Influenza and Public Health

Learning from Past Pandemics

Tamara Giles-Vernick, Susan Craddock

• Publisher: Routledge
• Year: 2010
• ISBN:
  9781136532078
• Edition: 1
• Topic: Medizin
• Subtopic: Gesundheitswesen, Verwaltung & Pflege

Major influenza pandemics pose a constant threat. As evidenced by recent H5N1 avian flu and novel H1N1, influenza outbreaks can come in close succession, yet differ in their transmission and impact. With accelerated levels of commercial and population mobility, new forms of flu virus can also spread across the globe with unprecedented speed. Responding quickly and adequately to each outbreak becomes imperative on the part of governments and global public health organizations, but the difficulties of doing so are legion. One tool for pandemic planning is analysis of responses to past pandemics that provide insight into productive ways forward.

This book investigates past influenza pandemics in light of today's, so as to afford critical insights into possible transmission patterns, experiences, mistakes, and interventions. It explores several pandemics over the past century, from the infamous 1918 Spanish Influenza, the avian flu epidemic of 2003, and the novel H1N1 pandemic of 2009, to lesser-known outbreaks such as the 1889-90 influenza pandemic and the Hong Kong Flu of 1968. Contributors to the volume examine cases from a wide range of disciplines, including history, sociology, epidemiology, virology, geography, and public health, identifying patterns that cut across pandemics in order to guide contemporary responses to infectious outbreaks.

1 Globalized Complexity and the Microbial Traffic of New and Emerging Infectious Disease Threats

S. Harris Ali

Human-induced environmental shocks – overseas tourism, wetland destruction, a corporate ‘Livestock Revolution, and a Third World urbanization with the attendant growth of mega slums – are responsible for turning influenza’s extraordinary Darwinian mutability into one of the most dangerous biological forces on our besieged planet.

Mike Davis (2005)

Over the relatively short span of a quarter of a century, the world appears to have witnessed the proliferation of an unusually large number of what are referred to as ‘new and emerging diseases’ – that is, infectious diseases that are newly appearing in a population or that have been known for some time but are rapidly increasing in incidence or in geographic range (Morse, 1995). Examples of these are numerous and include HIV-AIDS, SARS, E. coli 0157:H7, Clostridium difficile, West Nile virus, lyme disease, antibiotic-resistant tuberculosis, the ebola virus and avian influenza (Garrett, 1994; Drexler, 2003; Levy and Fischetti, 2003; Nikiforuk, 2006). In this chapter, using SARS and influenza A/H1N1 (Swine flu) as illustrative examples, I examine through the lens of complexity theory the question of how historically specific processes related to intensified globalization have influenced the emergence and spread of new diseases. As will be discussed, the complexity perspective offers a conceptual framework that is especially well-suited for the analysis of the multiple social and ecological aspects of globalization associated with the contemporary origins and responses to pandemics.

Historical Transitions and Microbial Traffic

A. J. McMichael (2001) has documented how significant changes in the relationship between human beings and the environment at particular junctures in history were accompanied by the concomitant rise of certain types of infectious diseases. The first such shift involved a change in settlement patterns 10,000 years ago as hunter-gatherers adapted to agrarian-village living based on herded food and agriculture. This shift created new ecological opportunities for the spread of disease as it enabled countless novel strains of bacteria/viruses to make the jump from domesticated herd animals and rodents to relatively stationary human beings. The origin of many diseases including smallpox, measles, tuberculosis, leprosy, influenza, the common cold, malaria, dengue and bubonic plague could be traced to this period (McMichael, 2001). During the time span of the past 1000 to 2500 years, increased trade, travel and military movement led to a new phase in disease emergence. Examples here include the spread of smallpox and measles from the Indian subcontinent to Europe via Roman Empire troops returning from settling unrest in Syria in AD 2; trade along the Silk Route that subsequently spread these diseases from Europe to China; and the introduction of the bubonic plague to 14th-century Europe as the caravans and armies of the Mongol Empire entered the continent through the Black Sea. The colonialist period spanning the 17th-19th centuries represented a third major shift in disease spread, particularly in relation to the transoceanic spread of disease via European ships. McMichael (2001) concludes by speculating that we may be entering a fourth transitional period defined by globalization, as evidenced through dramatic increases in the volume and speed of human mobility, changes in food production practices and newer medical techniques, all of which have implications for disease emergence.

