Laura Janneck

Diarrheal Diseases in Global Health

Outline

I. Impact

Morbidity and Mortality

The Most Vulnerable

Cycle of Poverty

II. Infectious Causes

Rotavirus

E. coli

Salmonellosis- Salmonella

Cholera- Vibrio cholerae

Shigellosis- Shigella

Giardiasis- Giardia lamblia

Cryptosporidiosis- Cryptosporidium

Amebiasis- Entamoeba histolytica

III. Medical Treatments

Oral Rehydration Therapy (ORT)

Intravenous Fluids

Antibiotics

IV. Prevention Efforts

Immunizations

Breastfeeding and Nutrition

Water Supply

Hygiene Promotion

V. The Role of International Organizations

UNICEF

WHO

VI. What You Can Do

Learn More

Get Involved

Diarrhea is a symptom that virtually everyone has experienced. For adults there is usually little morbidity associated with it, besides some discomfort and annoyance. However children are prone to severe consequences of diarrhea such as dehydration, and diarrheal diseases as a group are a leading cause of death and illness in children around the world. The causes of diarrhea are numerous, including viruses such as rotavirus, bacteria such as E. coli, Salmonella, Vibrio cholerae, and Shigella dysenteriae, and protozoa such as Giardia lamblia, Cryptosporidium, and Entamoeba histolytica. This chapter will begin with an overview of the impact of diarrheal diseases on public health and economics. Then there will be a discussion of the most common causes of diarrhea, followed by medical interventions to prevent dehydration. The chapter will conclude with a discussion of the systemic approaches to addressing diarrheal illnesses, examples of organizations using these approaches, and advice on what you can do to aid in these efforts and learn more.

I. Impact

Morbidity and Mortality

The World Health Organization (WHO) estimates that diarrhea causes 18% of all deaths in children under the age of five, including 17% of deaths in children ages 1-59 months, and 3% of deaths in neonates [1]. Forty percent of deaths due to diarrhea occur in the WHO Africa region [1]. A meta-analysis of studies published between 1992 and 2000 estimated that 21% of deaths for children under 5 years were attributable to diarrhea, and approximately 2.5 million children died every year from diarrheal diseases [2]. Over the years, mortality from diarrheal diseases has been falling, but morbidity remains high. Disability adjusted life years (DALYs) are a measure of morbidity often used to compare the impacts of disease burdens. In 1990, diarrheal diseases were the second leading cause of lost DALYs in the world, after lower respiratory infections [3].

Numerical estimates of the global burden of diarrheal diseases should be taken with a grain of salt, since data is unavailable or sparse in many parts of the world, and the available data that is compiled comes from a variety of unrelated sources. That said, it is clear that the burden both in terms of morbidity and mortality is astonishingly high, especially considering that most diarrheal episodes are preventable by methods already known and used in some parts of the world.

The Most Vulnerable

Diarrheal diseases exert their greatest burden on young children under the age of five years. Diarrhea also disproportionately affects people in certain geographical regions. In sub-Saharan Africa, the risk factors of poor water, sanitation, and hygiene accounts for 10.1% of all DALYs lost. Proportions in other regions include 9.5% in India, 8.8% in the Middle Eastern crescent, 7.4% in Asia (besides China) and Pacific islands, and 5.3% in Latin America and the Caribbean. These proportions are much higher than those in established market economies (0.1%) and former socialist economies of Europe (0.2%) [3].

Data from 2002 indicates that in the WHO African region, diarrheal diseases accounted for 6.6% of all deaths, compared to 0.9% in the Americas region, and 0.2% in Europe [4]. Data from 2002 indicates that in the WHO African region, diarrheal diseases accounted for 6.4% of all DALYs lost, compared to 1.6% in the Americas region, and 0.5% in Europe [4].

Cycle of Poverty

Diarrheal diseases are more prevalent and less appropriately treated in impoverished populations. Various factors account for this, including the lack of safe drinking water, lack of education, and lack of access to known prevention and treatment methods. While poverty amplifies the effects of these illnesses, diarrheal diseases exacerbate poverty.

It is difficult to quantitatively estimate the economic impact of diarrheal diseases. Extrapolating from mortality and morbidity statistics, one can presume that diarrheal diseases impart a major economic burden not only at the individual and family level, but at the community, national, and international levels. Diarrheal diseases can be a significant deterrent for travelers, and thus negatively impact tourism industries in many parts of the world. Keeping children out of school and employees out of work adds up to a substantial burden on local economies. Medical costs for treatment of diarrheal diseases are also significant, considering their prevalence.

