Calls are mounting for the government to expand the scope of coronavirus tests in part of Yau Ma Tei and Jordan following a surge in infections there.
At present, residents of the area must undergo Covid-19 tests if there is one or more confirmed cases in the building where they live.
But infectious disease specialist Joseph Tsang from the Hong Kong Medical Association said people who live or work in the vicinity of the affected buildings should also be required to undergo compulsory tests.
Speaking on an RTHK programme on Monday, Tsang also said it would be best to test these people more than once.
Residents of blocks with Covid-19 cases were given until Monday to take a mandatory test, but Tsang said the deadline should be put back so more people could get tested.
Almost a hundred cases from the Yau Ma Tei/Jordan area were confirmed in recent days, with another 80 preliminary positive cases reported on Sunday.
Tsang said that, as a precaution, the government should consider conducting screening tests for residents of areas where there are a lot of old tenement buildings, such as Sham Shui Po, To Kwa Wan and Kwun Tong.
He also urged the government to order mandatory tests for construction workers, following a number of outbreaks involving building sites.
His views were echoed by microbiologist Ho Pak-leung from the University of Hong Kong.
Ho said residents in affected buildings in the designated Yau Ma Tei and Jordan area should get tested for a second time, five days after the first test, and those working in "high risk jobs" like construction should be ordered to stay at home and receive no visitors until they get their test results.
He also urged authorities to test residents of this area before any cases emerge in the buildings they live in, so as to identify infections sooner and cut the chains of transmission.
Also speaking on an RTHK programme, DAB lawmaker Vincent Cheng said all residents of the area should get tested. He said the government should also examine the pipes of old buildings there to prevent the virus from being spread via the sewage system.
More than 7,000 resident in the Yau Ma Tei/Jordan area have undergone tests in the past two days.