“An infodemic is an overabundance of information, accurate or not, in the digital and physical space, accompanying an acute health event such as an outbreak or epidemic” [1] .

Introduction

Each epidemic and pandemic is accompanied by an infodemic. An infodemic refers to an overabundance of information that includes accurate information, mis- and disinformation, and the dynamic contexts within which this information is generated, sought out, and shared during an epidemic.

Infodemics are not a new phenomenon and have been witnessed during previous disease outbreaks including Zika, Ebola [2], polio, and measles [3]. For example, during the yellow fever epidemic in Angola in 2016, there were rumours that one could not drink alcohol following vaccination or that the vaccine might result in infertility. This negatively impacted vaccine coverage, especially among young men [4]. By working with traditional leaders to listen to people’s concerns and provide reliable information about the vaccine, gradually these false beliefs were changed.

The COVID-19 pandemic, however, presents an unrivalled example of an infodemic. There was an exponential increase in the generation of scientific evidence and information that was distributed widely in both pre-print and publication versions, making the quality of information more difficult to assess. In addition, numerous experts and scientists aired their views and opinions regarding science and public health guidance, stimulating a polarised discourse around many pertinent subjects, both off- and online. This was accompanied by an increase in media coverage, with highly sensationalised and potentially manipulative content. Credible health information was ‘lost in the noise’, and in many settings, the questions and concerns of individuals and communities went unaddressed, creating further space for rumours and myths.

The New Information Ecosystem

Each individual experience of an infodemic is different as it is influenced by the information ecosystem within which a person lives – the information ecosystem refers to the complex dynamic infrastructure, sources, and relationships through which information flows and reaches an individual [5]. This includes both the digital and physical information environments, and a number of structural and behavioural factors such as an individual’s access to and interactions with the health system, their health behaviours, information-seeking behaviours, and barriers that can affect access to information. All of these factors shape an information ecosystem.

When there is an epidemic, it is natural that with an increase in uncertainty and fear, people seek information differently by searching for different sources, talking to others about the disease and its impact, and listening to opinions and thoughts from peers, experts, and community leaders [6]. People also tend to generate and share information more. The change in information-seeking behaviour that is experienced at the individual level is reflected in changes in the overall information ecosystem. New sources of health information emerge and existing sources transform. Many outlets may disseminate accurate information, misinformation, disinformation, and outdated information simultaneously. This makes it difficult for a person to identify trustworthy sources, absorb and process the information, and make informed decisions to protect their health. Furthermore, during an epidemic, an individual’s perception of risk may be altered, which further impacts their acceptance of and response to health information [7][8][9][10]. Responses to an infodemic often focus on reducing mis- and disinformation. However, a more effective approach is to take into consideration the entire information ecosystem, including how it evolves during times of crisis, and develop a comprehensive strategy to manage the infodemic.

Science and evidence-generation during epidemics 

During epidemics, the volume and speed with which scientific evidence is generated, analysed, published, and shared increases exponentially. During the first six months of the COVID-19 pandemic, more than 20,000 articles related to COVID-19 were published [11]. Many publications were of suboptimal quality and lacked scientific rigour, leading to misinterpretation of results, confusion, and diminishing trust in science. While the rapid and transparent sharing of scientific information on open access platforms is positive, the speed of publication must not happen at the expense of rigour (for example, peer review and editorial validation). In addition, efforts must be made to bridge the gap between the scientific community and the public’s understanding of how scientific evidence is generated and why it might change. For example, an article published in a reputable journal on the use of hydroxychloroquine as a treatment for COVID-19 [12] was retracted and rumours ensued, stating that scientific information was being manipulated by health authorities.