VII. Infectious Causes

Viral Gastroenteritis- Rotavirus

According to the Centers for Disease Control, rotavirus, named for its wheel-like appearance under an electron microscope, is the most common cause of diarrhea in children around the world [5]. There are several strains of rotavirus, which are nonenveloped with double stranded RNA genomes [5]. One of the most important features of these viruses is that they are stable in the environment [5], meaning they can live outside the body. In addition, sanitary measures that are generally adequate for controlling bacteria are ineffective against rotavirus [6]. Rotaviruses are transmitted via the fecal-oral route, and diagnosis is done by detecting the virus in the stool [5]. Because large numbers of particles are passed in the stool of an infected person, they can easily transmit the virus through contaminated hands, objects, water, and food [7]. In temperate climates, rotavirus has a winter seasonal pattern, with epidemics from November until April [5]. Viral gastroenteritis, the illness caused by rotaviruses, is self-limiting in health people and usually resolves in a few days [5]. Viral gastroenteritis is characterized by vomiting and watery diarrhea [8]. The virus proliferates in the cells of the intestine, causing decreased absorption of salts and water [7]. Young children are at risk for dehydration from severe loss of fluids, and treatment consists of oral rehydration therapy [8]. Approximately one in forty children will need IV fluids for not being able to take fluids orally [5]. Mortality from rotavirus-associated gastroenteritis reaches about 500,000 cases per year, with 80% of those cases occurring in developing countries [9]. Partial immunity is acquired after infection, with less severe symptoms for subsequent infections [5]. In 1998, a vaccine for rotavirus called RotaShield was approved for distribution, but it was withdrawn a year later because it was found that it might contribute to an increased risk of intussusception in one of every 12,000 vaccinated children [10]. Recently, a new vaccine called RotaTeq® was approved by the Food and Drug Administration.

E. coli O157:H7

Escherichia coli O157:H7 is one of hundreds of strains of the bacteria Escherichia coli [11] in the enterohemmorhagic group (EHEC) [12]. Most strains are part of the normal flora of the human intestine, but E. coli O157:H7 produces a toxin that causes severe illness [11]. Most infections come from undercooked beef, but it can also be acquired from unpasteurized milk or juice, sprouts, lettuce, or contaminated water [11]. E. coli O157:H7 can also be spread by the oral-fecal route when handwashing is inadequate [11]. The illness caused by these bacteria can have a range of manifestations, but it is usually characterized by bloody diarrhea and abdominal cramps [11]. In 2-7% of cases, E. coli O157:H7 can cause hemolytic uremic syndrome, which leads to kidney failure [11]. The bacteria can be detected in the stool for diagnosis, and the illness usually resolves within 5-10 days with or without antibiotics [11]. As with rotavirus, the danger of dehydration exists especially for small children, and oral rehydration therapy should be used to prevent such complications. Hemolytic uremic syndrome leads to abnormal kidney function in about one third of the cases, and dialysis is needed by a few [11]. Approximately 73,000 cases are reported annually in the United States alone, with 61 fatalities per year [13]. E. coli is uncommonly reported in less industrialized countries [13].

Salmonellosis- Salmonella

There are several kinds of Salmonella bacteria, including S. typhi, which causes typhoid fever. The strains that are common causes of diarrhea are S. enteridis [14]. Salmonellosis is characterized by fever, abdominal cramps, and diarrhea lasting for 4 to 7 days [14]. Barring complications from dehydration, most people recover fully, however in severe cases the bacteria may spread through the bloodstream to the bones and joints, possibly leading to arthritis [14]. Oral rehydration therapy should be used to prevent dehydration [14]. Antibiotics do not shorten the course of the illness, and should only be used if the bacteria spread to the bloodstream [15]. Humans are usually infected by consuming undercooked foods contaminated with feces from animals or from an infected food handler [14].

