Santa Clara County's public health leaders on Wednesday put their foot down against changes in federal COVID-19 testing guidelines and urged the public to continue to be tested for the deadly coronavirus if they have symptoms or have been in close contact with a positive case.

Calling the changes "bizarre," county Health Officer Dr. Sara Cody said the Centers for Disease Control and Prevention's new guidance "undercuts our very basic tenets of how we control an infectious disease."

"Having individuals know their status is foundational to our ability to control an infectious disease and certainly our ability to control COVID," she said at a livestreamed news conference in San Jose.

Cody said she learned about the CDC's guidance changes on Tuesday. "When I first heard about this change in the guidelines, I actually didn't believe it. It seemed entirely bizarre," she said.

The CDC's new guidelines state that anyone with mild symptoms "may wish" to be tested and may be tested, which conflicts with local guidance and the county's order that anyone with symptoms of COVID-19 should be tested right away, Cody said.

The CDC's guidelines also state that anyone who has come in close contact with a confirmed case of COVID-19 does not necessarily need a test.

"This is the part of the guidance that frankly felt the most bizarre. The truth is, if you've been in contact with someone who is infectious with COVID, you absolutely need to get a test," Cody said.

The county's health order requires health care facilities to test contacts. Testing is a way out of the pandemic, and the way back to opening the economy and schools, she said. Since the very beginning of the health crisis, adequate testing has been an Achilles' heel for our country and for our county in getting us out," she added.

"It's absolutely foundational. Here in our county we are going to continue to work with our health care partners to continue to offer testing."

Dr. Marty Fenstersheib, head of the county's testing program, said the county has gone from 1,000 tests per day to 6,000 to 8,000 tests per day. Up to 35% to 40% of cases may be asymptomatic, he said.

"We need to follow the science. … I respect the CDC — always have throughout my career. However, I believe that these changes in the testing guidance have not come from the CDC. I believe these changes have come from further up the chain in the federal government, from the White House, and they are totally misdirected. Failing to test is not going to end this pandemic. Failing to test will not make the virus go away.

"Lacking a strong testing program, I think nationally, has been one of the greatest failures of our federal government, however we will not change our guidance because of this," he said. "We will continue to have a strong basis in science. We will continue to encourage people to be tested so we can contain this pandemic."

Find comprehensive coverage on the Midpeninsula's response to the new coronavirus by Palo Alto Online, the Mountain View Voice and the Almanac here.