26 August 2011

Sanitation and hygiene

General: According to the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC), nearly 2.4 billion people in the world do not have access to clean water or waste management facilities. This figure represents almost 40% of the Earth's population. This lack of access to clean drinking water may expose people to numerous infectious, possibly life-threatening, diseases.



General: According to the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC), nearly 2.4 billion people in the world do not have access to clean water or waste management facilities. This figure represents almost 40% of the Earth's population. This lack of access to clean drinking water may expose people to numerous infectious, possibly life-threatening, diseases.

Despite global efforts to improve sanitation, some developing countries do not follow safe personal hygiene techniques due to a lack of knowledge of personal hygiene principles or lack of proper resources.

For example, in 2007, human and animal waste could be found on public streets, near schools, businesses, and residential areas in many cities in developing countries. The waste clogs canals and creates areas of stagnant fetid puddles. The open waste serves as a breeding ground for disease organisms and disease-transmitting insects. In the some densely populated cities, many of the houses and schools lack toilets. With proper sanitation facilities unavailable, or not in working order, residents risk exposure to contaminated soil and drinking water.

The United Nations (UN) General Assembly has estimated that nearly 5,500 children die every day from diseases caused by fecal-contaminated food and water, and more than 400 million school-aged children have intestinal infections due to poor sanitation and poor hygiene. Cambodia, China, Lao PDR, Thailand, and Vietnam have the world's highest percentage of infections within their populations.

The September 2000 meeting of the UN General Assembly underscored the need to rectify these disease-causing circumstances, and the 2002 World Summit on Sustainable Development in Johannesburg outlined a global target to improve living conditions for billions of people as a basic human right.

Developed areas, such as the United States, Western Europe, Australia, New Zealand, and Japan, have sophisticated water and sewage management infrastructures. In contrast, few developing nations currently have firm sanitation governmental policies. A study in 2005, by the U.S. Agency for International Development (USAID), found that among developing nations, only Nepal, Republic of South Africa, and Uganda had established written governmental sanitation promotion policies. Even with written policies, many areas lack the resources to apply or enforce sanitation regulations.

Data from a WHO report in 2000 suggest that among developing regions, best access to improved sanitation could be found in the northern regions of Africa, with almost 90% of that population having safe water and waste disposal access. South-central Asia showed the least available sanitation, with only 38% of that population having access to clean water or sewage facilities.

International concern has recently been raised over the ongoing deterioration of water and sanitation systems within the former Soviet Union Block nations. The dismantling of the Soviet Union in the 1990s leaves some former Soviet-Block countries without a centralized governmental to fund and repair their aging water and sanitation systems. Therefore, more and more regions are losing their access to drinkable water and working sewer systems.

In 2000, the WHO estimated that 15% of governmental money in Asia went to sanitation, while 38% of Latin America and Caribbean governmental funds went to sanitation. These designated funds were spent on building sanitation and water supply systems and do not include money needed for maintenance or repair. The UNUN's Development Recommendation Program suggests governments in developing countries allocate at least one percent of their gross budget for sanitation and sewage projects. However, most developing countries have not followed that directive, with only 0.4% of government funds put toward sanitation in Kenya, and only 0.1% in Pakistan.

While governments struggle to obtain funding and conquer the logistical problem of supply, international health organizations continue to work toward sponsorship arrangements where funding is obtained from foreign agencies.

Water: A 2005 report by the Environmental Policy Committee of the UN in the Ukraine, considered one of the most industrialized areas of the former Soviet Union, concluded that more than 800,000 rural people relied on vendors for their water. In Tajikistan, which is still recovering after the end of their civil war in 1997, the UN estimates that more than 60% of the existing water supply system is not working or is contaminated by sewage. One area, Kyrgyzstan, has created a water-sector policy, and is attempting to repair and correct its water supply system based on donors and international financing.

In the past, governments, communities, and outreach organizations have focused solely on water access, without consideration of the waste/water interrelationship of many communicable diseases. As international organizations offer educational instruction to governments, governments understand the need to address both issues. Experts share technical data with these regions on how best to supply access to water and sanitation within the vastly different requirements of rural and urban areas.

Even as governments shift from the earlier narrow view of providing only water systems to a more comprehensive view of sanitation wherein water supply and waste management are seen as interdependent, funding issues impede progress.

