From NY Times article - The lost month: How a failure to test blinded U.S. to Covid 19.

“Testing is the crack that split apart the rest of the response, when it should have tied everything together,” said Dr. Nahid Bhadelia, ​the medical director of the Special Pathogens Unit at Boston University School of Medicine.

“It seeps into every other aspect of our response, touches all of us,” she said. “The delay of the testing has impacted the response across the board.”