Cholera- Vibrio cholerae

About one in five people infected with V. cholerae develop acute watery diarrhea, of which 10-20% experience severe watery diarrhea with leg cramps, and vomiting [16]. The diarrhea is profuse and can lead to rapid fluid loss and dehydration, which is much more severe than most diarrheal illnesses, and can result in death within hours [17]. Untreated, cholera has a case fatality rate of 30-50% [16]. Because of the speed fluid loss, rehydration therapy, either oral or IV, must be initiated promptly to counteract fluid loss [17]. With treatment, case fatality drops to around 1% [16]. Antibiotics may shorten the length of the illness, and may be used in addition to, but not as a substitution for rehydration therapy [17]. Infection usually occurs from consuming contaminated water or food in endemic areas; while nearly eliminated in the United States, cholera is epidemic in sub-Saharan Africa, and prevalent in poor countries in other parts of the world [17].

Grey areas: countries with cholera cases. Black dots: countries with imported cholera cases [16].

Shigellosis- Shigella

Shigellosis is a disease caused by the Shigella bacteria. Infected individuals develop bloody diarrhea, fever, and stomach cramps about one day after infection and the disease resolves after 5-7 days [18]. In children under 2 years of age, the fever may lead to seizures [18]. There are several types of Shigella bacteria, but the strain that causes deadly epidemics in the developing world is Shigella dysenteriae. Shigellosis is diagnosed by seeing the bacteria in stool samples, and can be treated with antibiotics, but the illness usually resolves without treatment [18]. Shigella is transmitted via the fecal-to-oral route, and therefore hygiene and sanitation can be helpful in reducing transmission [18].

Giardiasis- Giardia lamblia

Giardiasis is caused by a single-celled parasite called Giardia lamblia or Giardia intestinalis, which is not a bacterium but a protozoan [19]. The microorganisms are passed in the stool of an infected person as cysts with hard coverings that can survive in cold water for several months [19]. When a person ingests these cysts from contaminated water or food, the Giardia hatch from the cysts, multiply, and attach to the small intestines using sucking disks [19]. The Giardia do not invade the intestine; but by covering the surface of the small intestines they prevent absorption of fluids and nutrients. This leads to diarrhea, abdominal pain, and greasy stools [20]. Giardiasis usually begins about 1 week after infection and lasts for several weeks [20]. There are some prescription drugs (metronidazole and furizolidone) available to treat giardiasis, but when those are not available, hydration must be maintained until the disease resolves [20]. Giardia are prevalent around the world, very contagious, and a common cause of traveler’s diarrhea [20].

Cryptosporidiosis- Cryptosporidium

Cryptosporidiosis is caused by another protozoan called Cryptosporidium, which infects humans and many animal species [21]. Infected individuals excrete cysts in their feces that contain 4 microorganisms each [21]. Like Giardia, these cysts can be ingested by drinking contaminated water, and once ingested hatch to release the infectious forms called sporozoites [21]. They then invade the cells lining the small intestine and reproduce, eventually releasing more cysts into the stool [21]. Symptoms start to occur around one week after infection, and last one to two weeks in immunocompetent people [21]. Watery diarrhea, abdominal pain, and nausea are common symptoms, and can result in dehydration and vomiting [21]. Diagnosis is made by finding the cysts in the stool under microscope [21]. Treatments are not needed in immunocompetent patients since the infection is self-resolving, but in immunocompromised individuals, nitazoxanide can be used [21]. Water can be decontaminated by boiling or running through absolute 1-micron filters [21].

Amebiasis- Entamoeba histolytica

Amebiasis is a diarrheal disease caused by the protozoa Entamoeba histolytica. These parasites are found around the world and about one in ten people getting sick from the infection [22]. Each year, 40-50 million people are infected worldwide, resulting in 40,000 deaths per year [23]. Like Giardia and Cryptosporidium, E. histolytica is passed in the stool of infected individuals as cysts, which can survive for weeks outside the host [24]. These cysts transmitted by the fecal-oral route, hatch in the small intestine, and migrate to the large intestine [24]. Infection can also occur through anal sexual contact, in which case both cysts and hatched organisms can be infectious [24]. Unlike Giardia, which attach to the intestinal cells, E. histolytica invades the intestinal lumen, and may get into the bloodstream and invade other parts of the body including the liver, brain, and lungs [24]. In the intestine, E. histolytica can cause bloody diarrhea, colitis, appendicitis, and toxic megacolon [24]. Extra-intestinal infection can result in abscesses in the liver, lungs, and brain [24]. Diagnosis of amebiasis can be difficult because E. histolytica from the stool looks like other amoebae under a microscope. The infection can be treated with antibiotics, but usually resolves within a few weeks if left untreated [25].