Food: According to the U.S. CDC, about 76 million cases of foodborne diseases occur each year in the United States. More than half are caused by viruses, parasites, and bacteria. The CDC estimates that there are 325,000 hospitalizations and 5,000 deaths related to foodborne diseases annually in the United States.

The most severe cases of foodborne disease tend to occur in the very old, infants and children, those who are already ill, or in those who have had extreme exposure to the organism.

The CDC and the U.S. Food and Drug Administration (FDA) suggest that consumers and travelers can protect themselves by frequent hand washing; proper refrigeration of meats, seafood, and eggs; cooking to the proper internal temperature instructed for that meat; and frequent disinfecting of cooking counters, utensils, and equipment.

Personal hygiene: Personal hygiene is defined by the CDC as a population having facilities for the safe disposal of human feces and urine, and the ability to maintain personal cleanliness by such techniques as hand washing and bathing.

As efforts are made to improve the hardware of water and sanitation, other agencies are addressing the problem at an individual level through personal-hygiene education programs. Starting in Africa, school educational theatrical plays are designed to help teach children about the importance of personal hygiene. Hygiene education programs are now found throughout the world.

In order to accomplish adequate personal hygiene, clean uncontaminated water must be available, as well as appropriately placed and planned human waste management in effective sanitation facilities such as latrines.

In many regions of the world, such as in the southern regions of Africa, female personal hygiene may be lacking due to social or safety issues. According to the United Nations Children's Fund (UNICEF), more girls than boys drop out of school at puberty due to the lack of private and appropriate sanitation facilities.

Organizations such as UNICEF promote the belief that hygiene and sanitation should be available to everyone. UNICEF sponsors an educational approach to community and household hygiene principles. The organization teaches local families why health depends on simple cleanliness techniques such as hand washing, using latrines to dispose of waste, storing drinking water safely, and treating water.

Despite this work, the concept of responsible personal hygiene is still rarely included in policy planning at national or local governmental levels.

Global attention to the lack of these services has brought many groups together to exchange knowledge. The Inter-American Association of Sanitary and Environmental Engineering (AIDIS) focuses on improving conditions in North, Central, and South America. In 2003, conferences were held in the United States, Brazil, Chile, Colombia, Ecuador, Haiti, Nicaragua, Peru, and Puerto Rico to encourage the exchange of technical information and problem solving. These developing countries have benefited from the ongoing exchange of information and experience as they adapt current technology to their specific needs.


General: Human health is greatly impacted by the availability of drinkable water, adequate sanitation, and conscientious attention to safe handling of food and water.

Appropriate personal hygiene is a requirement during any food handling or preparation. Experts from the National Institutes of Health (NIH) and the World Health Organization (WHO) caution that people with open sores, diarrhea, fever, or signs of illness should not be involved in food or drink preparation.

Travelers who visit areas of poor sanitation need to be aware and informed as to the potential health risks, symptoms of the native communicable diseases, and proper techniques to reduce exposure to infectious diseases and pathogens. Sanitation and water are interconnected. Effective sanitation is dependent on adequate water. In the United States, access to adequate and clean water is routinely expected; however, many areas of the world lack sufficient water to provide a formal drinking water system or support a sophisticated sewer system.

Water: The WHO's objectives for safe water include: preventing fecal contamination of drinking water, treating water with an appropriate method to reduce or remove existing contaminants, and maintaining safe storage and handling of drinking water.

Water that meets these standards is considered "improved." Improved drinking water access is defined as water that is consistently available and safe to drink. These sources would include: public water standpipes, a bore hole to an underground water source, a protected well, a protected natural spring, or rainwater collection. The method of protection depends on the particular area and may include a wall or cover to deter animal or human contamination of a well or bore hole and fencing to protect a natural spring, standpipe, or rainwater collection container. Water must be able to be maintained in its improved state despite changes in weather, population density, wildlife, and agriculture.

Unimproved, and therefore potentially unsafe, sources of water frequently used by residents include unprotected wells, springs, rivers, or ponds. In many areas that do not have a natural source of water, or in times of drought, purchased water is supplied by a tanker-truck or provider-supplied water delivery service. In most areas of the world, including the United States, independent water suppliers may not be regulated by the government, and their water is not tested for purity.