Furthermore, even when high-quality scientific work is published, intentional efforts are needed to translate the science into different contexts and cultures in order to make it relevant and actionable. This can be supported by interventions to build scientific literacy before and during the crisis, as this will enable an understanding of the iterative process of evidence generation, interpretation, and evaluation, which, in turn, helps to build trust in science and resilience to misinformation [13]. Scientific literacy usually starts with a well-functioning education system where critical thinking skills are built from an early age. However, during an epidemic or pandemic, efforts to build scientific literacy can include working with science and health journalists or identified social media influencers who can support ongoing science translation efforts, or providing communication training to scientists and other health professionals who are exposed to the public. Scientific literacy is one of many literacies (health, digital, media, and information) that influences the individual’s ability to process, understand, and act on information.

Impact of an Infodemic

An infodemic can cause direct harm to public health. For example, early in the COVID-19 pandemic, misinformation stated that methanol was a treatment, resulting in a large number of deaths in Iran [14].

It can also negatively impact the public health response to the epidemic by undermining trust in interventions (e.g., vaccination, wearing masks) and increasing mistrust in health authorities, the government, or the scientific community. Ultimately, the polarisation and politicisation of public health information and action can undermine social cohesiveness, the repercussions of which can be long lasting.

It is possible to avoid these harms if certain elements of an infodemic are understood so that the situations within which they occur can be addressed. Figure 34.1 details the different elements of an infodemic, which increase in the potential to cause harm (from left to right):

Situations where misinformation, disinformation, and narratives are circulating are situations with the most potential to cause harm. Most people who share misinformation are not aware that it is misinformation; however, misinformation is often packaged in emotionally compelling ways and in formats that are easy to share. Disinformation is often motivated by economic or political profit and is reshared by people who either believe it or identify with a particular cause. Addressing disinformation requires a more comprehensive approach that may go beyond the health system or legal or consumer protection interventions. As more people become concerned about a specific topic, the discussion that is generated can become a narrative which can be characterised by an organised set of mutually reinforcing information elements. Narratives are trending topics discussed offline, online, and in the media, and while they may grow from information voids, and mis- and disinformation, they can also be influenced by social, political, and economic factors.

Infodemic management — the four essential components

Pandemics and epidemics are evolving situations characterised by high levels of uncertainty and variable levels of societal and individual-level disruption, from the disease itself, or from the interventions put in place to stop transmission. During epidemics, people are asked to rapidly change behaviours for a limited time period to protect their individual health and that of their community. If there is limited trust in the authorities or in the scientific communication, individuals and communities may not be inclined to change behaviours and practices. Infodemic management recognises that trust is a valuable social capital that must be nurtured. However, trust is complex; it can take a long time to build but can be destroyed very quickly. Successful infodemic management requires multi-stakeholder engagement [15] and a comprehensive understanding of infodemics, the overall information ecosystem, and its interdependency with epidemics [16][17]. It also requires that important aspects of trust are considered equally. An enhanced approach to managing an infodemic is based on three important shifts:

• It takes into consideration the entire information ecosystem of individuals and communities.

• It always starts with listening to individual and community concerns (rather than an approach that involves top-down dissemination of messages from “experts” to passive recipients).

• It focuses on meaningful engagement of communities to co-develop guidance and solutions to mitigate the impact of an epidemic (See Chapter 33, RCCE).

Listen to concerns

Listening increases understanding of the concerns of communities, the contexts within which they live, and their experience and knowledge related to the outbreak or epidemic. Listening is the first step towards formulating interventions, guidance, and communication in a way that is more relevant, implementable, and acceptable to communities. In the current information ecosystem, much listening can occur on social media platforms, and incorporating sentiment analysis to social digital listening at scale [18] can generate useful insights. Sentiment is emotion portrayed in social media or media content, which can be an indicator of popular feeling towards a health topic or issue. Sentiment analysis can contribute to the production of infodemic insights and recommendations. Other offline or interpersonal platforms for listening can be built into physical spaces such as workplaces, health or community centres, places of worship, or schools. For social listening to be useful and effective, however, it needs to happen in real time and must also be grounded in an analytical framework [19] that makes it possible to rapidly operationalise the knowledge that is generated. In general, during epidemics, questions can be grouped into four categories:

• the disease (its symptoms, the sequelae)

• the cause and aetiology of the disease (e.g., the virus) and explanation of the disease (why me, why us?)

