Cholera is a bacterial infection spread through contaminated drinking water. Improper or nonexistent sanitation processes can create a breeding ground for the bacteria, which when ingested can cause severe diarrhea. The bacteria can also be present in food that has been exposed to contaminated water.
The most common way to develop a case of cholera is by drinking water infected with the bacteria. In areas where there are improper or poor sanitation practices, standing water can be a major breeding ground for the bacteria. Many countries that do not treat or purify their water can have thousands of cases develop each year. The bacteria can exist in freshwater sources, allowing the problem to easily spread through drinking water. They can also occur in saltwater, making shellfish vulnerable to picking up the bacteria.
Shellfish are one of the most common causes of cholera outbreaks in developed countries. The bacteria can often be found within the shell of the animal, and it is this type of food that often causes cholera in countries such as the United States. Bad oysters are one of the most common offenders, and still spread cholera to areas with treated and sanitized drinking water.
The bacteria are carried through the feces of an individual that has been exposed. While the disease is generally not spread from one person to another by direct contact, improperly built or maintained sanitation and sewer systems can allow infected waste materials to access drinking water and reservoirs. When individuals travel, the disease can be introduced to new and previously uncontaminated water sources. Bathing in or near drinking water is another of the causes of cholera bacteria.
Vaccinations are available to protect individuals against cases of cholera. A vaccinated individual can still contract the virus, however, as the vaccination is generally not foolproof. Travelers should protect themselves against the bacteria that cause cholera and be sure to properly treat water or drink bottled water as a precaution.
Water that has been contaminated can be treated and made safe for drinking. Boiling water is not always enough; in order to kill the bacteria, the water must be boiled continuously for more than one minute. Chemical treatments such as chlorine tablets are also available in many areas. Bacteria can still be spread through improperly treated water, however, care should be taken to follow instructions on chemical treatments and boil water thoroughly.