The Centers for Disease Control and Prevention updated its isolation guidance Aug. 3 based on the latest science about COVID-19 showing that people can continue to test positive for up to 3 months after diagnosis and not be infectious to others. But, the CDC says that contrary to media reporting Friday, the science does not imply a person is immune to reinfection with SARS-CoV-2, the virus that causes COVID-19, in the 3 months following infection. The latest data simply suggests that retesting someone in the 3 months following initial infection is not necessary unless that person is exhibiting the symptoms of COVID-19 and the symptoms cannot be associated with another illness.
There are no confirmed reports to date of a person being reinfected with COVID-19 within 3 months of initial infection. However, additional research is ongoing. Therefore, if a person who has recovered from COVID-19 has new symptoms of COVID-19, the person may need an evaluation for reinfection, especially if the person has had close contact with someone infected with COVID-19. The person should isolate and contact a healthcare provider to be evaluated for other causes of their symptoms, and possibly retested.
People with COVID-19 should be isolated for at least 10 days after symptom onset and until 24 hours after their fever subsides without the use of fever-reducing medications.
There have been more than 15 international and U.S.-based studies recently published looking at length of infection, duration of viral shed, asymptomatic spread and risk of spread among various patient groups. Researchers have found that the amount of live virus in the nose and throat drops significantly soon after COVID-19 symptoms develop. Additionally, the duration of infectiousness in most people with COVID-19 is no longer than 10 days after symptoms begin and no longer than 20 days in people with severe illness or those who are severely immunocompromised.
CDC will continue to closely monitor the evolving science for information that would warrant reconsideration of these recommendations. Until the CDC knows more, CDC recommends that all people, whether or not they have had COVID-19, continue to take safety measures to avoid becoming infected with COVID-19 (wash hands regularly, stay at least 6 feet away from others whenever possible, and wear masks).