Cholera still kills tens of thousands of people a year. Are you at risk?
While cholera may have been killing people as far back as 400 B.C., it didn't start affecting the Americas until the second cholera pandemic began in 1829. Numerous other cholera pandemics followed, killing hundreds of thousands of people, including both the eleventh and twelfth presidents of the United States, James K. Polk and Zachary Taylor.
Today, cholera is a disease that largely impacts less developed and impoverished countries, "typically in regions of the world with poor infrastructure, conflict or displaced people who do not have access to the preventive measures that are needed such as safe drinking water and latrines," says Dr. Louise Ivers, director of the Harvard Global Health Institute at Harvard University.
In such places, cholera infects between one and four million people every year, per the World Health Organization, and contributes to some 21,000 to 143,000 deaths annually.
Here's what cholera is, what causes it and how it can be prevented and treated.
What is cholera?
Cholera is a bacterial infection of the intestines that leads to severe diarrhea and rapid dehydration, "which can quickly become life-threatening without treatment," says Dr. Jason Nagata, a pediatrician at UCSF Benioff Children’s Hospital in San Francisco.
Other symptoms include vomiting, extreme thirst, fatigue, muscle cramps, dizziness "and the severe dehydration that can lead to death within hours without prompt treatment," says Nagata. Indeed, without treatment, research shows that cholera can be fatal in 30% to 50% of cases. "A perfectly healthy young adult can be working in the field in the morning and be dead by evening," explains Dr. David Sack, a professor in the international health department at Johns Hopkins Bloomberg School of Public Health.
The infected individual loses so much fluid and nutrients from the diarrhea and vomiting that they become severely dehydrated and experience organ failure as their systems go into shock.
At the same time, not everyone who is infected experiences a serious case of the disease and some people may pass the bacteria in their feces and have only mild symptoms or no symptoms at all.
What causes cholera?
Cholera is caused by ingesting a bacteria known as Vibrio cholerae. It's found in contaminated water and food, explains Ivers, which then produces a toxin in the small intestine that leads to the severe diarrhea and rapid fluid loss.
Common sources of the bacteria "include raw shellfish and untreated water or food prepared with contaminated water," says Nagata. It's more common in poorer countries because often they lack running water or clean/filtered water, which can also become contaminated by ineffective or nonexistent plumbing.
In other words, "the feces and vomit from infected people can contaminate the water supply or the food and thereby transmit the disease to others," says Sack. What's more, he adds, "often people living in the same household and neighbors nearby are at higher risk because they may have been exposed to the same food or water source as the sick individual."
How is cholera prevented and treated?
The surest way to prevent cholera is by drinking safe water and eating food prepared with clean water. "It's also wise to avoid consuming raw or undercooked seafood and to follow proper sanitation and good hygiene practices," says Nagata. "And cholera vaccines are available for travelers to cholera-endemic areas," he adds. The FDA-approved vaccine is an oral one named Vaxchora, and the U.S. Centers for Disease Control and Prevention recommends getting it at least 10 days before traveling to an area of the world where cholera is present.
Cholera is treatable by drinking plenty of clean fluids or by getting such fluids intravenously. "Since dehydration is the primary problem, the treatment is rehydration," says Sack. He adds that antibiotics are also sometimes provided, "to shorten the purging and kill the bacteria to reduce the onward transmission of the disease." Prompt treatment like this "lowers the fatality rate of cholera to less than 1%," says Nagata.
While clean water and basic medical interventions are easy to provide in developed countries, "the challenge," Ivers says, "is that many of the people most at risk of cholera are also the same people with limited access to safe water or healthcare."