Pandemics and Cities: Examples from History

A pandemic is the global outbreak of a disease that can occur through a variety of modes of transmission, ranging from blood and body fluids, to vector-borne, to fecal-oral, to respiratory (airborne and respiratory droplets). In contrast, epidemics are diseases that affect populations within a single community or region. The world has endured many notable pandemics, including the Black Death, Flu, HIV, and Ebola, that caused widespread morbidity and mortality as well as social and economic disruptions. Throughout modern history, epidemic and pandemic crises have had particularly adverse effects in cities due to increased exposure to the millions of people who live in high-density urban areas. Often the urban poor face the most severe incidence and longest recovery during pandemics, a phenomenon well documented using historic GIS methods in the London cholera epidemic.

Due to multiple modes of transmission, each pandemic requires specific preparedness and response strategies. Previous disease outbreaks – such as the flu pandemic of 1918 and localized epidemics of tuberculosis and cholera –  each led to specific and important urban transformations, such as introducing water and sewage systems to improve sanitation and prevent water-borne disease, public parks to improve air quality and opportunities for physical activities, and housing regulations to reduce overcrowding to prevent airborne disease.

Resources

This section provides an introduction to epidemiological definitions and statistics, illustrated by several prior pandemics and their effects on cities, that can help inform the present-day study of the COVID-19 pandemic.