The director of the Centers for Disease Control and Prevention was asked at a congressional hearing on Thursday who was in charge of making sure that people can be tested for Covid-19, especially health care workers.

Was it he, the vice president or someone else?

Dr. Robert Redfield, the C.D.C. director, replied that his responsibility was only to ensure that state public health laboratories have access to the test. Pressed further, he said he would look into who was in charge.

If he didn’t know, that’s a problem. On Friday morning, President Trump took a belated but welcome step by designating Brett Giroir, the assistant secretary of health, to be responsible for the government’s testing response.

There’s no reason the testing infrastructure can’t be up and running in seven days so that every person in America who needs a test can be tested. The president should demand it.