Introduction
If not managed carefully and effectively, mass gatherings are highly visible events with the potential for serious public health and political consequences.Reference Brennan, Keim and Sharp1-Reference Thackway, Churches, Fizzell, Muscatello and Armstrong4 Mass gatherings have been reported to have significant impact upon public health systems throughout the world.Reference Wharton, Spiegel and Horan5-Reference Blyth, Foo and van Hal10 Local, provincial, and national public health and medical agencies frequently are involved before, during, and after a major event. Therefore, public health preparedness is a key element for the effective management of mass gatherings.
The 2010 World Exposition in Shanghai China (Expo) was the largest mass gathering in world history, attracting a record 72 million visitors. More than 190 countries participated in the Expo, along with more than 50 international organizations. The 2010 Expo was six months in duration (May 1 through October 30, 2010), and the size of the venue site comprised 5.28 square kilometers. Great challenges were imposed on the public health system in Shanghai due to the high number and density of visitors, long duration of the event, and other risk factors (ie, high temperatures, typhoons). This paper reviews actions taken by a major metropolitan public health agency in preparing for, and responding to, the potential health impact of the world's largest mass gathering to date.
Report
Methods for Public Health Preparedness
The Shanghai Municipal Center for Disease Control and Prevention (SCDC) implemented the following key elements of public health preparedness leading up to the start of the Expo: (1) partnerships for capacity building; (2) enhancement of internal organizational structure; (3) risk assessment; (4) strengthened surveillance; (5) disaster planning and exercises; (6) laboratory management; (7) vaccination campaign; (8) health education; (9) health intervention; (10) risk communication and mass media surveillance; and (11) technical support for health inspection.
Partnerships for Capacity Building
China-US Collaboration
Early on, the SCDC began to establish partnerships that would assist in building capacity for public health emergency preparedness and response related to the Expo. In 2008, the Shanghai Municipal Center for Disease Control and Prevention partnered with the US Department of Health and Human Services, Centers for Disease Control and Prevention (USCDC) to develop a comprehensive approach for managing the risk of public health emergencies during the 2010 World Exposition. This collaboration included training and technical assistance related to public health emergency management, risk assessment, as well as emergency operations planning and disaster exercises. The USCDC also assisted SCDC with identifying a metric for measuring public health preparedness before and during the event. Using the SCDC emergency operations plan as the standard, a gap analysis also was performed that would guide preparedness activities leading up to the Expo. In addition, a direct videoconferencing linkage was established between SCDC in Shanghai, China and USCDC in Atlanta, Georgia USA that would allow real-time exchange information and consultation during the Expo and beyond.
Other International Collaboration
In addition to the cooperation with USCDC, SCDC also established close collaboration with other international organizations, such as the World Health Organization (WHO) and the European Centre for Disease Prevention and Control (ECDC). During August 2009, the WHO held an international seminar in Shanghai during which preparations for Shanghai Expo were discussed and a framework for agreement involving collaboration was reached. In response to this framework, the SCDC convened a seminar during April 2010 on communicable diseases prevention and control for the Expo. It covered several crucial issues regarding Expo preparation, including infectious disease surveillance, laboratory testing, and risk communication. The ECDC also sent experts to Shanghai for training of mass-media surveillance. Moreover, the ECDC also provided internships for SCDC staff to learn how to operate the ECDC Threat Tracking Tool (TTT, version 0.1, developed by ECDC, Stockholm, Sweden), a database that allowed SCDC to keep track of verified events with a known or possible impact on public health.
