A 66-year-old local woman who lives in Fai Chi Kei has tested positive for COVID-19 in Zhuhai, because of which all those who live or work in the neighbourhood are required to undergo three nucleic acid tests (NATs) in three days between yesterday and tomorrow.

The building where the woman lives was locked down yesterday afternoon, i.e., after having been listed as a Red Code Zone. The building’s residents are prohibited from leaving their homes and are required to undergo regular nucleic acid tests during the lockdown period, which is provisionally slated to end next Tuesday.

The Macau Health Bureau (SSM) yesterday urged residents “not to worry too much” about the situation, and underlined that for the time being it had provisionally concluded that following the case Macau was facing a low risk of the occurrence of COVID-19 community transmissions.

The case was first revealed in a Novel Coronavirus Response and Coordination Centre statement yesterday afternoon. According to the statement, Zhuhai’s health authorities informed their Macau counterparts about the case yesterday morning. The centre convened a press conference yesterday afternoon where Health Bureau Director Alvis Lo Iek Long announced details of the case and special COVID-19 measures in response to the case.

10-in-1 mixed samples in Zhuhai

According to Lo, Zhuhai’s health authorities told the Macau Health Bureau at around 9 a.m. yesterday that a batch of 10-in-1 mixed samples in the adjacent city had tested positive for COVID-19, and that eight of the 10 testees were in Macau. Consequently, Lo said, the Health Bureau then contacted the eight people and transferred them to the public Conde de São Januário Hospital Centre for a follow-up nucleic acid test.

The 66-year-old woman came up with a positive result in her test at the public hospital, while the other seven people tested negative for COVID-19, Lo said.

Regular COVID-19 NAT programmes in Macau and the mainland normally adopt a 10-in-1 mixed testing approach, where 10 swabs are mixed in a batch of pooled samples.

The 10-in-1 mixed sampling technique enables laboratories to come up with results in a much shorter time. However, if a batch of pooled samples tests positive, the 10 testees will need to have their swabs taken again – in which case their swabs will not be mixed – in order for laboratory technicians to identify which of them tested positive for COVID-19.

The 66-year-old woman lives with her son and her younger sister. Lo said that after the detection of the woman’s case, the Health Bureau carried out a COVID-19 nucleic acid test on her son and her sister, and both were negative.

The woman lives in Weng Heng Building in Fai Chi Kei, which was listed as a Red Code Zone yesterday afternoon after the case’s detection, Lo said.

Lo said that the findings of the Health Bureau’s epidemiological investigation indicate that the woman travelled between Macau and Zhuhai “many times” over recent days, but he underlined that her recent visit history in Macau had been relatively “simple”, i.e., having visited just a few venues in recent days.

CT value

According to Lo, the positive COVID-19 result of the woman’s nucleic acid test in Zhuhai, which was carried out on Tuesday night, had a cycle threshold (CT) value of 32, indicating a low viral load, while the positive result of her follow-up test in Macau yesterday came up with a CT value of 16.6, indicating a higher viral load. A high CT value indicates a low viral load.

Lo said that the changes in the CT values of the woman’s tests indicated that her COVID-19 infection was detected “in the early stage”, i.e., she has been infected with the novel coronavirus for just a short period of time.

In addition, Lo also said that the “epidemiological characteristics” of the woman’s case indicate that her case was likely to have been imported into Macau, because of which, he said, for the time being the Macau Health Bureau concluded that the level of the risk of the novel coronavirus being spread in the community was relatively low.

Nevertheless, Lo was quick to add that the Macau government will not let its guard down as it has rolled out stringent COVID-19 precautionary measures.

NAT campaign’s area

The ongoing three-day NAT campaign for those who live or work in the vicinity of the 66-year-old woman’s home, which started at 4 p.m. yesterday, covers an area surrounded by Avenida do Conselheiro Borja, Rua Norte do Patane, Rua Sul do Patane, Avenida do Almirante Lacerda, and Avenida do General Castelo Branco.

According to a Novel Coronavirus Response and Coordination Centre statement yesterday afternoon, all those who live or work in the area were required to undergo their first nucleic acid test before 11:59 p.m. yesterday. Afterwards, they are required to undergo two more nucleic acid tests, one today and one tomorrow, which means that they are required to undergo three tests within three days.

The statement also said that those who had stayed in the area for more than half an hour on or after Monday are also required to undergo the three nucleic acid tests.

The Health Bureau has sent an SMS about the NAT campaign to all those living in the area. Those living in the area who fail to undergo their nucleic acid tests in compliance with the required schedules will have their Macau Health Code colour turn yellow, yesterday afternoon’s statement said.

Those covered by the ongoing three-day NAT campaign must self-test for COVID-19 with a rapid antigen test (RAT) kit at home and upload their negative RAT result onto the bureau’s platform first before going to NAT stations for their nucleic acid tests.

About four dozen NAT sampling stations are currently operating across the city.

Lo said during yesterday evening’s press conference that around 26,000 people are living in the area covered by the ongoing three-day NAT campaign.

Lo underlined that the Macau government will decide other possible special COVID-19 measures for the next step in line with results of the three-day NAT campaign, results of tests for those living in the Red Code Zone, and results of tests for those more directly affected by the woman’s case, such as her close contacts.

As of last night, no COVID-19 positive results had been reported.

Carrier has not been vaccinated

Meanwhile, Health Bureau official Leong Iek Hou said that at the time of yesterday afternoon’s press conference the 66-year-old woman had not come down with any COVID-19 symptoms. Leong also said that the woman has not been vaccinated against COVID-19, and neither have the two family members living with her. She underlined that COVID-19 vaccinations can lower the risk of infection, and significantly reduce the risk of developing a serious condition or complications in case of still having been infected.

Leong said yesterday that the woman walked from her home to the nearby Qingmao checkpoint on Friday, Saturday, Sunday and Tuesday evening en route to Zhuhai. She went to a supermarket near Zhuhai’s Gongbei checkpoint to shop each time and returned to Macau via the Qingmao checkpoint at night.

Leong also said that the woman tested negative for COVID-19 in Zhuhai on Sunday.

Lo also said yesterday that if Macau does not report any COVID-19 community cases following the detection of the 66-year-old woman’s case, it would not affect the upcoming resumption of mainlanders’ tour group travel to Macau.

The resumption of mainlanders’ tour groups to Macau is slated to get off the ground late this month or early next month. The measure will initially cover tour groups from Guangdong as well as Fujian, Jiangsu, Shanghai and Zhejiang.

70 students & teachers in locked-down building 

Meanwhile, the Education and Youth Development Bureau (DSEDJ) said last night that around 70 school or university students and teachers are living in the Red Code Zone. The DSEDJ statement said that their respective schools or universities will arrange for the affected students to have home online teaching.

As of last night, Macau’s COVID-19 tally stood at 793 confirmed and 1,739 asymptomatic cases, of which 787 and 1,731 had been cured. The COVID-19 death toll remained at six.

Police officers in protective gear prepare to lock down Weng Heng Building in Fai Chi Kei yesterday afternoon where a 66-year-old local woman who has tested positive for COVID-19 lives. – Photo: Maria Cheang Ut Meng

People queue to be tested for COVID-19 at an outdoor nucleic acid test (NAT) sampling station in Fai Chi Kei yesterday afternoon. – Photo: Maria Cheang Ut Meng