water borne diseases research paper

• Open access
• Published: 24 July 2023

Severity of waterborne diseases in developing countries and the effectiveness of ceramic filters for improving water quality

• Godfrey Michael Shayo   ORCID: orcid.org/0000-0001-6082-5897 1 ,
• Elianaso Elimbinzi 1 ,
• Godlisten N. Shao 1 &
• Christina Fabian 1  

Bulletin of the National Research Centre volume  47 , Article number:  113 ( 2023 ) Cite this article

9509 Accesses

24 Citations

Metrics details

It is anticipated that three (3) billion people will experience water stress by 2025 due to limited access to clean water. Water-related diseases and fatalities affect both industrialized and developing countries. Waterborne diseases are challenging worldwide, especially in developing countries. This article evaluates strategies used by various countries, particularly developing countries, to combat waterborne diseases. These strategies have been largely successful in reducing the prevalence of water-related diseases in developing countries.

Main body of the abstract

The effectiveness of these strategies is evaluated in terms of their ability to remove water contaminants such as bacteria, viruses, and chemicals. Different strategies can be used, including traditional water treatment techniques such as boiling, chlorination, flocculation, solar disinfection and ceramic-based water filtration systems. These methods can help improve water quality and safety. The choice of strategy depends on the specific contaminants in the water and the desired outcome. Proper implementation of these strategies is key to ensuring safe drinking water.

Short conclusion

It was revealed that in developing countries, multiple water treatment techniques are used. This has led to the reduction in waterborne diseases from 50 to 90%. Ceramic-based water purification systems are reportedly the modern and least expensive technique, since they are highly efficient and can be made locally. Thus, ceramic water filtration systems are widely used due to their affordability and easy maintenance.

Waterborne diseases are conditions caused by pathogenic microorganisms such as bacteria, protozoa, and viruses transmitted through water. When measures are delayed, these pathogens may cause adverse effects on human health, such as disability, illness, disorders, or death (Landrigan et al. 2020 ). Transmission of these pathogens occurs while using infected water for drinking, food preparation, and washing clothes (WHO 2022 ). However, most waterborne infections are spread by the fecal–oral pathway, which happens when human feces are consumed by drinking contaminated water or eating infected food, which is mostly caused by inadequate sewage management and sanitation. Waterborne pathogens, which accelerate waterborne diseases, significantly affect people’s health by causing mortality and morbidity (Ferreira et al. 2021 ; Gall et al. 2015a , b ; Shailemo et al. 2016 ). Waterborne diseases can cost people their lives and their socioeconomic status. Several research reports, government and non-government resources demonstrate this quietly. Access to clean water and sanitation facilities is essential for the prevention of waterborne diseases and the protection of public health. Proper management of water resources is critical for the prevention and control of waterborne diseases. Water quality monitoring and surveillance is necessary to protect public health.

Globally, 2.1 billion people lack access to clean and safe drinking water, resulting in 2.2 million deaths from waterborne diseases each year (UN 2019 ). Domestic water supplies must be free of disease-carrying microbes and other chemical contaminants to be safe for human consumption. It was once anticipated that until 2021, only 44% of the world’s population would have access to safe sources of water. This left a larger population, i.e., 56% of the world’s population, with access to unsafe and contaminated water from sewage, septic tanks, latrines, agricultural activities, and other human activities (World Health Organization 2020 ). Contamination of surface and groundwater ensures that waterborne diseases persist, particularly in developing countries. Currently, the global picture of water and health has a strong local dimension, with 1.1 billion people still lacking access to improved drinking water sources and 2.4 billion to adequate sanitation. There is extensive evidence that water-related, sanitation, and hygiene-related diseases account for 2.2 million deaths annually and an annual loss of 8.2 million disability-adjusted life (Anyango 2019 ; Kätzl 2019 ). The severity is much higher in developing countries than developed countries.

Waterborne diseases are one of society's most persistent and economically disastrous biological threats. Four-fifths of all illnesses in developing countries are caused by waterborne diseases, with diarrhea being the leading cause of childhood deaths (Luby et al. 2018 ). Generally, 1.8 million people die every year from waterborne diseases including cholera, typhoid, urinary tract infections, schistosomiasis and other diarrheal diseases. Nevertheless, waterborne diarrhea remains a prominent cause of mortality and sickness among children in developing nations, with 90% of diarrhea fatalities occurring in children under five. Rural residents in developing countries use discharge near or around neighboring shrubs and jungles for defecation, which results in fecal pollution of water in rural African and other developing-country locations. (Manetu and Karanja 2021 ). Common waterborne diseases include bacteria-caused diseases such as cholera, typhoid, and diarrhea, protozoa such as amoebiasis, and viral diseases such as retrovirals, hepatitis A, hepatitis E, and polio infections.

