Diarrheal Diseases and Water Quality: Are You at Risk?

What Are Diarrheal Diseases?

Diarrhea, or diarrhoea as it’s spelled in British English, is usually caused by parasites, viruses, or bacteria, although it can also have a non-infectious cause such as lactose intolerance, irritable bowel syndrome (IBS), or ulcerative colitis. It’s defined as having loose or watery bowel movements frequently or multiple times in one day, and may occur alongside nausea, vomiting, abdominal pain, and other symptoms.

• Diarrhea can be grouped into three categories:
• Acute or short-duration watery diarrhea
• Acute or short-duration bloody diarrhea
• Persistent diarrhea that lasts longer than two weeks

Diarrheal disease — or diarrhoeal disease — includes a wide range of causes and side effects, and is associated with dehydration, malnutrition, and even death. For example, cholera is a diarrheal disease spread by contaminated water, while dysentery refers to gastroenteritis that causes short-duration bloody diarrhea.

How Are Diarrheal Diseases Transmitted?

Diarrheal diseases are transmitted by exposure to the viruses, bacteria, or parasites that cause it, usually through contaminated food or water sources. They can also be transmitted by contact with contaminated surfaces, such as touching a doorknob or shaking hands with an infected person who hasn’t washed their hands.

Diarrheal diseases with a viral cause are especially contagious, and include common viruses such as the norovirus, adenovirus, and rotavirus. Bacterial infections may be caused by Salmonella, Escherichia coli (E. coli), and other common bacteria, while some parasites that cause diarrhea include Giardia and Cryptosporidium.

In addition to spreading from person to person, or from contaminated food and water sources, diarrhea can also spread through contact with animals.

What Role Does Contaminated Water Play in Their Spread?

Contaminated water is closely linked to the spread of diarrheal diseases in low-income countries. Although it’s less of a concern in high and middle-income countries, the risk of diarrhea from contaminated water supplies has a major impact on global health.

The WHO reports that over 1.7 billion people rely on a contaminated source of drinking water, which can spread dysentery, cholera, typhoid, and other diarrheal diseases. The primary danger is fecal contamination from latrines or sewage systems, but microbial contamination can also occur due to unhygienic water storage and handling.

Which Regions Are Most Affected by Diarrheal Diseases Related to Water Quality?

The regions of the world most affected by diarrheal diseases are rural areas with a lack of access to safe drinking water sources or water treatment facilities. According to an article in “Frontiers in Public Health,” India had the highest number of deaths linked to diarrheal diseases, while Chad, Somalia, and the Central African Republic had the highest rate of deaths related to diarrheal disease and water quality.

According to “Grist,” climate change also has a role in the impact of water contamination on diarrheal diseases: “Children face a heightened risk … after extreme weather events in regions of the world where climate change is prompting dry seasons to become drier and wet seasons to become wetter,” including in parts of Africa and South America.

High- and middle-income countries have a lower incidence of infectious disease due to unsafe water, but outbreaks still happen. According to the Centers for Disease Control and Prevention (CDC), diarrheal diseases are a “persistent threat,” especially among certain age groups, and primarily associated with untreated groundwater.

What Waterborne Pathogens Are Associated With Diarrheal Diseases?

Waterborne illnesses include those that are spread through contaminated drinking water as well as those that are spread through environmental exposure, such as swimming in a body of water that’s contaminated with sewage. In some cases, the same pathogens can be found in both drinking water systems and recreational water sources.

For example, Recreational Water Illnesses (RWIs) include Cryptosporidium, E. coli, and Shigella. Swimmers can accidentally ingest these microorganisms while swimming, and they can also make their way into the municipal water supply. Many local water utilities test for these microorganisms and use chemical disinfectants to remove them.

In low-income countries, pathogens like Vibrio cholerae (which causes cholera) and Salmonella enterica (which causes typhoid) are a major cause of diarrheal disease, although chlorination has virtually eliminated these contaminants in the United States.

How Can Access to Clean Water Prevent Diarrheal Diseases?

Diarrheal diseases are considered a preventable cause of death, because we know how the most common germs, viruses, and bacteria are spread through contaminated water and what interventions are needed to eliminate them. But according to the WHO, 2.2 billion people lack access to safely managed or improved water sources.