• treatments

• epidemic response interventions (personal protective equipment, vaccines, masks etc.)

Grouping questions into a limited number of categories facilitates social listening and faster reactive risk communication. Health authorities can simultaneously prepare communications that are tailored and encompassing.

Communicate risk and translate science

Risk communication is a core capacity within the monitoring and evaluation framework of the International Health Regulations [20] (See Chapter 33, RCCE). Regular, transparent communication that acknowledges uncertainty is essential to reassure communities and keep them informed. For individuals to adopt, change, and sustain new behaviours during epidemics, they need to:

• be aware of the recommendations

• understand the context and rationale behind the recommendations

• trust the authority/messenger recommending them

• have the ability to enact the recommendations in their living/social/work/faith setting

Science translation is challenging in epidemics where scientific understanding evolves quickly and is generated rapidly, often leading to changes in guidance. Health workers, in addition to the vital services they deliver, can play a critical role in translating science, allaying fears, and understanding individual and community information needs during epidemics [21][22][23].

Promote resilience to negative impacts of the infodemic

To build resilience to misinformation at an individual level, it is crucial to:

• strengthen an individual’s ability to distinguish between accurate and inaccurate information

• recognise media manipulation

• successfully debunk misinformation with friends and family

Building resilience to misinformation takes time and requires investment during preparedness, prior to an outbreak. During an epidemic, people tend to seek information actively, thereby increasing their exposure to all types of information. In addition, fear and uncertainty may impair a person’s ability to analyse information objectively. Strengthening health and digital literacy is an important and often undervalued component of infodemic management that can enhance resilience to misinformation. At a community level, resilience to mis- and disinformation requires structural approaches. A resilient community has both access and the ability to disseminate credible, accurate information that is tailored and acceptable to the population. A resilient community also has a localised ability to fact check claims, has access to trusted messengers who have been trained in effective infodemic management principles, and has a feedback loop with the health system to share rumours, questions, and concerns, and elicit rapid responses.

Engage and empower communities

Active engagement of communities is essential to epidemic response. In the current information ecosystem, the concept of communities is evolving. In localised epidemics, geographical communities are an important focus. However, in the current hyperconnected world, each individual belongs to multiple communities, including: 

• traditional communities (neighbours, friends, family)

• virtual communities (social media platforms and networks)

• communities defined by similar vocations or interests (faith, sport, workplace)

These different communities may be represented by leaders who are often a trusted voice; by engaging trusted voices within communities to both feedback on concerns and needs and help deliver recommendations, it is possible to make recommendations more acceptable and accessible to local communities. Community engagement in the 21st century must account for this new network structure. Without the knowledge, expertise, and experience of these networks feeding into the ‘operationalisation’ of scientific knowledge and technical guidance, there is a risk that it remains too technical or its implementation is not feasible. It is also important to ensure that certain groups such as migrants, minority language communities, and hard-to-reach populations are identified and supported through intentional and respectful efforts to facilitate listening, increase access to credible health information, and build resilience to misinformation. Often, peer-to-peer approaches [24] are effective in these situations. For example, engaging religious leaders from within local communities to feedback on community concerns and co-develop public health messaging that resonates with their constituents, or increasing the capacities and resources of healthcare providers and community health workers to engage, converse with, and feedback on behalf of patients.

Infodemiology – an emerging scientific discipline

Infodemiology is an emerging scientific discipline underpinning infodemic management, drawing on concepts from data science, epidemiology, physics, chemistry, anthropology, behavioural sciences, sociology, psychology, philosophy, political science, and communication [26]. Infodemiology produces the evidence necessary to improve infodemic management by deepening the knowledge base regarding the nature of infodemics. For instance, infodemiology will answer the following critical questions:

• How can exposure to information be measured?

• How does an individual’s information diet influence behaviours?

• How can the effectiveness of infodemic management strategies, interventions, and policies be evaluated and their impact be measured?

• What are the diverse impacts of the potentially harmful situations within an infodemic?

• What makes some individuals and communities more resilient to misinformation than others?