In contrast to many other outbreaks of diseases with incurable diagnoses or expensive preventions and treatments (Paliwal 2021 ), waterborne infections can be combated with local, affordable resources, minimal lifestyle changes, culturally relevant solutions, and clear and affordable awareness campaigns. Due to their ambiguity and variable applicability to different societies, environments, and durations, these sorts of solutions are called acceptable strategies. This paper reviews several strategies on their efficacy in combating waterborne diseases, particularly in rural regions of developing countries. Researchers have reported on several different strategies previously. A number of suggestions are provided, especially for developing countries that still suffer the brunt of waterborne disease. Finally, it suggests cost-effective and easy strategies when employed.

Severity of waterborne diseases in the world, developing countries and rural areas

Waterborne infections are transmitted through infected drinking water and food sources. The major causes of contamination are poor hygiene and sanitation. According to the World Bank, 2.6 billion people worldwide lack access to basic sanitation, which is defined as a clean and safe toilet or latrine (Gall et al. 2015a , b ; Weststrate et al. 2019 ). As a result, more than a quarter of the world's population must defecate behind buildings, in fields, or near communal water supplies. Disease transmission is significant when fecal matter is not properly disposed of. Infection and sickness can result from unintentional contact with excrement by people or other living things like pets or flies. In addition, using untreated human waste as fertilizer in agricultural techniques results in many infectious diseases. Additionally, due to a lack of control over the movement and habitat of most animals, pollution of nearby water sources by the feces of both domesticated and wild animals is a significant issue that is frequently more challenging to manage (Diedrich et al. 2023 ) .

Around 15% of the world's population lives in water-stressed areas (Javed and Kabeer 2018 ). Rural areas in developing nations lack access to reliable clean water supply points. Thus, they are vulnerable to waterborne diseases (Gwenzi and Sanganyado 2019 ). On the other hand, around 2.5 billion people lack access to proper sanitation, and 2–2.5 million people die from diarrhea each year (Javed and Kabeer 2018 ). Therefore, most people in these places drink untreated water from readily available contaminated sources, putting them at risk of contracting waterborne diseases. Generally, contaminated water is commonly used as a medium for disease transmission (Shailemo et al. 2016 Ali and Ahmad 2020 ).

The prevalence of waterborne intestinal pathogens such as bacteria, viruses and protozoa in domestic water sources poses a serious health risk to humans (Wen et al. 2020 ). The majority of outbreaks, though infrequent, are usually associated with sewage-contaminated or inadequately treated water. Figure  1 illustrates the transmission of waterborne diseases in the human population. Contaminated water sources serve as the primary reservoir for various contaminants, including bacteria, viruses and chemicals. These contaminants can enter the human body through ingestion, inhalation, or contact with contaminated water. Inadequate sanitation and poor hygiene practices further facilitate the spread of waterborne diseases. Once inside the body, these pathogens can cause a range of illnesses, such as gastroenteritis, cholera, hepatitis, and parasitic infections. Effective prevention and control measures, such as access to clean drinking water, proper sanitation systems, education on hygiene practices and the employment of water treatment techniques such as filtration, are crucial for reducing the incidence and impact of waterborne diseases. By addressing these factors, we can safeguard public health and promote a safer and healthier environment. Furthermore, sewage system failure and overpopulation raise the danger of infectious disease transmission, either via the virtual presence of a large number of bacteria in the environment or through contaminated drinking water (Mwambete and Tairo 2018 ).

Schematic presentation of waterborne diseases transmission in human being

Although access to clean water is somehow managed in urban areas of developing countries, the situation is still poor or non-existent in rural parts of these countries (Murei et al. 2022 ). Approximately, 49% of unimproved sources, such as dug wells, natural springs, and other surface water sources are observed in rural areas. Diarrhea occurs worldwide and causes 4% of all deaths and 5% of disability loss. For example, in Bangladesh, 35 million people are daily exposed to elevated arsenic levels in their drinking water. This will ultimately threaten their health and shorten their life expectancy (World Health Organization 2020 ). Infection is common in low-income and middle-income countries with poor sanitary conditions and hygiene practices, where most children almost 90%, have been infected with the hepatitis A virus before 10 years, most often without symptoms (WHO 2022 ). Infection rates are low in high-income countries with proper sanitary and hygiene conditions.

Strategies in combating waterborne diseases

There are ways for disadvantaged people all over the world, especially those living in rural regions, to get access to clean water for drinking and other household needs. These may be referred to point-of-use (POU). Several domestic treatment methods, including boiling, sun disinfection, filtration, chemical disinfection like chlorination and flocculation, and/or sedimentation, have been implemented by several developing nations as part of their adaptation to treatment tactics (Branz et al. 2017 ; Lantagne and Yates 2018 ). The main treatment methods are shown in Table 1 along with each method's characteristics. People use these methods to prevent waterborne illnesses. Results for addressing various water pollutants, such as color, total solids, turbidity, and odor, are highly encouraging. However, in some cases, they cannot remove other water contaminants such as virus, chemicals that is, chlorine, heavy metals and other organic contaminants and bacteria contaminants. This leaves it up to researchers to investigate the efficacy of creating a ceramic filtration system with multiple capabilities for water purification. This includes the incorporation of nanomaterials like silver, copper, and gold to remove bacterial and pathogenic microorganisms. However, the incorporation of hydroxyapatite helps to remove heavy metal chemical contaminants and improve pores structure for correction of color, pH, turbidity, total dissolved solids and biological oxygen demagnetization.

