The cure was simple: the antibiotic doxycycline. Mr. Springer took it and was discharged five days later.

The coronavirus outbreak has ratcheted up interest in rapid genomic tests. Developers of the some of the devices say that once the genetic sequence of a novel pathogen has been made publicly available, the information could be quickly uploaded and used to identify those infected.

“With a traditional reference lab, by the time a clinic takes a sample and ships it off, you’ve lost 12 to 24 hours,” said Dr. Jack Regan, the chief executive of LexaGene, a Massachusetts company that hopes to sell its coffee maker-size instrument to airports, schools and clinics. “We can get results in under an hour, which makes a huge difference during deadly outbreaks.”

A wider rollout of these tests faces a number of hurdles. Most of the tests identify a patient’s infection 80 to 90 percent of the time — regulators would like that figure to be closer to 100 percent — and many of them are still awaiting a green light from the F.D.A. But health experts say a larger impediment to their widespread use is economics: Most of the tests run $500 to $3,000 (the test used to diagnose Mr. Springer was $2,000) and because few private insurances companies cover them, the costs are largely borne by hospitals or patients.

“The technology is incredibly promising but the challenge right now is how to get insurers to pay for it,” said Prof. Outterson of Boston University. “We need a system in which hospitals can at least break even for doing the right thing.”

John A. Prendergass, associate director of digital health at Ben Franklin Technology Partners, who invests in medical device start-ups, said he was concerned by the high costs, false negatives and low sensitivity of the tests he had looked at.