El Niño Events and the History of Epidemic Disease Incidence

Abstract

The history of El Niño incidence can help shed light on some aspects of the history of disease and epidemics. A comparison of the chronologies of severe El Niño events and the chronologies of major disease pandemics indicates close connections between the two patterns, particularly in the case of plague, malaria, cholera and influenza, probably the four biggest epidemic killers historically. Most of these epidemic diseases flourish in El Niño periods because their (mainly mosquito) vectors flourish in the changed hydrological conditions that are characteristic of El Niño occurrences. This information on historical El Niño now allows us, for the first time, to present a synthesis of the evidence linking El Niño with disease epidemics and an evaluation of the arguments for climatic agency.