Asymptomatic coronavirus carriers are just as contagious as those with symptoms, study shows

A study now backs up what many scientists expected about the coronavirus all along.

People who are infected with COVID-19 but don't show symptoms carry about as much of the virus in their nose, throat, and lungs as those with symptoms, a study published Thursday in JAMA Internal Medicine shows. They also carry that viral load just as long as symptomatic people, revealing that even asymptomatic COVID-19 carriers can spread the very contagious virus, The New York Times reports.

While COVID-19 can be devastating and even deadly for people who contract it, approximately 30 percent of people who have the disease show no symptoms, the study showed. That essentially makes it impossible to know if a person is transmitting the virus or not, and is a big reason coronavirus is so hard to contain, the Times notes. Still, there have been debates over just how contagious people are before they begin showing symptoms, versus whether completely asymptomatic people spread the disease just as much.

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This study largely clears that up. Measuring the virus' genetic material, researchers determined there was just as much of it in asymptomatic patients as in symptomatic. Following a person's chain of transmission or growing a live virus would've helped prove the similarities more definitively, the Times continues.

The study looked at 193 symptomatic patients and 110 asymptomatic people in isolation in South Korea, with a median age of 25. A previous study showed children, who are largely asymptomatic when infected with the disease, also hold as much of the virus as adults.