I’ve heard that young people are asymptomatic, so they shouldn’t be worried about gathering. Can asymptomatic people spread the disease? Is this only theoretical, or are we seeing it happen?
Alison Bernstein, Ph.D.:
Young people do tend to have milder cases of Covid-19 than older people. However, young people may still develop serious or fatal cases of Covid-19.
Yes, people without symptoms can spread the disease, as even if they do not feel sick they are able to shed the virus. Multiple studies have documented spread from people without symptoms and estimates for it are that as much as half of the cases of Covid-19 were from people who were not showing symptoms of the disease.
The use of the words asymptomatic and presymptomatic has caused a lot of confusion, because these are words that are used differently by scientists and lay people. Regardless of which word is correct, what we need to know as people trying to make our way through this pandemic is that you cannot rely on your perception of health as an indicator that you are not infected. This is why it is important to wear masks, practice good hygiene and physical distance even if you feel healthy.
Irving Vega, Ph.D.:
The main reason for our lack of clarity on asymptomatic spreaders is that COVID-19 testing has been directed at symptomatic individuals.
Interestingly, in the same households you can find asymptomatic and symptomatic individuals. In my lab’s community testing study, we identified asymptomatic individuals. Upon testing their significant other, we found that they were infected too. This was true for all asymptomatic cases we tested.
Comprehensive and accurate contact tracing with universal testing is required to answer the question about the role that asymptomatic individuals play in the spread of COVID-19.