Internal Organizational Structure
It often is necessary to enhance routine public health organizational structures in order to meet the increased demands of emergency preparedness and response activities.Reference Tsouros and Efstathiou3, Reference Thackway, Churches, Fizzell, Muscatello and Armstrong4 In April 2009, in order to ensure efficiency of public health preparedness and planning activities, the SCDC established a Steering Group of Public Health Security for the World Expo 2010. Under the Steering Group, the SCDC Office of Public Health Security for Shanghai Expo (Expo Office) was placed in charge of all routine preparedness work. In addition, six working groups were formed under the direction of the Expo Office with responsibilities for the following areas: (1) risk assessment; (2) surveillance and precaution; (3) intervention; (4) planning and exercise; (5) mass-media surveillance and risk communication; and (6) anti-terrorism. Risk assessments were performed in six subject areas including: (1) communicable diseases; (2) public health events related to food hygiene, environmental health, occupational health, and radiation health; (3) injury; (4) security of the laboratory; (5) disasters due to natural hazards; and (6) terrorism. The SCDC internal organization structure as established for all Expo-related public health preparedness and response efforts is in Figure 1.
Figure 1 Internal Organization Structure for 2010 Expo-related Public Health Preparedness and Response Efforts
Results from the Risk Assessments Group were used to guide further planning of preparation work. The Surveillance and Precaution Group was responsible for constructing an enhanced surveillance network so as to ensure early detection of potential outbreaks and other events. The Intervention Group was intended for the planning and implementation of health education and health promotion strategies and measures. The Planning and Exercise Group evaluated and optimized the current emergency plans and organized several exercises in order to improve emergency response capabilities. The Mass-Media Surveillance and Risk Communication Group was responsible for designing and implementing surveillance of the mass media. This group also focused on risk communication as well as internal and external communication mechanisms. The Anti-terrorism Group was designed to provide subject-specific technical support in preparation for World Expo.
Besides the above six tasks, the SCDC also has carried out two major campaigns: (1) laboratory capacity building targeting on emerging technical needs; and (2) a vaccination campaign that included: seasonal influenza; novel H1N1 influenza; vaccination for local residents; and vaccinating Expo employees with vaccines such as hepatitis A and measles.
Risk Assessment
A series of risk assessments were performed in order to identify and prioritize potential disaster hazards, and in order to assist with the prioritization of preparedness activities. The approach was based on the AS/NZ 4360:2004 Standard for Risk Assessment, and was modified according to a methodology provided by USCDC.11 The risk assessment was based on the following qualitative equation:
$$ {\bf{p(R)}}\, {\bf{ = }}\, {\bf{k [\bf p(H)}}\, {\bf{x}}\, {\bf{p(V)] {\bf- AC}}} \eqno\rm$$
Where: p(R) = the risk of disaster occurrence, p(H) = the probability of hazard occurrence; p(V) = the probability of population vulnerability; and AC = absorptive capacity of the SCDC (as estimated during the gap analysis). Hazard risk, (H) is calculated according to the equation H = L x I; where L = likelihood and I = impact of the hazard.
From April to August 2009, the SCDC carried out the first round of the risk assessment and identified the following risks: 26 infectious diseases; 21 public-health-related risk events; 19 injury related risks; eight laboratory biosafety risks; and seven categories of disasters due to natural hazards or other emergencies (46 individual events).
From the results of risk assessment, the SCDC put forward 37 recommendations to 28 government departments in Shanghai.
Ongoing assessments were used to better estimate the dynamic risk situation, and to provide updated recommendations for public health preparedness activities. In March 2010, the SCDC performed a gap analysis for emergency preparedness. At that time, the current state of the SCDC's capabilities and capacities was identified using the Emergency Operation Plan as the standard. The SCDC identified capabilities and measures of capacity that may be required during an emergency or disaster event during the Expo. The SCDC implemented the second round of the risk assessment in March to April, 2010. Compared with the previous round, the second risk assessment was closer to the real situation, as time for the opening of Expo drew near.
