Cholera pandemic

Seven cholera pandemics have occurred in the past 200 years, with the first pandemic originating in India in 1817. The seventh cholera pandemic is officially a current pandemic and has been ongoing since 1961, according to a World Health Organization factsheet in March 2022. Additionally, there have been many documented major local cholera outbreaks, such as a 1991–1994 outbreak in South America and, more recently, the 2016–2021 Yemen cholera outbreak.

Although much is known about the mechanisms behind the spread of cholera, this has not led to a full understanding of what makes cholera outbreaks happen in some places and not others. Lack of treatment of human feces and lack of treatment of drinking water greatly facilitate its spread. Bodies of water have been found to serve as a reservoir, and seafood shipped long distances can spread the disease.

Between 1816 and 1923, the first six cholera pandemics occurred consecutively and continuously over time. Increased commerce, migration, and pilgrimage are credited for its transmission. Late in this period (particularly 1879–1883), major scientific breakthroughs toward the treatment of cholera develop: the first immunization by Pasteur, the development of the first cholera vaccine, and identification of the bacterium ''Vibrio cholerae'' by Filippo Pacini and Robert Koch. After a long hiatus, a seventh cholera pandemic spread in 1961. The pandemic subsided in the 1970s, but continued on a smaller scale. Outbreaks occur across the developing world to the current day. Epidemics occurred after wars, civil unrest, or natural disasters, when water and food supplies had become contaminated with ''Vibrio cholerae'', and also due to crowded living conditions and poor sanitation.

Deaths in India between 1817 and 1860 in the first three pandemics of the nineteenth century, are estimated to have exceeded 15 million people. Another 23 million died between 1865 and 1917, during the next three pandemics. Cholera deaths in the Russian Empire during a similar time period exceeded 2 million.

Pandemics

The first cholera pandemic occurred in the Bengal region of India, near Calcutta (now Kolkata), starting in 1817 through 1824. The disease dispersed from India to Southeast Asia, the Middle East, Europe, and Eastern Africa through trade routes. The second pandemic lasted from 1826 to 1837 and particularly affected North America and Europe, due to the result of advancements in transportation and global trade, and increased human migration, including soldiers. The third pandemic erupted in 1846, persisted until 1860, extended to North Africa, and reached South America, for the first time specifically affecting Brazil. The fourth pandemic lasted from 1863 to 1875, and spread from India to Naples and Spain, and to the US in 1873. The fifth pandemic was from 1881 to 1896 and started in India and spread to Europe, Asia, and South America. The sixth pandemic started in India and lasted from 1899 to 1923. These epidemics were less fatal due to a greater understanding of the cholera bacteria. Egypt, the Arabian peninsula, Persia, India, and the Philippines were hit hardest during these epidemics, while other areas, such as Germany in 1892 and Naples from 1910 to 1911, also suffered severe outbreaks. The seventh pandemic originated in 1961 in Indonesia and is marked by the emergence of a new strain, nicknamed ''El Tor'', which still persists (as of 2019) in developing countries.

Cholera did not occur in the Americas for most of the 20th century after the early 1900s in New York City. It reappeared in the Caribbean toward the end of that century and seems likely to persist.

First, 1817–1824

The first cholera pandemic, though previously restricted, began in Bengal, and then spread across India by 1820. Hundreds of thousands of Indians and ten thousand British troops died during this pandemic. The cholera outbreak extended as far as China, Indonesia (where more than 100,000 people succumbed on the island of Java alone) and the Caspian Sea in Europe, before receding.

Second, 1829–1837

A second cholera pandemic reached Russia (see Cholera Riots), Hungary (about 100,000 deaths) and Germany in 1831; it killed 130,000 people in Egypt that year. In 1832 it reached London and the United Kingdom (where more than 55,000 people died) and Paris. In London, the disease claimed 6,536 victims and came to be known as "King Cholera"; in Paris, 20,000 died (of a population of 650,000), and total deaths in France amounted to 100,000. In 1833, a cholera epidemic killed many Pomo people which are a Native American tribe. The epidemic reached Quebec, Ontario, Nova Scotia and New York in the same year, and the Pacific coast of North America by 1834. In the center of the country, it spread through the cities linked by the rivers and steamboat traffic.

Similarly, in Washington DC (where there are no reliable mortality figures), Michael Shiner, an enslaved laborer at the Washington Navy Yard recorded, “The time the colery holerabroke out in about June and July August and September 1832 it Raged in the City of Washington and every day they wher eretwelve or 13 carried out to they heirgraves a day." By late July 1832 cholera had spread to Virginia and on 7 August 1832, Commodore Lewis Warrington confirmed to the Secretary of the Navy Levi Woodbury cholera was at the Gosport Navy Yard, “Between noon of that day, Augustand the morning of Friday August when all work on board her USS ''Fairchild'' stopped, several deaths by cholera occurred and fifteen or sixteen cases (of less violence) were reported."

The epidemic of cholera, cause unknown and prognosis dire, had reached its peak. Cholera afflicted Mexico's populations in 1833 and 1850, prompting officials to quarantine some populations and fumigate buildings, particularly in major urban centers, but nonetheless the epidemics were disastrous.

During this pandemic, the scientific community varied in its beliefs about the causes of cholera. In France doctors believed cholera was associated with the poverty of certain communities or poor environment. Russians believed the disease was contagious, although doctors did not understand how it spread. The United States believed that cholera was brought by recent immigrants, specifically the Irish, and epidemiologists understand they were carrying disease from British ports. Lastly, some British thought the disease might rise from divine intervention.

The social importance of the government having a direct role in the development and application of science was demonstrated through the U.S. Government's support of efforts to control the epidemic.

Third, 1846–1860

The third cholera pandemic deeply affected Russia, with over one million deaths. Over 15,000 people died of cholera in Mecca in 1846.Asiatic Cholera Pandemic of 1846–63
. UCLA School of Public Health. A two-year outbreak began in England and Wales in 1848, and claimed 52,000 lives.

In 1849, a second major outbreak occurred in France. In London, it was the worst outbreak in the city's history, claiming 14,137 lives, over twice as many as the 1832 outbreak. Cholera hit Ireland in 1849 and killed many of the Irish Famine survivors, already weakened by starvation and fever. In 1849, cholera claimed 5,308 lives in the major port city of Liverpool, England, an embarkation point for immigrants to North America, and 1,834 in Hull, England. In Vietnam and Cambodia, cholera hit in summer 1849, killing approximately 589,000 to 800,000 people within one year, along with its consequential famine.

An outbreak in North America took the life of former U.S. President James K. Polk. Cholera, believed spread from Irish immigrant ships from England, spread throughout the Mississippi river system, killing over 4,500 in St. Louis and over 3,000 in New Orleans