This Saturday marks the 40th anniversary of Bangladesh's war for independence from Pakistan. Given how bloody the war proved to be, and how limited development progress in the country has been since then, it might seem like a dubious occasion for those of us far from Dhaka to celebrate. But the war does have one unambiguously positive legacy: It gave the world an approach to dealing with cholera and other diarrheal diseases that has since saved many more lives than were lost during the fighting.
Cholera outbreaks have been a regular feature of urban living worldwide for centuries. The disease spreads through contaminated water and produces a toxin in the small intestine that leads to musclespasms, abdominal pains, vomiting, and -- deadliest of all -- gushing diarrhea. This highly infectious liquid is the usual culprit in cholera outbreaks -- it contaminates water supplies, thereby reaching new hosts.
After a series of outbreaks in mid-19th century London took tens of thousands of lives, doctors and civic leaders pinned the blame, accurately, on the city's appallingly inadequate sanitation system. Writers at the time described huge piles of human and animal excrement collecting in the streets and fetid rivers almost solid with waste. The solution, devised by civil engineer Joseph Bazalgette and completed in 1865, was a network of five new sewer lines that transported waste out of the city. With that momentous project, London freed itself from major cholera outbreaks.
The problem, however, was that such solutions were expensive and complicated. Lacking the genius of Bazalgette and the wealth of empire, most of the rest of the world went on suffering from diarrheal disease without much respite well into the 20th century. But while it is still the case today that only half of the developing world's population has access to well-built latrines or septic and sewage systems, the death toll from waterborne disease has been dropping dramatically around the globe. And the gains against cholera and its relatives are mostly due not the model of Victorian England, but to the type of approaches pioneered in war-torn, poverty-stricken Bangladesh.
As troops loyal to West Pakistan fought Bengali paramilitaries and Indian troops over the course of 1971, 9 million refugees flooded across the border of what was then East Pakistan into India. At the time, Dr. Dilip Mahalanabis was working in a refugee camp in Bangaon, in India's state of West Bengal, home to more than 350,000 refugees. He faced an epidemic of diarrheal disease spreading death throughout the camp, with mortality rates among infected patients running as high as 20 to 30 percent. At the time, intravenous salt solution was the standard response to diarrheal dehydration. But Mahalanabis had only two aides capable of administering intravenous drips, and supplies were running out. Overwhelmed, he turned to what hospital workers considered a decidedly inferior approach to tackling dehydration: giving people sugar-salt solution to swallow, or oral rehydration.
We usually rehydrate orally: it is called drinking. Unlike intravenous drips, downing a glass of solution doesn't take skilled assistance -- it also tastes great to people who are dehydrated (though less so to the rest of us -- imagine drinking sweetened sea water). Mahalanabis just set up drums of the solution and told family members to keep on coming back with cups and bottles to fill until their relatives refused to drink more of the stuff. Rather than treating a few lucky victims who managed to make it to the clinic, the doctor was reaching people all across the camp. Death rates dropped from 20 to 30 percent to a stunning 3 percent.
Since 1971, and with the active support of the World Health Organization and donors, this type of oral rehydration has become a standard treatment for diarrheal disease. Sugar-salt packages mixed in the right proportions are now widely available for a few cents a dose, and even cheaper tools of prevention are available. There are bottles designed to use sunlight to disinfect water; programs encouraging people to add a small amount of bleach to drinking water have reduced diarrhea cases by between 50 and 80 percent.
As cheap prevention and treatment techniques have spread around the globe, cholera deaths are increasingly rare worldwide. (An exceptional outbreak in Zimbabwe that took the lives of more than 4,000 people in 2008 and 2009 was a sign of how far Robert Mugabe's regime had driven public health provision into the ground in that country.) Related to this change, the impact of piped water and network sanitation access on health outcomes has declined, to the extent that one multicountry study of child mortality in the developing world suggested that universal access to improved water and sanitation would reduce global child mortality rates by as little as 3 percent. The potential impact of parents learning more about prevention and treatment -- and acting on the knowledge -- was more than 10 times as great.
There is still a long way to go in spreading knowledge, of course. According to the World Bank, in sub-Saharan Africa only one-third of children under 5 with diarrhea are treated with oral rehydration and continued feeding. As I noted in my most recent book, the percentage of parents in India who think the correct treatment for a child with diarrhea is to reduce the amount they are given to drink -- absolutely the wrong thing to do -- varies considerably from state to state. Less than 5 percent give this wrong answer in states like Kerala. More than 50 percent suggest this response in West Bengal, the original proving-ground of oral rehydration therapy -- where child mortality in the 1990s was about three times higher than it was in Kerala.
Nonetheless, progress in the technologies of public health and the spread of health knowledge have dramatically reduced cholera's toll. It used to take armies of engineers and considerable wealth to achieve what today's illiterate parent can achieve for cents. And that suggests something about policymaking.
In the perfect world, everyone would have 24-hour access to clean water and networked sanitation services. In the meantime, it's important to remember that each networked sewage connection costs magnitudes more than home-based prevention and other underutilized treatment options. Perhaps governments and aid agencies should take some of the money dedicated to recreating Bazalgette's subterranean cathedrals like the troubled Fallujah sewage project in Iraqand spend it instead on teaching people how to mix oral rehydration solutions or disinfect water. As we learned from Dr. Mahalanabis 40 years ago, a little sweetened seawater goes a long way.