Studies show people with the coronavirus are most infectious just at the point when they first begin to feel unwell, World Health Organization (WHO) experts said on Tuesday.
This feature has made it so hard to control spread of the virus that causes COVID-19 disease, but it can be done through rigorous testing and social distancing, they said.
"It appears from very limited information we have right now that people have more virus in their body at or around the time that they develop symptoms, so very early on," Maria van Kerkhove, a WHO epidemiologist and technical lead on the pandemic, told a live session on social media.