WASHINGTON, Aug. 26 (Xinhua) -- The U.S. Centers for Disease Control and Prevention (CDC) has changed its COVID-19 testing guidelines, no longer recommending testing for most people without symptoms.

The new guidelines, updated earlier this week, ask people to get tested if they have symptoms of COVID-19, or have had close contact (within 6 feet of an infected person for at least 15 minutes) with someone with confirmed COVID-19, or have been asked or referred to get testing by their healthcare provider, local or state health department.

"Not everyone needs to be tested," said the new guidelines.

The agency no longer recommends testing for most people without symptoms.

Previously, the CDC said viral testing was appropriate for people with recent or suspected exposure, even if they were asymptomatic.

The updated guidelines prompted concerns from some doctors and experts, who warned asymptomatic carriers play a major role in spreading COVID-19.

Testing and isolating those silent emitters are vital to containing the spread of the pandemic, experts said.