Water quality and resource protection are still funded by international and non-governmental groups. Several cases of aquatic infectious diseases have been documented (Annan et al. 2018 ). Incorporating nanoparticles of noble metals into filtration technology seems to be a viable option. Some studies have reported the removal of viral and chemical contaminants through doping conventional ceramic water filters with metal oxide. Conventional ceramic water filters have been advantageous in the filtration of some water contaminants, such as bacteria, protozoa and other contaminants with ≥ 2 µm diameter size (Nigay et al. 2019 ). Recently, some studies have reported the removal of viruses through doping of standard ceramic water filters with metal oxides, such as aluminum oxide, magnesium oxide, iron oxide and titanium oxide (Mutuma et al. 2015 ; Nigay et al. 2019 ; Shao et al. 2014 , 2015 ) and chemical contaminants through hydroxyapatite (HA) doping (Haider et al. 2019 ; Nigay et al. 2019 ; Farrow et al. 2018 ). For a decade, the filtration of water contaminants such as physical, chemical and biological contaminants has been in practice in several countries. This is to address the problem of lack of safe and clean drinking water.

Viral waterborne diseases in developing countries

Viruses are the tiniest microorganisms of all parasites, with an approximate size ranging from 0.03 to 0.1 µm. Viruses are present in drinking water sources but their impact on human health is less widely understood and acknowledged. However, swallowing them can have major health consequences (Gall et al. 2015a , b ; Adelodun et al. 2021 ). More than 100 different human and animal enteric viruses have been identified as water transmissible. Rotavirus, enterovirus, norovirus and hepatitis A and E are all viral infections spread through water. Researchers have had limited success in deactivating or eliminating viruses from drinking water (Annan et al. 2018 ). Surface water contamination with enteric viruses due to human waste disposal is a public health hazard. This is especially true if these surface waterways are used for recreational, irrigation or drinking water production (Gall et al. 2015a , b ; McKee and Cruz 2021 ). Polluted water transfers viruses, including drinking and recreational water. Outbreaks involving huge numbers of diseased people are typical because numerous people may ingest a batch of water or come into contact with contaminated materials (McKee and Cruz 2021 ). Viral gastroenteritis outbreaks are mostly caused by norovirus, whereas viral hepatitis outbreaks are mostly caused by Hepatitis A Virus and rarely by Hepatitis E Virus (Bosch et al. 2011 ; McKee and Cruz 2021 ).

Viral infections, particularly those caused by rotavirus, are the most common causes of acute diarrheal diseases. Over half a million people worldwide die each year from the rotavirus, which is so pervasive that it infects almost every child by the age of five (Charoenwat et al. 2022 ). Typically, viral hepatitis affects the liver. It can be acute (fresh infection, fast onset) or chronic (long onset) (Aggarwal 2011 ; Kim et al. 2021 ). Infection with one of the five known hepatotropic viruses (hepatitis A, B, C, D and E viruses) causes viral hepatitis. Viral-based waterborne diseases can also be transmitted through inhalation or contact with skin and eyes which can both spread viruses, resulting in respiratory and ocular diseases. For healthy people, viral infections are typically self-limiting, but in children under five, the elderly, immune-compromised adults and pregnant women, they are at higher risk (Gall et al. 2015a , b ). Waterborne virus-based infections may be more common in developing countries, where hunger is common, and there are huge populations of HIV-positive (Gall et al. 2015a , b ; WHO 2022 ).

For this paper, only waterborne hepatitis viruses A and E will be discussed. In populations with unsafe water and inadequate sanitation, viral hepatitis A and E are food and waterborne diseases that can cause acute epidemics. They do not cause chronic infection or liver damage, and there is no treatment for them. Improvements in sanitation, food safety, and immunization are all effective prevention methods (Aggarwal 2011 ; Kim et al. 2021 ). The most typical clinical outcome of hepatitis A or E virus infection is a sickness typified by an abrupt onset of fever and systemic symptoms, followed by jaundice a few days later.

Hepatitis A and E viral waterborne diseases

Hepatitis A is a self-limiting liver illness caused by Hepatitis A virus infection. Hepatitis A viral infection spreads by the fecal–oral route, which can be transmitted directly from person to person or indirectly through the intake of feces-contaminated food or water (Foster et al. 2019 ). Because the hepatitis A virus is abundantly discharged in feces and may live in the environment for extended periods of time, it is usually a food-waterborne illness (Foster et al. 2019 ; Gullón et al. 2017 ). In regions where sanitation is inadequate and living conditions are dense, infections arise early in life. Infections are delayed due to increased sanitation and hygiene, and the number of people vulnerable to the disease rises (Gullón et al. 2017 ). In these circumstances, fecal contamination from a single source might result in explosive epidemics. Adults are increasingly contracting hepatitis A virus infections in most developed countries, where hepatitis A is no longer considered a childhood illness (Foster et al. 2019 ; Gullón et al. 2017 ).

