COVID-19 control strategies in Taizhou city, China

Abstract Problem On 21 January 2020, the city of Taizhou, China, reported its first imported coronavirus disease 2019 (COVID-19) case and subsequently the number of cases rapidly increased. Approach To organize the emergency responses, the government of Taizhou established on 23 January 2020 novel headquarters for prevention and control of the COVID-19 outbreak, by coordinating different governmental agencies. People at high risk of acquiring COVID-19, as well as probable and confirmed cases, were identified and quarantined. The government closed public venues and limited gatherings. The Taizhou Health Commission shared information about identified COVID-19 patients and probable cases with affected agencies. To timely track and manage close contacts of confirmed cases, Taizhou Center for Disease Control and Prevention did epidemiological investigations. Medical institutions or local centers for disease control and prevention reported confirmed cases to the national Center for Disease Control and Prevention. Local setting Taizhou, a city in Zhejiang province with about 6 million residents, reported 18 confirmed COVID-2019 cases by 23 January 2020, which ranked it third globally in number of cases after Wuhan and Xiaogan cities in the Hubei province. Relevant changes In total, 146 confirmed cases (85 cases imported and 61 cases through community transmission) and no deaths due to COVID-19 had been reported in Taizhou by 1 June 2020. Between 16 February and 1 June 2020, no confirmed case had been reported. Lesson learnt Identifying and managing imported cases and people at risk for infection, timely information sharing, limiting gatherings and ensuring collaborations between different agencies were important in controlling COVID-19.


Introduction
In December 2019, reports on cases of pneumonia of unknown etiology emerged from Wuhan, China. Subsequently, researchers identified the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent. The outbreak grew and the virus spread to other cities in China 1 and across the world. On 11 March 2020, the World Health Organization announced the coronavirus disease 2019 (CO-VID-19) outbreak a pandemic. 2,3 Containing the spread of the virus from imported cases and preventing community transmission is important for controlling virus transmission in the early stage of an outbreak. Here we describe how decision-makers in the city of Taizhou, China, took newly-developed approaches to control the spread of SARS-CoV-2.

Local setting
In 2018, Taizhou, situated in Zhejiang Province, had about 6 million residents. 4 The city reported its first COVID-19 case on 21 January 2020. As of 23 January 2020, the city had reported 18 confirmed cases, ranking it the third most affected city after Wuhan and Xiaogan in the Hubei province, China.
On 20 January 2020, the National Health Commission decided that COVID-19 should be classified as a notifiable infectious disease, according to the Chinese law. 5 Any new confirmed case must be reported to the national Center for Disease Control and Prevention (CDC) within 2 hours through the national reporting system of infectious disease and all health administrations should make the number of daily reported cases publicly available. Furthermore, Chinese citizens must report any issue related to COVID-19 through a government service hotline or contact community workers. For the epidemiological investigation, a citizen must include exposure history, symptoms and close contacts, and anyone who conceals facts could be subjected to criminal detention and other penalties.

Approach
To respond to the outbreak, the government of the Zhejiang province launched the first level response to a major public health emergency on 23 January 2020. This launch included the establishment of novel provincial, municipal and district headquarters for COVID-19 epidemic prevention and control, which organized the emergency responses according to the decisions of the Chinese State Council. 6 The Taizhou municipal headquarters consisted of staff members from the Taizhou Health Commission, Taizhou CDC, hospitals and other affected sectors. On 24 January 2020, Taizhou implemented nine measures to address the increasing COVID-19 cases (Box 1). 7 Furthermore, school resumption date was announced to be postponed on 29 January 2020 and all non-essential businesses were closed on 31 January (Fig. 1).
To manage the high-risk populations efficiently, the Health Commission staff summarized the information of high-risk populations, including their demographic characteristics and exposure history. CDC and medical observation sites shared the information of confirmed cases in real time (within 2 hours from the time when the patient Lessons from the field Taizhou's responses to COVID-19 epidemic Haijiang Lin et al. is confirmed) through the national reporting system of infectious disease.
The diagnosis and treatment for COVID-19 were made free of charge, either by basic insurance or government subsidies. All level of governments provided subsidies for medical devices, such as thermometers, respirators, extracorporeal membrane oxygenation systems and negative pressure isolation ambulances.
Headquarters implemented six major control strategies, which we describe below in detail.

