City: From home of microbes to coronavirus hotspot
– Xenia Kokoula, TU Berlin

Homes of microbes
Street, sidewalk, façade: What makes this picture instantly recognizable as a late 19th century urban setting is not its architecture but rather the crowds that populate every corner [Image 1]. Walking on the sidewalk, standing in front of shop windows, sitting on the doorsteps, playing on the street, looking down from the windows, the figures merge into the tumultuous urban mass so vividly described by Edgar Allan Poe. In the foreground the children play on top of piles of waste against the backdrop of shops with immigrant sounding names on their signs. What these shops sell is not discernible apart from the prominent sign advertising Wines and Liquors in the center. The heading on top of the image informs us of the concrete location, the city of New York. The subheading on the bottom makes clear what we cannot see but have to assume: The city streets are declared to be the homes of microbes.

Almost 150 years later another invisible pathogen, the novel coronavirus SARS-COV-2 is lurking on the cities’ streets, prompting us to reexamine the long and tangled history of the city as a breeding ground for disease. This history is well documented: The most seminal books on urbanism commonly start with an account of the unsanitary metropolis of the 19th century as “a diseased condition […] a monstrous deformity […] a chancre, a cancer, a leprous body”1. Starting from this “city of dreadful night”2, the narrative then moves to the architectural, political and technological developments which made the transition from a dark to a radiant city possible. Now already in the 20th century, and with many of the most lethal urban epidemics a distant memory, the urbanistic discourse gradually moves away from the discussion of pathogens and pathologies to focus on other, less mundane issues of design and planning.

This simple narrative progressing from the 19th to the 20th century, from the unsanitary to the modern city, is, in reality, much more complex and multifaceted. Beyond the consensus that the 19th century city was bad for people’s health, there are moral and psychological implications. These have played a major role in the planning debate and have been influencing anti-urban stances well into the 20th century. Additionally, a narrow focus on architecture and planning debates overlooks the parallel process of building citywide infrastructural networks, which not only helped eliminate endemic diseases but also had a lasting impact on the built environment. They shaped an urban realm as distinct and separate from a natural one and defined the latter’s role as resource and reservoir for the former. Meanwhile the city has kept its strong hold on the collective imagination as a site of contradictions, of pleasure and danger, fascination and disillusionment: In 2017 a multidisciplinary research team led by one of Germany’s most renowned psychiatrists, Mazda Adli, published Stress and the City, a book exploring “why cities make us sick and why they are still good for us”3.

The historical, cultural and infrastructural discourses around the city as a breeding ground for disease are usually considered separately within the confines of distinct academic fields. Revisiting these discourses and untangling their complex relations has become imperative at the time of a worldwide pandemic, when cities seem once again to make us sick. Between the city as the home of microbes and the city as a coronavirus hotspot there are significant parallels as well as major shifts. Linking the historical, cultural and infrastructural debates and contextualizing them around an urban discourse is crucial in order to better understand how cities are constituted as coronavirus hotspots around the world.

Image 1: Street urchins playing in filthy sewers in an immigrant neighborhood. Source: Puck magazine, 18854.

Spatial diseases
Historical epidemiological data mainly from western Europe has reinforced the notion of urban penalty, a detrimental effect on mortality due to an ostensibly unhealthy as well as immoral urban way of life5. Modern medicine and its celebrated victories against infectious disease are closely linked to their urban settings: In the medical discourse, as well as the popular imagination diseases has long been spatial and indeed urban. This premise places architecture and planning at the core of public health discourse: If disease is directly or indirectly caused by space then it should be possible to design the urban environment with the explicit aim of promoting health.

Image 2: Tony Garnier, Une Cité Industrielle, l’ hôpital, 1917. Source: Wikimedia Commons6.

