https://www.theguardian.com/world/2020/feb/22/coronavirus-asympto...

https://www.theguardian.com/world/2020/feb/22/coronavirus-asymptomatic-wuhan-woman-shows-why-outbreak-will-be-hard-to-stop

"A 20-year-old Chinese woman from Wuhan travelled hundreds of miles to another city where she is believed to have infected five relatives without showing signs of infection, scientists in China have said, offering fresh evidence that the new coronavirus can be spread asymptomatically.The case study, published in the Journal of the American Medical Association, offered clues about how the coronavirus is spreading, and suggested it might be difficult to stop.

According to the study, by Dr Meiyun Wang of the People’s Hospital of Zhengzhou University and colleagues, the woman travelled 400 miles (650km) from Wuhan to Anyang in Henan province on 10 January and visited several relatives. When they started getting sick, doctors isolated the woman and tested her for coronavirus. Initially, the young woman tested negative for the virus, but a follow-up test was positive.All five of her relatives developed Covid-19 pneumonia, but as of 11 February, the young woman still had not developed any symptoms, her chest CT remained normal and she had no fever, stomach or respiratory symptoms, such as cough or sore throat."