Cholera, an acute diarrheal disease, is one of Mother Nature’s greatest weapons of mass destruction. Recent reports of cholera epidemics in Haiti, Africa and Asia are strong reminders that this ancient disease stands ready to surge given half a chance. This disease wreaks havoc in poor countries and communities that lack basic public health measures. It affects over 200,000 people annually, virtually all in the developing world, causing about 5,000 deaths. Infants, children and the elderly are the most vulnerable. Society’s main defense against cholera is protecting and disinfecting its water supplies.
Caused by the Vibrio cholerae bacterium, cholera is generally termed a waterborne disease because most of its pathways from victim to victim involve water. For example, a river used as a source of community drinking, cooking and bathing water may become contaminated with Vibrio cholerae because of inadequate sewage treatment facilities or latrines. When no means of disinfecting the water supply has been set in place, there is little to stop a full-blown cholera epidemic from spreading throughout the community with alarming speed.
Cholera: Tracking the Menace
A person infected with Vibrio cholerae passes the disease to others via unsanitary excreta disposal. Just one newly infected victim is capable of discharging a sufficient number of pathogens to infect hundreds of others. When this is coupled with improper hand washing, failure to sanitize food preparation surfaces, using contaminated water for preparation of food, beverages, and ice, unsafe disposal of cholera-infected materials, or many other similar scenarios numerous pathways of transmission are opened. Most victims become severely ill; others display only mild symptoms and remain ambulatory but are capable of transmitting the disease to others.
There are no effective antibiotics for cholera. Rehydration of cholera patients, either orally or intravenously, remains the only effective treatment. If fluids and essential salts lost in the diarrhea are not replaced promptly, death may occur within hours of the disease’s onset. Immunization is only partially effective and short lived and has never been successfully utilized to curtail an epidemic of this disease. Because curative measures simply cannot keep up with the rapid propagation of the disease, the best strategies to combat cholera epidemics always include preventive components, especially the chlorination of drinking water supplies.
A Chlorine Intervention
Because a relatively low chlorine concentration rapidly kills Vibrio cholerae, chlorination of drinking water remains a keystone public health measure that is efficient and cost effective for preventing or controlling cholera epidemics. Fortunately, this intervention can be carried out on a community, institutional or household basis. In Haiti, for example, the humanitarian aid group International Action has been supplying communities in and around Port-au-Prince with water chlorinators, to disinfect local drinking water supplies. Each chlorinator provides safe drinking water for 20,000 people. Chlorine tablets are also being distributed and households trained in their use to disinfect water supplies at the household level. Residents of remote African villages are gaining access to in-home water treatment products, thanks to the efforts of humanitarian groups like Population Services International. Instead of waiting for the day when community water treatment and delivery infrastructure are a reality, families are being enabled to take advantage of life-saving water treatment technologies right now.
Chlorine disinfection is a key ally in the battle against this old and deadly disease. It’s not rocket science, just a chemistry that has been proven many times over to work.
Fred Reiff, P.E., is retired from the Pan American Health Organization, and lives in the Washington, D.C., area.