In many areas, clean natural water is unavailable or unsustainable. For these regions, water purification methods become indispensable for the maintenance of health.

The U.S. Environmental Protection Agency (EPA) warns both local residents and travelers to areas without safe water to use only water that has been properly disinfected for drinking, cooking, making prepared beverages, and brushing teeth. The agency cautions that very small amounts of contaminated water, such as used when brushing teeth, may cause severe human disease. Experts from the EPA also caution that the inadvertent ingestion of contaminated water during recreational activities may become a source of infection.

In the United States, during extreme conditions such as floods and hurricanes, residents may need to purify local water.

Water purification techniques: According to the U.S. Centers for Disease Control (CDC) and the American Red Cross, when clean, safe drinking water is not available, purification of water is best accomplished with one or more of these methods of treatment: boiling, filtering, or adding chlorine or iodine.

The CDC cautions that even bottled water purchased in foreign countries may not be entirely safe, as bottles may be refilled from contaminated sources.

Boiling: If bottled water from a clean source is not available, there are methods by which water can be made safer. Boiling water is the preferred method of purification, as it will eliminate many parasites and infectious organisms. If the water is cloudy, colored, or has debris, it should be allowed to settle, then filtered through a clean cloth prior to boiling. Water should be maintained at a rolling boil for one minute (three minutes if altitude is higher than one mile). After cooling, the boiled water should be stored in a clean, non-rusting, covered container. Water should be dispensed by pouring into another container before use.

Chlorine: If boiling is not possible, the Red Cross recommends that water be treated with chlorine tablets according to the manufacturer's recommended treatment process. For travelers, chlorine tablets are convenient and easily transported. All manufacturers' recommendations for handling and storing should be followed carefully.

Iodine: Iodine tablets may also be used for water purification. One tablet for each quart of water is the usual dosage level; however, travelers should always follow the instructions on the packaging label. The CDC cautions against the use of iodine-treated water by pregnant women or anyone with iodine allergies or thyroid disorders.

Filtration: Mechanical filtration systems are used in some areas of the world, such as the United States and Western Europe, for water purification. The success of these units varies depending on the quality of the filters used and the characteristics of the infectious organism. In general, filters must be able to remove organisms with an absolute size less than or equal to one micron. (Such a filter is formally identified as a NSF Standard 53 or 58 rated cyst reduction or removal filter.)

The National Sanitation Foundation International (NSF) is an independent testing company that certifies water filters for the ability to remove single-celled organisms, called protozoa. They do not certify filters to remove bacteria or viruses. The NSF maintains a list of acceptable protozoan filters for travelers outside of the country, as well as in some regions of the United States that use personal wells for drinking water. The CDC cautions that the NSF's scientific testing has not been conducted on specific name brands of filters.

Mechanical filtration systems of the size needed to be effective are difficult to use while traveling. They would be appropriate for stationary household use. According to the CDC, the only filters that reliably remove Cryptosporidium and Giardia (parasitic protozoa), which are present in most areas of the world (including the United States), must carry one of the following labels, worded exactly: "Reverse osmosis; Absolute pore size of =1 micron; Tested and certified by NSF Standard 53 or 58 for cyst removal" or "Tested and certified by NSF Standard 53 or 58 for cyst reduction." Filters labeled as "approved by the EPA" or "registered with the EPA" should be suspect, as the EPA does not test or register filters based on the ability to remove pathogens.

The CDC warns that most portable filter systems on the market may remove some parasites; however, they do not remove bacteria or viruses. When using a filter, additional purification efforts, such as boiling the water, should be taken.

Filters act by removing and collecting organisms from the water; therefore, handling used filters may pose a risk to anyone who has a weakened immune system. Replacement of filter cartridges should be performed by a healthy individual who is wearing gloves. Hand washing should follow any filter maintenance.

Food: Foodborne infections are spread by the use of impure water to clean food, crops grown in sewage-contaminated soil, or preparation of the food item with unclean hands.

Public health officials investigate outbreaks of food-related illnesses and track the source of the contamination if possible. Health providers and food inspectors must report outbreaks of some foodborne illnesses, such as salmonellosis and botulism, to the public health department. This information is then passed to the CDC, which monitors outbreaks across the nation. Food supply safety is placed under the regulation of the U.S. Department of Agriculture (USDA), as well as the U.S. Food and Drug Administration (FDA). These agencies work closely with the CDC if food contamination is suspected.

