People who have had mild to moderate COVID-19 can be released from isolation after 10 days and do not need to be retested before returning to work, according to the new CDC guidelines.
© Gregory Bull, AP
Vi employees at the La Jolla retirement complex hold signs and wave flags for quarantined senior residents for weeks in San Diego on April 8, 2020. As residents watch from their balconies, employees dance and shout words of encouragement at an almost daily rally. .
Symptoms, not tests, are the guide. If the patients had a fever, it must have been gone for at least 24 hours.
The document from the Centers for Disease Control and Prevention, released Wednesday, says symptoms are a better indicator of how infectious a person is, so they “don’t stay unnecessarily isolated and excluded from work or other responsibilities.” .
The document acknowledges that SARS-CoV-2, the virus that causes COVID-19, is so new that doctors are still gathering evidence of how it works. As more data becomes available, the medical community is gaining a better understanding of how infected people can avoid transmitting the disease. The new guidelines reflect the latest ideas.
“We did not have this type of data in the early days of the pandemic. Now they are moving towards science-based recommendations as we apply the data that is coming in, ”said Dr. Roger Shapiro, professor of immunology and infectious diseases at the Harvard Chan School of Public Health.
People with severe COVID-19, many of whom are hospitalized, could be infectious for 20 days, although most are not.
Most people with severe illness, over 88%, were no longer infectious after 10 days. Ninety-five percent were no longer infectious after 20 days, the CDC said.
Infectious before I know you’re sick
COVID-19 is a cunning virus in the sense that patients appear to be most infectious two to three days before they begin to show symptoms, Shapiro said.
“Once you are symptomatic, you become less infectious,” he said.
A large study in Taiwan cited by the CDC found that people were much more likely to get COVID-19 if they were exposed to someone who was sick within the first five days that the person had symptoms. That study found no cases of infection if a person was exposed to someone with COVID-19 six or more days after the onset of the disease.
An unknown proportion of those who are infected with COVID-19 have asymptomatic disease and many never know that they are infected.
“While I would say that a completely asymptomatic patient is less likely to transmit the disease, it certainly can,” Shapiro said.
Can you reinfect yourself?
So far there have been no confirmed cases of people who have been reinfected with COVID-19, the CDC said.
He did note that the SARS-CoC-2 virus only emerged in December and there are not many places where there have been many infections during all that time, so possible reinfection is still under investigation.
If someone develops new symptoms consistent with COVID-19 after testing positive for the disease and then recovering within the past three months, the CDC urged consultation with an infectious disease expert.
Reinfection is something immunologists and infectious disease researchers are looking for, said Dr. Otto Yang, professor of medicine and head of infectious diseases at UCLA’s David Geffen School of Medicine.
“Our antenna is up,” he said.
Two things may be happening that make it seem like people are being reinfected, according to the CDC document.
The first is that tests can find fragments of the virus in the nasal cavity of a recovered patient, but the viral particles are no longer able to reproduce. The test result could be positive, but the person could not infect others.
“Evidence of viral particles can still be found, but that did not correlate with infectious risk,” Shapiro said.
It is also possible that a small number of people continue to clear the virus in their secretions, so they can test positive several times over many weeks.
For those people, their bodies may initially be able to fight the virus, but at some point something affected their immune system and they were able to resurface, Shapiro said.
“These cases are atypical, these are less than 0.1%. There are so many people with COVID-19 in this country that there will be strange presentations here and there, ”she said.
Video: Ones For Wellness: Coronavirus Vaccine (CBS Dallas)
UNTIL NEXT TIME
Keep reading