Hepatitis E is an acute hepatitis caused by the Hepatitis E Virus infection. The virus spreads predominantly by the fecal–oral route, and it is extremely prevalent in certain underdeveloped nations where drinking water might be contaminated (Aggarwal 2011 ; Magana-Arachchi and Wanigatunge 2020 ). It manifests itself as outbreaks and occasional instances of acute hepatitis in these highly endemic locations. The illness is usually self-limiting and resembles other hepatotropic viruses. However, in some cases, the condition progresses to severe liver failure (Magana-Arachchi and Wanigatunge 2020 ). The Indian subcontinent, China, Southeast and Central Asia, the Middle East and northern and western Africa are all highly endemic to hepatitis E (Yekta et al. 2021 ). Hepatitis E outbreaks of various magnitudes have been documented in these regions. Furthermore, hepatitis E virus infection is responsible for a substantial number of sporadic acute hepatitis cases in these locations. The most prevalent mode of illness transmission in these places is water (Yekta et al. 2021 ). The hepatitis E virus has been linked to a 25% mortality rate in pregnant women (World Health Organization 2022 ). Several strategies have been discussed to combat hepatitis A and E viral waterborne infections including physical elimination, chemical treatment and UV light disinfection.

Strategies for combating viral waterborne diseases in developing countries

In the elimination of viral water contaminants from drinking water, several strategies have been used. However, there are two common and effective strategies used in the world and particularly in developed countries, which are physical elimination of pathogens by conventional treatment and the inactivation of viral pathogens using ultraviolet irradiation or chemical oxidants such as chlorine, chloramines, ozone and chlorine dioxide (Gall et al. 2015a , b ). Because viruses are so small, conventional treatment methods, such as filtration, are unsuccessful in physically eliminating them (Gall et al. 2015a , b ; Nigay et al. 2019 ). Disinfectants are heavily dependent on water chemistry and local restrictions. A common disinfection technique in recent years has been chlorination, where free chlorine is derived from hypochlorous acid and hypochlorite ions that are dissolved in water and hydrolyzed. This strategy has been used to disinfect water since the early 1900s (Branz et al. 2017 ; Gall et al. 2015a , b ; Lantagne and Yates 2018 ). This powerful oxidant renders most viruses dormant. However, free chlorine treatment may release harmful disinfection by-products and fails to control Cryptosporidium, a protozoan that causes diarrhea and spreads through water (Khan et al. 2019 ; Gall et al. 2015a , b ). To control the formation of regulated toxic disinfection by-products, some drinking water utilities are switching to monochloramine which is formed by mixing chlorine and ammonia with the latter in slightly excess; and/or either monochromatic (254 nm) or polychromatic (200–300 nm) ultraviolet (UV) light to control both disinfection by-products formation and Cryptosporidium contamination. In spite of these modifications to the disinfection method, the UV light technique comes with a very high cost for virus control compared to other conventional methods (Gall et al. 2015a , b ; Ibrahim et al. 2021 ).

In order to deal with the viral-based waterborne situation, total abstinence from all water sources such as streams, ponds, rivers and lakes is necessary, as well as other water sources that may be contaminated by waterborne pathogens and other chemicals. With a variety of methods, some developed countries, such as the United States, Canada, the Netherlands, and Western Australia, have shown efficiency in wastewater treatment. This is due to differences in socioeconomic factors (Ferreira et al. 2021 ). Most waterborne illnesses are not prevalent in developed countries because of sophisticated water systems that filter and chlorinate water to eradicate all disease-carrying organisms. In developing countries, however, waterborne diseases such as Hepatitis A and E, remain prevalent. The strategies employed in developed countries may not be feasible, particularly in rural areas where proper sanitation and infrastructure for water management are difficult to attain (Levy et al. 2018 ). As a result, this review recommends using point-of-use water treatment technology as a replacement, particularly for ceramic water filters that can be produced at a price affordable for rural residents when doped with metal oxides like alumina, titania, iron oxide, zinc oxide, or magnesium oxide (Mutuma et al. 2015 ; Nigay et al. 2019 ).

Bacterial waterborne diseases

Bacteria are single-celled or non-cellular, spherical, spiral or rod-shaped microorganisms that reproduce by fission and are key pathogens and biochemical characteristics. Bacteria are well-known diarrhea-causing diseases transmitted through contaminated drinking water. Depending on the bacteria kind and number present, these bacteria may or may not be detrimental, but the cumulative effect might be devastating. Bacteria are generally between 0.5 and 2 µm long (Annan et al. 2018 ). Vibrio cholerae , Salmonella sp., Campylobacter sp., Shigella sp., and Staphylococcus aureus are all bacteria spread through water. Coliform bacteria are a group of microorganisms found in the environment and mammals' intestines. They are usually harmless, but their presence indicates that drinking water's microbiological quality is of concern (Mwambete and Tairo 2018 ; World Health Organization 2006 ). Some coliforms bacteria include Escherichia, Serratia, Enterobacter, Proteus, Klebsiella, Citrobacter, Yersinia and Hafnia species . However, E. coli is the only member found in the intestines of mammals including humans; thus, its presence indicates recent fecal contamination and the possible presence of other waterborne pathogens.

