Washington, DC, February 14, 2002 (PAHO) - When cholera struck the Americas in 1991 for the first time

In response, the Pan American Health Organization, PAHO, diverted human, technical, and financial resources to combat cholera, especially since hurricanes, earthquakes, and floods create ideal conditions for the spread of the disease, given the breakdown in sanitary conditions and prevention activities that occurs in the wake of such disasters.

These efforts resulted in a steep decline in the epidemic: as of December 2000, the number of cholera cases and deaths in the Region decreased to 2,703 cases and 40 deaths.

It was January 1991 when Vibrio cholerae 01 made its appearance in a town on the Peruvian coast, spearheading the seventh pandemic of cholera in Latin America. By the year 2000, the epidemic had stricken 21 of the 35 countries of the Region of the Americas. Canada, Uruguay, and the Caribbean remain disease-free, and in 1999 no cases were reported in Argentina, Bolivia, Chile, Costa Rica, French Guiana, Guyana, Paraguay, Panama, and Suriname.

In the 19th and early 20th century, cholera was highly lethal, killing between 30 and 50 per cent of those affected. However, the epidemic that began in Latin America in the 1990s was rural in nature, and much less lethal, killing less than 2 per cent of the patients. It is also becoming endemic, staying in those countries, according to Dr. Marlo Libel, adviser in PAHO's Program on Communicable Diseases.

"Natural and man-made disasters that produce overcrowding, a scarcity of drinking water, improper disposal of human waste, and contamination of food during or after its preparation are risk factors for the spread of the disease," says Dr. Libel.

Knowledge of the causes of cholera and its modes of transmission plays a key role in prevention. To increase this knowledge, PAHO launched a wide-ranging public awareness campaign that included a publication on the standards to follow to combat and prevent the disease in disaster situations--information that is also useful as general knowledge.

Cholera is an intestinal infection caused by Vibrio cholerae, toxigenic group O-1 or O-139. This microorganism enters the body through water or food, especially raw seafood that has been contaminated with the stool of infected people. If the bacterium survives the acidity in the stomach (the first major barrier), it colonizes the small intestine and begins producing a toxin that stimulates intestinal secretions, triggering a serious loss of fluids with a high bile content--ideal for the growth of the microorganism. Vibrio cholerae does not colonize tissues or organs apart from the intestine, where it promotes the elimination of fluids and salt.

A common problem is the correct diagnosis of the disease, especially when an epidemic has been unleashed. The principal steps to take with a suspected case of cholera are: assess the patient to determine whether he is dehydrated; rehydrate with solutions of oral rehydration salts; observe the patient; replace lost fluids; administer oral antibiotics only to patients with serious dehydration; and feed the patient.

Dr. Libel explains that treating cholera does not necessarily require a highly sophisticated health system. Fluids and simple electrolyte replacement therapy produce remarkable results in the majority of cases. Serious cases may need antibiotics (doxycycline or tetracycline for adults; trimethoprim-sulfamethoxazole for children). These interventions can be employed at the primary level, he says.

Contrary to what popular belief might suggest, PAHO insists that vaccines should not be used to combat this disease. "The traditional cholera vaccine (based on whole killed cells) has a low level of efficacy and high reactogenicity, which means that it is not recommended for controlling epidemics. New oral vaccines could be considered, but a reduction in protection measures then occurs due to a false sense of security. Resources should be directed to more useful control methods," emphasizes Dr. Libel.

The contagiousness of this disease aroused international concern about travel and tourism to and from the affected areas in Latin America. However, people who adhere to the usual tourist itineraries and observe food safety recommendations are at virtually no risk when they visit countries where cases of cholera have been reported, says Dr. Libel.

In fact, travel and trade restrictions between countries or between different areas within a country are not recommended, since they do not prevent the spread of the disease. In addition to being ineffective, travel and trade restrictions promote the suppression of information on cholera outbreaks. WHO modified its International Health Regulations in 1973 so that a cholera vaccination certificate would no longer be required of travelers.

PAHO also functions as the Regional Office for the Americas of the World Health Organization. Officially established in 1902, it is the world's oldest health organization and works with all the countries of the Americas to improve health and raise their standard of living.

More information on cholera is available at:

Cholera: Number of Cases and Deaths in the Americas (1991-2001)