In 1910 Dr Wu Lien-teh travelled to Harbin in northeast China to lead the fight against an outbreak of plague. He pioneered he use of face masks to combat infection, and inspired descendants to follow him and become doctors.

Slurs that dehumanise people can linger in the public domain, especially if the media is complicit in their use, as several US examples show. It's time for Hong Kong to stop the degrading name-calling.