The CDC just changed the rules on COVID-19 quarantine

New guidelines for how long people with COVID-19 should isolate, when they can return to work, and how they should be tested and re-tested for coronavirus have been released by the CDC, in a significant update on the agency's pandemic policy. The US Centers for Disease Control and Prevention said that, among other reasons, an attempt to limit "unnecessary use of laboratory testing resources" was a key motivator behind the new guidance.

Testing has proved to be a contentious topic since the beginning of the COVID-19 pandemic. Countries where widespread testing was implemented early, and consistently, have generally seen faster containment of the virus and, in turn, more straightforward reopening. Locations where testing has been less aggressive, however, have generally struggled with a recurrence of infections.

Amid all that, this week the CDC revamped its advice on how quarantine for COVID-19 patients should be handled, and it reduces the number of times individuals might expect to be tested. Beforehand, the CDC's advice was to quarantine for 14 days upon a positive test result for coronavirus, if the patient was showing symptoms. Only upon re-testing twice, at least 24 hours apart and with a negative result each time, could that person leave isolation.

Now, that advice has been pared back. "Accumulating evidence supports ending isolation and precautions for persons with COVID-19 using a symptom-based strategy," the CDC suggests. "This update incorporates recent evidence to inform the duration of isolation and precautions recommended to prevent transmission of SARS-CoV-2 to others, while limiting unnecessary prolonged isolation and unnecessary use of laboratory testing resources."

The CDC now says that most people diagnosed with COVID-19 can generally exit quarantine 10 days after showing symptoms, assuming those symptoms have improved without the use of medicines to reduce fever. Only those "who are severely immunocompromised" should be tested again. "For all others, a test-based strategy is no longer recommended," the CDC says.

Those who test positive for COVID-19, but remain asymptomatic, are also advised to isolate for 10 days as per the previous guidance. That's measured "after the date of their first positive RT-PCR test for SARS-CoV-2 RNA."

As for repeat testing, the CDC now suggests that those who were diagnosed with symptomatic COVID-19, and who remain asymptomatic after recovery, should not have a retest within three months. Neither, the agency advises, do they need to re-quarantine, even if they come into close contact with someone currently infected with coronavirus.

Only if symptoms reemerge should another test be carried out.

The amended guidance brings the CDC's advance for the general population more in line with its earlier updates for healthcare personnel (HCP) specifically. In mid-July, the agency advised that healthcare personnel could return to work after ten days in isolation, assuming their symptoms had cleared. Test-based strategies were "no longer recommended" the CDC explained, "because, in the majority of cases, it results in excluding from work HCP who continue to shed detectable SARS-CoV-2 RNA but are no longer infectious."

Confusion around exactly who should isolate, upon what conditions, and for how long is likely to persist for some time. Meanwhile, the CDC continues its moves to reduce reliance on testing, having recently released a new list of questions that must be answered before a COVID-19 diagnostic is completed.

That's despite recognition by the agency that early estimates of coronavirus prevalence were significantly undercounting the number of cases across the US. Recently, the CDC director theorized that, were everyone in the US to consistently wear face masks, COVID-19 could be brought down to a manageable level in just four to eight weeks.