It is readily apparent that changes in the flow of individuals and pathogens are key aspects of disease emergence no matter the epoch under consideration. This emphasis is captured by the notion of ‘microbial traffic’ proposed initially by Morse (1993) and refers to the mobility of a pathogen and how that will vary according to characteristics associated with cross-species transfer, pathogenic evolution (including changes in the structure and immunogenicity of earlier strains), spatial diffusion and changes in the human–environment relationship (Mayer, 2000). In what follows, using the lens of complexity theory, I will refer to the above-mentioned dimensions of microbial traffic to make the case that globalization may indeed represent another transformative epoch in the emergence of infectious disease.

Globalization and microbial traffic globalization is defined in various ways (Held et al, 2002) but a fundamental aspect of most definitions is that of time-space compression (Giddens, 1990; Harvey, 2005). Time-space compression refers to the idea that, largely because of modern technologies, there has been a dramatic increase in the speed at which the movement of people, money, images and information occurs, thus resulting in situational circumstances in which distance is not as insurmountable or as significant a barrier as it once was in the past. Time-space compression has some obvious implications for the spread of disease. Notably, the effects become evident when considering the time horizons associated with air travel and disease incubation (i.e. the period between infection and symptom onset). Thus, the 2–7 day incubation period of SARS and a similar incubation period for Influenza A/H1N1 (Picard, 2009c; Tuite 2009), has meant that those infected could easily complete a transcontinental flight before their symptoms developed, thereby increasing the potential for pandemic spread overall.

The enhanced and accelerated mobility of pathogens has also meant that a ‘reterritorialization’ of risk has occurred leading to the problematization of traditional territorially based strategies of disease control in which it was assumed that pathogens were biologically stationary targets that could be geographically sequestered (Garrett, 1996). This territorial notion of disease has immediate political and social implications for the manner in which disease spread is conceptualized by both the general public and the elites. It is in this context that King (2002) notes that the history of infectious disease control is very much influenced by the legacy of colonialism and territorialism in which the colonizers sought to protect themselves from disease through the creation of administratively cohesive and geographically bounded regimes. Yet, as we shall see, the rapid spread of SARS and Influenza A/H1N1 worldwide has dramatically demonstrated how the assumptions of territoriality no longer hold in an increasingly interconnected and globalizing world, despite response strategies that to some extent are still informed by territorializing assumptions. The highly mobile nature of new and emerging diseases, coupled with the advent of qualitatively different types of interactions between humans and animals have contributed to the emergence of pandemic as a unique and complex phenomenon distinct to our historical epoch – a distinctiveness which, as we shall see, is associated with changes in the scale and intensity of economic globalization. The analysis of contemporary pandemics therefore requires new tools, particularly those that emphasize the contingent and multifactorial causes of disease. In this light, the recent work in complexity theory may prove to be a useful starting point in the analysis of pandemics (Ali and Keil, 2007; Ali, 2008).

Complexity theory is a systems perspective that emphasizes the role of such features as: punctuated equilibrium, non-linearity, emergence, feedback loops and tipping points in the development of phenomena. It is of interest to us here because it enables a conceptualization of pandemic in terms of the interdependence of biophysical and sociopolitical factors, thus avoiding a tendency towards a narrowly defined essentialist stance that overemphasizes at either extreme the biological or the social. Furthermore, analysing pandemics through the complexity perspective may help us acquire a more critical position by directing analytical attention to the questions of how and why alterations in microbial traffic come about through human-induced (and therefore politically based) changes in society and the environment. For example, in considering the longue durée, we see that periods of social and economic stability are interrupted by changes in the relationship between human beings and the environment that dramatically alter the existent microbial traffic pattern. In this sense, the periods of stability interspersed with changes in microbial traffic patterns, some of which result in epidemics, may be thought of in terms of a series of punctuated equilibria. What is perhaps alarming is how, over the last few decades, the periods of relative calm and stability between the periodic changes in microbial traffic have shortened considerably. Thus, over the last decade alone we have faced a barrage of new and emerging diseases such as SARS, avian flu and influenza A/H1N1. Second, the extent to which the microbial traffic pattern now involves a global dimension is noteworthy.

To address the question of why in even greater detail than has been employed up until this point, it is useful to consider the notions of non-linearity and tipping points. Non-linearity refers to how small changes in a system may lead to sudden and dramatically disproportionate shifts, usually triggered by exceeding some critical parameter or tipping point. The tipping points represents the dramatic moment in an epidemic when everything can change all at once (Gladwell, 2002).¹ Often it is only a relatively minor change in the external environment that can have an unusually high and disproportionate impact on the way a biological and social system functions (Gladwell, 2002). In the case of SARS, for example, a tipping point in the pandemic spread occurred when an infected physician from Guangzhou stayed at the Metropole Hotel in Hong Kong, inadvertantly initiating the simultaneous spread of the disease to different global cities across the world.² The suddenness of the unknown diseases’ arrival meant that hospital staff in the various affected cities were unprepared to protect themselves. Consequently, during these early stages, a positive feedback loop was established in which those infected would lead to even more becoming infected – an increase defined as multiplicatively geometric rather than incremental linear/arithmetic.