Access to clean water can prevent the transmission of diarrheal diseases, and reduce the risk of secondary infections and severe dehydration associated with them.

The United Nations’ Sustainable Development Goals include access to clean water and sanitation for all. Not only does improved water quality reduce the incidence of diarrheal diseases, but it can improve lives in other ways, such as increased school attendance and less money spent on healthcare costs.

What Sanitation and Hygiene Practices Are Crucial in Preventing Waterborne Diarrheal Illnesses?

Most diarrheal diseases caused by contaminated water can be prevented with better sanitation and hygiene practices. The CDC uses the acronym WASH — safe water, sanitation, and hygiene — to describe these conditions and practices.

The most effective practices include:

• Maintaining clean and sanitary toilets or latrines
• Using handwashing facilities with soap and clean water
• Developing household water treatment and storage systems
• Following safe food handling practices to avoid contamination
• Breastfeeding babies for the first six months

Improved health education and distribution of the rotavirus vaccine can also help to reduce the prevalence of diarrheal diseases.

If a person does get sick with a diarrheal disease, they can use oral rehydration salts (ORS) and zinc supplements to reduce the duration and severity.

What Is the Impact of Poor Water Quality on Diarrheal Disease Prevalence?

Poor drinking water quality is one of the major contributors to diarrheal disease, but it isn’t the only risk factor. In fact, the journal of “Tropical Medicine and Health” found that “the effects of [improved water and sanitation] had a larger impact on the reduction of diarrheal diseases than the improvements to water or sanitation alone.”

In addition to water quality, organizations working to reduce diarrheal diseases also need to consider water access. For millions of people, safe water sources are more than 30 minutes away, adding to the physical burden of water collection.

In other words, organizations will have to take a multi-factor approach to achieve the U.N.’s Sustainable Development Goals for water security.

What Are the Challenges in Providing Safe Water and Sanitation Facilities to Communities at Risk of Diarrheal Diseases?

According to an article in PubMed, some of the barriers to providing safe water in some parts of the world (in this case, Southern Africa) include “rurality, climate change, low investments in WaSH infrastructure, inadequate knowledge of water-borne illnesses, and lack of community engagement.”

They explain that many rural water schemes are only “intermittently functional,” and the use and quality of latrines can vary depending on whether they’re owned by individual households or maintained communally.

Even when clean water and sanitation facilities are available, malnutrition can increase the frequency and severity of diarrheal diseases, especially among children.

Which Organizations Are Working to Address Water-Related Diarrheal Diseases Globally?

Several organizations are working to address water-related diarrheal diseases on a global level, including the following NGOs and governmental bodies:

• UNICEF focuses on providing WASH-related resources and services in 100 countries around the world.
• The Gates Foundation provides access to vaccinations for several diarrheal diseases, including rotavirus, cholera, and typhoid.
• The CDC’s Waterborne Disease Prevention Branch has a Domestic WASH Epidemiology Team, a Global WASH Team, and other teams that work on tracking and preventing outbreaks of waterborne illnesses.

What Technologies Are Being Used to Improve Water Quality and Reduce Diarrheal Diseases?

Technologies to prevent diarrheal diseases range from those that track and detect the prevalence of disease-causing organisms to better water filtration systems.

For example, in the U.S., the National Wastewater Surveillance System uses advanced testing and analysis to identify levels of infection in a given community. At a local level, water utilities are continuing to monitor for microorganisms like Cryptosporidium, and implementing new treatment and filtration systems to address the threat.

Around the world, Household Drinking Water Treatment Technologies, including solar disinfection (SODIS), BioSand Filters (BSF), and Ceramic Water Filters (CWF), offer cost-effective ways to improve water quality and prevent diarrheal diseases.

Can Home Water Filters Prevent Diarrheal Diseases?

Diarrheal diseases are a greater risk in some parts of the world than others, but even in regions with good water quality, low levels of Cryptosporidium and other pathogens may be present. Individuals are most at risk of diarrheal diseases if they rely on untreated water sources or if they have underlying health conditions.

Ultraviolet (UV) light water treatment is effective at removing E. coli, Cryptosporidium, and other viruses and bacteria, while other home water filters, like reverse osmosis filters, are more effective at removing chemicals and other contaminants.

Check your local water quality report to find out more, and consider using the VIQUA Ultraviolet Light Water Disinfection System to disinfect your water.