Testing Backlogs May Cloud the True Spread of the Coronavirus

As demand for coronavirus testing surges around the nation, laboratories that process samples are again experiencing backlogs that have left anxious patients and their doctors waiting days — sometimes a week or more — for results.

At the city and state levels, testing delays could mask persistent rises in case numbers and could cloud ways to combat the coronavirus, as health officials continue to find themselves one step behind the virus’s rapid and often silent spread, experts said.

Dr. Francis Collins, the director of the National Institutes of Health, acknowledged the dangers associated with such delays in an interview on NBC’s “Meet the Press” that aired on Sunday.

“The average test delay is too long,” Dr. Collins said. “That really undercuts the value of the testing, because you do the testing to find out who’s carrying the virus, and then quickly get them isolated so they don’t spread it around. And it’s very hard to make that work when there’s a long delay built in.”

Though the coronavirus testing landscape continues to expand, most patient samples must still be routed through laboratories for processing, and the demand is once again straining supplies, equipment and trained technicians and causing shortages.