* * * *

The bright side of the grim statistics surrounding diarrheal diseases is that prevention and treatment methods already exist, and are known to be very effective in reducing both the prevalence of diarrheal diseases and the severity of the consequences for those who get infected. Management of most cases of diarrhea can be maintained with oral rehydration therapy. Extreme cases call for intravenous fluids and sometimes pharmaceuticals. With these measures, the mortality and morbidity of diarrheal diseases decline precipitously. Prevention methods include vaccines for a few of the infectious agents, avoidance of contaminated water ingestion, creation of more hygienic living conditions, and promotion of hygienic behaviors. These methods generally call for systemic changes to be made at the local, national, and international levels, and are therefore cumbersome to achieve despite their straightforwardness. Management methods for patients will be discussed first, focusing on children since they incur the greatest morbidity and mortality from these illnesses. This will be followed by a discussion of the systemic prevention methods that can be implemented to address these illnesses.

III. Medical Treatments

Oral Rehydration Therapy (ORT)

Diarrhea is dangerous, especially for children, because it can cause severe dehydration and electrolyte imbalance. Sodium concentrations in extracellular fluid have to be maintained between 135 and 150 mmol/liter for proper functioning [26]. When a patient experiences diarrhea, these levels can drop significantly. Therefore, treatments for all diarrheal diseases are supportive and aimed at rehydration to prevent the severe effects of dehydration [27].

In developing nations, the primary treatment for dehydration is oral rehydration therapy (ORT). In a diarrheal state, levels of sodium (an electrolyte) drop because the normal mechanism for sodium absorption is impaired [27]. Therefore, simply giving saline solution would not work, and the excess sodium in the lumen would actually lead to more water secretion and loss [26]. In the 1960's, researchers discovered another possible mechanism for sodium absorption in the diarrheal state. Glucose absorption is not affected by the diarrheal state, and if sodium is given with glucose, the sodium is brought across the intestinal wall via a cotransport mechanism on a 1 to 1 ratio with the glucose [26]. As the sodium concentration in the blood rise, water reabsorption occurs by osmosis [26]. The discovery of this co-transport mechanism has been called “potentially the most important medical advance this century [28].” This discovery led to the development of ORT which was adopted by the World Health Organization (WHO) in 1978 as its principle strategy for preventing diarrheal deaths [27]. The proportion of diarrheal episodes treated with oral rehydration therapy around the world is estimated to have risen from less than 15% in 1984 to approximately 40% in 1993 [29]. ORT may be one of the main reasons why mortality from diarrheal diseases has fallen in recent years, despite relatively steady incidence [2].

Contents of oral rehydration salts (ORS) recommended by WHO [27]:

Reduced osmolarity ORS	g/L	Reduced osmolarity ORS	mMol/L
Sodium chloride	2.6	Sodium	75
Glucose, anhydrous	13.5	Chloride	65
Potassium chloride	1.5	Glucose, anhydrous	75
Trisodium citrate, dihydrate	2.9	Potassium	20
		Citrate	10
Total Weight	20.5	Total Osmolarity	245

ORT packets cost only a few cents each. The problem, however, is distribution. While it is estimated that ORT is used to treat about half the cases of diarrhea in the developing world, there are still millions of children yet to be reached [27].

In addition to these packets, ORT can be made at home. The ingredients consist of one liter of water, one level teaspoon of salt, and eight level teaspoons of sugar [31]. Proper measurement is important because too much sugar (more than 3%) can worsen diarrhea due to osmotic effects. Homemade formulas are recommended for people who do not have access to packaged ORS, and can help with the prevention of diarrhea. However, it is not as effective for treatment because it does not contain potassium, another essential electrolyte, or bicarbonate which prevents acidosis [27]. While it is relatively easy to make homemade ORT, the information for doing so has not been distributed to many parents in the developing world. There are several efforts underway to disseminate this information (along with the materials), but there is still much progress to be made [27].

Intravenous Fluids

In developed nations such as the United States, severe dehydration caused by diarrheal diseases is often treated with intravenous fluids [27]. Researchers, after analyzing several studies comparing the effectiveness of ORT and IV fluids, have found that there is no discrepancy in the effectiveness of the two alternatives [27]. ORT has several practical advantages over IVs; they are cheaper, less traumatic to the child, easier to administer, and can be given at home. Therefore, ORT is recommended as the first choice in treating dehydration [32].

