Most infectious at 1st signs
Studies show people with the novel 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, 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," said Maria van Kerkhove, a WHO epidemiologist.
Preliminary studies from Germany and the US suggest that people with mild symptoms can be infectious for up to 8-9 days, and "it can be a lot longer for people who are more severely ill", she said.
Mike Ryan, WHO's top emergencies expert, said that the novel coronavirus lodges in the upper respiratory tract, making it easier to transmit by droplets than related viruses such as SARS or MERS, which are in the lower tract.