Non-Hong Kong residents will be banned from entering the territory or transiting through Hong Kong Airport from midnight on Wednesday, local time.
It comes after a doctor working at the airport, issuing quarantine orders to visitors, was confirmed as infected with COVID19.
Other new cases include a Cathay Pacific flight attendant who had travelled to Britain and a Cathay manager who had visited Britain and Spain, according to the China Morning Post.
The last Cathay Pacific Europe-bound flights that will be allowed to accept transit passengers at Hong Kong Airport will be CX219/25MAR for Manchester, CX255/25MAR for Heathrow and CX289/25MAR for Frankfurt.
After that, only Hong Kong residents with a valid visa, identity card or proof of right of abode will be allowed entry into the territory.
Cathay Pacific passengers can refund, reschedule or rebook using Manage Booking via cathaypacific.com or should contact their travel agents.
Cathay Pacific has cancelled flights CX257 and CX238 between Hong Kong and London Heathrow from 30 March to 7 April.
Other scheduled services to and from Heathrow will be maintained.
Afterwards, Cathay will maintain three-times-weekly services to and from London Heathrow until May.