However, in the most serious cases, when the patients are vomiting so severely that they are unable to keep down fluids taken orally, they need IV fluids. In cases where IV fluids are needed, unavailability often leads to fatality [27], and impoverished areas where the facilities to provide IV fluids are unavailable, fatality rates are highest [33].

Antibiotics

Oral rehydration therapy and intravenous fluids save lives by preventing dehydration and electrolyte imbalance from diarrhea, but they do not mitigate the infections that cause it, nor do they decrease the duration of illness. Thus a major challenge for caretakers of children with diarrheal diseases is that they must administer ORT for up to several weeks, which is time-consuming and tedious.

Another step in the provision of care is administration of antibiotics or other pharmaceutical agents to treat the infections that cause diarrhea, thus diminishing the length and severity of illness. However, the proper antibiotics must be administered depending on the infectious agent, so diagnostic techniques must first be employed. In most cases, this entails laboratory analyses of stool samples, and the facilities for such analyses are not present in most areas of the world. Even where they are available, some infections, such as rotavirus, are unable to be diagnosed under a microscope and require more complicated antigen tests. If diagnosis does occur, then the next issue is the access to and cost of drugs to treat the illnesses. Many people in the world live without access to antibiotics, and could not afford them anyway. Fortunately, diarrheal illnesses are generally self-limiting and resolve on their own within a few weeks if left untreated. This is not to say that efforts should not be made to create diagnostic facilities and provide pharmaceuticals to patients who can benefit from them. But these efforts should be pursued as part of an integrative approach to increasing access to general medical care. This topic is a complicated issue in its own right; refer to Amanda Perkett’s chapter on International Public Health and the World Health Organization for a more detailed discussion [34].

IV. Prevention Efforts

Immunizations

Vaccine efforts have been slow for diarrheal diseases. Currently, there is a vaccine available for rotavirus and a short-duration vaccine for traveler’s diarrhea (E. coli and cholera).

RotaShield is a live attenuated rotavirus vaccine that was approved by the FDA in 1998, but removed from the market only a little more than a year later [35]. Shortly after the approval, cases of intussusception were reported to the Vaccine Adverse Event Reporting System (VAERS), a surveillance system which collects information about possible side effects of licensed vaccines [35]. Intussusception is a condition in which one segment of the bowel enfolds within another segment, causing obstruction [35]. Due to this surveillance, the CDC recommended that vaccine use be suspended until further studies could be performed [35]. These findings prompted the Advisory Committee on Immunization Practices (ACIP) to withdraw its recommendation of RotaShield [35]. The makers of RotaShield, Wyeth-Ayerst had withdrawn the vaccine from the market a week earlier [35].

In February of 2006 the FDA approved another rotavirus vaccine called RotaTeq®, made by Merck [36]. RotaTeq® is based on a bovine strain of rotavirus that replicates less prolifically in the human gastrointestinal tract than the simian strain used for RotaShield [37]. RotaTeq® is given orally at three different times, all before 32 weeks of age [38]. Since the vaccine is so recently approved, information is lacking about efforts to immunize children around the world with RotaTeq®.

Another recently approved vaccine is one effective against E. coli and cholera for three months, marketed to residents of developed nations as a vaccine for traveler’s diarrhea [39]. The vaccine, called Dukoral, is taken orally in two doses one week apart, and boosters are needed every three months to maintain protection [39]. Durkoral is not approved for children under the age of 2 [39] and must be kept refrigerated [40]. These qualities make it an inferior candidate for global distribution and prevention of endemic diarrheal disease.

Vaccine efforts for other illnesses are in the pipeline. Candidates for cholera are in phase II trials, and candidates for Shigellosis are in phases I, II, and III [41].

Breastfeeding and Nutrition

Breastfeeding promotion is an area in diarrhea prevention that, along with ORT, is recognized as cost-effective, straightforward, and relatively easy to achieve in low-income settings. Babies who are breastfed have lower morbidity and lower mortality from diarrhea than babies who are not breastfed [42]. This is largely attributed to the antibodies in breastmilk that protect infants from infections while they are still too young to make their own [43]. Recent research has shown that specific glycans in breastmilk, especially oligosaccharides, are major constituent of the immune protection conferred from human milk to infants for enteric pathogens [42]. Breastfeeding also supplies adequate nutrients for growth, which is indirectly protective because malnutrition has been shown to prolong the duration of diarrheal episodes and increase the risk of death [2]. Health-system and community based interventions that increase the prevalence of breastfeeding reduce the incidence of diarrhea and associated healthcare costs in infancy [44].