Screening and quarantine
To identify people at high risk of acquiring COVID-19, government officials screened people passing traffic entrances to the city, people in the community and people with a fever visiting outpatient clinics. People suspected of having CO-VID-19 were identified by measuring body temperature and taking travel and/ or contact history. Identified high-risk people were required to stay at home for 14 days. The isolated person had to measure his or her body temperature twice a day, which they reported daily via phone to the health-care workers or community workers. Health-care workers could also make home visits to measure temperature. Those who had a temperature of 37.3 °C or higher, judged by a health community worker, were sent to designated medical institutions.
Since 22 January 2020, people who had visited the Hubei provinces were regarded as a high-risk population and since 29 January 2020, the same crite-Box 1. Nine measures taken to stop the spread of SARS-CoV-2, 24 January 2020, Taizhou, China (i) Cancellation of holidays for main leaders of the Party and governments in counties and towns during the Spring festival (24 January to 2 February 2020); (ii) medical insurance coverage for all people with confirmed COVID-19 regardless of previous insurance status; (iii) designated hospitals for COVID-19 care opened and probable patients were given priority treatment; (iv) medical observation of all close contacts to probable or confirmed cases; (v) closing of all public gathering places, such as entertainment places, internet cafes, cinemas, libraries and museums; (vi) cancellation of all public gathering activities; (vii) people entering hotels, transport stations, airports, and entrances and exits of main roads of the community must measure their temperature and report any symptom and exposure history;  ria applied for people who had visited Wenzhou city, Zhejiang province. To identify this population, the Taizhou´s governmental big data bureau analysed data of mobile phone movement. Community health workers identified people in their homes by door-to-door visits. At headquarters, a special taskforce, composed by personnel from the big data bureau, public security bureau and the health commission of Taizhou, collected and managed the data on the demographic characteristics and exposure history of this population. Before the Taizhou electronic epidemic prevention and control information management system was established, they managed the data by using paper-based records.

Traffic entrance management
On 24 January 2020, the public security bureau established checkpoints to inspect passengers entering Taizhou through highways, railways and airplanes. Each community or village had only one entrance open, where a checkpoint was established. Each checkpoint was staffed with at least one worker from the public security department and one worker from the local primary health centre. The checkpoint staff inquired anyone presenting with respiratory symptoms and/or a temperature of 37.3 °C or higher (when measured by a hand-held thermometer) about their travel, residence and close contact history in the past two weeks.
Depending on the risk, the checkpoint staff used different observation and quarantine strategies. For people with exposure history and fever or respiratory symptoms, checkpoint staff sent paper-based information regarding demographic characteristics and exposure history of the identified person to headquarters. An ambulance took the patient to the local fever clinic in the designated hospitals.
If there were accompanying individuals in the car, they were required to be home quarantined. People with exposure history, but no symptoms in the checkpoints were sent to the medical observation site, which was a converted hotel now containing a medical examination room, a medical observation area, an office and living area for staff members and a logistic support area. People without exposure history, but with a fever were sent to the local fever clinic to exclude the possibility of having COVID-19, by using SARS-CoV-2 nucleic acid test, chest X-ray and blood tests. People testing negative were followed up by community health workers through a telephone call or home visit. People without exposure history or fever could pass through the checkpoint.

Medical observation site
The medical observation site is composed of at least one public security staff, one clinician and one nurse. The nurse measured the person's body temperature twice a day and asked for the symptoms, especially cough and shortness of breath. If the person presented symptoms, s/he would be sent to a designated COVID-19 hospital. After the 14-day observation period the person would be released if no symptoms had been shown.

Medical institutions
There were 27 designated hospitals for the diagnosis and treatment of COVID-19 across the nine counties in Taizhou. Personnel wore work clothes, disposable work caps, disposable gloves, disposable medical protective clothing, medical protective masks or powered air supply filter respirators, protective screens or goggles and work shoes or rubber boots with waterproof boot covers. In the reception, a senior nurse would identify probable cases based on people's body temperature, respiratory symptoms and exposure history. A specialized expert group from the infection department, respiratory department and radiation department would jointly provide consultation for the patients. Confirmation of COVID-19 was done with a SARS-CoV-2 nucleic acid detection kit (Shanghai BioGerm Medical Biotechnology Co., Ltd, Shanghai, China).

