China says a mysterious coronavirus that has killed four people and caused another 200 to fall ill can be spread between humans.
Health officials in the central city of Wuhan where the virus originated now say 15 of their medical staff have been diagnosed with the virus.
Canada and a number of countries around the world have adopted screening measures at airports for travellers arriving from China in an effort to prevent a global outbreak.
Canada's chief public health officer says three people in the country have been tested for the coronavirus and cleared after they began to show similiar symptoms.