Drinking water is a significant vehicle for bacterial waterborne infections such as cholera, diarrhea and typhoid fever (Gwenzi and Sanganyado 2019 ; Mwambete and Tairo 2018 ; World Health Organization 2006 ). Cholera is caused by the bacteria Vibrio cholerae , which causes severe diarrhea, vomiting, dehydration and death. It can be severe if not treated properly, up to 50% of the time. However, medication can reduce the severity to as little as 1% of the time. Cholera causes 100,000 deaths worldwide (Lee et al. 2017 ). Salmonella typhi bacteria are the source of the potentially fatal bacterial infection known as typhoid fever. There are still roughly 21 million cases of typhoid fever each year in developing nations. Only people carry Salmonella typhi . Typhoid fever patients have bacteria in their blood and intestines. Few people, called carriers, recover from typhoid fever but still carry the germ. Sick persons and carriers excrete S. typhi in their stools. Consuming or drinking food or beverages that have been touched by someone shedding S. typhi bacteria or drinking or washing food with sewage contaminated with S. typhi bacteria can result in typhoid fever (Brockett et al. 2020 ).

In developing countries, E. coli is the most common cause of diarrheal disease infections and human gastrointestinal tract infections caused by ingesting contaminated water (Gwenzi and Sanganyado 2019 ). In Africa, for instance, a severe cholera epidemic broke out in Zimbabwe in 2008 and quickly spread to neighboring nations (Zambia, Botswana, Mozambique and South Africa). Due to poor sanitation and waste management practices and a limited supply of clean piped water, the scarcity of safe drinking water in Zimbabwe's urban areas had a significant role in the development and spread of the disease. Poor water sanitation and hygiene are linked to a higher proportion of intestinal parasitic infections, with the majority being fecal–oral (Gwenzi and Sanganyado 2019 ; Gwimbi et al. 2019 ). In rural regions of most developing nations, where water supplies are communally shared and exposed to many fecal–oral transmission paths within their neighborhood boundaries, bacterial contamination of drinking water is a major contributor to waterborne illnesses (Reece et al. 2017 ; Iwu and Okoh 2019 ). E. coli infections linked to polluted water continue to be a serious public health problem, as their presence indicates the prevalence of deadly disorders such as diarrhea (Iwu and Okoh 2019 ). Despite the fact that the endemicity and intensity of bacterial waterborne illnesses have decreased in developing countries, the case fatality rates in cholera cases remain significantly higher in Africa (about 60%) than in Asia (29%) (Montufar-Salcedo, 2018 ). However, the World Health Organization (WHO) reports that 1.3 million suspected cases of typhoid fever have been recorded in Africa since 2021, with 502 deaths (2%) out of 30,934 confirmed cases in DRC. These are the most common bacterial-associated waterborne diseases in most developing countries (Gwimbi et al. 2019 ).

Strategies for combating bacterial waterborne diseases

Recently, bacterial-based water contaminants have been solved thanks to the availability of common point-of-use water treatment technologies. In most developing countries, the technologies include boiling, chlorination of contaminated water, solar disinfection and filtration techniques such as bone char, bio-sand, slow sand, membrane purifiers and ceramic filters (Farrow et al. 2018 ). Although all of them work effectively in bacterial removal, ceramic filters are perceived by most users and developers due to their easy and affordable cost of fabrication, as they require the availability of regional materials such as clay, soil, sawdust, starch, wheat flour, and milled rice husk which hence makes their dissemination to people cost-effective and economically sound. The incorporation of noble metals into ceramic water filters ensures the efficient functioning or performance of the filters, this is to say, by increasing bacterial disinfection or by increasing bio-film disinfection ability. Metal oxide nanoparticles' antibacterial capabilities, manufacturing techniques and microorganisms removed during water treatment are summarized in Table 2 .

From Table 2 , based on the different Lewis-dot structures, metal oxides display diverse physicochemical and functional properties, including magnetic, optical, mechanical, and electrical properties/features (Raghunath and Perumal 2017 ). They have shown the ability to interact with bacteria through electrostatic interactions through prokaryotic cell walls and enzyme or DNA alteration through reactive oxygen species (ROS) production (Gold et al. 2018 ). Under light exposure (He et al. 2016 ), magnesium oxide nanoparticles act as antibacterial agents and produce ROS. The ROS then enters the bacterial cell membrane while reducing both oxidative stresses on the cell organelles and lipid peroxidation, thereby preventing oxidative degradation of lipids (Gold et al. 2018 ). Since titania is a strong photocatalytic material with high oxidizing power and long-term stability, it can generate ROS with a wavelength of around 320–385 nm, hence its ability as an antimicrobial agent (Kumaravel et al. 2021 ). The action of metal oxide antimicrobial agents involves several working mechanisms, including cell membrane damage due to electrostatic interaction, disruption in metal/metal ion homeostasis, production of ROS and oxidative stress, protein and enzyme dysfunction, genotoxicity, signal transduction inhibition, and photo-removal (Raghunath and Perumal 2017 ).

