Despite the controversy and confusion that followed after the U.S. Centers for Disease Control and Prevention announced new Covid-19 isolation guidelines, local doctors appear united in defending the decision.
On Monday, the CDC announced that Covid-19 positive people can stop isolating after five days if they are asymptomatic, and mask another five days. Previously, the guidance dictated 10 days of isolation.
“CDC’s updated recommendations for isolation and quarantine balance what we know about the spread of the virus and the protection provided by vaccination and booster doses,” said CDC director Dr. Rochelle Walensky in a media statement. “These updates ensure people can safely continue their daily lives.”
Walensky explained that “the majority” of transmission happens during the first two days, before symptoms show up, and roughly two to three days after. So, if after a covid-positive person isolates for five days and continues to mask, they can still “minimize the risk of infecting others.”
Dr. Jake Scott, an infectious diseases specialist at Stanford University, said the CDC ruling was long overdue.
“People are basically infectious for a shorter amount of time if they have been immune from either vaccination or infection-induced immunity,” said Scott. “So I definitely think that for vaccinated individuals, and previously infected individuals, 10 days of isolation was excessive.”
The announcement comes as omicron overtakes Bay Area numbers. It is a variant, epidemiologists agree, that is far more transmissible than others, but vaccinations appear to render the effects milder. While hospitalizations are starting to rise in San Francisco, overall hospitalizations appear stable. And, the majority of San Francisco is vaccinated with two doses.
Like other local doctors, Scott emphasized the possible consequences of being isolated longer than necessary, especially with largely vaccinated populations. People may not want to get tested if they know they have to isolate for 10 days, Scott said.
“It’s obviously difficult for people to get childcare, not a lot of people have sick leave,” Scott said. “It’s a big impact on the economy.” Whittling the period down to a shorter five-day period may motivate test-taking, he said.
The effects of staff out sick are already being felt. On Tuesday, Mayor London Breed announced the cancellation of the 2021 New Year’s Eve city fireworks show because staff at city public safety agencies are isolating and quarantining, causing overall shortages.
For similar reasons, the San Francisco Department of Public Health appears to agree with the new CDC guidelines. “We recognize the disruption that longer isolation and quarantine periods pose to our daily lives, especially now that Covid-19 cases of the omicron variant are being detected at an accelerated rate,” health officials wrote in an email. “We understand the importance of the new CDC guidelines to businesses and workers, and are in support to the extent we can implement them safely.”
Other regions hit hard by the omicron variant, such as South Africa and the United Kingdom, recently revised guidance or shortened the isolation period, too. The new CDC guidance, then, is “just responding to how frequent people are getting mild breakthroughs,” said Dr. Monica Gandhi, an infectious disease specialist and professor at UC San Francisco. “I do recognize there are a lot of people who criticize it, but they are still advising people to wear the mask.”
Doctors agreed that as long as people continue to wear a mask for the full five days after exiting the five-day isolation period, the guidance is solid. The CDC announcement didn’t deter questions, however; some challenged the idea that people would mask the entire time.
Other people pointed out that the covid studies the orders are based on come from data established pre-omicron. Data is “still to be determined,” Scott said, but a variant is still part of the same virus, and early information suggests the incubation period for omicron is shorter. “If anything, it comes and goes faster.”
People also wondered whether someone should retest after they are asymptomatic and isolated. Scott thinks it is unnecessary at present because tests don’t check infectiousness; Gandhi is in the camp that if it is possible, one should test again.