| Fourth cholera pandemic | |
|---|---|
 Oyster seller in Washington D.C. claims "CHOLERA PANIC OVER" in October 1866 | |
| Disease | Cholera |
| First outbreak | Ganges Delta of theBengal region |
| Dates | 1863–1875 |
Thefourth cholera pandemic of the 19th century began in theGanges Delta of theBengal region and traveled withMuslim pilgrims to Mecca. In its first year, the epidemic claimed 30,000 of 90,000 pilgrims.[1] Cholera spread throughout theMiddle East and was carried to theRussian Empire, Europe, Africa, and North America, in each case spreading via travelers fromport cities and along inland waterways.[2]
In 1866, there was a localized epidemic in theEast End of London, primarily because the local section of theLondon sewerage system was still under construction and this region of London was experiencingovercrowding. The 1870s North American cholera outbreak spread fromNew Orleans via passengers along theMississippi River and to ports on its tributaries.
The pandemic reached Northern Africa in 1865 and spread tosub-Saharan Africa, killing 70,000 inZanzibar in 1869–70.[3] Cholera claimed 90,000 lives in Russia in 1866.[4] The epidemic of cholera that spread with theAustro-Prussian War (1866) is estimated to have taken 165,000 lives in theAustrian Empire (including 30,000 inHungary), 30,000 inBelgium, and 20,000 in theNetherlands.[5]
In June 1866, a localized epidemic in theEast End of London claimed 5,596 lives, just as the city was completing construction ofits major sewage and water treatment systems; the East End section was not quite complete.[6] It was also caused by the city'sovercrowding in the East End, which helped the disease to spread more quickly in the area. EpidemiologistWilliam Farr identified theEast London Water Company as the source of the contamination. Farr made use of prior work byJohn Snow and others, pointing to contaminated drinking water as the likely cause of cholera in an1854 outbreak. In the same year, the use of contaminated canal water in local water works caused a minor outbreak atYstalyfera inSouth Wales. Workers associated with the company, and their families, were most affected, and 119 died.[7]
The deaths of more than 1,100 people in New York City in 1866 resulted in the establishment of theNew York Metropolitan Board of Health.[8]
In 1867,Italy lost 113,000 to cholera, and 80,000 died of the disease inAlgeria.[3] Outbreaks in North America in the 1870s killed some 50,000 Americans as cholera spread fromNew Orleans via passengers along theMississippi River and to ports on its tributaries.[9]