Page 2a | Examples of epidemic periods associated with different eras of human transportation (land, maritime and air travel) are shown. Overland trade networks and war campaigns are thought to have contributed to multiple epidemics in the Mediterranean in late classical antiquity (green), beginning with the Antonine plague, which reportedly claimed the life of the Roman emperor Lucius Verus125,126,127,128. Maritime transportation (red and grey) leading to European contact with the Americas and the subsequent Atlantic slave trade resulted in the importation of Plasmodium falciparum malaria and novel viral pathogens129. In modern times, air travel (purple) resulted in the importation of severe acute respiratory syndrome (SARS) coronavirus to 27 countries before transmission was halted130. b | In recent years, increases in air travel, trade and urbanization at global (left) and regional (right) scales have accelerated, indicating ever more frequent transport of people and goods between growing urban areas (source World Bank). c | Log deaths from major epidemics in the twenty-first century (source World Health Organization). d | Disability-adjusted life years lost from infectious diseases (source Our World in Data). MERS, Middle East respiratory syndrome; NTD, neglected tropical disease. |