Risk-based management of international sporting events during the COVID-19 pandemic.

Mass gatherings include a diverse range of events such as sporting competitions, religious ceremonies, entertainment activities, political rallies and cultural celebrations, which have important implications for population well-being. However, if not managed properly, these events can amplify health risks including those related to communicable diseases, and place undue strain on health systems in host countries and potentially in attendees' home countries, upon their return. The coronavirus disease 2019 (COVID-19) pandemic has provided a unique opportunity to evaluate the risk factors associated with mass gatherings and the effectiveness of applying mitigation measures during infectious disease emergencies. The pandemic has also allowed event organizers and health officials to identify best practices for mass gathering planning in host countries. To guide decisions about whether to hold, postpone, modify or cancel a mass gathering during the COVID-19 pandemic, the World Health Organization and its partners developed normative guidance and derivative tools promoting a risk-based approach to mass gathering planning. This approach involves three steps to guide decision-making around mass gatherings: risk evaluation, risk mitigation and risk communication. The approach was applied in the planning and execution of several mass gathering events, including the Tokyo 2020 and Beijing 2022 Olympic and Paralympic Games. Lessons identified from these large-scale international events offer insights into the planning and implementation of mass gathering events during a pandemic, and the broader impacts of such events on society. These lessons may also further inform and refine planning for future mass gatherings.

Les rassemblements de masse désignent un large éventail d'événements tels que des compétitions sportives, cérémonies religieuses, activités de divertissement, manifestations politiques et fêtes culturelles. Tous ont un impact considérable sur le bien-être de la population. Toutefois, s'ils ne sont pas gérés correctement, ils peuvent augmenter les risques sanitaires, notamment concernant les maladies transmissibles, et exercer une pression excessive sur les systèmes de santé des pays hôtes, voire sur ceux des pays d'origine des participants après leur retour. La pandémie de maladie à coronavirus 2019 (COVID-19) a offert une occasion unique d'évaluer les facteurs de risque associés aux rassemblements de masse, ainsi que l'efficacité des mesures visant à limiter la propagation dans des situations d'urgence liées à des maladies infectieuses. Cette pandémie a également permis aux organisateurs d'événements et responsables de santé d'identifier les bonnes pratiques à appliquer dans les pays hôtes pendant les rassemblements de masse. Afin de guider les décisions relatives au maintien, au report, à la modification ou à l'annulation d'un rassemblement de masse durant la pandémie de COVID-19, l'Organisation mondiale de la Santé et ses partenaires ont mis au point des orientations normatives et des outils dérivés favorisant une approche tenant compte des risques au moment de la planification. Cette approche comprend trois étapes contribuant à la prise de décision: l'évaluation, la réduction et la communication des risques. Elle a été déployée lors de la planification et de l'exécution de nombreux rassemblements de masse, comme les Jeux olympiques et paralympiques de Tokyo 2020 et Beijing 2022. Les leçons tirées de ces événements internationaux à grande échelle fournissent des informations sur leur organisation et leur mise en œuvre en cas de pandémie, ainsi que les impacts de tels événements sur la société. Elles sont en outre susceptibles de faciliter et d'améliorer la planification des futurs rassemblements de masse.

