Centers for Disease Control and Prevention should have their home surface cleaning guidelines updated in good time before this week, the dean of Brown University’s School of Public Health said Tuesday.

“It’s incredibly frustrating,” said Dr. Ashish Jha on CNBC’s “The News with Shepard Smith”. “I think I started saying in April and May that a lot of us in public health are quitting wiping surfaces.”

“I really don’t understand why it took CDC so long to get really clear. This virus is spreading through the air,” Jha said.

The CDC said Monday that a thorough soap-and-water scrub is enough to prevent the spread of Covid-19 around the home. However, the use of disinfectants is recommended in schools and private homes where a suspected or confirmed virus case has appeared within 24 hours.

“In most situations, regular cleaning of the surfaces with soap and detergent is enough to not necessarily disinfect these surfaces to reduce the risk of the spread of COVID-19,” said CDC Director Dr. Rochelle Walensky in a meeting at the White House on Monday.

Jha noted that the CDC’s public health news was part of a larger pattern of bad government news when it comes to Covid.

“I would say the first few months were confusing, but by April and May of last year it was clear that this was in the air,” Jha said. “It was frustrating that our federal officials didn’t always get this out consistently.”

The CDC did not immediately respond to CNBC’s request for comment.

Host Shepard Smith also asked Jha about the highly contagious variant B.1.1.7 after Michael Osterholm, director of the Center for Research and Policy on Infectious Diseases, warned on Sunday that the variant could infect children more easily than previous strains.

Jha said he was “concerned” about the B.1.1.7 variant in children, particularly because they have not yet been vaccinated.

“We don’t see a lot of infections in older people because we get them vaccinated and that makes young adults and children really susceptible to B.1.1.7,” noted Jha. “One of the reasons we can’t fully relax right now is because we really need to cut those numbers of infections.”

Every state in the country has reported at least one case of variant B.1.1.7, which was first discovered in the UK, CDC data shows. Walensky said Wednesday that the variant is becoming the predominant strain of Covid in many regions of the United States