Cholera Cholera is an acute bacterial infection of the intestinal system. It may vary in severity; however, even persons with severe cases may respond dramatically to fluid- and electrolyte-replacement therapy. Cholera is generally acquired by ingesting contaminated food or water. Travelers to cholera-infected areas are advised to take appropriate food and beverage precautions, including the avoidance of uncooked food, especially fish and shellfish, and peeling fruits themselves. Carbonated bottled water and carbonated soft drinks are usually safe. Few, if any, countries continue to require documentation of vaccination against cholera. A single dose of vaccine is sufficient for entry. The complete primary series (two doses given at least one week apart) is suggested for special high-risk groups that work and live in infected areas under inadequate sanitary conditions. Protection against cholera is greatest during the two months following vaccination and usually does not last beyond six months. At this time, cholera vaccine is no longer available in the United States.