Las concentraciones masivas incluyen una gran variedad de eventos, como competiciones deportivas, ceremonias religiosas, actividades de entretenimiento, mítines políticos y celebraciones culturales, que tienen importantes implicaciones para el bienestar de la población. Sin embargo, si no se gestionan adecuadamente, estos eventos pueden amplificar los riesgos para la salud, incluidos los relacionados con las enfermedades transmisibles, y suponer una carga excesiva para los sistemas sanitarios de los países anfitriones y, potencialmente, de los países de origen de los participantes a su regreso. La pandemia de la enfermedad por coronavirus de 2019 (COVID-19) ha brindado una oportunidad única para evaluar los factores de riesgo asociados a las concentraciones masivas y la eficacia de aplicar medidas de mitigación durante las emergencias por enfermedades infecciosas. La pandemia también ha permitido a los organizadores de eventos y a las autoridades sanitarias identificar las mejores prácticas para la planificación de concentraciones masivas en los países anfitriones. Para orientar las decisiones sobre la celebración, el aplazamiento, la modificación o la cancelación de una concentración masiva durante la pandemia de la COVID-19, la Organización Mundial de la Salud y sus asociados elaboraron orientaciones normativas y herramientas derivadas que promueven un enfoque de la planificación de concentraciones masivas basado en los riesgos. Este enfoque consta de tres pasos para orientar la toma de decisiones en torno a las concentraciones masivas: la evaluación, la mitigación y la comunicación de riesgos. El enfoque se aplicó en la planificación y ejecución de varias concentraciones masivas, incluidos los Juegos Olímpicos y Paralímpicos de Tokio 2020 y Pekín 2022. Las conclusiones extraídas de estos eventos internacionales a gran escala permiten comprender mejor la planificación y ejecución de concentraciones masivas durante una pandemia, así como las repercusiones más generales de estos eventos en la sociedad. Estas lecciones también pueden informar y perfeccionar la planificación de futuras concentraciones masivas.

Unraveling the causes of the Seoul Halloween crowd-crush disaster.

As the world steadily recovers from the COVID-19 pandemic, managing large gatherings becomes a critical concern for ensuring crowd safety. The crowd-crush disaster in Seoul in 2022 highlights the need for effective predictive crowd management techniques. In this study, an empirical analysis of this incident is conducted using data from various sources, and model-based simulations are created to replicate hazardous crowd conditions in high-risk areas. In the empirical analysis, mobile device data indicates a significant increase in population above normal levels in the disaster area just hours before the incident occurred. In the simulations, a hydrodynamic model is employed to simulate a bidirectional collision, which quantitatively demonstrates that the average density during the crush reached 7.57 ped/m2 (with a maximum of (9.95)ped/m2). Additionally, the average crowd pressure peaked at 1,063 N/m (with a maximum of 1,961 N/m), and the maximum velocity entropy was 10.99. Based on these findings, it can be concluded that the primary causes of the disaster were the substantial population, bidirectional collision, and escalating panic. The results of controlled simulations under various management strategies are then presented. By implementing effective crowd management techniques, crowd safety can be enhanced through quantitative comparisons of these key indicators.

Escalating climate-related health risks for Hajj pilgrims to Mecca.

BACKGROUND: Global temperatures are on the rise, leading to more frequent and severe heatwaves with associated health risks. Heat-related illnesses (HRIs) are an increasing threat for travellers to hot climate destinations. This study was designed to elucidate the interplay between increasing ambient temperatures, incidence of HRIs and the effectiveness of mitigation strategies during the annual Hajj mass gathering over a 40-year period. METHODS: An observational study was conducted utilizing historical records spanning four decades of meteorological data, and the rates of heat stroke (HS) and heat exhaustion (HE) during the Hajj pilgrimage in Mecca, Saudi Arabia. With an annual population exceeding 2 million participants from over 180 countries, the study analysed temporal variations in weather conditions over two distinct Hajj hot cycles and correlated it with the occurrence of HS and HE. The effectiveness of deployed mitigation measures in alleviating health vulnerabilities between the two cycles was also assessed. RESULTS: Throughout the study period, average dry and wet bulb temperatures in Mecca escalated by 0.4°C (Mann-Kendall P < 0.0001) and 0.2°C (Mann-Kendall P = 0.25) per decade, respectively. Both temperatures were strongly correlated with the incidence of HS and HE (P < 0.001). Despite the intensifying heat, the mitigation strategies including individual, structural and community measures were associated with a substantial 74.6% reduction in HS cases and a 47.6% decrease in case fatality rate. CONCLUSION: The study underscores the escalating climate-related health risks in Mecca over the study period. The mitigation measures' efficacy in such a globally representative setting emphasizes the findings' generalizability and the importance of refining public health interventions in the face of rising temperatures.

Mass Gathering Event Medical Preparedness and Response: A Review of Canadian Legislation and Guidelines.