As global trade and food imports have increased, so has the potential for large-scale foodborne disease outbreaks.

Sanitation: Preventing the contamination of clean water supplies by human or animal fecal material is the central issue in disease control.

According to the United Nations' (UN) report of 2006, 53% of the developing world had improved sanitation facilities. Their report indicates that almost 25% of the developing world lives without any form of sanitation, using open-space defecation and urination. An additional 15% of the world's population does not separate human feces from its living areas. The CDC defines improved sanitation facilities as a connection to a public sewer system, connection to a septic tank system, a pour-flush latrine, a ventilated pit latrine, a public or shared latrine, an open pit latrine, or a simple bucket latrine. The technical method of waste management used depends on the geographical requirements, governmental regulations, and financial constraints of the area.

Latrines function in a mechanical way to confine and prevent fecal contamination of soil and water. Over time, the contents of the latrine decompose, and after a year or longer, they are neutralized. At this point, the contents may be safely handled. In some geographical areas, decomposed feces are used as garden compost.

The simplest form of waste sanitation is the bucket latrine, or conservancy system. Once filled, the bucket is covered with dirt, and another site is dug. In some areas of Southeast Asia, the buckets are freestanding and emptied several times per week. Problems exist with this arrangement, as much of the bucket contents are frequently poured down a street drain or into a canal, where it runs into streams and rivers. For this reason, bucket latrines are illegal in India.

A pit latrine, and its various modifications, uses the principle that liquids will infiltrate the surrounding soil and be dispersed. These latrines are difficult to construct properly in some regions if the ground water level is high or the land is rocky. The latrine is typically a narrow trench, dug from 3-6 feet deep. The individual straddles the trench during defecation.

In some areas of the world, such as Zimbabwe, the ventilated improved pit latrine has been used as a low-cost approach to sanitation. A ventilated pit latrine is a dug pit with a screened vent pipe and an enclosed structure over the pit. This approach helps to decrease odor and flies.

In the crowded poor areas of urban cities in Brazil, multiple families may share the cost and use of a common latrine. This approach has been successful in decreasing open-air piles of human waste.

A more structured approach to waste management is the septic tank. This method uses water and gravity to move the waste into a buried holding tank or large container. The tank holds the solids and allows the liquid to seep into the soil. Many rural areas of the United States use septic tanks and are closely regulated by local governmental and public health requirements. In some areas of the world, multiple families with indoor bathrooms use a single large septic tank system. The families share the cost of emptying and maintenance.

The most sophisticated and effective waste management system is the sewer system. Found throughout countries such as Western Europe, United States, and Canada, sewer systems are routinely found in large urban areas with high-density populations. Sustainable access to large amounts of water is necessary for this system to work properly in moving solids along the pipelines. Included in this method is a central waste management area where waste is collected and treated. While highly effective in waste and disease control, sewer systems are expensive to install and maintain and are not feasible in many parts of the developing world.

International financial assistance has been common in the area of sanitation development, and some countries have been able to increase sanitation due to this outside funding.

Personal hygiene: Organizations such as UNICEF, the CDC, and WHO have added a focus on personal hygiene behavior to their water and sanitation efforts for both residents and travelers.

Epidemiologists agree that hand washing is the primary action used to prevent fecal-oral transmission of numerous diseases and parasites.

Hands should be washed before preparing or consuming food or drinks. They should also be washed after defecating or urinating; changing diapers or bathing a child; assisting anyone who is ill; handling uncooked meat, poultry, or fish; coughing, sneezing, or blowing the nose; handling an animal or its waste; or handling any object touched by flood water or sewage. The hands should also be washed before and after dressing a wound.

To properly cleanse the hands with water, wet the hands with clean water; rub the hands together for at least 20 seconds with soap; include the wrists, fingers, back of hands, and under the fingernails in the process.


Sanitation and water: Thailand has steadily worked on a rural sanitation program for the past 40 years. In 1989, on-site latrines were required for household residency. As of 1999, according to Luong et al., 92% of rural residents had access to improved drinking water, while 98% had improved sanitation facilities. These improvements showed a correlative 90% reduction in deaths due to diarrheal diseases. The government has focused not only on providing the latrines, but also on training staff at the local and national levels through mobile health educational programs.

