Most infectious at 1st signs
新冠患病初期传染性强

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.
世界卫生组织专家6月9日称，研究显示，新冠病毒患者一开始感到身体不适时最具传染性。

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.
这一特点使得控制新冠病毒传播非常困难，但仍可通过严格检测和社交距离得以实现。

"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.
世卫组织流行病学家范克尔克霍夫称，就我们目前掌握的非常有限的资料看，人们在出现症状前后，体内的病毒量更多。

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.
德国和美国的初步研究表明，出现轻微病征的患者的传染力可持续8-9天，而情况更严重患者的传染期可能更长。

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.
世卫组织顶级紧急事务专家迈克·瑞安表示，新冠病毒存在于上呼吸道，这使它比存在于下呼吸道的非典型性肺炎或中东呼吸综合症等相关病毒更容易通过飞沫传播。