Science hasn’t managed to span the diagnosis gap

Star Trek’s Dr. McCoy had no problem finding out what ailed his patients. He simply waved a handheld scanner over them, and the tricorder spat out a diagnosis — even if the patient was a Romulan.

Earthbound diagnostics haven’t yet measured up to the extragalactic version, alas. Go to the doctor, and it’s likely to take a variety of tests to come up with a diagnosis. And even then, the cause may still elude the experts. 

The lack of precise, reliable tests takes a toll on patients and the physicians who care for them. Devising better screening and diagnostic tools remains a focus of research across multiple scientific disciplines. In this issue, contributing correspondent Laura Beil explains how the current standard test for Lyme disease comes up short, causing many people to miss out on early treatment as they go on a protracted search for the reasons for their symptoms. Scientists are trying to solve that problem by devising more accurate tests for Lyme disease, Beil explains, including ones that would detect genetic changes in the body shortly after a bite from an infected tick.

When it comes to cancer, early detection is crucial. U.S. colorectal cancer rates have declined by more than 45 percent since the 1980s. Much of that success is thanks to early detection with stool-based tests or colonoscopy. Still, a worrisome rise in the cancer among younger people prompted the American Cancer Society to recommend last year that people start getting screened at age 45 (SN: 6/23/18, p. 12).

The inconvenience and ick factor of an invasive test like a colonoscopy can deter people from getting screened. Thus the allure of something that might be cheap, fast and painless: detecting chemical signals in the breath for diseases such as tuberculosis, heart failure and lung cancer (SN: 11/16/13, p. 18). It’s not as farfetched as it may sound; a breath test for infection with Helicobacter pylori, the bacterium that causes stomach ulcers and increases the risk of gastric cancer, was approved by the U.S. Food and Drug Administration back in the 1990s.

But if you want farfetched, scientists are trying that, too. Last year Science News reported on a capsule stuffed with electronics, about the size of a hard candy. Researchers in Australia sent the capsule on a tour of the human gut, from whence the device transmitted reports on gas levels out to a smartphone (SN Online: 1/8/18). That advance reminded me a bit too much of the 1960s film Fantastic Voyage, in which actress Raquel Welch and colleagues hopped in a submarine and shrank down to the microscale so they could remove a blood clot from the brain of a famous scientist.

Clearly we’re far from having detector-bots cruising our innards; the inventors of the gas-monitoring pill don’t yet have a clear sense of how it would be used for diagnoses. And for too many people, the search for a diagnosis ultimately fails, even after big investments of time and money. So for now, we’ll continue to wrestle with the ambiguities of diagnosis and the mysteries of the human condition, while scientists of all stripes strive to devise better means of divining what goes on within us.

Nancy Shute is editor in chief of Science News Media Group. Previously, she was an editor at NPR and US News & World Report, and a contributor to National Geographic and Scientific American. She is a past president of the National Association of Science Writers.

More Stories from Science News on Science & Society