In other parts of the world, such as in Bangladesh, government attempts to improve water and sanitation have met with less success. The government's goal of improving sanitation has been impeded by the lack of funds to purchase latrine hardware, congested living quarters (which make access for service difficult) and a lack of social knowledge.

Food: Some foodborne illnesses are caused by direct contamination from unclean water or soil. Other disease-causing organisms may be introduced by infected food handlers, or by cross contamination from other raw agricultural products. In order to prevent the contamination of restaurant food with pathogens such as hepatitis A, strict public health rules require workers to wash their hands after using the bathroom. Public health inspectors also watch for the potential for food contamination by unwashed cooking surfaces, repeated use of cooking utensils, or unclean kitchen equipment.

Washing fruits and vegetables can decrease, but not completely eliminate, bacterial contamination. Washing produce with poor-quality water has been the source of some diseases. In some countries where human and animal manure is used for fertilizer, improperly composted manure may be a source of contamination of vegetable crops.

Personal hygiene: Led by the United Nation's Children's Fund (UNICEF), school sanitation has been a major part of hygiene education for the past 10 years. Since 2000, UNICEF has sponsored education programs in Burkina Faso, Colombia, Nepal, Nicaragua, Vietnam, and Zambia.

According to an international health report on Sanitation and Hygiene Promotion in 2005, improving health hygiene involves changing behaviors. Attempts to educate the world population have been met with varied success, depending on local customs, gender issues, and taboos. The authors state that changing hygienic behaviors is a long-term process.

The Brussels-based organization, Cooperative for Assistance and Relief Everywhere (CARE), developed the Sanitation and Family Education Project specifically to address issues in Bangladesh. This program's goal was to encourage change in personal behaviors that might have been leading to illness and infection, such as drinking pond water or uncovered well water, improper water storage techniques, poor or absent hand washing, and failure to teach children younger than age of five to use a latrine. The end of the project saw a two-thirds reduction in diarrhea and an increase in protective personal hygiene techniques among the participants. Since this region already had latrines and wells in place, the reduction in disease rate was considered to be linked to the improvement in personal hygiene behaviors.

In Zimbabwe, a community-based educational program, called ZimAHEAD, provides information and education on improving household hygiene. This program continues to see success despite increasing budgetary constraints.


Overview :

General: Eating or drinking contaminated food or water increases the risk of acquiring a variety of infectious diseases, including: Escherichia coli (E. coli), giardiasis, cryptosporidiosis, noroviruses, hepatitis A and E, typhoid fever, cholera, rotavirus, and a wide variety of parasites. Consumption or immersion in contaminated water is a primary route of infection.

Attempts to eradicate infectious water- and soil-borne food diseases have been unsuccessful to date. Hampered by the current inability to test for many of the pathogens, medical practitioners are unable to provide appropriate healthcare for these populations or prevent re-infection.

The National Institutes of Health (NIH) reports that more than 72 species of parasites can infect humans. Diagnostic and testing methods are available for only a few of these parasites.

Travelers can obtain information on disease outbreaks from a wide array of sources. GeoSentinel is a global surveillance network that follows current disease outbreaks worldwide. It collects data on travel-related deaths and diseases and makes its data available to health professionals. Instituted in 1995 by the International Society of Travel Medicine and the U.S. Centers for Disease Control (CDC), GeoSentinel now has a network of 41 globally-placed medical clinics on all continents, including 15 clinics in the United States. This organization maintains more than 97,000 patient records with final diagnoses from travel exposure in over 237 countries. Sixty major diagnoses are tracked on a month-by-month basis.

The CDC recommends that travelers to regions lacking proper water, food, and waste sanitation be prepared with a comprehensive travel healthcare kit in addition to any prescription drugs. This kit might contain items such as: antimalarial medications, antidiarrheal medications, emergency antibiotics, digital thermometer, oral rehydration solution packets, antibacterial hand wipes or lotion (60% alcohol), and water purification tablets. This kit should be carried on the traveler, not packed in suitcases.

Water: According to the World Health Organization (WHO), in 2005, 3.1% of deaths (1.7 million) were due to unsafe water, sanitation, and poor hygiene. Ninety-nine percent of all diseases in developing countries resulted from exposure to contaminated water and food.

