Question: My son has been out for almost two weeks with Covid and is still testing positive on antigen tests. He still has mild symptoms as you would with any cold or virus — residual stuffiness and cough. Can he return to school? I am confused about the rules — as is everybody else I speak to. Is he still infectious 12 days after his first positive test? He would have had symptoms before that also.
Dr Grant replies: What we know about Covid-19 continues to evolve and this is why the guidelines are updated regularly. The Omicron (BA1) variant of Covid-19 has a shorter incubation period (time between exposure to first symptom) and substantially higher transmission rates than all other prior variants. The latest variant BA2 (currently in circulation) is even more transmissible, akin to measles and chicken pox and according to experts it may be the most transmissible virus we have even come across.
It seems your son has already completed his isolation period and remained off school for 12 days now which is laudable. As per current guidelines: You need to self-isolate (stay in your room) for seven full days and can stop isolating after seven days if you have had no symptoms for the last 48 hours.
When you stop self-isolating after seven days, you need to take extra care for another three days to reduce the risk of passing Covid-19 on. You may stop self-isolating even if you have a mild cough or changes to your sense of smell as these symptoms can last for weeks after the infection has gone.
Most children without underlying medical conditions are considered fully immune-competent. Therefore he is not still infectious on day 12 despite having some mild upper respiratory stuffiness and cough. From the early scientific data published from the first six months of 2020, this is prior to the role-out of vaccination programmes, the last day during which Covid was detected was at day 10. For patients with mild-to-moderate illness, they are highly unlikely to be infectious beyond day 10 of symptom onset.
Patients with severe-to-critical illness or immuno-compromised may take longer to shed infectious viruses. This data was replicated more recently in The Journal of Infectious Diseases October 2021, which revealed viable Covid virus was not present in any 35 tested individuals after 10 days of symptom onset.
Considering all of the above, I would recommend your son’s return to school on the basis that he has no underlying health conditions. Upon return, ensure he takes it easy as he returns to activities and daily routine. Perhaps also have a chat with his teachers to ensure a smooth return and assess how he’s getting on.
Dr Jennifer Grant is a GP with Beacon HealthCheck