CDC recommendations allow COVID-19 patients to be considered non-contagious without needing confirmation testing.
In recent guidelines published by the Centers for Disease Control and Prevention (CDC), the recommendation for a 14-day quarantine has been adjusted. This change comes as recent research has indicated that “replication-competent virus” is not present after 10 days following the onset of symptoms.
“Accumulating evidence supports ending isolation and precautions for persons with COVID-19 using a symptom-based strategy,” stated the CDC in its new guidance. “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.”
3 Points of Impact in New CDC Quarantine Guidelines after Symptom Onset
The CDC guidelines were initially released July 18, 2020, then updated on July 22. These guidelines make recommended changes to:
- guidance on isolation and precaution timeframes;
- the role of PCR testing in those who previously had a SARS-CoV-2 infection; and
- reinforced the context in which serology testing should be used.
Regarding guidance on isolation and precaution timeframes, the CDC guidance states: “For most persons with COVID-19 illness, isolation and precautions can generally be discontinued 10 days after symptom onset and resolution of fever for at least 24 hours, without the use of fever-reducing medications, and with improvement of other symptoms.” The CDC does clarify that this only applies to those with mild to moderate symptoms and that those with severe symptoms should consult their physician and take precautions up to 20 days.
Use of RT-PCR and Serologic Testing in Updated COVID-19 Isolation Precautions
The new CDC guidelines also address the use of RT-PCR testing in discontinuing precautions. Those who are severely immunocompromised should still consider using RT-PCR testing before discontinuing precautions. For those who are not severely immunocompromised, “a test-based strategy is no longer recommended.” The CDC does, however, still recommend using RT-PCR testing when discontinuing isolation or precautions earlier than the recommended timeframe.
The CDC guidelines also address using RT-PCR testing for those who have previously been infected with SARS-CoV-2. “For persons previously diagnosed with symptomatic COVID-19 who remain asymptomatic after recovery, retesting is not recommended within 3 months after the date of symptom onset for the initial COVID-19 infection,” the guidelines state. “In addition, quarantine is not recommended in the event of close contact with an infected person.” The guidelines do, however, recommend diagnostic testing within the three-month timeframe for symptomatic individuals.
The guidelines also reinforce that, “Serologic testing should not be used to establish the presence or absence of SARS-CoV-2 infection or reinfection.”
The guidelines depart from the more test-centered approach for discontinuing isolation or precautions. “Nursing homes and hospitals are likely to feel the biggest effects of the change,” Dr. William Schaffner, a preventive medicine specialist with the Division of Infectious Diseases at Vanderbilt University School of Medicine, told the New York Times in a recent interview.
“For example, many nursing homes will not accept hospitalized elderly patients after they recover until they pass the two diagnostic tests,” Schaffner told the Times. “That has sometimes added weeks to these hospital stays for no medical reason.”
These changes are likely to have an impact on SARS-CoV-2 test volumes. With the stated goal of reducing the unnecessary use of laboratory testing resources, the CDC guidelines will likely lead to a reduction in the need for diagnostic testing. While this will reduce the stress on clinical laboratories trying to accommodate an increased need for testing, it may also reduce this potential source of revenue for labs.
—By Caleb Williams, Editor, COVID-19 STAT