Natural disasters, such as typhoons, hurricanes, tsunamis, floods, and earthquakes, can magnify the incidence of water and soil contamination, even in areas that were not at high-risk for pathogens previously.

Food: The CDC suggests that consumers take precautions to protect themselves from foodborne diseases, such as using a food thermometer to test meat and poultry for the proper internal temperature, washing hands after handling raw poultry or meat or any utensil used in its preparation, refrigerating leftovers, and not eating raw produce that may have been washed in unclean water.

Experts from the NIH and the WHO also recommend that individuals avoid water, ice, or raw fruits or vegetables on commercial airlines or ships that restock their supplies in countries that are considered high-risk for infectious diseases. The WHO and the U.S. Agency for International Development (USAID) have coined the slogan, the "4-Fs," as a way to educate both local residents and travelers about the need for proper hygiene; disease transmission is spread by feces on: fingers, fluids, flies, and fields/floors. These avenues contaminate another "F," food. If contaminated food is eaten, the new host may contract the disorder. These international organizations are now focused on teaching proper household food management techniques.

Common pathogens :

Bacteria: Campylobacteriosis is an infectious bacterial disease and one of the most common causes of human diarrheal illness in the United States. Travelers in foreign countries are also at risk of infection. Human symptoms include diarrhea, cramping, abdominal pain, and fever. Symptoms begin around 2-5 days after exposure and may last one week. Contaminated water, raw meat, and unpasteurized milk are sources of infection, as are infected animals. The CDC estimates that more than 2.4 million people become infected with campylobacteriosis each year. A rare disease called Guillian-Barre© syndrome may develop in one in every thousand cases of campylobacteriosis, in which the immune system attacks the nerves, causing paralysis that may last for weeks.

Cholera is an acute disease caused by the bacterium called Vibrio cholerae. Cholera usually spreads by way of contaminated water. Shellfish eaten raw have also been connected with cholera. In addition to diarrhea, patients may experience dehydration, abdominal cramps, nausea, and vomiting. The CDC maintains current information on cholera outbreaks that is available to travelers

Escherichia coli (E. coli) is a highly contagious bacteria found in the feces of humans and animals. It is frequently the cause of fever, sudden severe abdominal cramps, and large amounts of bloody diarrhea. The bacteria may cause sores to develop in the lining of the intestines. If severe, a complication called Hemolytic Uremic Syndrome may occur a few days after the initial symptoms. The blood becomes low in red blood cells and platelets and kidney failure may follow. Infection may occur from eating undercooked meat, drinking contaminated water, and person-to-person transmission.

Leptospirosis is a disease caused by bacterial organisms of the genus Leptospira that are found worldwide. These organisms are most commonly found in warm tropical areas, and in the southern part of the United States. Four distinct strains have recently been identified, and all are carried by a wide variety of wild and domestic animals. The average backyard pet may expose its owner, having contracted the bacteria from visiting wildlife. Leptospira may enter the body through the mucous membranes of the mouth, nose, or eye; though a cut in the skin; or by ingesting contaminated water. Whitewater rafting, water skiing, kayaking, and swimming in lakes and ponds, where accidental ingestion of contaminated water is possible, increases the potential for exposure. Symptoms include fever, chills, nausea, diarrhea, muscle ache, and reddening of the white of the eyes.

Typhoid fever is caused by a bacterium called Salmonella typhi. Typhoid is spread when a person drinks or eats food or water contaminated by human waste (stool or urine). Contaminated shellfish, raw produce that has been grown in human excrement, and unpasteurized milk products have also been implicated in the disease. Human symptoms of acute infection include sudden onset of high fever, severe headache, nausea, and loss of appetite. It is sometimes accompanied by a hoarse cough, constipation, or diarrhea. The WHO estimates there are between 16 and 33 million new cases and as many as 600,000 deaths each year from typhoid. This disease can be particularly severe in people who are 5-19 years old.

Parasites: Ascariasis is a parasitic infection that is caused by a roundworm called Ascaris lumbricoides. The parasite can be transmitted when humans eat produce that is grown in soil that has been mixed with infected human feces. This is most common in tropical and subtropical developing countries where human feces are used as fertilizer for crops or where there is poor sanitation. Open-air latrines may contaminate the surrounding soil, and the parasite's eggs are picked up by humans. Infection may cause a delay in the growth of children. Researchers estimate that about 25% of the world's population is infected with the parasite.

