There were 116 locally transmitted infections, and 12 of them could not be traced, involving patients who live in Mong Kok, To Kwa Wan, Ho Man Tin, Kowloon Bay, Tsz Wan Shan, Ma On Shan, Kwai Chung, Tai Wo Hau and Tin Shui Wai.
The head of the Centre for Health Protection, Dr Edwin Tsui, said the city has about 30 untraceable infections overall, warning that there are dozens of hidden transmission chains in the community.
He called on the public to avoid gatherings, especially cross-family functions, during the Lunar New Year holiday.
Tsui also acknowledged contact tracing is not easy.
“We are opening a new team to handle contact tracing of more cases occurring every day. The problem of contact tracing is that once there are many cases occurring daily, although we try our best to obtain the details and also the history of the case, there are still some unlinked cases,” he told a press conference.
Tsui added that the major outbreak at Kwai Chung Estate appears to be easing, with the number of additional families affected at Yat Kwai House and Ying Kwai House down to single digits.
So far, 332 patients were linked to the two blocks, with the caseload of the entire estate exceeding 370.
Meanwhile, the Hospital Authority is recruiting nurses to help man extra quarantine facilities at the AsiaWorld-Expo to fight the pandemic, with the number of cases expected to remain high.
Officials also reported around 100 preliminary-positive cases on Thursday.