INTRODUCTION: The mass gathering event (MGE) industry is growing globally, including in countries such as Canada. MGEs have been associated with a greater prevalence of injury and illness when compared with daily life events, despite most participants having few comorbidities. As such, adequate health, safety, and emergency medical planning is required. However, there is no single entity regulating these concerns for MGEs, resulting in the responsibility for health planning lying with event organizers. This study aims to compare the legislative requirements for MGE medical response systems in the 13 provinces and territories of Canada. METHODS: This study is a cross-sectional descriptive analysis of Canadian legislation. Lists of publicly available legislative requirements were obtained by means of the emergency medical services directors and Health Ministries. Descriptive statistics were performed to compare legislation. RESULTS: Of the 13 provinces and territories, 10 responded. For the missing 3, a law library review confirmed the absence of specific legislation. Most (n = 6; 60%) provinces and territories referred to provisions in their Public Health laws. Four confirmed that MGE medical response was a municipal or local concern to be addressed by the event organizers. CONCLUSIONS: No provinces could list specific legislation guiding safety, health, and medical response for an MGE.

Modelling disease mitigation at mass gatherings: A case study of COVID-19 at the 2022 FIFA World Cup.

The 2022 FIFA World Cup was the first major multi-continental sporting Mass Gathering Event (MGE) of the post COVID-19 era to allow foreign spectators. Such large-scale MGEs can potentially lead to outbreaks of infectious disease and contribute to the global dissemination of such pathogens. Here we adapt previous work and create a generalisable model framework for assessing the use of disease control strategies at such events, in terms of reducing infections and hospitalisations. This framework utilises a combination of meta-populations based on clusters of people and their vaccination status, Ordinary Differential Equation integration between fixed time events, and Latin Hypercube sampling. We use the FIFA 2022 World Cup as a case study for this framework (modelling each match as independent 7 day MGEs). Pre-travel screenings of visitors were found to have little effect in reducing COVID-19 infections and hospitalisations. With pre-match screenings of spectators and match staff being more effective. Rapid Antigen (RA) screenings 0.5 days before match day performed similarly to RT-PCR screenings 1.5 days before match day. Combinations of pre-travel and pre-match testing led to improvements. However, a policy of ensuring that all visitors had a COVID-19 vaccination (second or booster dose) within a few months before departure proved to be much more efficacious. The State of Qatar abandoned all COVID-19 related travel testing and vaccination requirements over the period of the World Cup. Our work suggests that the State of Qatar may have been correct in abandoning the pre-travel testing of visitors. However, there was a spike in COVID-19 cases and hospitalisations within Qatar over the World Cup. Given our findings and the spike in cases, we suggest a policy requiring visitors to have had a recent COVID-19 vaccination should have been in place to reduce cases and hospitalisations.

Healthcare policies, precautionary measures and outcomes of mass gathering events in the era of COVID-19 pandemic: Expedited review.

With the onset of the COVID-19 pandemic in early 2020, several countries suspended or restricted mass gathering (MG) events to mitigate the risk of superspreading events. Prohibiting MGs aimed to lessen the likelihood of highly infectious persons coming into close contact with many others. Now that the world has opened its doors wide and removed most of precautionary measures, many questions arise. In this review, we aimed to summarize the current evidence regarding the policies and regulations that were implemented for the safe return of MG events. Besides, we highlighted the impact of the return of MG events during 2021 on the trajectory of COVID-19 spread. Canceling MG events can carry religious, societal, economic, and public negative consequences necessitating the safe return of these events. The experience with the COVID-19 pandemic was the foundation for the recommendations for the safe conduction of MG events during the pandemic by international public health bodies. When policymakers adequately applied precautionary measures and strategic approaches, we witnessed the safe holding of huge MG events without aggravating the COVID-19 situation or increasing the number of new cases beyond the capacity and readiness of the national healthcare system.

Mass gathering in Qatar 2022 World Cup. What should be especially monitored?

OBJECTIVES: At the end of 2022, the football world championship will be held in Qatar. These types of meetings require a risk analysis. It proposes an approach to determine which health risks should be prioritized. METHOD: We use a mixed methodology (Hierarchical Process Analysis, World Health Organization STAR and European Commission INFORM) to determine the risk level of a total of 12 health entities. RESULTS: Our analysis identifies 6 health entities with a moderate risk. There are 4 whose valuation is as low risk and 2 as very low. CONCLUSIONS: In our work we focus the analysis from a point of view of the route of transmission or presentation of health events, which facilitates a visualization of the preventive measures to be implemented, both organizationally and individually by the attendees.

