Although cholera has existed for many centuries, the disease gained momentum in the 19th century, when a deadly outbreak occurred in India. Since then, numerous epidemics and seven global cholera pandemics have occurred. Every year, cholera infects 1.3 to 4 million people worldwide, or between 21,000 and 143,000 people, according to the World Health Organization (WHO).
What is cholera?
Cholera is an infectious disease caused by a bacteria called Vibrio cholerae. Bacteria typically live in somewhat salty, warm waters, such as estuaries and waters along coastal areas. People contract V. cholerae after drinking liquids or eating foods contaminated with the bacteria, such as raw or undercooked shellfish.
There are hundreds of strains or “serogroups” of the cholera bacteria: V. cholerae serogroups O1 and O139 are the only two strains of the bacteria known to cause epidemics.
These strains produce the cholera toxin which causes the cells lining the intestines to release accumulated amounts of water, leading to diarrhea and rapid loss of fluids and electrolytes (salts). A single episode of diarrhea can cause a million-fold increase in the number of bacteria in the environment, according to the National Institute of Allergy and Infectious Diseases.
Cholera symptoms
About 80 percent of people who contract the bacteria do not develop cholera symptoms and the infection goes away on its own. And among people who develop cholera, 20 percent have serious symptoms, including severe diarrhea, vomiting and leg cramps. These symptoms can cause dehydration, septic shock, and even death within just a few hours.
People who contract V. cholerae non-01 or non-1039 may also get diarrheal illness, but it is less serious than cholera itself.
Today, the cholera is treated with fluid replacement and antibiotics. Cholera vaccines are available, but they only provide about 65% immunity, according to the WHO.
Origins of cholera
It is not known exactly when cholera first affected people.
Early texts from India (by Sushruta Samhita in the 5th century BC) and Greece (Hippocrates in the 4th century BC and Areteus of Cappadocia in the 1st century AD) include isolated cases of illness resembling cholera.
One of the first detailed accounts of a cholera epidemic comes from Gaspar Correa, a Portuguese historian and author of Legendary India, who described an outbreak in the spring of 1543 of a disease in the Ganges Delta, located in the southern region. Asian from Bangladesh. and India. Local people called the disease « moryxy », and it reportedly killed victims within 8 hours of the onset of symptoms and had such a high mortality rate that locals had difficulty keeping track of all the deaths.
Numerous reports of cholera outbreaks along the west coast of India by Portuguese, Dutch, French and British observers followed over the next centuries.
The first cholera pandemic
The first cholera pandemic appeared in the Ganges Delta with an outbreak in Jessore, India, in 1817, caused by contaminated rice. The disease quickly spread across most of India, to modern-day Myanmar and modern-day Sri Lanka using trade routes established by Europeans.
By 1820, cholera had spread to Thailand, Indonesia (killing 100,000 people on the island of Java alone), and the Philippines. From Thailand and Indonesia, the disease spread to China in 1820 and Japan in 1822 through infected people on ships.
It has also spread beyond Asia. In 1821, British troops traveling from India to Oman spread cholera across the Persian Gulf. The disease finally spread to European territory, reaching today Turkey, Syria and southern Russia.
The pandemic died out 6 years after it began, probably thanks to a harsh winter in 1823-1824, which could have killed living bacteria in water supplies.
Cholera infects Europe and the Americas
The second cholera pandemic began around 1829.
Like the one that preceded it, the second pandemic is believed to have originated in India and spread along trade and military routes to Central and East Asia and the Middle East.
By the fall of 1830, cholera had reached Moscow. The spread of the disease temporarily slowed during the winter, but resumed in the spring of 1831, reaching Finland and Poland. She then moved to Hungary and Germany.
The disease then spread throughout Europe, notably reaching Britain for the first time via the port of Sunderland in late 1831 and London in the spring of 1832. Britain adopted several measures to help curb the spread of the disease, including by implementing quarantines and creating local councils. of health.
But the public became gripped by a widespread fear of the disease and a distrust of authority figures, particularly doctors. Unbalanced reporting in the press led people to believe that more victims were dying in hospitals than at home, and the public began to believe that victims taken to hospitals had been killed by doctors for a . anatomical dissection, a result they described as “Burking”. This fear gave rise to several “cholera riots” in Liverpool.
By 1832, cholera had also reached the Americas. In June of that year, Quebec experienced 1,000 deaths from the disease, which quickly spread along the St. Lawrence River and its tributaries.
Around the same time, cholera was imported to the United States, appearing in new York and in Philadelphia. In the following years, this practice would spread throughout the country. It reached Latin America, notably the Mexico and Cuba, in 1833.
The pandemic would fade and re-emerge in many countries for almost two decades until it subsided around 1851.
How scientists studied cholera
Between 1852 and 1923, the world would experience four more cholera pandemics.
The third pandemic, which lasted from 1852 to 1859, was the deadliest. It devastated Asia, Europe, North America and Africa, killing 23,000 people in Britain alone in 1854, cholera’s worst year.
That year, British physician John Snow, considered one of the fathers of modern epidemiology, carefully mapped cholera cases in London’s Soho district, allowing him to identify the source of the disease in the region: contaminated water from a public well pump. .
He convinced the authorities to remove the pump handle, immediately dropping cholera cases in the region.
The fourth and fifth cholera pandemics – occurring from 1863 to 1875 and 1881 to 1896, respectively – were less severe overall than previous pandemics, but had their share of deadly outbreaks. Between 1872 and 1873, for example, Hungary experienced 190,000 deaths from cholera. And Hamburg lost nearly 1.5 percent of its population to cholera during the 1892 epidemic.
In 1883, the German microbiologist Robert Koch, founder of modern bacteriology, studied cholera in Egypt and Calcutta. He developed a technique allowing him to cultivate and describe V. cholerae, then show that the presence of the bacteria in the intestines causes cholera.
However, the Italian microbiologist Filippo Pacini had identified the cholera bacteria – naming it cholerogenic vibrations – in 1854, although this fact was not widely known (and was probably unbeknownst to Koch).
During the fifth pandemic, Britain and the United States were mostly safe thanks to improved water supplies and quarantine measures.
The sixth cholera pandemic (1899–1923) did not affect Western Europe or North America due to advances in public health and sanitation. But the disease continues to ravage India, Russia, the Middle East and North Africa. By 1923, cases of cholera had dissipated in much of the world except India: it had killed more than half a million people in India in 1918 and 1919.
Cholera today
Unlike previous pandemics, which all originated in India, the seventh and current cholera pandemic began in Indonesia in 1961. It spread across Asia and the Middle East, reaching Africa in 1971. In 1990, more than 90 percent of all cholera cases reported to the WHO. were originally from the African continent.
In 1991, cholera appeared in Peru and returned to South America after a 100-year absence. It killed 3,000 people in Peru in the first year and then spread to Ecuador, Colombia, Brazil and Chile, then to Central America and Mexico.
Although the current cholera pandemic has affected some 120 countries, it largely affects poor and less developed countries.
In recent years there have been a number of devastating outbreaks, including that in Zimbabwe in 2008-2009, which affected some 97,000 people (killing 4,200).
Cholera was first reported in Haiti in October 2010. The outbreak is estimated to have affected more than 800,000 people across the country, or 9,792 people, between October 2010 and February 2019.
In 2017, cholera outbreaks broke out in Somalia and Yemen. By August 2017, the outbreak in Yemen had affected 500,000 people and killed 2,000.
Spotted on History
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