Strengthened Surveillance
During August to December, 2009, the SCDC optimized the surveillance system by adjusting surveillance frequency, expanding surveillance objectives, and increasing surveillance sites. The updated surveillance system is composed of 10 subsystems:
1. Surveillance for abnormalities of clinic visits within Expo site—Data were collected from five clinics within the Expo site for further analysis so as to detect any abnormalities and provide early warning and response;
2. Surveillance for public health risk factors within Expo site—Risk factors of nosocomial infection in Expo clinics were monitored for continuous quality improvement of disinfection and infection control;
3. Surveillance for designated hospitals outside the Expo site—Respiratory and enteric surveillance were strengthened in the designated hospitals. Additionally, surveillance for methicillin-resistant Staphylococcus aureus and chemical poisonings also was undertaken in these hospitals;
4. Case surveillance for notifiable diseases—Since 2004, China has a national Web-based case-reporting system for notifiable diseases. During the Expo, data analysis was strengthened and bulletins were issued from monthly basis to daily basis;
5. Surveillance for major infectious diseases outside of Expo site—Routine infectious diseases surveillance was enhanced by means of expanding surveillance sites, increasing surveillance samples, and raised surveillance analysis. The strengthened surveillance included: respiratory diseases (ie, influenza, measles); enteric diseases (ie, hepatitis A, dysentery); vector-borne diseases (ie, Japanese encephalitis, dengue fever); and blood-borne diseases (ie, syphilis, gonorrhea);
6. Surveillance for public health risk factors outside of Expo site—Food, water, and public places were major concerns for public health risk factors; thus, food contaminants, water quality, and sanitary conditions of public places were under enhanced surveillance in order to ensure public health security;
7. Surveillance for absenteeism from school—According to previous experience, school students’ absenteeism is a sensitive indicator for public health emergencies. In collaboration with the Shanghai Education Bureau, an online reporting system was established, and data were collected and analyzed on a daily basis;
8. Surveillance for mass media—Ninety-four domestic and foreign websites were chosen for mass-media surveillance for early detection of outbreaks or emergencies, especially for early warning of imported cases;
9. Surveillance for public health emergencies—Besides the Web-based, national case-reporting system, in 2004 a system for reporting public health emergencies was established in China. This system was monitored closely before and during the Expo; and
10. Trans-regional and trans-departmental surveillance for infectious diseases—Taking the huge numbers of tourists into consideration, additional surveillance was established in collaboration with the local Tourist Council. It facilitated the detection of aggregated respiratory cases and diarrhea cases among tourist groups.
All the surveillance subsystem plans were compiled, and the Shanghai Medical Health Bureau dispatched the documents to district medical health bureaus, district Centers for Disease Control, and related hospitals in order to ensure implementation. The SCDC served as the common point for data collection, analysis, and reporting. These 10 surveillance subsystems provided comprehensive, ongoing, and scientific data for further decision making.
Among these subsystems, the one most directly related to the Expo site was the Surveillance System for Abnormalities of Clinic Visits within the Expo sites. A Surveillance Information System was developed from January to March, 2010 and provided online surveillance data input and real time analysis. It later proved very helpful in detecting potential outbreaks, food poisonings, heat-related illness, and other events.
Planning and Exercises
Taking the risk assessment results and public health security needs into consideration, the SCDC improved 30 emergency plans during August to December 2009, and established a planning system with eight major categories: (1) generic plans; (2) infectious disease; (3) poisoning; (4) environmental events; (5) groups of diseases with unknown reasons; (6) vaccination and prophylaxis; (7) anti-terrorism; and (8) other events.
The SCDC then validated each of the above plans by organizing a series of emergency exercises during October 2009 to April 2010. These exercises ranged from tabletop exercises to functional and full-scale exercises. The exercises were based on an all-hazard, capability-based approach, with scenarios designed to cover the following: (1) groups of diseases with unknown etiology; (2) disinfection and infection control; (3) chemical poisoning response; (4) vector control; (5) infectious disease emergency response; (6) radiological event response; (7) laboratory safety; and (8) food safety; among others. Fifteen exercise sessions were held, and approximately 1,100 people were involved.
