The new recommended isolation period for patients with confirmed COVID-19 infection is reduced from 14 to 10 days. This recommendation is based on evidence that most patients with a mild COVID-19 infection continue to shed the virus from their upper airways for approximately 7-12 days. Furthermore, the presence of detectable virus when testing does not necessarily imply infectiousness. It has been proven that in mild cases, virus cultures are generally only positive for 8-9 days after symptom onset.
The duration of infectiousness in patients with severe disease (i.e. requiring admission due to clinical instability) is less well established. In general, patients with severe disease may continue to shed virus at higher levels for longer periods than patients with mild disease. To provide a buffer, it is recommended that such patients be de-isolated 10 days after clinical stability has been achieved, rather than 10 days after symptom onset. To illustrate this in simple terms, if a patient was admitted and placed on oxygen, we advise
that when they oxygen supplementation is discontinued, the patient must remain in isolation for another 10 days. This continued isolation provides clinical comfort that the patient is no longer infectious.