Sanitation

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Sanitation

Introduction

Poor sanitation permits infectious diseases to spread as fecal matter contaminates drinking water. In the developed world, water treatment has practically eliminated cholera, typhoid, and dysentery. In the third world, however, the absence of safe drinking water and latrines is associated with high rates of diarrheal illness. Unimproved sanitation includes public or shared latrines, pit latrines without slabs or open pits, hanging toilets or hanging latrines, bucket latrines, and an absence of facilities that forces people to use any area for defecation.

At the start of the twenty-first century, there were about 2.6 billion people in the world without adequate sanitation facilities. A lack of proper sanitation killed about 4,500 children per day while sentencing their neighbors to sickness and squalor. The elderly are more susceptible and more likely to die from diseases related to sanitation than other adults.

History and Scientific Foundations

Before the development of microbiology, the specific causes of diseases were unknown. Diseases such as cholera, typhoid, and dysentery were common in the United States, Europe, and other parts of the world. In 1854, during an Asiatic cholera epidemic in London, physician John Snow linked a contaminated well to deaths. A house privy emptying into a cesspool overflowed to a drain passing close to the well. Feces infected with the bacterium Vibrio cholerae contaminated the water and produced a toxin that caused diarrhea, vomiting, and severe fluid and electrolyte loss. Snow's discovery tied poor sanitation directly to disease and death.

In subsequent years, links between sanitation and typhoid, typhus, and dysentery were established. Dehydration is the outstanding characteristic of these diseases and the main cause of death. Typhoid is caused by bacterium called Salmonella typhi. A different pathogen (disease-causing organism), Salmonella paratyphi, causes paratyphoid fever. S. typhi and S. paratyphi are passed in the feces and, occasionally, in the urine of infected people. Most cases of typhoid result from contaminated drinking water and poor sanitation. Typhoid causes fever, rash, delirium, and diarrhea.

Dysentery is also known as traveler's diarrhea. The two most common causes of dysentery are Shigella bacteria or amebic infection by the Entamoeba histolytica. Both forms of dysentery are spread by fecal contamination of food and water. Amebic dysentery is prevalent in regions where human excrement or “night soil” is used as fertilizer. Cysts (inactive amebas) are excreted in the feces of an infected person. When cysts are ingested with contaminated water, they become active amebas in the intestine and dysentery results. Dysentery was once known as “the bloody flux” because in produced blood in the feces.

Poor sanitation and hygiene are also prime contributors to the spread of schistosomiasis and soil-transmitted helminthiasis (worms). Children are particularly prone to infections because their high level of activity brings them into regular contact with contaminated water and soil.

Impacts and Issues

Diarrhea resulting from inadequate sanitation and a lack of clean drinking water affected the daily life of 42% of the world's population in 2000 according to the World Health Organization (WHO). In sub-Saharan Africa, about 769,000 children under five years of age died annually from diarrheal diseases between 2000 and 2003. Of the 57 million children under five years old in the developed nations, about 700 died annually from diarrheal diseases in the same period. A baby in sub-Saharan Africa has almost a 520 times greater chance of dying from diarrhea than an American or European child.

With so few families in the developing nations having access to a latrine or to water for hygiene, many people live in a environment that permits disease to spread rapidly. Chronic poor health robs children of the cognitive development necessary for schooling and takes earning power away from adults.

Oral rehydration therapy (ORT) is an inexpensive and effective way of saving lives. The widespread availability of oral hydration salts has contributed to significant reductions in infant deaths from diarrhea in the third world. However, ORT does not address the root causes of diarrhea.

