ANKARA 

Hong Kong detected an untraceable variant of coronavirus, forcing evacuation of a residential plot and immediate quarantine of the close contacts of the infected person, a health authority said.

According to a statement released by the Hong Kong Department of Health on Thursday, a positive case with the N501Y mutant strain of coronavirus was reported late evening.

“As N501Y mutant strain is with high transmissibility, the Centre for Health Protection decided to carry out prudent measures on infection control and prevention to arrange compulsory quarantine for asymptomatic residents of all units on all floors of the building concerned, so as to stop the potential risk of spread of N501Y mutant strain,” read the statement.

The source remains unknown, it said.

The case involves a 39-year-old woman from the Philippines who is a domestic helper and caretaker of a 10-month-old baby girl who also tested positive for COVID-19.

Health authorities issued evacuation order for quarantine in Tung Chung area of the city. Asymptomatic residents of all units on all floors of the building, involving about 400 units, were transferred to quarantine centers, the statement added.

It said the symptomatic residents will be hospitalized for treatment and will undergo compulsory quarantine for 21 days.

The variant carrier did not have any recent travel history.

She had visited a church and the Centre for Health Protection asked for compulsory quarantine for the close contacts who had attended church gathering with the woman.

“As there is a locally infected case of COVID-19 with unknown source involving N501Y mutant strain, it is imperative for people to get vaccinated,” the health body said.

Hong Kong has reported 11,771 coronavirus cases, including 209 deaths, thus far.