It wasn't an early information from China. Chinese tend to wear masks as it is, even if there is no epidemic. It was our authorities telling us that masks won't help.
First off, do masks work?
“For most people, no. A mask that you buy in the pharmacy can never give total protection against a virus that is transmitted through the air,” said Eric Litvack, medical chief for preventive medicine and control in Montreal’s Public Health Department.
But they can help if they’re worn by people who are sick, because they act as a barrier to stop the tiny droplets that are expelled when they cough or sneeze, Litvack said.
Physicians do not recommend that the general population wear a mask, said Charles Frenette, medical director of infection control at the McGill University Health Centre, because once it’s been used by a sick person it is contaminated and should be discarded immediately. People who are unaware of this may touch the mask with their hands or leave it lying around.
Also, people don’t tend to practice proper etiquette while wearing a mask. For example, someone may still touch their mouth, risking infection.
In China, where thousands have been infected and may not be aware of it, masks could reduce the spread of the virus, he said. But the masks don’t give a hermetic seal, so very small drops suspended in the air can still get through."
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Then why do medical workers wear masks in hospitals?
"In that case, they work as part of an overall strategy to limit the spread of diseases.
At the McGill University Health Centre, medical workers caring for people who have respiratory tract infractions like influenza or the rhinovirus employ “droplet precautions” like wearing a surgical mask, gloves, eye protection and a gown, Frenette said. For more virulent strains, like chickenpox, measles, tuberculosis, ebola and the new coronavirus, workers must wear the N95 mask, which provides more coverage and has a better filter.
Presently, the World Health Organization and the Public Health Agency of Canada recommend those caring for a patient use a medical mask, while the United States is recommending the N95 mask."
January 29, 2020
Why a mask won’t protect you from the Wuhan coronavirus