Improved sanitation reduces deaths from diarrhea by an average of 32%. Accordingly, the WHO advises the construction of flush/pour-flush facilities to piped sewer systems, septic tanks, or pit latrines; pit latrines with slabs; and composting toilets. Communal facilities for groups of homes are not, as a rule, maintained in a clean and sanitary condition. They are not recommended. WHO further advises that the political environment in developing nations needs to be changed to support improved sanitation. WHO seeks legislation and regulations in support of sanitation; an increase in national capacity in the form of sanitation engineers and stronger institutions; governmental allocation of financial resources; educational programs that link sanitation, hygiene, health, and economic development; and improved information flow from producers to users.

WORDS TO KNOW

FECAL-ORAL ROUTE: The transmission of minute particles of fecal material from one organism (human or animal) to the mouth of another organism.

PATHOGEN: A disease causing agent, such as a bacteria, virus, fungus, etc.

SENTINEL: Sentinel surveillance is a method in epidemiology where a subset of the population is surveyed for the presence of communicable diseases. Also, a sentinel is an animal used to indicate the presence of disease within an area.

TOXIN: A poison that is produced by a living organism.

IN CONTEXT: DISEASE IN DEVELOPING NATIONS

According to the World Health Organization (WHO):

“In 2002, 2.6 billion people lacked access to improved sanitation, which represented 42% of the world's population.
Over half of those without improved sanitation—nearly 1.5 billion people—live in China and India.
In sub-Saharan Africa sanitation coverage is a mere 36%.
Only 31% of the rural inhabitants in developing countries have access to improved sanitation, as opposed 73% of urban dwellers.
In order to meet the sanitation Millennium Development Goals target, an additional 370 000 people per day up to 2015 should gain access to improved sanitation.”

The Centers for Disease Control recommends that travelers avoid raw food in areas where sanitation is inadequate. The only foods safe to consume in these regions are either cooked or fruit that has been washed in clean water and then peeled by the traveler personally. Additionally, accidentally swallowing small amounts of fecally contaminated water can cause illness. Pools that contain chlorinated water are considered safe places to swim if the disinfectant levels and pH are properly maintained. All travelers who have diarrhea are advised to refrain from swimming to avoid contaminating recreational water. Travelers with open cuts or abrasions that might serve as entry points for pathogens are warned to avoid swimming and wading in areas with poor sanitation.

Improvements in sanitation bring immediate and enduring benefits in health and dignity. However, these improvements can be beyond the financial means of some governments, particularly those in third world nations. In the 1980s, Brazil developed a condominial sewer system. Condominial systems provide less expensive, localized hookups for poor neighborhoods by connecting groups of houses, rather than individual houses, to the larger grid and by using cheaper materials. However, they have not been adapted in other developing countries as quickly as is needed. Bolivia built condominial systems only after it received assistance from the Swedish International Development Cooperation Agency and the World Bank's Water and Sanitation Program. These support agencies provided technical skills as well as funds. Other developing nations require the same sort of help.

China has used tightly sealed excreta vats for years to store human excrement for use as fertilizer. The vats produce ammonia and albuminoid nitrogen under anaerobic (without oxygen) conditions, which is reported to kill parasite eggs and reduce transmission of parasitic and infectious diseases. Chinese scientists have developed a biogas tank that is likely the future means of dealing with excrement. The tanks are tightly sealed to permit the fermentation and settling of excreta, livestock manure, crop stalks, weeds, and tree leaves. The tight seal prevents contamination of nearby water sources. About 60% of the gas produced in the tanks is methane. The methane from a family unit is used for cooking. This solution is both locally and globally environmentally friendly.

In 2004, Lee Jong-wook, then Director-General of the WHO, declared that sanitation is still a major sentinel (marker) for public health worldwide. Lee prefaced the 2004 “Water, Sanitation, and Hygiene Links to Health: Facts and Figures,” with “I often refer to it as ‘Health 101,’ which means that once we can secure access to clean water and to adequate sanitation facilities for all people, irrespective of the difference in their living conditions, a huge battle against all kinds of diseases will be won.” Included in the United Nations Millennium Goals is a specific target aiming to halve the number of people without access to safe drinking water and basic sanitation by the year 2015.