Since the miasma theory attributed disease to foul air, architecture and planning took up the task of ensuring circulation and ventilation7. On the architectural scale this was reflected in free standing typologies and building technologies that freed up the façade; on the citywide scale public parks were created to provide the urban population with healthy, clean air. Since quarantine has been historically proven an effective containment measure, the location and surroundings of poorhouses and hospitals – that is the separation of healthy and sick bodies – was a major consideration for urban planning: In Tony Garnier’s Cité Industrielle the hospital overlooks the residential area at a safe distance from the hillside, separated from it by a wide green belt [Image 2]. The discovery of germs and especially waterborne bacteria, such as cholera, is linked with a renewed focus of architecture and urban planning on regulating water flows and the subsequent disappearance of water from public space, apart from a few elaborately staged and controlled instances8.

While the focus is placed mainly on the body, spatial diseases were also considered detrimental for the psyche, and it is indeed here that the associations of immorality, disorder and bad health become most apparent. Anthony Vidler has written about Platzangst – literally the fear of space – which was first diagnosed in the urban centres of central Europe in the second half of the 19th century and whose etiology was commonly linked to the urban environment9. In the understanding of Camillo Sitte, this illness was just the pathological extreme of a much more common experience of unease or discomfort while crossing the large empty spaces of the metropolis, as opposed to the well proportioned traditional squares and plazas. Agoraphobia and claustrophobia (both of which are possible translations of the German Platzangst) are the most common out of many spatial neuroses: these include “atremia or stasophobia (fear of elevated or vertical stations), amaxophobia (exaggerated fear of carriages), cremnophobia (the fear of precipices), acrophobia or hypsophobia (fear of elevated places), oicophobia (aversion to returning home), lyssophobia (fear of liquids), hydrophobia (fear of water—also connected to agoraphobia by the fear of the sea as expanse, and of crossing a bridge), pyrophobia (fear of fire, which was often linked to claustrophobia), monophobia (fear of solitude), anthropophobia (fear of social contact), and a multitude of others, culminating in photophobia (the fear of fear itself )”. Whether space was the main cause or merely a trigger of those afflictions was heavily debated; in any case, space was recognised as a key part of the strategies that could help patients manage, or even cure them.

This debate about mental as well as physical illness in the metropolis was appropriated by modern architecture and planning to support the argument for a radically new spatial order. Light, air and sun, as well as the white plain surfaces of modern architecture, were not only hostile to germs but also “cleansed of all mental disturbance”10. However, building the new city could only achieve the desired result if its citizens were also able to adopt healthy habits. By the early 20th century, educating and training the citizens on matters of hygiene had become a major socio-political project11. The role of architecture and planning thus expanded from designing healthy spaces – public parks, green belts, free standing public facilities and well ventilated machines à habiter – to constructing the spatial mechanisms of enforcing hygiene, through supervision, surveillance and radical transparency.

The most radical modernist re-imaginings of the city share a clear anti-urban bias with many alternative forms of healthier settlement structures, from garden cities to suburban commercial developments. This anti-urbanism urbanity survived throughout the 20th century even if the largest urban epidemics had by then notably subsided. This can be attributed to the culturally ingrained association between illness, dirt, impurity and disorder and conversely, the perception of an ordered and regulated environment as an ultimately healthy one. The city would, indeed remain the dangerous home of microbes, even if those microbes could be effectively treated with antibiotics, as long as it deviated from a supposedly natural order, as long as it retained the promise of disruption, loss of control and chaos. Elizabeth Wilson identifies large scale ecological disasters, and the twin developments of suburbanisation and ghettoization of the inner city as the main forces behind a resurgent late 20th century anti-urbanism, which reinforced the perception of “the city as a dangerous and disorderly zone from which women – and others – must be largely excluded for their own protection”12.

Separating spheres
While architecture and planning debated questions of order, chaos and the meaning of urbanity, much of the physical transformation of the city throughout the 20th century was driven by the more mundane technological process of constructing networked infrastructures. By providing access to water and sanitation, along with energy, mobility and communication the citywide infrastructures contributed significantly to better health outcomes for the urban population. The project of constructing a single, city-wide, integrated infrastructural network out of locally limited and fragmentary resources was driven by a rhetoric of progress through universal access to amenities, that would, in turn, benefit the totality of the urban society. However, the actual process of building networked infrastructures through an already uneven urban fabric has often resulted in reproducing, rather than reducing inequality13.

