LSE LACC Blog: The history of epidemics in Latin America has much to tell us about COVID-19
by: Linda Newson
Epidemic diseases through the centuries
Epidemic diseases that result in high mortality have one feature in common: they all have their origins in animals, normally domesticated animals. Hence, smallpox is related to cowpox, influenza to swine flu, and measles probably to rinderpest and/or canine distemper. It has been suggested that COVID-19 may have originated in bats and perhaps spread to humans via a pangolin in a wet market in Wuhan, China.
When new diseases emerge, they cause high mortality because most humans lack immunity due a lack of previous exposure. This scenario has been repeated multiple times in the past, beginning in the Christian era when populations in China, India, and the Mediterranean grew sufficiently large to sustain acute infections. With the development of transoceanic trade and colonial expansion from the 15th century, their incidence increased dramatically.
Those regions most profoundly affected at that time were those that in the pre-colonial era had been relatively isolated, notably the Americas, Australasia, and the Pacific islands. The extent of the demographic impact of acute infections in the 16th century has been debated, but it has been suggested that in the Americas the population may have been reduced to one tenth of its previous size. Even those who dispute the level of demographic collapse agree that disease was a major cause, and most accept that a single epidemic like smallpox could cause 20 or 30 per cent mortality.