Only those in old residential compounds who live on the same floor as a positive COVID-19 case and share a kitchen or bathroom with that person will be considered close contacts and put under central quarantine, according to the Shanghai Center for Disease Control and Prevention.

Only people who live with a positive case in apartments with private kitchens and bathroom will be defined as close contacts, according to Sun Xiaodong, deputy director of the city's CDC.

Those living on the same floor or on the floors immediately above or below a positive case will be considered secondary contacts, who can quarantine in their homes if conditions allow, Sun said at the city's daily COVID-19 resurgence press conference on Tuesday.