However, from Table 2, it is anticipated that a higher concentration of MgO inhibits bacteria’s growth against E. coli which is higher than Bacillus sp . On the other hand, CuO provides more room to be used as a biocidal agent, such as against B. subtilis. This is due to its cost-effectiveness and better biocidal ability than other noble metal oxides (Hoseinnejad et al. 2018 ). In many studies, ZnO is proposed to have higher antibacterial ability than other metal oxides since they can pose a threat to both gram-positive and gram-negative bacteria. Furthermore, Al 2 O 3 at high concentrations has mild deactivation properties owing to the free radical scavenging capability of nanoparticles that prevent cell wall disintegration (Makvandi et al. 2020 ). Nevertheless, Al 2 O 3 has also been suggested to trap viral contaminants due to its positively charged surface (Nigay et al. 2019 ).

Chemical contamination of water

Water is a carrier of infectious microorganisms such as bacteria, parasites and viruses that spread via the fecal–oral route in water-based diseases. Similarly, chemicals are sometimes thought to be a source of infectious agents (Javed and Kabeer 2018 ). Water-stressed areas are home to about 15% of the world's population. Waterborne diseases are caused by chemical toxins, mostly found in industrial, municipal, and agricultural wastes (Javed and Kabeer 2018 ). For instance, heavy metals such as chromium, cadmium, nickel, lead, mercury and arsenic; cations, such as sodium, potassium, and calcium; anions, such as carbonates, bicarbonates, and nitrates; and pesticides, such as dichlorodiphenyltrichloroethane and benzene hexachloride enter water bodies from point and non-point sources and cause several health complications among people in many developing countries (Syafrudin et al. 2021 ).

Pesticide use has a number of advantages, including better food quality and quantity and reduced insect-borne diseases, but it has also prompted concerns about potential negative impacts on the environment, especially water sources (Syafrudin et al. 2021 ). Pesticides end up in bodies of water due to runoff from agricultural fields and industrial waste. Soluble pesticides are taken away by water molecules, which percolate lower into the soil layers and eventually reach surface waters and groundwater (Syafrudin et al. 2021 ). As a result, water quality deteriorates and drinkable water quantity decreases. Drinking water contaminated with heavy metals, pesticides, cations, and anions causes life-threatening complications in the gastrointestinal, renal, cardiovascular, pulmonary, and reproductive systems (Syafrudin et al. 2021 ). Furthermore, chemicals carried by polluted water can cause urinary tract burning and calculi, leukomelanosis, hyperkeratosis, black foot disease, neuropathy and cancer (Javed and Kabeer 2018 ; Syafrudin et al. 2021 ).

Chemicals in drinking water that exceed allowable levels may harm human health. This could be caused by human activities or natural occurrences. Chemical pollutants in drinking water have also been linked to a wide range of negative health impacts, including cancer, cardiovascular illness, neurological disease, and miscarriages. Leaching, spills, runoff, and air deposition are ways through which chemicals enter water systems (Annan et al. 2018 ). Heavy metals are found naturally in the earth's crust and are long-lasting environmental pollutants since they cannot be degraded or removed. They enter the human system in tiny amounts from food, air, and water, and bioaccumulate over time (Ali et al. 2017 ; Annan et al. 2018 ). Table 3 shows WHO and USEPA maximum permissible heavy metals in drinking water values.

With an acceptable concentration of 0.002 mg/L poisonous level, thallium and mercury are the most poisonous metals (Table 3 ). This puts human health at high risk compared to all other metals mentioned in the table. While nitrate, with a WHO rating of 11.3 mg/L and a USEPA rating of 10.0 mg/L, represents the highest allowable chemical concentration in the human body. Chemical contaminants in drinking water can pose a threat to human health sometimes, but the human body needs several heavy metal elements in their divalent cation forms, such as Zn 2+ , Fe 2+ and Cu 2+ . For instance, these metal divalents are required by the human body in the regulation of numerous physiological functions. These functions include protein and nucleic acid synthesis, antioxidant defense, and membrane stabilization. However, these metal divalents are required by the human body at very low concentration (Ali et al. 2017 ; Rehman et al. 2021 ). If their concentration exceeds the body's requirement level, metal divalent leads to health effects (Ali et al. 2017 ). Other heavy metals are poisonous to humans, such as Cd 2+ , Pb 2+ , Co 2+ , Pt 2+ and Ni 2+ . When the human body is contaminated with these metals, the kidneys, for instance, suffer the most. Hence, several effects are observed, including a decrease in essential elements entry due to heavy metal competition (Ali et al. 2017 ; Rehman et al. 2021 ).

