Cholera is a waterborne disease that causes severe dehydration through extreme diarrhea and vomiting. This level of dehydration can often kill cholera victims within one day of being infected. Overcrowding, poor sanitation, living without access to clean drinking water, lack of understanding about disease, and vectors carrying the contagion to food have all been factors that allowed cholera to infect and kill millions of people worldwide. Recently, the El Tor biotype has produced victims with mild symptoms who are more likely to travel and has increased cholera’s ability to spread to other countries. The countries that are at the greatest risk of exposure to cholera are less-developed countries.
This is due to public health sanitation advancements which are largely responsible for cholera’s limited ability to affect developed countries. These advancements were due to the work of several scientists and a local London priest, who revolutionized the understanding of cholera and diseases at the time. John Snow studied cholera during the 1854 epidemic in London. He tracked cholera to a contaminated well by creating diagrams of cholera deaths and realized that cholera was due to water contamination and not miasmas as previously believed. He faced significant resistance from the scientific community at the time, but with the help of a local priest (Henry Whitehead) he was able to convince the local population to discontinue the use of the Broad Street Pump. Whitehead was a proponent of the miasma disease model, but due to Snow’s evidence he changed his mind. The support of a locally respected priest greatly strengthened Snow’s credibility, while Whitehead was able to use his knowledge of the community to identify the index case (an infant whose diapers originally contaminated the Broad Street well) which led to the pump’s handle being removed. Their work combined demographics and scientific observation which set a new precedent in epidemiology. They showed how public sanitation and policy can affect public health and prevent diseases even without a specific agent being known. The agent was eventually discovered by two scientists on separate occasions and, as often happens with scientific discovery, the scientist who first discovered the bacterium was largely ignored.
This scientist, Filippo Pacini, discovered the cholera bacterium (Vibrio cholerae) by performing autopsies on victims using a microscope around the same time that Snow and Whitehead were combatting the disease in London. However, his published paper was ignored and his contributions were not recognized until 82 years after his death. Roughly 30 years later in 1883, Robert Koch (completely ignorant of Pacini’s work) also observed and named the cholera bacteria via autopsies. Since Pacini was published in an obscure journal, Koch received the recognition for discovering the cholera organism. By unsuccessfully attempting to infect animals with pure cultures of the bacterium, he also determined that animals are not susceptible to cholera. His work was used by future scientists to identify sources of cholera and thus prevent more deaths. However, simply knowing how to prevent or combat a disease is far from actually preventing it worldwide. Even in the 21st century there are still many places in the world, such as Haiti, that are affected by endemic cholera
Cholera in Haiti was brought about by the devastating earthquake in 2010 and the subsequent emergence of the El Tor biotype. This biotype produces mild symptoms in its victims which increases the probability that they will travel and allowed the disease to spread to the Dominican Republic. El Tor was most likely brought to Haiti by UN peacekeepers from Nepal who were trying to preserve peace following the earthquake. Cholera is now endemic in Haiti, and has killed thousands of people. Oral vaccines, hospitalization, and efforts to increase sanitation and clean water access are being used to combat the disease, but there are still hundreds of millions of people without access to clean drinking water. Cholera remains a constant threat to these people.