Dödligt virus från Kina orsakar panik (SARS-CoV-2, COVID-19)

What’s more, the one person who was asymptomatic carried a similar amount of virus as the symptomatic patients, “which suggests the transmission potential of asymptomatic or minimally symptomatic patients,” the researchers wrote.

In a separate New England Journal of Medicine paper, researchers in Germany were also able to isolate the virus from patients’ upper respiratory tract even before they showed any symptoms or were very mildly symptomatic — more evidence of the potential for spread of the virus from the nose and throat when people barely know they’re sick.

A yet-to-be published paper, also from German researchers, looked at nine of the country’s earliest confirmed Covid-19 patients. They too found evidence of the virus replicating in the upper respiratory tract — but that wasn’t the most interesting takeaway. The researchers discovered people generally aren’t infectious after about 10 days, and people with mild symptoms stop shedding the virus after about a week. But, unlike much of the data from China to date — which suggests most people present with fever and a dry cough — symptoms for many people in this group resembled a cold. So only two of the nine had a fever and seven had a cough, but just as common were symptoms like stuffy nose, runny nose, and sneezing.

What this means for stopping Covid-19
What does this imply about the contagiousness of Covid-19 and stopping the outbreak? “For a virus pretty closely related to SARS, it shows very effective person-to-person transmission, something nobody really expected,” Stephen Morse, a professor of epidemiology at Columbia University Mailman School of Public Health, told Vox.

Researchers currently believe one infected person generally infects two to more than three others, which would make the new coronavirus more contagious than seasonal flu, SARS and MERS.

Second, it means stopping the outbreak might be more difficult, since people start to become infectious early on in their disease or may even spread the virus when they’re asymptomatic or after symptoms go away.

But to confirm these findings, we’ll need more science, said Jennifer Nuzzo, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security. “We still don’t know to what extent people without symptoms can infect,” she pointed out.

Japan confirms first case of Corona reinfection.