It's funny how things change. When I lived in Hong Kong I always had a tough time remembering not to use my own personal chopsticks to grab the food in the shared dishes on the lazy Susan and to use the serving chopsticks instead. I always felt like I was breaking some kind of old tradition and one day I told a friend that and they responded, oh, it’s not a tradition, it started after SARS.
SARS (severe acute respiratory syndrome) was a warmup for Covid-19 and the ensuing pandemic. It was much more fatal but didn’t spread as rapidly; Hong Kong was affected badly and even more than 10 years later people are still using separate serving chopsticks to be extra safe. But that wasn’t the only change. Hand sanitiser is commonly seen on reception desks and by elevators, and people wearing surgical masks when sick never really went away after SARS. This is also part of the reason why despite Hong Kong’s population density Covid-19 didn’t really gain a huge foothold in the country initially.