Yellow fever in Buenos Aires

The Yellow Fever in Buenos Aires was a series of epidemics that took place in 1852, 1858, 1870 and 1871, the latter being a disaster that killed about 8% of Porteños: in a city were the daily death rate was less than 20, there were days that killed more than 500 people. The Yellow Fever would have come from Asunción, Paraguay, brought by Argentine soldiers returning from the war just fought in that country, having previously spread in the city of Corrientes. As its worst, Buenos Aires population was reduced to a third because of the exodus of those escaping the scourge.

Some of the main causes of the spread of this disease were the insufficient supply of drinking water, pollution of ground water by human waste, the warm and humid climate in summer, the overcrowding suffered by the black people and, since 1871, the overcrowding of the European immigrants who entered the country incessantly and without sanitary measures. Also, the saladeros (manufacturing establishments for producing salted and dried meat) polluted the Matanza River (south of the city limits), and the infected ditches full of debris which ran through the city encouraged the spread of the mosquito Aedes aegypti, which was responsible of transmitting Yellow Fever.

A witness to the epidemic of 1871, named Mardoqueo Navarro, wrote on April 13 the following description in his diary:

Since 1881, thanks to Cuban physician Carlos Finlay, it was known that the transmitting agent of Yellow Fever was mosquito Aedes aegypti. Before that discovery, doctors attributed the cause of many epidemics to what they called "miasmas" floating in the air.

...
Wikipedia