Regardless of whether the aim of universal access was achieved, the effects of expanding the infrastructural grid to encompass entire cities and city regions have been profound. Under the promise of order, hygiene and progress, urban metabolic processes have been reorganized and largely made invisible14. Using water infrastructure as an example Maria Kaika shows that by regulating water flows the infrastructural network essentially constructed three separate spheres or “spatial envelopes”: the home, the city and nature15. Apart from the water reliably flowing from the household tap there is no indication of how this network may function; its components remain hidden from view. In this scheme the water bodies and reservoirs are situated within the natural sphere, firmly outside the city, and the flow to the home is mediated by a complex yet invisible system of treatment plants, water pipes and sewers. With the connections between the autonomous urban and natural spheres highly regulated, any cross-contamination, in the literal and figurative sense, is avoided.

The separation of the natural and urban spheres establishes a clear system of order, which can in theory accommodate any urban expansion by expanding itself, by seeking resources and disposing of its waste in some supposedly extra-urban elsewhere. At the same time the infrastructural failures become more common and more dramatic. The sewage systems of Western-European cities are overwhelmed by heavy precipitation driven by climate change; intense storms and extended dry periods temporarily suspend the not-quite universal access to amenities that has been long taken for granted. Crises, disruptions and failures make us starkly aware of the hitherto invisible vast infrastructural network and reveal the carefully separated urban and natural spheres as mutually constitutive hybrids, “neither purely human¬made nor purely natural; outcomes of the same socio¬spatial process of the urbanization of nature.“16

Close calls
If infrastructural failures can draw attention to the hybridity and inseparability of urban-natural systems, the same can be said for the viral outbreaks of the recent past. In his almost prescient book on avian influenza Mike Davis gives an account of the SARS pandemic of 2003, the so-called first pandemic of the 21st century, as well as multiple other viral outbreaks that never rose to the pandemic level17. Davis’s in-depth analysis goes beyond the obvious role of global air travel to identify further factors within current urbanization patterns, which make cities once again the breeding grounds for disease. Among them the livestock revolution, driven by increasing demand for meat and the establishment of complex and globally interconnected urban food systems, combined with informal urbanization and lack of access to infrastructure and health care in large parts of the world, are the factors that make the next pandemic imminent. In this sense the outcome of any given viral outbreak is very much dependent on the urban condition, even if the disease itself is not directly caused by space.

Image 3: Adolf Bayer, L’ ordre, le désordre, 1948. Source: The Journal of Public Space, 201818.

In the course of separating, regulating, and reorganizing urban flows to create the modern, healthy city, livestock and other animals were gradually banished from the cityscape [Image 3]. As was the case with water, sewage and other resources, the keeping of live animals within the city was considered dangerous, disorderly and disruptive19. At the same time livestock and agriculture, once forming an integrated system, were also spatially separated in specialized, industrial scale production units. Paradoxically, this premise of separation, of making animals invisible, has been accompanied by the increasing encroachment of their habitats by human activity, and as a result intensified and reframed, rather than reduced human-animal interaction. Instead of keeping us healthy, the high-density industrial food production coupled with global urbanization and mobility patterns created favourable conditions for viral outbreaks.

As viruses evolve and mutate, they cross the species barrier to start a transmission chain among humans, as was the case for recent strains of avian flu, swine flu and the HIV pandemic. These close calls already make clear that the strategy of separating the urban from the natural sphere and making urban metabolism invisible, fails to inoculate us from globally circulating and mutating pathogens. If the city is once again a breeding ground for disease there is no nature beyond the urban and no insurmountable species barrier to protect us.

Coronavirus hotspots
As the COVID-19 pandemic disrupted everyday life in cities all over the world, the historical themes of the unsanitary city and the necessity of spatial interventions have resonated through the pandemic response. Quarantines have reinforced the separation of the home from a threatening, infectious urban environment. In public spaces and most notably at the interfaces between the public and private spheres new rituals have been established to soothe our revived spatial fears of touching, of proximity, of crowds and encounters. Ad hoc and temporary spatial interventions seek to enforce the separation between sick and healthy bodies, to ensure air circulation and ventilation, to promote social distancing. While the lack of universal access to housing, water and sanitation is decried, the more complex and challenging task of expanding those rights is at best postponed until after the pandemic is over. At the same time, at least one part of the urban metabolism which relies on human labour – the newly appreciated essential workers who staff meatpacking plants, warehouses and grocery stores – has been increasingly visible in public discourse.

