People visit a COVID-19 testing center setup outside the immigration headquarters in Hong Kong on April 24, 2021, after a returning Philippine domestic helper tested positive after completing a 21-day quarantine and later visited the building. (PETER PARKS / AFP)

Hong Kong’s 370,000 foreign domestic helpers have been ordered to undergo COVID­-19 tests before May 9, after a Filipino helper infected by a mutated strain was identified as the city’s first untraceable local case with the N501Y variant. 

However, helpers who had been fully vaccinated at least 14 days ago are exempted from the mandatory testing, Food and Health Secretary Sophia Chan Siu-­chee said at a briefing on Friday.

“As a public holiday is coming tomorrow, I appeal to domestic helpers in the city to avoid any gatherings before receiving negative results,” Chan said.

The Filipino helper infected with N501Y variant, who arrived in Hong Kong in 2019, developed a cough on April 23 and visited a doctor three days later. During her incubation period, she visited multiple places in the area, including St. Thomas the Apostle Church in Tsing Yi, and the Citygate Outlets shopping center in Tung Chung

At the same briefing, the government said it plans to make COVID­-19 vaccinations mandatory for helpers signing or renewing their contracts.

The announcements came as Hong Kong registered four new coronavirus cases, including two local cases — the 39­-year-­old female helper, and the 10-­month-old girl she cares for. The girl’s parents tested negative.

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The infections resulted in all 1,600 residents of Tower 11 of the Caribbean Coast in Tung Chung being evacuated on Thursday night and sent to government facilities for three weeks of quarantine.

The infected helper, who arrived in Hong Kong in 2019, developed a cough on April 23 and visited a doctor three days later. During her incubation period, she visited multiple places in the area, including St. Thomas the Apostle Church in Tsing Yi, and the Citygate Outlets shopping center in Tung Chung. Mandatory ­testing notices had been issued t workers and visitors there.

She was the second helper in the city to contract a mutation. The first was confirmed to be infected only after she returned to her employer’s home, but she is believed to have contracted the virus before finishing a three-week hotel quarantine on April 17.

In addition, the government plans to make it a requirement for helpers to get the shots when signing or renewing an employment contract in the city, Labour and Welfare Secretary Law Chik-wong said.

“Domestic helpers tend to gather with their fellows at holidays. Once they contract the virus, they are likely to spread the virus to multiple families. … We have to enhance the measures,” Law said.

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The other two cases on Friday were imported from India and Nepal. Flights from both countries to Hong Kong had been prohibited amid concerns over surging variants there.

Hong Kong’s total of confirmed cases stood at 11,774, with 209 related deaths.