Clinical pharmacy services in acute care setting during mass gatherings (Hajj): Insights from a task force.

BACKGROUND: Hajj is the largest mass gathering worldwide that takes place every year in Makkah, Saudi Arabia. This paper aims to provide a comprehensive guide and expectations for delivering and optimizing clinical pharmacy services during one of the largest mass gatherings in the world, Hajj pilgrimage METHODS: A task force initiated and included members of clinical pharmacists who previously participated in delivering clinical pharmacy services during the Hajj pilgrimage, members of the Saudi Society of Clinical Pharmacy (SSCP), and policymakers from different sectors and representatives from pharmaceutical care of the Ministry of Health (MOH). The members established an expert task force to conceptualize and draft the proposed suggestions highlighting the roles and responsibilities of clinical pharmacists during the annual Hajj season. RESULTS: The task force determined the following key domains 1) pharmaceutical care (administration and strategic plan, resources, formulary management); 2) pharmacists' activities (clinical pharmacy services and documentation, professional training and development, and staff credentials, and qualifications); 3) challenges and proposed solutions. The task force was divided into groups to draft each domain and provide suggested statements and insights for each section. Finally, the group members of the task force issued 15 opinion statements. CONCLUSION: Mass gatherings such as Hajj pilgrimage, represent a unique opportunity to demonstrate the value of pharmacists in advancing health care delivery within a multidisciplinary team. These suggestions and insights could guide the implementation of clinical pharmacy services in acute settings during mass gatherings (Hajj). Future studies should focus on assessing the applicability and the impact of the provided suggestions.

Emergency pharmacy workforce views and experience related to the provision of pharmaceutical care during mass gathering events: the FIFA World Cup Qatar 2022™ experience.

Purpose: This study aimed to explore emergency pharmacy workforce perspectives and experiences in providing pharmaceutical care during mass gathering events (i.e., FIFA World Cup Qatar 2022™). Methods: A qualitative methodology was employed using focus groups discussions. Emergency pharmacists across Hamad Medical Corporation were invited to participate using a combination of purposive and snowball sampling. Focus groups were audio-recorded, transcribed verbatim, and validated. Inductive thematic analysis was undertaken to generate key themes and subthemes. Results: Four focus groups were conducted which included 21 participants and generated five major themes. Whilst participants had mixed opinions in relation to their preparedness to practice during the World Cup, they perceived their experience as successful and smooth. The primary perceived facilitators were management support, mobile medical units, and high public health awareness. The main highlighted barriers were related to staff insufficiency, medications availability, and cultural and language challenges. Participants recommended pharmacist's role identification in mass gatherings, development of pharmacy action plan, and offering simulation training and pharmacy-specific training. Conclusion: Despite the perceived barriers, pharmacists reported positive views in relation to their experience in providing pharmaceutical care during mass gatherings. Future research should focus on the development of theory-driven action framework for pharmacy departments to adopt during mass gatherings.

What is 'agency' in torture and trauma recovery? An inquiry into the properties and explanations of the concept of agency and it's impacts.

This paper presents learnings from trauma recovery mechanisms and social movements from around the world relating to a survivor's role and as such- their agency. It unpacks various conceptual frameworks as possible alternative, effective and strategic pathways in torture rehabilitation. Ongoing and new challenges such as resourcing, cultural adaptability limitations, lack of access to services and inhumane foreign policies pose barriers to established systems that render some practices inadequate in terms of meaningful service delivery or social impact for torture survivors (Wheildon et al., 2022, p. 1689). It is well documented that "Torture aims to dehumanise survivors through calculated acts of cruelty to remove the survivors' dignity and make them powerless." (Luci and Di Rado, 2020, p. 3). As such this paper deliberately straddles multiple thematic fields, all grappling with relatable notions of restoring power or agency to survivors. At the risk of discursiveness into fields beyond torture rehabilitation then, this paper aims to showcase and learn from other successful movements. It also invites you as the reader into this discourse of inquiry and self-reflection, in order to counter the ten- dency of assuming a prescriptive, blanket (or blank) meaning of survivor engagement activities. Its findings suggest the manifestation of bespoke programming according to context and survivors' needs. It does not suggest a systematic overhaul, but rather a shift of incremental and cumulative changes that are recognised as advantageous. This paper deep dives into theories on agency, looking firstly at the broader archetypes that provide commonality and structure before then exploring particularities from different contexts. Implications for practice are then discussed, with nuances drawn out from the findings.