Laboratory Management
Laboratory Capacity Building and Technical Reserve
Rapid and accurate laboratory testing platforms for emergencies were crucial for Expo public health preparedness. Responsibilities for sentinel, referral, and confirming laboratory analysis were delegated among district and municipal CDCs of metropolitan Shanghai, with district CDCs performing routine testing, and the SCDC performing the more complex and sophisticated analyses.
The SCDC evaluated >1,500 testing items, and identified key priorities for laboratory capacity building. By February 2010, 340 new testing items were added as compared with those that existed two years prior, during the period of the 2008 Olympic Games.
Laboratory Safety
During preparations for public health security of Expo 2010, the SCDC placed great emphasis on laboratory safety issues. In September to October 2009, and March to April 2010, the SCDC held two rounds of audits followed by implementation of appropriate rectification measures that would ensure laboratory safety.
Moreover, since August 2009, the SCDC held a series of trainings to reinforce laboratory safety issues. These training topics included biological sample transportation and anti-terrorism vaccination.
Vaccination Campaign
In order to better prepare for potential outbreaks of novel H1N1 influenza and seasonal influenza, the SCDC learned from their experiences during the 2008 Beijing Olympic Games and developed an influenza vaccination plan for vulnerable groups, as well as a response plan for possible adverse events following immunization. By the beginning of 2010, 2.1 million doses of novel H1N1 influenza vaccines and 1.1 million doses of seasonal influenza vaccines had been administered to vulnerable groups. These groups included: primary and middle school students, elderly people, staff working within Expo sites, medical workers, food handlers, and others.
The SCDC also launched a vaccination campaign targeting the staff working within Expo sites. The food handlers and cleaning workers within Expo sites were vaccinated with hepatitis A and cholera vaccines. All Expo workers, (including administrative persons, security guards, shop assistants, and volunteers), received immunization for measles.
Health Education and Health Intervention
Beginning in January 2010, the SCDC developed a monthly health education training program dedicated to teaching a new topic each month. The target population was selected according to key areas and locations, as well as key vulnerabilities. The health interventions developed for use within Expo sites were focused on heat-related illness, tobacco control, and enteric infectious diseases.
Moreover, the SCDC compiled Travel Health Tips for Expo 2010: Shanghai, China catering to the health information needs of domestic and international travelers. The handbook provided: a Shanghai overview; introduction of Expo 2010 Shanghai China; major health resources in Shanghai; health hotline in Shanghai; health tips before your travel; health tips during your travel; vaccination; prevention for non-infectious risk factors; health tips for vulnerable populations; and contact information of some consulates in Shanghai.
By the end of April 2010, the first batch of 80,000 handbooks were printed and delivered to hotels in Shanghai, (eg, those rated at “three stars and above”). The SCDC also organized public health and medical workforce trainings in March 2010 for clinical doctors in major general hospitals, and technical persons within municipal and district CDCs.
Finally, the SCDC also identified the Expo as an opportunity for HIV and sexually transmitted diseases prevention efforts, and conducted a condom promotion program in hotels. According to the intervention plan, condoms were delivered to all hotels in metropolitan Shanghai.
Risk Communication and Mass-Media Surveillance
Public health security for the Expo relied on coordination among different organizations or sectors, and thus, it was vital to establish a risk communication mechanism. According to the conceptual framework, the jointly implemented prevention and control measures included three concentric circles, namely: (1) within Expo sites; (2) within Shanghai municipality; and (3) within the peripheral Yangtze River delta region.
Furthermore, the China CDC and the SCDC developed collaborative agreements for joint sharing of subject matter experts, surveillance reports, and a system for rapid transportation and analysis of laboratory samples. By April 27, 2012, the China CDC and the SCDC exchanged eight issues of bulletins related to the situational awareness of notifiable diseases and public health emergencies
In order to strengthen the communication with the public, the SCDC established the Expo column of the SCDC portal in December 2009 to publish health-related information. Internet users could find precautionary information on topics such as heat-related illness.