Strategies for combating chemical contamination of water

Several studies have reported some positive progress advances in the discovery of therapeutic tools, such as cell protectors and metal chelators. These tools can be administered when an individual has taken the chemicals in any way, particularly through contaminated drinking water. But treatment must be a last option if, at all costs, the situation can be prevented from happening. Studies have reported developing point-of-use water treatment technologies, such as ceramic water filters, among many others as speculated in Table 1 , being more feasible for many people due to their low cost and ease of fabrication (Gupta et al. 2018 ; Farrow et al. 2018 ). Ceramic filters can be boosted in their efficiency in the removal of heavy metals, pesticides, and organic chemical contaminants when doped with hydroxyapatite chemicals, and the chemical materials made from bones (Haider et al. 2019 ; Nigay et al. 2019 ; Farrow et al. 2018 ). Nigay et al. ( 2019 ) reported that through a substitution mechanism, HA chemicals can interchange their chemical contents, that is, calcium ions, hydroxyl groups, and phosphate groups, with the heavy metal chemicals present in the contaminated water (Nigay et al. 2019 ).

Future prospect

Ceramic water filters, as used in many developed countries such as the USA, Netherlands, Canada, and Western Australia, can be used in developing countries with some modifications. This will improve performance and efficiency at the point-of-use. Conventional ceramic water filters can improve water quality in several parameters but fail in others. For instance, most bacterial contaminants can be physically filtered through conventional ceramic water filters. However, after some time of filter use, bacteria and mold grow on the surface of the system. Incorporating ceramic water filters with noble metals such as silver, copper, or gold in their nanoparticle form removes bacteria and prevents the system from becoming infected with protozoa (Loza et al. 2020 ; Praveena and Aris 2015 ). However, for several years, viral-based contaminants have been linked to hepatitis A and E diseases, which may cause liver cancer if chronic. Removal of viruses is quite challenging due to their small size, so they cannot be removed through physical strains. However, doping ceramic water filters with metal oxides including titania, alumina, magnesium oxide, or iron oxide facilitates the adsorption of viruses from water (Haider et al. 2019 ; Mutuma et al. 2015 ; Shao et al. 2015 ). This is due to the fact that viruses have negative surface charges and hence can be attracted to metal oxides, which are positively charged. Additionally, chemicals can be removed from water by hydroxyapatite chemicals (Haider et al. 2019 ; Nigay et al. 2019 ; Farrow et al. 2018 ). Doping ceramic water filters with hydroxyapatite is feasible and increases chemical removal efficiency. Therefore, the feasibility of having one system that simultaneously removes bacterial, viral, and chemical contaminants is quite possible. This is when a ceramic water filter is incorporated with noble metal nanoparticles and doped with metal oxides and hydroxyapatite.

Conclusions

Regardless of the disinfection method employed by a drinking water utility, cross-contamination can happen throughout the water distribution infrastructure. This is due to cavitation and unintended depressurization when treated water moves from the treatment facility to the point-of-use. However, because municipal water services are typically not available in poor nations, residents must acquire water from other nearby sources. Most of these sources are tainted with pollutants and bacteria that cause waterborne illness. The World Health Organization estimated in 2017 that environmental changes including expanding access to clean drinking water and raising sanitation and hygiene standards may prevent 94% of cases of waterborne diarrhea diseases. However, the increasing water availability, sanitation, hand washing, and domestic water treatment and safe storage can reduce diarrhea episodes by 25%, 32%, 45% and 39%, respectively. Although, these distribution systems need additional disinfectants. This review also offers recommendations for how developing nations can lower waterborne illnesses prevalence. These include raising the quantity and quality of drinking water, ensuring safe sewage disposal, and offering accessible, affordable sanitation solutions. For example, the adoption of point-of-use water treatment technologies. These technologies are simple, low-cost, and have the potential to reduce waterborne illnesses significantly. Furthermore, these solutions should be combined with educational campaigns to ensure that people are aware of how to use and maintain the technologies.

Availability of data and materials

Not applicable.