The optimal duration of exclusive breastfeeding according to WHO is 6 months [45]. Interventions aimed at promoting exclusive breastfeeding for the first 6 months have come in the form of hospital policies and actions to encourage breastfeeding and discourage bottle feeding, counseling and education provided by peers or health workers, mass media and community education, and mothers' support groups [46]. Studies have demonstrated the effectiveness these interventions, especially hospital policies and interventions focused on education and counseling [46].

Maternal HIV infection presents a complication to the promotion of breastfeeding, since there is a trade-off between the possibility of vertical transmission of HIV via breastmilk, and the mortality and morbidity avoided by breastfeeding [46]. The current recommendation for HIV-positive women is acceptable, affordable, sustainable, and safe formula feeding, but if this option is not possible, there are four alternatives: heat-treated breastmilk, HIV-negative wet nurses, uncontaminated donor milk, or exclusive breastfeeding for six months and rapid discontinuation thereafter [47].

At the age of 6 months, complementary feeding should begin, but breastfeeding should continue for up to two years [47]. Safe complimentary feeding reduces mortality in children age 6 to 11 months, largely because it breaks the cycle in which sequential diarrheal disease leads to increasing malnutrition, impaired immune function, and greater susceptibility to infection [46]. Complementary foods can be kept safe and free from contamination through a variety of interventions including educating caregivers on hygienic practices, improving home food storage, or ingesting probiotic (non-pathogenic) bacteria that colonize the gut and help resist pathogenic bacteria [46].

Water Supply

The WHO estimated in 1990 that the risk factor of “water, sanitation, and hygiene” accounted for 5.3% of all deaths worldwide and 6.8% of all DALYs lost, and that about 90% of this disease burden occurs in children under the age of five [48]. This accounts for not only diarrheal diseases, but also other communicable diseases including typhoid, hepatitis A, and schistosomiasis.

Projects to provide safe drinking water to the estimated one billion people without it are varied in their approaches and success. Water and sanitation interventions have been shown to be more cost-effective in rural areas (US$1,974 per DALY) than in urban areas (US$6,396 per DALY) [49]. The nature of interventions largely depend on the nature of the target community: what are the local water sources, what facilities can be built, how the project can be financed. Some projects that introduce coagulant disinfectants to treat water have been shown to reduce diarrhea prevalence [50]. Other methods of disinfection are solar disinfection of drinking water (SODIS),[51, 52] closed mouth storage containers, dilute chlorine solution for home use [53], and household-based ceramic water filters [54], to name a few. Any of these strategies works best when combined with public health education about waterborne diseases, sensitivity to cultural and lifestyle differences, and motivation to achieve sustained use [51].

Hygiene Promotion

Sanitation promotion is another component of the systemic approach to reducing diarrheal illnesses. Especially in urban settings in poor countries, sanitation services are neglected since resources for any infrastructure are stretched thin [55]. Barriers to the provision of sanitation services include the reluctance of governing bodies to legitimize illegal occupation of land by providing social services, lack of experience, and lack of funding [55]. Yet the effectiveness of sanitation-focused interventions, including hand-washing and latrine promotion, has been shown; recent studies have found they reduce diarrheal incidence between 32% and 43% [55].

Hand washing has been shown to reduce diarrhea incidence by an average of 33%, but interventions must address the complexity of behavior change and the resources that are needed [46]. Plain hand soap must be provided, and washing hands after defecating or handling children's feces and before handling food entails an average of 32 hand washes per day, using a total of 20 liters of water per day [46]. Thus, these interventions must go hand-in-hand with projects to provide clean water. But, as with any systemic change, the details must be tailored to the needs and abilities of the target communities.

VIII. The Role of International Organizations

UNICEF

One of UNICEF’s major foci is on water, environment, and sanitation. They work with governments and other organizations to implement effective water sanitation interventions, with local organizations to ensure that households have clean water supplies, and with schools to make students healthier and allow girls to access education instead of fetch water for their families [30]. UNICEF is also present in emergency situations to bring clean water supplies to affected populations [30].