Giardiasis occurs when an intestinal parasite called Giardia lamblia (also called Giardia duodenalis) infects a human. Giardiasis typically causes abdominal pain, nausea, flatulence, greasy stools that float, and diarrhea. Weight loss and dehydration are common and may be life-threatening in infants. Giardia infections are highly contagious, and can be contracted after consuming food or water that is contaminated with the parasite. Giardiasis may also be contracted by hand contamination after sexual contact. Drinking water or ice made from contaminated water, or accidentally swallowing water during recreational activities, are other sources of infection. This parasite is common throughout the world, including the United States, and hikers and campers are particularly at risk of exposure.

Hookworm infection is caused by one of two different types of roundworms: Ancylostoma duodenale and Necator americanus. If not treated, hookworm infections can lead to abdominal pain, diarrhea, and iron-deficiency anemia. Researchers from the CDC estimate that about 20% of the world's population is infected with hookworms. The larvae can penetrate through the skin and travel to the wall of the small intestine. The worms feed on the blood of the host, which may lead to iron and protein deficiency. Severe infestation may cause fatigue, difficulty breathing, and congestive heart failure. The CDC cautions travelers against walking barefoot and eating contaminated crops, particularly in regions that use human waste as agricultural fertilizer.

Toxoplasmosis is a parasitic infection that is caused by a single-celled parasite, called Toxoplasma gondii. Most commonly connected to cat feces, toxoplasmosis may also be acquired by eating undercooked meat, blood transfusions, organ transplants, and drinking contaminated water. Developed countries, such as the United States, have had outbreaks of toxoplasmosis. Fruits and vegetables grown in contaminated soil may contain the parasite and have been known to transmit disease when the produce is eaten raw.

Whipworm infection occurs when a parasitic worm called Trichocephalus trichiura infects the large intestine. This infection most seriously affects children. Humans become infected after they consume foods that are contaminated with soil that contains whipworm eggs. Whipworms are found around the world, especially in countries with warm and humid weather.

Cryptosporidium is a protozoan parasite, a single-celled organism that can be acquired from exposure to human- and animal-contaminated water. Contaminated unpasteurized cider and swimming in contaminated pools and lakes have also been implicated. It is a worldwide cause of diarrhea and may severely affect individuals with compromised immune systems. Human symptoms include large amounts of watery diarrhea, weakness, vomiting, and abdominal cramps.

Viruses: Hepatitis A is a highly contagious liver infection that is caused by the hepatitis A virus. The WHO estimates that there are more than 1.5 million cases of hepatitis A every year. Although not usually as serious as other types of viral hepatitis, hepatitis A causes inflammation of the liver that may affect the liver's ability to function. This usually happens when a person consumes foods (especially produce that is grown in contaminated soil or food that is prepared by someone with dirty hands) or water that is contaminated with the virus.

Hepatitis E is a liver disease caused by the hepatitis E virus. Once confined to mostly tropical and subtropical regions, as of 2002, hepatitis E was confirmed in Europe. This virus causes an acute infection with symptoms of yellowing of the skin and the whites of the eyes. The urine may be dark in color, but the stool is pale. Loss of appetite, enlarged liver, abdominal pain, nausea and vomiting, and fever are symptoms of this disease. It is common in many parts of the world, with epidemics having occurred in Asia, Africa, and Mexico.

Noroviruses are a group of viruses that are responsible for gastroenteritis, or the stomach "bug." The group of viruses includes the Norwalk-like viruses (rotavirus, astrovirus, and enteric adenovirus), calciviruses, and round-structures viruses. The illness usually presents with nausea, vomiting, diarrhea, and stomach cramps. Headache, fever, chills, and fatigue are common. The infection usually starts suddenly and lasts about 1-2 days. Exposure is caused by consuming contaminated food or liquids. There is also evidence of an airborne transmission route, directly from an ill person. Viral shedding, capable of producing disease in another person, can last for as long as 14 days after exposure, even without clinical symptoms of the infection. Noroviruses are highly contagious and easily spread where people congregate, such as nursing homes, daycare centers, schools, and restaurants. Cruise ships have reported outbreaks lasting beyond 12 successive sailings, despite traditional disinfection methods.


