July 30, 2011 – Solving the sanitation problem is within reach, and it could avoid many deaths
“CHOLERA most forcibly teaches us our mutual connection. Nothing shows more powerfully the duty of every man to look after the needs of others.” So said Titus Salt, a Victorian wool baron who worked to put an end to cholera in Yorkshire. It was cholera, as much as the great stink, which led London’s masters to build vast sewers, install toilets, and promote hygiene. Cholera struck fear into 19th-century cities, sweeping away the rich along with the poor. America’s President James K. Polk died of the disease after a visit to New Orleans. His successor, Zachary Taylor, may also have succumbed.
The liquid diarrhoea and vomit jetted out by a body infected by the bacterium Vib rio choleraeis a reminder, in extreme form, of the danger lurking in the excrement which flows from every human settlement, creating a problem few want to go near. Not all human waste has the deadly bacterium; but all of it is dangerous and better disposal of faeces would go a huge way to stopping cholera and other deadly intestinal diseases.
And with the urban population in poor countries soaring, cholera is still a pressing concern. In Haiti the health ministry recently announced that 5,800 people had died of cholera since October last year. Another 250,000 had recovered, often after having lost work or schooling. Those numbers do not include Haitians believed to have died, helpless, in remote places.
Epidemiologists think the Haitian outbreak was caused by Nepalese peacekeepers dumping their sewage into a water source. An independent report says the Nepalese should have been screened for V. cholerae. But nobody is pointing fingers at the troops; the ultimate cause was bad sanitation and hygiene among Haiti’s poor.
The World Health Organisation says that out of 3m-5m cholera cases a year, 100,000 people die. The outbreaks are spread over 40-50 countries. Their severity typically reflects the level of development: the more squalid a country, the more virulent the cholera. The Haitian epidemic spread to the Dominican Republic where 13,000 people were infected, but better governance and health care kept deaths there to a handful. Cholera appears even in industrialised countries. But such outbreaks, like one this month near Donetsk in Ukraine, are soon stopped by disinfectants and bottled water. The disease is fairly easy to halt with simple rehydration fluids.
The river systems of India and Bangladesh are rife with diarrhoeal disease. Some cases arise from drinking filthy water, most are from ingesting traces of faeces from the hands or in food. Climate change may raise water levels, further contaminating drinking sources in Dhaka and Kolkata. Yet progress is being made in both countries on an oral vaccine against cholera, said to offer protection to infants. A large trial is under way. The Indian makers of one version say they can get the cost of treatment below $3, cheap enough to limit outbreaks.
Nine out of ten cholera cases are in Africa. Worst-hit are Ethiopia, Mozambique, Zimbabwe and Congo. Some 5,000 lives were lost to an outbreak of cholera in Zimbabwe that began in 2008. There have been 50,000 cases of acute watery diarrhoea in Somalia this year as pastoralists drink dirty water instead of the milk they used to get from animals, which have starved to death.
There is much concern about Congo, where a cholera outbreak is spreading down the Congo River from the city of Mbandaka. Some 280 have already died, out of 10,000 cases. The number could grow 20 times if cholera gets to the capital.
Because of its virulence, cholera is the ailment that catches the headlines, but the other diarrhoeal diseases kill 1.5m children a year. These illnesses “account for half of all hospitalisations in the developing world,” says Prince Willem-Alexander of the Netherlands, who chairs a UN board on sanitation.
What can be done? Andrea Rinaldo of Switzerland’s Polytechnic of Lausanne points out that cholera has the “advantage” of using water pathways to disperse pathogens. By mapping water in cities along with population movements and expected rainfall, it should be possible to predict where cholera will spread.
The WHO favours money for vaccines. It wants more clinical research on hand-washing, and more taps close to latrines. Simply washing hands, without soap, can stop cholera. Less clear is how to make hand-washing a norm. Campaigns such as Wash United, which uses footballers to promote the practice, do help. So would a drop in the price of water in the poorest slums. Some pundits think early warnings for cholera could be more sophisticated.
The WHO also points out that 2.6 billion people around the world lack access to a latrine that is not overflowing, that is affordable and that has a tap nearby to wash hands. Some 1 billion defecate outdoors. This is the cat method, where faeces are rolled in sand or dirt next to the village. That attracts flies and spreads disease, like eye infections. A solution entails better sanitation for all; that means reinventing the WC. Frank Rijsberman heads the sanitation effort at the Bill and Melinda Gates Foundation. Gates plans to spend $266m over the next five years on toilet initiatives. The toilet, Mr Rijsberman asserts, has saved more lives than any other health device. But a flush loo is no option in slums where rain is the only form of flushing.
Nor have clunky biogas projects, which first appeared in the 1970s, proved to be a panacea. The excitement is over cheap but advanced technologies—such as “zapping shit in a pit” by using microwaves to vaporise excrement, generating some electric power too. Other ideas include extracting water and leaving a dry residue for use as fuel or fertiliser, or making latrines into fly traps, hence cutting the spread of disease.
Some 22 universities around the world are working with Gates. The goal is to make a toilet that is robust, easy to clean, water- and energy self-sufficient, and costs a user less than five cents a day. This would be a feat, mixing design, engineering and biochemistry and microbiology. But sanitation and prevailing against diarrhoea must also involve sociology (getting women to help) and better handling of waste for those who do have toilets. Why, for instance, do water users in a megacity like Lagos not pay an extra charge to get cesspits pumped out? The practice in most African and some Asian cities is for private lorries to suck up human waste and dump it in rivers. But town halls could find better ways to handle the stuff, and make money. In tackling the shit problem, economics could well be a clincher.