Haiti’s immense cholera outbreak in 2010 reminded us that this fatal disease is still a major problem despite public health breakthroughs in sanitation and infection control over the last century. With about 74,558 cholera cases and 8,972 deaths in Haiti, cholera was a hot topic as public health officials sought to find the source of the epidemic.
Unlike Ebola, cholera is well-known in the field of public health and is caused by the bacterium Vibrio cholerae. Ingesting the organism via contaminated food or water can cause serious intestinal problems. The bacterium’s toxin loosens tight junctions in the intestine and increases liquid release, which is why victims suffer from watery diarrhea and characteristic “rice” stools. The profuse diarrhea can cause dehydration, shock, and death within just a few hours.
Although we associate cholera with developing countries, cholera was once commonplace in cities like London and hardly anything was known about it. Before London became the gleaming, beautiful city we think of today, it underwent its own public health tribulations.
Picture London in the 1830s – streets lined with open sewers, cesspools of excrement beneath houses, animal droppings on the streets, and old-fashioned water pumps that used nearby groundwater.
Four cholera outbreaks in various parts of London were documented between 1831 and 1854 with no changes in health or sanitation between outbreaks. By the end of 1853, over 10,000 had died of cholera. But on August 31, 1854, the greatest epidemic began in the Soho district. Over 120 people died within three days and almost 3/4 of the Soho residents had died within one week. The death toll rose to 500 by September 10th.
But open sewage and dirty water were not likely culprits in those times because people thought diseases like chlamydia, cholera, plague, and obesity were spread by breathing “bad air.” This ideology was known as the miasma theory.
The miasma theory was well-accepted, yet some were skeptical of it. One such person was John Snow, a British physician who had been investigating the previous cholera outbreaks and was convinced that the disease spread through food or water, not by air. By interviewing people and mapping out affected areas, he discovered that many of those who were ill drank water from a particular pump on Broad Street.
No one suspected water as the cause of disease, but Snow convinced officials to remove the handle to the water pump so no one could draw water from it again. Although the epidemic was dwindling by that point (perhaps because most people had died!), the epidemic ceased to spread thanks to Snow’s investigative work.
Unfortunately, his beliefs about water being the source of the outbreak were not accepted, and he died long before more evidence shed convincing light on his theory.
Later, others like Louis Pasteur, Robert Koch, and Ignaz Semmelweis added to the overwhelming evidence of germs as being the cause of disease- not just pollution or bad air! This gave rise to the germ theory.
This supported the existence of cholera germs in the Broad Street pump and it helped implement water sanitation and sewage systems in the years to come. Additionally, Snow gave rise to the field of epidemiology, which is a core component of public health today. In fact, today’s epidemiologists still interview people who may have been exposed to or affected by a disease.
Although we now know how cholera spreads, we still have outbreaks in developing countries where water gets infected with bacteria. In the 2010 Haiti epidemic, it was established that a United Nations (UN) camp of peacekeeping soldiers had been the source of the outbreak as the river next to the encampment tested positive for cholera1. All other evidence pointed to that particular peacekeeping camp.
Outbreaks like these are what fuel public health to work towards infectious disease surveillance, control, and prevention. The Haiti epidemic was one of countless others.
The World Health Organization (WHO) reports that millions of cholera cases arise each year and 28,000 to 148,000 people die from it2. John Snow would be happy to know medication is now available for cholera victims, but its far-reaching presence and emergence of new, more deadly strains would surely trouble him.
As we travel to developing countries and rural areas of the world, we are advised to drink bottled water or to use proper sanitation methods prior to drinking local water. But what about the people who live in those countries? They need prevention and treatment, too.
The WHO is aware of this global concern and embarked on an effort to vaccinate those in endemic regions, or hot spots, around the world. In the summer of 2015, WHO reported that over 2 million doses of oral cholera vaccines had been delivered to areas of need2. Although WHO has not released specific statistics related to this venture, they reported that a significant impact on the presence and transmission of cholera was evident in the places that received vaccines.
With vaccinations that can be administered to children and adults that confer 65-85% immunity, it’s a step in the right direction to prevent the onset of disease. But prevention ultimately relies on the sanitation of local water sources, which is a costly but longer-lasting solution.
Although 1854 seems far from 2016, we still have more Broad Street pumps to tend to and many more Soho districts to help. Snow’s work is unfinished, but his legacy lives on.
John Snow was not alive to receive the credit he deserved, but he is commemorated today through his life-saving work that fueled science and public health to work in tandem. Snow’s work remains at the Broad Street pump in Soho as a symbol of the history that has taught us so much and reminds us there’s much more to be done.
1) Piarroux, R., & Frerichs, R.R.(2015). Cholera and blame in Haiti. The Lancet Infectious Diseases, 15(12), 1380-1381.
2) World Health Organization Cholera Fact Sheet
Photo Credit: Shen Stone (Broad Street Pump)