NEW YORK (NewsNation) — The Centers for Disease Control and Prevention updated its guidelines for COVID-19 testing, now saying those who have been in close contact with someone who has had the virus may not need to be tested.

The site now says: “If you have been in close contact (within 6 feet) of a person with a COVID-19 infection for at least 15 minutes but do not have symptoms, you do not necessarily need a test unless you are a vulnerable individual or your health care provider or State or local public health officials recommend you take one.”

Under the previous guidelines, testing was appropriate for those with recent or suspected exposure, even if they were asymptomatic.

There was a caveat, however. Testing may be recommended for those with health problems that make them more likely to suffer severe illness from an infection, or if their doctor or local state officials advise they get tested.

It is unclear why the U.S. Department of Health and Human Services updated the guidelines. The change has left many doctors puzzled.

Health professionals understand that testing is necessary for keeping outbreaks in check. The CDC confirmed about 40% of the people infected are symptom-less.

“I was taken aback and didn’t know that it was under consideration,” said John Auerbach, president of Trust for America’s Health, a non-partisan public health policy, research and advocacy organization that works to improve U.S. preparedness against disease. “The recommendation not to test asymptomatic people who likely have been exposed is not in accord with the science.”

Dr. Carlos del Rio, an infectious disease specialist at Emory University, suggested in a tweet that there are two possible explanations: testing supply issues and/or President Trump desiring to see case counts drop by discouraging testing.

Dr. Tom Frieden, who headed the CDC during the Obama administration, said the move follows another recent change: to no longer recommend quarantine for travelers coming from areas where infections are more common.

“Both changes are highly problematic” and need to be better explained, said Frieden, who now is president of Resolve to Save Lives, a nonprofit program that works to prevent epidemics.

Frieden said he, too, believes HHS forced the CDC to post the changes. He called it “a sad day” because “CDC is being told what to write on their website.”