The Guangzhou municipal people's government information office held a COVID-19 control and prevention press conference on March 11, in which the deputy director-general and spokesperson of the Guangzhou health commission Chen Bin reported that one close contact of another patient tested positive, with mild symptoms, in the designated quarantine facility.

The patient is a 35-year-old woman who is a colleague of the positive case reported on March 10. They work at the same stall. The patient tested negative on March 9 in the wide-scale testing conducted for all people linked to possible exposure sites. She was transported to a quarantined hotel for centralized health administration purposes in the early morning of March 10 and tested positive in the early morning of March 11. She was then transported to No 8 Affiliated Hospital of Guangzhou Medical University. The medical treatment expert panel studied the clinical and imaging manifestations, as well as the laboratory test results, and concluded that the patient had been infected by SARS-Cov-2 (mild). Currently, the patient is stable.

Through intensive epidemiological investigation and screening, by 15:00 on March 11, 19 people had been identified as close contacts and six people had been identified as secondary close contacts before the patient was quarantined, all of whom had been placed under health administration measures. As of now, the test results of close contacts and secondary close contacts have all come back negative.

The number of possible exposure sites increased by five, all located within Baiyun district, including Community Health Service Center in Yuncheng neighborhood, Xinxian Fruit Store on Alley Five of Xiaogang Dongyue West Street, Meizhixuan Convenience Store (Xiaogang Dongyue Store), Kaixin Guoyuan Fruit including:  Store on Alley Fourteen of Dongyue North Street, and Alley One of Dongyue Avenue.

Lockdown zones: Alley One of Xiaogang Dongyue Avenue (No 10, 17, 17-2, 19, 19-1, 21, 23, and 23-1) and No 20 Dongyue West Street. The aforementioned areas must be completely locked down. All residents inside these areas are under mandatory home quarantine, while necessary services and goods will be delivered to their doorsteps.

Partial lockdown zones: The area encircled by Xiaogang Dongyue South Street in the south, row two of Xiaogang Dongyue West Street in the east, Dong'an Community Committee Parking Lot in the west, and Alley One of Dongyue West Street in the north. Residents of this area must not leave the partially lockdown zones and deliveries must be collected on a staggered schedule.

Restricted zones: The area encircled by Yuncheng West Road in the east, Yunxiao Road in the south, Jichang Road in the west, and Qifu Road in the north. Social activities will be restricted and people are strictly forbidden to gather in these areas. Dining-in service will be suspended and facilities inside closed spaces will be temporarily closed in these areas.

Following COVID-19 control and prevention requirements, universal nucleic acid testing began in the Yuncheng neighborhood of the Baiyun district. By 15:00, 48,000 samples had been taken and none of the tests have returned positive results. Around 34 neighborhoods in Yuexiu, Liwan, Baiyun, and Haizhu are conducting a second round of universal nucleic acid testing, with residents from these neighborhoods encouraged to actively work with relevant departments to take the test.

Guangzhou has rolled out a rigorous plan to curb the infection risk of these two cases. It has conducted thorough epidemiological investigations and accelerated its efforts in identifying close contacts, secondary close contacts, and key groups. It aims to ensure that sufficient containment measures are in place. Lockdown zones, partial lockdown zones, and restricted zones have been identified through a science-based approach. Containment measures applied to different areas are differentiated and risk-based. Nucleic acid tests have been conducted in an orderly manner around possible exposure sites. According to expert analysis, new cases may appear later because these two patients work at a crowded place where there were a large number of visitors.

Guangzhou officials would like to draw public attention to the following matters:

Rigorously implement all the COVID-19 control and prevention measures. Residents who have recently been issued yellow Suikang Codes are advised to go through a seven-day health monitoring process at home. One thing to bear in mind is that even if a person's yellow code turns green after the first nucleic acid test came back negative, they will still need to take the subsequent two nucleic acid tests, as well as follow other health monitoring measures. Residents of the lockdown zones, partial lockdown zones, and restricted zones are advised to follow relevant requirements, as well as work with their neighborhoods and communities to take nucleic acid tests regularly, monitor body temperature, and report illnesses or conditions.

Personal protection remains imperative. Everyone is the primary person responsible for their health. All residents must wear masks, scan, and present the Suikang Code when using public transportation or entering public sites. Residents are advised to maintain proper ventilation at home and in the office. Residents are advised to stay one meter away from others when queuing in line and refrain from gathering. Residents are also advised to receive COVID-19 vaccines. If everyone takes these small steps, we can collectively build a solid shield against COVID-19.