says Kevin Hrusovsky, Quanterix's CEO.
The catch: "Testing is a conservative field," notes PathogenDx's Patel. There's good reason for that — we've already witnessed the damage that inaccurate tests can do — but it does mean that new technologies may be rolled out too slowly to make a major difference for the first wave of the pandemic.
The bottom line: COVID-19 struck us in a surprise attack, but better diagnostics could help ensure that we aren't caught off guard again.