The U.S. Centers for Disease Control and Prevention (CDC) collect infectious disease data from 10 states with a total population of 46 million. Data from these states are used to represent the entire United States and form the basis of future public health policies and procedures.

The increase in global food imports, the inability to test for many of the disease-causing organisms, the complexity of providing an inspection process, and the ability of microorganisms to adapt have caused concern among domestic and international health experts.

Experts from the World Health Organization (WHO) and the CDC agree that new microbial pathogens are continually emerging, and many are spreading worldwide. Increasing numbers have become resistant to currently available disinfectants. Some are able to survive and multiply under the right environmental conditions even in improved water distribution systems. Once-rare pathogens such as legionella and mycobacterium avium complex have now been found in some hospital hot-water supply systems.

Researchers are looking for better ways to treat known diseases, as well as newer emerging pathogens. For example, recent medical reports suggest that there may be a fecal-contamination water-transmission route for Helicobacter pylori, which may lead to a new and more effective treatment in the future.

The United Nations Children's Fund (UNICEF) has been a major source of assistance during emergency responses to disasters when the risk of water and soil contamination increases. This non-profit organization pledges to continue efforts to supply clean water, water containers, purification tablets, and help build latrines during and after natural disasters.

The United Nations' Millennium Development Goal aims to reduce by 50% the number of people without access to safe drinking water and basic sanitation by 2015. This will involve providing water supplies to nearly 1.1 billion additional people and sanitation to an additional 1.6 billion. It incorporates the goal to reduce the death rate of children younger than five years by two-thirds. However, 2008 data suggest that South Asia, sub-Saharan Africa, West Asia, Eurasia, and Oceania are falling behind in their progress toward that goal. Remote rural areas, homelessness due to war or famine, rapid increases in population, and outbreaks of disease are making improvements difficult to achieve.

The WHO has created the Initiative to Estimate the Global Burden of Foodborne Diseases. This project will provide access to information and treatment methods of foodborne diseases for public health agencies in developing countries.

The need to detect, control, and treat current and future causative pathogens caused by poor human sanitation and personal hygiene has become a global medical concern.


This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (

  • AlOtaibi EL. Bacteriological assessment of urban water sources in Khamis Mushait Governorate, southwestern Saudi Arabia. Int J Health Geogr. 2009 Mar 21;8:16. View abstract
  • Centers for Disease Control and Prevention (CDC).
  • Diallo MB, Anceno AJ, Tawatsupa B, et al. Infection risk assessment of diarrhea-related pathogens in a tropical canal network. Sci Total Environ. 2008 Dec 15;407(1):223-32. View abstract
  • GeoSentinel.
  • Kittigul L, Uthaisin A, Ekchaloemkiet S, et al. Detection and characterization of hepatitis A virus in water samples in Thailand. J Appl Microbiol. 2006 Jun;100(6):1318-23. View abstract
  • Lahiri S, Chanthaphone S. Water, sanitation and hygiene: a situation analysis paper for Lao PDR. Int J Environ Health Res. 2003 Jun;13 Suppl 1:S107-14. View abstract
  • Leclerc H, Schwartzbrod L, Dei-Cas E. Microbial agents associated with waterborne diseases. Crit Rev Microbiol. 2002;28(4):371-409. View abstract
  • Luong TV. De-worming school children and hygiene intervention. Int J Environ Health Res. 2003 Jun;13 Suppl 1:S153-9. View abstract
  • National Institutes of Health (NIH).
  • Natural Standard: The Authority on Integrative Medicine.
  • United Nations Children Fund (UNICEF).
  • U.S. Agency for International Development (USAID) Environmental Health Activities.
  • U.S. Environmental Protection Agency (EPA).
  • Water Supply and Sanitation Collaborative Council (WSSCO).
  • World Health Organization (WHO).

Copyright © 2011 Natural Standard (

Read Health24’s Comments Policy

Comment on this story
Comments have been closed for this article.

Live healthier

Exercise benefits for seniors »

Working out in the concrete jungle Even a little exercise may help prevent dementia Here’s an unexpected way to boost your memory: running

Seniors who exercise recover more quickly from injury or illness

When sedentary older adults got into an exercise routine, it curbed their risk of suffering a disabling injury or illness and helped them recover if anything did happen to them.