In the 1800s, a germ native to India's Ganges Delta started spreading to other lands. One outbreak followed another, killing millions of people across the world. The germ is now known as Vibrio cholerae, and the disease is called cholera, an intestinal illness that causes violent and sometimes life-threatening diarrhea. Today, many people in the United States know about cholera largely through romantic books and films such as Horseman on the Roof, Love in the Time of Cholera, The Painted Veil, and others set in Europe, Latin America, and China during cholera epidemics.
While the potentially deadly illness has essentially disappeared from countries with reliable sewage-treatment plants and other basic services -- the last major outbreak in the United States occurred in 1911 -- it continues to threaten developing countries across the world, especially in Africa. Outbreaks are common in war zones, refugee camps, and other places where people live close together in squalid conditions, such as Haiti in the aftermath of the devastating earthquake.
According to the World Health Organization, there are an estimated 3 to 5 million cases and between 100,000 and 120,000 deaths due to cholera every year. As long as wars and sprawling populations continue to overwhelm attempts to improve hygiene and public health, the number of cases will likely climb.
How do people get cholera?
The bacterium that causes cholera is versatile. It naturally occurs along ocean coasts, and if it gets the chance, it will live quite happily in the human digestive tract. If a water supply becomes contaminated with human sewage, the germ can thrive there, too. Most victims, in fact, catch the germ from such contaminated water. It's also possible to become infected from raw fruits and vegetables that have come in contact with sewage or tainted water. You can pick up the germ from raw fish and shellfish, too. But you can't get sick simply through casual contact with someone who has the disease.
What are the symptoms of cholera?
Cholera's nasty reputation is well deserved, yet most people infected with the germ never get especially sick. In those cases, the infection may not cause any symptoms at all, or it might set off a mild case of diarrhea. But for about 10 percent of people who catch it, the symptoms can be life threatening. The biggest dangers -- and the most obvious symptoms -- are vomiting and a watery diarrhea starting one to five days after the infection. The diarrhea, often milky in color, comes on so hard and fast that a person can lose a quart of fluids every hour. Without rapid treatment and replacement of lost fluids, a victim can become severely dehydrated and go into shock within hours. Other symptoms of cholera include nausea and muscle cramps.
What is the treatment for cholera?
It's crucial to seek medical help immediately if you develop vomiting and severe diarrhea in an area where cholera is common, since cholera is one of the most rapidly developing fatal illnesses. Without treatment, some people die within three hours of the onset of symptoms.
Yet cholera is actually fairly easy to treat, which makes every death that much more tragic. Most people simply need extra fluids to relieve dehydration. When there's an outbreak, relief agencies and health organizations often distribute special solutions of water, sugar, and salt to counteract the effects of diarrhea. A single dose of the antibiotic azithromycin can help shorten the bout of diarrhea.
How can cholera be prevented?
It's pretty rare for travelers to catch cholera, but if you're visiting an area where cholera is a concern, it's still a good idea to follow the advice of the Centers for Disease Control and Prevention: "Boil it, cook it, peel it, or forget it." In other words, don't drink any water from a well or tap if it hasn't been boiled. (Carbonated water from bottles or cans -- without ice -- is safe.) And don't eat salads or any raw or undercooked foods, especially fish, shellfish, and ceviche; it's also a good idea not to buy food from street vendors. Raw fruits and vegetables that you can peel are generally safe, but only if you peel them yourself with clean hands. It's also important not to bring perishable seafood back to the United States from a trip abroad.
Following this advice will protect you from many other illnesses, including giardia, travelers diarrhea, and dysentery. You won't need any special shots to protect yourself from cholera before traveling. Although a vaccine exists, it's no longer offered in this country.
On a global level, it will take better sanitation, education, and universal access to clean water to prevent cholera. In other words, it's a disease that isn't going away anytime soon.
Mayo Clinic. Cholera. April 16, 2009.
Centers for Disease Control and Prevention. Travelers' Health: Cholera. 2009.
World Health Organization. Cholera. June 2010.
Centers for Disease Control and Prevention. Cholera. October 2010.