Contact tracing
For each confirmed or probable case, local CDC professionals did an epidemiological investigation within 24 hours of diagnosis by consulting data and by interviewing to understand the natural history of each case and to trace the source of infection and close contacts. Anyone who has had a close contact (that is, within 1 m distance) within two days before the onset of any symptoms in the confirmed patient was regarded as a close contact. On aircrafts equipped with air filters, passengers who were sitting up to three rows in front of or behind the patient, plus the aircrew, were regarded as close contacts. On trains, buses, ferries or aircrafts without air filters, all passengers were regarded as close contacts.
Close contacts were sent to the local medical observation site for a 14-day quarantine and were tested for SARS-CoV-2 when symptoms appeared. If they were confirmed to be having COVID-19, their residences were disinfected by CDC professionals.

The Health Code
Since 19 February, the government of Taizhou has been using the Health Code, a quick response (QR) code showing the probability of a person having CO-VID-19. All citizens had to download the mobile application, such as Alipay or WeChat, containing the QR code to their smartphones. They filled in a questionnaire about their symptoms and exposure history in the applications when applying the QR code for the first time. When entering into traffic checkpoints, workplaces, communities and other public places they had to display the real-time Health Code and their temperatures were measured. The Health Code will be marked as red for confirmed or probable patients and they would be sent to the designated hospital immediately. Other high-risk populations, such as people from cities with a severe epidemic and contacts of confirmed or probable patients would also be marked with a red code and require a 14-day home quarantine. People with fever or any respiratory symptoms, but without other risk factors, such as exposure to high risk areas, would be marked with a yellow code and require a 14-day home quarantine. After filling in the personal health information in the smartphone application every day during the quarantine period, the red code would automatically turn green at the end of the quarantine if the person was symptom free. If a person entered symptoms into the Health Code during quarantine, s/he would be sent to a designated COVID-19 hospital. Residents without any symptoms or risk factors would be marked with a green code and could pass through all checkpoints freely. Fig. 1 shows the timeline of events and the number of confirmed cases per day. After the outbreak reached its daily peak of new cases on 29 January 2020, the epidemic situation rapidly improved. On 11 February 2020, no new cases were re-Lessons from the field Taizhou's responses to COVID-19 epidemic Haijiang Lin et al.

Relevant changes
ported for the first time and by 11 March 2020 all hospitalized patients had been discharged from the hospitals. Up to 1 June 2020, 146 confirmed cases (85 cases imported and 61 cases through community transmission) and no deaths due to COVID-19 had been reported. As of 1 June 2020, all townships were deemed at the lowest risk for an outbreak.
In total, 85 796 people had been quarantined by 29 February 2020. Of those, 30 813 people from Hubei and 40 614 people from Wenzhou had been traced in Taizhou. The ratio of secondary cases to imported cases was 0.72: 1, indicating that the control strategies had effectively eased the transmission from imported epidemic to the local community.

Lessons learnt
Prevention of community-level transmission from imported cases was an effective strategy in containing the spread of COVID-19 in Taizhou. Through active screening strategy among the high-risk populations to detect early-stage cases and effective control strategy on infected patients, probable cases and their close contacts, the government of Taizhou minimized the risk of transmission. However, the prevention and control work had some challenges. First, the disease prevention and control system lacked capacity for a major public health emergency and per-sonal protective equipment needed for the work was insufficient. Therefore, the government integrated the resources of various agencies and organizations, created fever clinics in medical institutions, strengthened the monitoring and early warning of public health events and purchased personal protective equipment. The government also supported manufacturing enterprises by reducing taxes and giving preferential loans to incite production of medical supplies and personal protective equipment. Second, finding all high-risk people and COVID-19 positive individuals was cumbersome. Hence the government ensured that the information was shared among different departments, and big data analytics and community screening were used, as well citizens mobilized for reporting any issue related to CO-VID-19. Third, to address the panic felt by some citizens, the government strengthened health education and publicity to citizens, shared information and acted in a timely manner to the epidemic.