A Retrospective Application of the Arbon and Hartman Models to the Union Cycliste International Mountain Bike World Cup.

INTRODUCTION: Outdoor activities have accelerated in the past several years. The authors were tasked with providing medical care for the Union Cycliste International (UCI) mountain biking World Cup in Snowshoe, West Virginia (USA) in September 2021. The Hartman and Arbon models were designed to predict patient presentation and hospital transport rates as well as needed medical resources at urban mass-gathering events. However, there is a lack of standardized methods to predict injury, illness, and insult severity at rural mass gatherings. STUDY OBJECTIVE: This study aimed to determine whether the Arbon model would predict, within 10%, the number of patient presentations to be expected and to determine if the event classification provided by the Hartman model would adequately predict resources needed during the event. METHODS: Race data were collected from UCI event officials and injury data were collected from participants at time of presentation for medical care. Predicted presentation and transport rates were calculated using the Arbon model, which was then compared to the actual observed presentation rates. Furthermore, the event classification provided by the Hartman model was compared to the resources utilized during the event. RESULTS: During the event, 34 patients presented for medical care and eight patients required some level of transport to a medical facility. The Arbon predictive model for the 2021 event yielded 30.3 expected patient presentations. There were 34 total patient presentations during the 2021 race, approximately 11% more than predicted. The Hartman model yielded a score of four. Based on this score, this race would be classified as an "intermediate" event, requiring multiple Advanced Life Support (ALS) and Basic Life Support (BLS) personnel and transport units. CONCLUSION: The Arbon model provided a predicted patient presentation rate within reasonable error to allow for effective pre-event planning and resource allocation with only a four patient presentation difference from the actual data. While the Arbon model under-predicted patient presentations, the Hartman model under-estimated resources needed due to the high-risk nature of downhill cycling. The events staffed required physician skills and air medical services to safely care for patients. Further evaluation of rural events will be needed to determine if there is a generalized need for physician presence at smaller events with inherently risky activities, or if this recurring cycling event is an outlier.

Psychosocial interventions and strategies to support young people at mass gathering events: a scoping review.

OBJECTIVES: To improve health and safety outcomes at mass gathering events (MGEs) for young attendees, it is essential to understand the psychosocial factors that may influence behaviour so that the implementation of support strategies before, during and after MGEs can be developed to enhance outcomes. This review identifies the psychosocial outcomes that may occur at MGEs, including social connection, substance use, risky behaviours and psychological distress and examines what interventions have been implemented to target these outcomes. STUDY DESIGN: Scoping review. METHODS: This study examined MGE psychosocial interventions with predominantly youth attendees was conducted using the Preferred Reporting Items of Systematic reviews and Meta-Analysis extension for Scoping Reviews guidelines. Papers were collected from the databases CINAHL, MEDLINE, Embase and PsycINFO. Titles and abstracts were scanned for relevance, followed by a full-text screening. Information relevant to the research question was extracted from papers meeting the inclusion criteria. RESULTS: Twenty-six papers met the inclusion criteria. The psychosocial factors that were most studied included social influence, social interactions and psychological stressors, which lead to behaviours such as excessive alcohol consumption, drug taking, risky casual sex and risk taking amongst psychological factors of young attendees. Effective interventions implemented before or during MGEs, such as alcohol-free zones, antidrinking campaigns, psychoeducation and disapproval from parents with regard to drinking alcohol, showed promise in reducing harms. CONCLUSION: Psychosocial interventions have the potential to reduce harms and enhance well-being for young people attending MGEs. This review has identified gaps and opportunities in the current literature with regard to psychosocial interventions and strategies to support young people at MGEs and makes recommendations to support the development and refinement of evidence-based interventions aimed at young MGE attendees.

