Several years ago, I searched 19th Century Jagielnica vital records for my Denker and Geller families.
There were usually less than 100 deaths per year. Then I noticed a disturbing change. By 1865 the total number was about 300 - most caused by Cholera.
During the 19th Century, Cholera had spread across the World from its original source - the Ganges River delta in India. Six subsequent pandemics killed millions of people across all continents. Deaths in India, in three pandemics between 1817 and 1860, were estimated to have exceeded 15 million people. During the next three Indian pandemics between 1865 and 1917, another 23 million died.
The fourth Cholera pandemic (1863-1875) spread to Europe. During the Austro-Prussian War (1866), Cholera is estimated to have taken 165,000 lives in the Austrian Empire. The same year 1866, Cholera claimed 90,000 lives in the Russian Empire.
Cholera deaths in the Russian Empire during this entire period exceeded 2 million.