Contagious Cities: people and pathogens, microbes and migration

On the centenary of the 1918 flu pandemic, Wellcome is exploring the relationship between cities and infections through Contagious Cities, an international cultural collaboration.

Detail from a map showing yellow fever cases near the New York waterfront in 1797
Map detail showing yellow fever cases near New York's waterfront in 1797
Credit: Wellcome Collection

Michael Regnier, a science writer at Wellcome who has written about urbanisation and health, considers why cities are hotspots for contagions – and sources of solutions.

Global centres

Contagious Cities is taking the global challenge of preparing for disease outbreaks and giving it a local cultural context, working with creative people and institutions in New York, Hong Kong and Geneva. Each city is a financial centre with a streak of independence, a significant presence beyond its borders, and a history of dealing with epidemics.

New York is one of the few truly global cities. It exists as much in the imagination of billions of people as on the physical island of Manhattan and its environs. More than 20,000 New Yorkers died of flu in 1918, but the death rate was lower than any other eastern US city. New York had learned from its 19th-century experiences with infections like tuberculosis, a significant killer. And TB re-emerged with the rise of HIV/AIDS in the 20th century.

Hong Kong is perhaps the most connected city on earth – its airport serves over 150 destinations. Compared to Europe and North America, the 1918 flu pandemic was mild in Hong Kong, but 50 years later a new global flu pandemic started here, killing 1 million people around the world. Hong Kong was also at the centre of the 2003 epidemic of severe acute respiratory syndrome (SARS), unwittingly spread by some of its international travellers.

Half of all Geneva’s citizens caught flu in 1918 – some companies reported that up to 80 per cent of their staff were off sick. At the height of the outbreak, theatres, cinemas and nightclubs were closed, religious services banned and deaths unmarked by the ringing of church bells. Today, Geneva hosts more international organisations than anywhere else, including the World Health Organization which has a healthy interest in promoting ‘healthy cities’.

Pathogenic paradise

Many infectious diseases leapt into humans when we began farming animals 10,000 years ago, but our modern cities offer germs so many more enticing bodies to colonise: the urban jungle is a pathogenic paradise.

Swirling around our everyday interactions on the street or the subway are a myriad of microscopic trades of viruses, bacteria and parasites, each looking – much like us – for a good home.

The growth of cities, whether in Europe in the 19th century or Asia in the 21st, is associated with artistic, economic and social opportunity, but also with dirt, delinquency and an unhealthy level of mental stress.

Compared to the countryside, we think of cities as sites of extreme vice and extreme virtue – shining edifices and filthy slums, criminal haunts and humanitarian movements. They are local and global, drawing resources from the suburban and rural communities around them even as they reach out to the rest of the world.

And while presenting huge challenges, they are a source of solutions, too. If the city is a hotbed of contagion, it is also an opportunity to build a hospital, a research lab, a biotech hub.

The city brings people together, unites us in a mass huddle through a shared sense of identity, community and purpose. It nurtures ideas and then, like any other contagion, helps spread them far and wide.

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