How the Italian Formula 1 Grand Prix 2022 Mass Gathering Event Compares to the Arbon Model: A Descriptive Study.

OBJECTIVE: To describe the health-care resources implemented during the Italian Formula 1 Grand Prix (F1GP) and to calculate the patient presentation rate (PPR) based on both real data and a prediction model. METHODS: Observational and descriptive study conducted from September 9 to September 11, 2022, during the Italian F1GP hosted in Monza (Italy). Maurer's formula was applied to decide the number and type of health resources to be allocated. Patient presentation rate (PPR) was computed based on real data (PPR_real) and based on the Arbon formula (PPR_est). RESULTS: Of 336,000 attendees, n = 263 requested medical assistance with most of them receiving treatment at the advanced medical post, and n = 16 needing transport to the hospital. The PPR_real was 51 for Friday, 78 for Saturday, 134 for Sunday, and 263 when considering the whole event as a single event. The PPR_est resulted in 85 for Friday, 93 for Saturday, 97 for Sunday, and 221 for the total population. CONCLUSIONS: A careful organization of health-care resources could mitigate the impact of the Italian F1GP on local hospital facilities. The Arbon formula is an acceptable model to predict and estimate the number of patients requesting medical assistance, but further investigation needs to be conducted to implement the model and tailor it to broader categories of MGE.

Clashes and crowds: protests, riots, and other mass gathering events in North America 2021-2022.

OBJECTIVE: This study aimed to provide an overview of the scope and challenges of historic events and help better prepare emergency healthcare services for future similar mass gathering events. STUDY DESIGN: This was a retrospective descriptive analysis of protest and conflict events in North America from 2021 to 2022. INTRODUCTION: Recent protests, riots, and other conflict events in North America have highlighted the increasing challenges hospital-based and prehospital healthcare providers face. This study provides a retrospective descriptive analysis of protest and conflict events in North America from 2021 to 2022, which may aid emergency healthcare services in understanding the scope and challenges of historic events and help better prepare for future similar mass gathering events. METHODS: Data collection was performed using a retrospective database search through the Armed Conflict Location & Event Data Project (ACLED) database. The ACLED database was searched using the internal database search functions for recorded events that occurred in North America from January 1, 2021 to December 31, 2022. Date, event type, event subtype, the country of incident, and fatality numbers were extracted. The results were exported into an Excel spreadsheet and analyzed independently by L.C., H.S., and R.H. RESULTS: There were a total of 52,529 recorded events of political conflict in North America, with 30,269 events in 2021 and 29,260 in 2022. Political conflict events included protests (40,934, 68.8%), violence against civilians (11,532, 19.4%), strategic developments (2,819, 4.7%), battles (2,293, 3.9%), riots (1,909, 3.2%), and remote violence (42, 0.1%). Violence against civilians caused the highest fatalities (13,466, 82.6%), followed by battles (2,662, 16.3%), riots (111, 0.7%), strategic developments, remote violence, and protests (57, 6, and 3 respectively). CONCLUSION: Mexico and the United States accounted for most of the political conflicts in North America across 2021 and 2022. In Mexico, protests and violence against civilians were the most common types of conflict, with the latter accounting for the comparatively high fatality compared with the other countries. Battles in Mexico between cartels were the most deadly political conflicts recorded in North America.

The effect of environmental information on evolution of cooperation in stochastic games.

Many human interactions feature the characteristics of social dilemmas where individual actions have consequences for the group and the environment. The feedback between behavior and environment can be studied with the framework of stochastic games. In stochastic games, the state of the environment can change, depending on the choices made by group members. Past work suggests that such feedback can reinforce cooperative behaviors. In particular, cooperation can evolve in stochastic games even if it is infeasible in each separate repeated game. In stochastic games, participants have an interest in conditioning their strategies on the state of the environment. Yet in many applications, precise information about the state could be scarce. Here, we study how the availability of information (or lack thereof) shapes evolution of cooperation. Already for simple examples of two state games we find surprising effects. In some cases, cooperation is only possible if there is precise information about the state of the environment. In other cases, cooperation is most abundant when there is no information about the state of the environment. We systematically analyze all stochastic games of a given complexity class, to determine when receiving information about the environment is better, neutral, or worse for evolution of cooperation.