Across the coronavirus hotspots new virus-human constellations emerge and leave their mark on the urban environment. How spatial disciplines respond remains to be seen. Context-based research carried out by some of the authors in this issue reveals that the notion of the city as coronavirus hotspot cannot be generalized. The concrete historical, cultural and spatial realities shape this term to address specific challenges, be it mobility in Buenos Aires or low-quality housing in Germany. At the same time these hotspots cannot be considered in isolation but as part of expanded regional and global spatial systems that connect and sustain them.

1. Choay, F. (1969) The Modern City: Planning in the 19th century. Translated by M. Hugo and G. Collins. New York: George Braziller.
2. Hall, P. (1988) Cities of Tomorrow: An Intellectual History of Urban Planning and Design in the Twentieth Century. Oxford: Blackwell.
3.Adli, M. and Dengler, F. (2017) Stress and the City: warum Städte uns krank machen. Und warum sie trotzdem gut für uns sind. München: C. Bertelsmann.
4. Image source: Puck magazine (1885) [online]. Available at: [Accessed 27 December 2020].
5. Vögele, J. and Koppitz, U. (2006) Sanitäre Reformen und der epidemiologische Übergang in Deutschland 1850-1920, in Frank, S. and Gandy, M. (eds) Hydropolis. Wasser und die Stadt der Moderne. Frankfurt & New York: Campus Verlag, pp. 75–93.
6. Image source: Garnier, T. (1917). La Cité Industrielle, l’ hôpital [online]. Available at:,_Cit%C3%A9_industrielle,_l%27h%C3%B4pital.jpg [Accessed 27 December 2020].
7. Arnold, D. (2013) The Spaces of the Hospital: Spatiality and Urban Change in London 1680-1820. Abington & New York: Routledge.
8. Bernhardt, C. (2005). Die Vertreibung des Wassers aus der Stadt und aus der Planung: zur Hygienisierung der öffentlichen Räume im 19. Jh am Beispiel Berlins, in Bernhardt, C. and von Petz, Ursula (eds) Geschichte der Planung des öffentlichen Raums. Dortmunder Beiträge zur Raumplanung, 122. Dortmund: IRPUD. pp. 71-84.
9. Vidler, A. (2000). Warped Space: Art, Architecture, and Anxiety in Modern Culture. Cambridge, Mass: MIT Press.
10. Ibid. p. 51.
11. Overy, P. (2007). Light, Air & Openness: Modern Architecture Between the Wars. Thames & Hudson.
12. Wilson, E. (1991). The Sphinx in the City. Urban Life, the Control of Disorder, and Women. London: Virago Press.
13. Graham, S. and Marvin, S. (2001). Splintering Urbanism: Networked Infrastructures, Technological Mobilities and the Urban Condition. London; New York: 14. Giseke, U. (2018). The city in anthropocene – Multiple porosities’, in Wolfrum, S. et al. (eds) Porous City. From Metaphor to Urban Agenda. Basel: Birkhäuser, pp. 200–204.
15. Kaika, M. (2005). City of Flows: Modernity, Nature, and the City. New York: Routledge.
16. Ibid. p. 5.
17. Davis, M. (2005). The Monster at our Door: The Global Threat of Avian Flu. New York: New Press.
18. Image source: Bayer, A. (1948). L’ ordre, le désordre [online]. Available at: [Accessed 27 December 2020].
19. Voigt, A. et al. (2020) Wilde Urbaniten: Tier-Mensch-Regime im Habitat Großstadt. sub\urban. zeitschrift für kritische stadtforschung, 8(1/2), pp. 253–262. doi: 10.36900/suburban.v8i1/2.557.


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