As for mass-media surveillance, the SCDC imported “Threat Tracking Tool” techniques from the ECDC in 2009, and developed a Chinese version. Using this software, the SCDC monitored mass-media reports related to the Expo on a daily basis, analyzed the risks, and shared the information in a timely manner.
Technical Support for Health Inspection
The SCDC organized 18 field testing and evaluation teams consisting of 78 technicians, who were chosen from 18 district CDCs. These teams were made available for health and safety evaluation of the completed pavilion constructions prior to acceptance.
Discussion
The World Health Organization regards mass gatherings as a stress test for public health. But not all mass gatherings need enhanced extensive public health preparations. It really depends on political and religious consideration, event duration, the geographic spread and number of international visitors.Reference Thackway, Churches, Fizzell, Muscatello and Armstrong4 As for the largest mass gathering in world history, the 2010 Expo had highly political consideration, six months’ duration, and high density of population within the Expo sites. In this case, without careful and effective preparation the mass gathering could have serious impact both on public health and social stability.Reference Brennan, Keim and Sharp1-Reference Thackway, Churches, Fizzell, Muscatello and Armstrong4
Risk assessment was the leading foundation for all the other preparation measures. It was implemented during the preparation stage for lots of mass gatherings, such as Atlanta,Reference Sharp, Brennan and Keim2 Sydney,Reference Thackway, Churches, Fizzell, Muscatello and Armstrong4 Beijing Olympic Games and the Hajj to Mecca.Reference Ahmed, Arabi and Memish9 The ongoing risk assessments associated with the capacity building were crucial. A series of risk assessments were used to better estimate the dynamic risk situation so as to guide public health preparedness activities. Preparation for heat-related illness was the best example. The risk assessment estimated that heat-related illness would be one of major health threats for Shanghai Expo. Therefore, enhanced heat stroke surveillance had been implemented and suggestions to create heat-stroke prevention environments within Expo sites proposed by the SCDC had been adopted by the Shanghai Expo Bureau. Moreover, the risk assessment results also indicated which capacity-building gaps should be filled during the preparedness activities. The 30% increase in laboratory testing capacity enhanced the surveillance capability, especially for emerging infectious diseases which could be imported and become potential threats to Shanghai. Due to the success of risk assessment in Shanghai Expo, since then it has been introduced to routine emergency preparation nationally on a monthly basis supported by the China Ministry of Health.
The experience of previous Olympic GamesReference Brennan, Keim and Sharp1, Reference Tsouros and Efstathiou3, Reference Jin, Ljungqvist and Troedsson12 suggested that it is crucial and necessary to set up an additional active surveillance system for such big events. Shanghai Expo followed the practice and established an online surveillance information system focusing on abnormalities of clinic visits within Expo sites. It realized the objectives of real-time monitoring of the situation and early detection and immediate response, while alleviating the workload for surveillance staff and facilitating the public health security in the city as a whole. On the basis of this online surveillance system, daily health statistics of the Expo Bureau were disseminated to mass media and as guidance for tourists.Reference Yongchao, Qinneng and Yi13 Moreover, surveillance results had been shared among all the partners and stakeholders regionally, domestically, and internationally. This surveillance mechanism could be adapted for future mass gatherings.
Conclusion
The 2010 World Exposition was the world's largest and longest-duration mass gathering to date. The potential for overloading the public health system during such an event, therefore, must be lessened through careful planning and preparedness. Clear-cut organizational structures and job responsibilities, as well as comprehensive operational and scientific preparations, are essential for effective public health preparedness for mass-gathering events. Planners and organizers for future mass gatherings can learn from this unique experience and improve service for public health security in the future.
Abbreviations
- ECDC:
European Centre for Disease Prevention and Control
- SCDC:
Shanghai Municipal Center for Disease Control and Prevention
- USCDC:
United States Centers for Disease Control and Prevention
- WHO:
World Health Organization