Quantifying the effect of isolation and negative certification on COVID-19 transmission.

Isolation of close contact people and negative test certification are used to manage the spread of new coronavirus infections worldwide. These effectively prevent the spread of infection in advance, but they can lead to a decline in socio-economic activity. Thus, the present study quantified the extent to which isolation and negative test certification respectively reduce the risk of infection. To this end, a discrete-time SEIR model was used as the infectious disease model, and equations for calculating the conditional probability of non-infection status given negative test results on two different days were derived. Then the respective non-infection probabilities with two negative PCR test results, and with one negative PCR test result and one antigen test result, were quantified. By substituting initial parameters of the SEIR model into these probabilities, the present study revealed the following: (1) isolating close contact individuals can reduce by [Formula: see text] the risk of infection during the first 5 days, but five more days are needed to reduce the risk [Formula: see text] more, and seven more days to reduce the risk [Formula: see text] more; and (2) if an individual with a negative PCR test result has a negative antigen test result the next day, then his or her infection probability is between 0.6 and [Formula: see text]. Our results show that 5-day isolation has a proportionally greater effect on risk reduction, compared to longer isolation; and thus, if an isolation period of longer than 5 days is contemplated, both the risk reduction and the negative effects from such increased isolation should be considered. Regarding negative test certification, our results provide those in managerial positions, who must decide whether to accept the risk and hold mass-gathering events, with quantitative information that may be useful in their decision-making.

Effectiveness of Public Health Digital Surveillance Systems for Infectious Disease Prevention and Control at Mass Gatherings: Systematic Review.

BACKGROUND: Mass gatherings (MGs; eg, religious, sporting, musical, sociocultural, and other occasions that draw large crowds) pose public health challenges and concerns related to global health. A leading global concern regarding MGs is the possible importation and exportation of infectious diseases as they spread from the attendees to the general population, resulting in epidemic outbreaks. Governments and health authorities use technological interventions to support public health surveillance and prevent and control infectious diseases. OBJECTIVE: This study aims to review the evidence on the effectiveness of public health digital surveillance systems for infectious disease prevention and control at MG events. METHODS: A systematic literature search was conducted in January 2022 using the Ovid MEDLINE, Embase, CINAHL, and Scopus databases to examine relevant articles published in English up to January 2022. Interventional studies describing or evaluating the effectiveness of public health digital surveillance systems for infectious disease prevention and control at MGs were included in the analysis. Owing to the lack of appraisal tools for interventional studies describing and evaluating public health digital surveillance systems at MGs, a critical appraisal tool was developed and used to assess the quality of the included studies. RESULTS: In total, 8 articles were included in the review, and 3 types of MGs were identified: religious (the Hajj and Prayagraj Kumbh), sporting (the Olympic and Paralympic Games, the Federation International Football Association World Cup, and the Micronesian Games), and cultural (the Festival of Pacific Arts) events. In total, 88% (7/8) of the studies described surveillance systems implemented at MG events, and 12% (1/8) of the studies described and evaluated an enhanced surveillance system that was implemented for an event. In total, 4 studies reported the implementation of a surveillance system: 2 (50%) described the enhancement of the system that was implemented for an event, 1 (25%) reported a pilot implementation of a surveillance system, and 1 (25%) reported an evaluation of an enhanced system. The types of systems investigated were 2 syndromic, 1 participatory, 1 syndromic and event-based, 1 indicator- and event-based, and 1 event-based surveillance system. In total, 62% (5/8) of the studies reported timeliness as an outcome generated after implementing or enhancing the system without measuring its effectiveness. Only 12% (1/8) of the studies followed the Centers for Disease Control and Prevention guidelines for evaluating public health surveillance systems and the outcomes of enhanced systems based on the systems' attributes to measure their effectiveness. CONCLUSIONS: On the basis of the review of the literature and the analysis of the included studies, there is limited evidence of the effectiveness of public health digital surveillance systems for infectious disease prevention and control at MGs because of the absence of evaluation studies.