Another tipping point to consider in relation to pandemics involves the point at which the virus has evolved to such an extent that it is able to survive within a human host and then be transmitted between human hosts. During times of stability, the viruses which affect humans tend to evolve relatively slowly in a process referred to as antigenic drift. This leads to the eventual development of new viral strains that require new vaccines on an annual basis. In contrast, occurring much more infrequently (every human generation or so), is a much more revolutionary shift where a bird or pig type of influenza A will exchange genes with a human type of influenza, thus enabling the virus to vault over the species barrier in a process known as antigenic shift – a shift that signals the beginnings of a pandemic (Davis, 2005, p11). As alluded to above, it appears that the frequency of tipping point initiations through antigenic shifts have increased dramatically over recent times. To understand why requires us to enquire how the nature of the relationships between animals and humans, as well as those between humans themselves, have changed during the recent past.

One area of comparatively dramatic change is the increased global demand for meat and poultry, resulting in the imposition of immense stresses on the biophysical environment and animals through the intensification of livestock operations (also referred to as factory farming). Many of these negative effects (or externalities) are hidden from urban dwellers who rely on such operations to maintain their meat-based diets, yet they have real consequences for altering microbial traffic patterns and inducing disease outbreaks and pandemics. For example, the development and spread of a lethal strain of E. coli could be traced to factory farming practices involving the international cattle trade (Ali, 2004). Similarly, the development of avian and swine flu strains is related to the factory farming of poultry and swine where opportunities for animal-to-human transmission (or vice versa) abound. The likelihood that a more virulent strain will develop under the conditions of globalized agrocapitalist operations is amplified in numerous ways, including an increased risk that animals will become more susceptible to infectious diseases due to the stresses endured in over-crowded factory farms or from the development of antibiotic resistance resulting from widespread administration of sub-therapeutic doses to promote weight gain.

Other global developments that can impinge on the microbial traffic of new and emerging diseases and the associated ecology of disease are those associated with intensified urbanization. Increasing poverty, particularly in the last 30 years, has driven exponentially more dispossessed people from rural areas to the peripheries of megacities across the developing world (Davis, 2005). If globalized factory farming contributes to the development of new and emerging pathogens, then mega-slums provide them with an environment in which they can flourish. Underserviced slum areas often lack proper sanitation and basic amenities and are overcrowded with a large pool of available susceptible human hosts – settings that are especially favourable to the spread of disease. This potential for epidemics to flourish is especially noteworthy given that 95 per cent of the world future population growth will be in the poorer cities of the Global South (Davis, 2005, p56) and that for the first time in history, more than half the world’s population is now residing in urban areas (United Nations Population Fund, 2007). At the same time, it should be noted that the conditions conducive to disease spread are not necessarily found only in urban settings, but are common to those areas more generally characterized by poverty and lack of health-related amenities. In this light, certain non-urban areas are just as prone (if not more) to disease outbreaks as revealed by the extent to which influenza A/H1N1 has become widespread on some First Nations Reserves in Canada.

The SARS Pandemic

In November 2002, the city of Foshan, Guangdong Province, China experienced an outbreak of a mysterious and highly contagious respiratory disease, then referred to as ‘atypical pneumonia’. The disease spread quickly to other cities in the province including Heyang and Guangzhou, then subsequently to others in the country, most notably Beijing (Kaufman, 2006). Although the Chinese government initially took steps to keep knowledge of the outbreaks secret, by late February 2003 news about the outbreaks travelled through informal channels on text messaging and the internet –a notable development considering that in the past, such information could not be transmitted so readily across the country in such a short period and could thus be controlled by government to a greater extent (Heymann, 2005). Once confirmations of the informal rumours were received, the World Health Organization (WHO) coordinated a network of scientists from around the world to work together to characterize the disease agent, originally suspected to be a strain of influenza (Abraham, 2004). Much to the surprise of many infectious disease experts, however, the identification and subsequent characterization of the causative agent – completed in the unprecedented span of a few weeks – revealed i...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright
• Contents
• List of Figures
• List of Contributors
• Foreword by Alice Dautry
• Acknowledgements
• List of Acronyms and Abbreviations
• Introduction
• 1. Globalized Complexity and the Microbial Traffic of New and Emerging Infectious Disease Threats
• Part 1: Reframing 1918: States, Pandemics and Public Health
• Part 2: Epidemiology, Virology and 20th-Century Epidemics
• Part 3: Governmental and Nongovernmental Institutions and the Politics of Epidemic Management
• Index