Epidemiological risks in international travel in the 19th century

Abstract

International travel is a factor in the risk of transmission of infectious diseases and their spread to new areas. Because infections have a limited incubation period, their spread is significantly affected by people’s speed of travel, which has greatly increased in the past 100 years. The authors of this article have attempted to carry out a comparative analysis of the risks of transmission of infectious diseases. They have assessed the epidemiological risks for travellers at the end of the nineteenth century (using the information in Jules Verne’s novel Around the World in Eighty Days) and in the twenty- first and analysed potential ways for infectious diseases to spread. Data on the speed of passenger travel (in the nineteenth century and 2020) has been taken into account and compared with the incubation periods of endemic infectious diseases. The authors analyse endemic diseases (cholera, plague, smallpox, leprosy, malaria, filariasis and equine influenza) in the regions mentioned in Around the World in Eighty Days, and disease incubation periods are compared with travel times. There is also an assessment of sanitary conditions in nineteenth- century London. The warfare and poor sanitary conditions in nineteenth-c  entury Europe meant that the risk of being infected with many highly contagious diseases remained extremely high, whereas the likelihood of catching tropical diseases was low because travel was slower than it is today. In the twenty-fi  rst century, social conditions have improved, but the speed of travel has made it possible for any infectious disease to reach anywhere in the world within 48 hours.