COVID-19 more infectious at earlier stage of onset: Experts

The novel coronavirus is more infectious at the earlier stage of onset, therefore China would be very aware of foreign imported cases, said Zhong Nanshan, a top Chinese epidemiologist, during a video conference with American medical professionals on Friday afternoon.

Based on data shared by Zhong's team, virus loads are much higher in upper airway at the early stage of onset, and decreases remarkably one week later, which means "the earlier stage of patient's onset, the higher infectivity," he explained.

Zhong stressed China would be very aware of imported cases, as should other countries.