The global research agenda for infodemiology is rapidly building the evidence base needed to guide future interventions on infodemic management. However, there is still much to learn about dynamic information ecosystems, how individuals and communities communicate during acute health events, and subsequent behaviours.

Conclusion

Infodemic management should be considered an intervention of equal importance to other epidemic response interventions such as the development of medical countermeasures.

As the world recovers from the COVID-19 pandemic, there is a growing acknowledgement of the importance of preparedness for the next pandemic. Infodemic management preparedness must be a critical component of broader pandemic preparedness efforts. Infodemic preparedness needs to be established at global, regional, national, and subnational levels. It requires strategic action plans that include relevant stakeholders, the establishment of surveillance and monitoring systems, and the creation of interventions for various scenarios that could arise in future crises. In this sense, infodemic management is similar to all aspects of outbreak response in that effective management requires comprehensive preparedness.

Contributor biographies

Sarah Hess is a public health expert skilled in global public health policy, health emergency preparedness, infectious diseases, community engagement, and communication. She currently serves as a World Health Organization technical officer with the Health Emergencies Program on High Impact Events Preparedness. Sarah also works in the “Infodemic Management” pillar of the COVID-19 response, leading work on partnerships and community empowerment.

Sylvie Briand is currently leading the Global Preparedness Monitoring Board (GPMB) secretariat which is co-convened by the World Health Organization and the World Bank. She previously was the Director of the Epidemic and Pandemic Preparedness and Prevention department at WHO headquarters. She has been at the forefront of managing epidemic and pandemic preparedness and response for more than 20 years including COVID-19, MERS, avian and pandemic influenza, Ebola, Zika, yellow fever, plague, Nipah, cholera, smallpox, mpox, and many other Public Health emergencies of international concern.  She holds a Medical Doctor degree with a specialization in infectious diseases, a Ph.D. in Health Systems’ Analysis, a master’s degree in Sociology and Anthropology and a master’s degree in public health.

Tim Nguyen is the Head of Unit for High Impact Events in the Epidemic and Pandemic Preparedness and Prevention Department of the WHO Health Emergencies Programme (WHE). His unit develops innovative approaches to community co-creation and decision-making tools. Joining WHO in 2006 working as a Technical Officer in the Yellow Fever Programme which coordinated an initiative funded by the GAVI Alliance to provide 40 million doses of vaccine to most at risk populations. In 2008, he joined WHO’s Global Influenza Programme and took part in the global response work to the first influenza pandemic of the 21st century. From 2014-2017, he was the Unit leader for Knowledge Management, Evidence and Research for Policy-Making at the WHO Regional Office for Europe based in Copenhagen, Denmark. There, he established the scientific journal Public Health Panorama and developed the WHO/Europe resolution and action plan for evidence-informed policy-making.

Elisabeth Wilhelm is an award-winning global health expert in social behaviour change, infodemic management and public health communication and strategy with broad experience across immunisation, maternal and child health and infectious diseases. She has worked at US CDC, UNICEF, and USAID, among other global health organisations. She has advised and led teams on domestic and global emergency and outbreak responses, served as principle investigator on implementation science research projects in multiple countries, and trained thousands of US and global communicators and public health professionals. Elisabeth has a keen research and practice interest in infodemiology and infodemic management to address uniquely 21st century challenges to health of misinformation, information overload and information disorder, and how it affects communities, health systems and society.

Tina D. Purnat  is a Doctor of Public Health (DrPH) student and Prajna Leadership Fellow at the Harvard T.H. Chan School of Public Health. Her work focuses on enhancing services for vulnerable and at-risk communities facing social, economic, and health information disparities. With over two decades of global experience in health informatics, Tina has worked across academia, the World Health Organization (WHO), and public health organizations, advancing digital public health, AI technologies and health information systems, and addressing health misinformation. She is passionate about modernizing public health through the integration of cutting-edge technology and human-centered solutions. Tina is a recognized conference speaker and academic lecturer, particularly in the areas of health misinformation and AI for health.