WHO

The World Health Organization is a division of the United Nations, governed by 192 member states through the World Health Assembly. The mission of WHO is “is the attainment by all peoples of the highest possible level of health. Health is defined in WHO's Constitution as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity [56].” There are several programs through WHO that focus on reducing diarrheal diseases around the world. The International Network to Promote Household Water Treatment and Safe Storage (HWTS) works to improve access to safe drinking water and provide interventions to people without safe drinking water [57]. The publication International Travel and Health offers guidance for travelers in avoiding various diseases, including diarrheal ones [56]. The WHO Global Taskforce on Cholera Control provides technical support for cholera control and prevention in several countries, trains health professionals in prevention, preparedness, and response to diarrheal disease outbreaks, and disseminates information on cholera and other enteric diseases to health professionals and the general public [58]. The Initiative for Vaccine Research (IVR) has vaccine programs for rotavirus, cholera, and Shigella [59].

VI. What You Can Do

Learn More

This chapter serves as an introduction to the complexities of one of the most common causes of mortality for children around the world. More information can be found through any of the sources used for this chapter, or through the following links:

Disease Control Priorities Project http://www.dcp2.org/pubs/DCP/19

American College of Physicians http://www.acpmedicine.com/sample/ch0403s.htm

Rx for Survival

http://www.pbs.org/wgbh/rxforsurvival/series/diseases/diarrheal_diseases.html

Get Involved

There are countless ways that you can personally get involved in the efforts to end the preventable deaths and illnesses caused by diarrheal diseases around the world. For information on how to volunteer:

Institute for OneWorld Health http://www.oneworldhealth.org/how/volunteer.php

Save the Children http://www.savethechildren.org/involved/

Water Partners International http://www.water.org/involved/index.htm

Peace Corps http://www.peacecorps.gov/index.cfm?shell=Learn.whatvol.healthhiv.water

For more information on advocacy efforts:

Save the Children http://www.savethechildren.org/advocacy/

Sanitation Connection http://www.sanicon.net/titles/topicintro.php3?topicId=1

Global Health Council http://www.globalhealth.org/view_top.php3?id=228

For information on making donations:

Institute for OneWorld Health http://www.oneworldhealth.org/how/donate.php

Save the Children https://secure.ga4.org/01/support_now?stationpub=i_hpddh1_adv1

Water Partners International http://www.water.org/donate/

International Center for Diarrheal Disease Research, Bangladesh

http://202.136.7.26/activity/?typeOfActivity=Contribute

For information on employment in the field:

Institute for OneWorld Health http://www.oneworldhealth.org/how/listing.php

Save the Children http://www.savethechildren.org/careers/

International Center for Diarrheal Disease Research, Bangladesh

http://202.136.7.26/job/job.jsp

Most importantly, stay safe and implement prevention measures for yourself and your household. More information can be found here:

CDC http://www.bt.cdc.gov/disasters/hurricanes/katrina/diarrheal.asp

References

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4. http://www.who.int/healthinfo/bodgbd2002revised/en/index.html. Estimates by WHO region, mortality.

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6. http://www.cfsan.fda.gov/~mow/chap33.html

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10. http://www.rotavirusvaccine.org/vaccine-facts.htm#_ednref9

11. http://www.cdc.gov/ncidod/dbmd/diseaseinfo/escherichiacoli_g.htm

12. http://people.ku.edu/~jbrown/ecoli.html
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14. http://www.azdhs.gov/phs/edc/edrp/es/salmonellosisf.htm

15. http://www.about-salmonella.com/page3.htm

16. http://www.who.int/topics/cholera/surveillance/en/index.html

17. http://www.cdc.gov/ncidod/dbmd/diseaseinfo/cholera_g.htm

18. http://www.cdc.gov/ncidod/dbmd/diseaseinfo/shigellosis_g.htm

19. http://www.dpd.cdc.gov/dpdx/HTML/Giardiasis.htm

20. http://www.cdc.gov/ncidod/dpd/parasites/giardiasis/factsht_giardia.htm

21. http://www.dpd.cdc.gov/dpdx/HTML/Cryptosporidiosis.htm

22. http://www.cdfound.to.it/html/enta3.htm

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