Abbreviations

Reactive oxygen species

Escherichia coli

United State Environmental Protection Agency

World Health Organization

Point of use

Ceramic water filters

Human immunodeficiency virus

Hydroxyapatite

Ultraviolet light

Hepatitis A viruses

Hepatitis E viruses

United Nation

Adelodun B, Ajibade FO, Ighalo JO, Odey G, Ibrahim RG, Kareem KY et al (2021) Assessment of socioeconomic inequality based on virus-contaminated water usage in developing countries: a review. Environ Res 192:110309

Article   CAS   PubMed   Google Scholar  

Aggarwal R (2011) Clinical presentation of hepatitis E. Virus Res 161(1):15–22. https://doi.org/10.1016/j.virusres.2011.03.017

Aggarwal R, Naik S (2009) Epidemiology of hepatitis E: current status. J Gastroenterol Hepatol 24(9):1484–1493. https://doi.org/10.1111/j.1440-1746.2009.05933.x

Article   PubMed   Google Scholar  

Ali A, Ahmed A, Gad A (2017) Chemical and microstructural analyses for heavy metals removal from water media by ceramic membrane filtration. Water Sci Technol 75(2):439–450. https://doi.org/10.2166/wst.2016.537

Ali SA, Ahmad A (2020) Analysing water-borne diseases susceptibility in Kolkata Municipal Corporation using WQI and GIS based Kriging interpolation. GeoJournal 85(4):1151–1174

Article   Google Scholar  

Annan E, Agyei-Tuffour B, Bensah YD, Konadu DS, Yaya A, Onwona-Agyeman B, Nyankson E (2018) Application of clay ceramics and nanotechnology in water treatment: a review. Cogent Eng 5(1):1476017

Anyango MJ (2019) Water, sanitation and hygiene practices as predictors of diarrhoea occurrence among school age children in Ganze Sub County, Kenya. 206

Azam A, Ahmed AS, Oves M, Khan MS, Habib SS, Memic A (2012) Antimicrobial activity of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria: a comparative study. Int J Nanomed. https://doi.org/10.2147/IJN.S35347

Bitew BD, Gete YK, Biks GA, Adafrie TT (2018) The effect of SODIS water treatment intervention at the household level in reducing diarrheal incidence among children under 5 years of age: a cluster randomized controlled trial in Dabat district, northwest Ethiopia. Trials 19(1):412. https://doi.org/10.1186/s13063-018-2797-y

Article   PubMed   PubMed Central   Google Scholar  

Bosch A, Sánchez G, Abbaszadegan M, Carducci A, Guix S, Le Guyader FS, Netshikweta R, Pintó RM, van der Poel WHM, Rutjes S, Sano D, Taylor MB, van Zyl WB, Rodríguez-Lázaro D, Kovač K, Sellwood J (2011) Analytical methods for virus detection in water and food. Food Anal Methods 4(1):4–12. https://doi.org/10.1007/s12161-010-9161-5

Branz A, Levine M, Lehmann L, Bastable A, Ali SI, Kadir K, Yates T, Bloom D, Lantagne D (2017) Chlorination of drinking water in emergencies: a review of knowledge to develop recommendations for implementation and research needed. Waterlines 36(1):4–39. https://doi.org/10.3362/1756-3488.2017.002

Brockett S, Wolfe MK, Hamot A, Appiah GD, Mintz ED, Lantagne D (2020) Associations among water, sanitation, and hygiene, and food exposures and typhoid fever in Case-Control studies: a systematic review and meta-analysis. Am J Trop Med Hyg 103(3):1020

Bui XT, Nguyen PT, Nguyen VT, Dao TS, Nguyen PD (2020) Microplastics pollution in wastewater: characteristics, occurrence and removal technologies. Environ Technol Innov 19:101013

Bulta AL, Micheal GAW (2019) Evaluation of the efficiency of ceramic filters for water treatment in Kambata Tabaro zone, southern Ethiopia. Environ Syst Res 8(1):1. https://doi.org/10.1186/s40068-018-0129-6

Burleson G, Tilt B, Sharp K, MacCarty N (2019) Reinventing boiling: A rapid ethnographic and engineering evaluation of a high-efficiency thermal water treatment technology in Uganda. Energy Res Soc Sci 52:68–77

Charoenwat B, Suwannaying K, Paibool W, Laoaroon N, Sutra S, Thepsuthammarat K (2022) Burden and pattern of acute diarrhea in Thai children under 5 years of age: a 5-year descriptive analysis based on Thailand National Health Coverage (NHC) data. BMC Public Health 22(1):1–10. https://doi.org/10.1016/j.erss.2019.02.009

Diedrich A, Sivaganesan M, Willis JR, Sharifi A, Shanks OC (2023) Genetic fecal source identification in urban streams impacted by municipal separate storm sewer system discharges. PLoS ONE 18(1):e0278548

Article   CAS   PubMed   PubMed Central   Google Scholar  

El-Taweel GE, Ali GH (2000) Evaluation of roughing and slow sand filters for water treatment. Water Air Soil Pollut 120(8):21–28.

Article   ADS   CAS   Google Scholar  

Farrow C, McBean E, Huang G, Yang A, Wu Y, Liu Z, Li Y (2018) Ceramic water filters: a point-of-use water treatment technology to remove bacteria from drinking water in Longhai City, Fujian Province. China J Environ Inf 32(2):63–68

Google Scholar  

Ferreira DC, Graziele I, Marques RC, Gonçalves J (2021) Investment in drinking water and sanitation infrastructure and its impact on waterborne diseases dissemination: The Brazilian case. Sci Total Environ 779:146279. https://doi.org/10.1016/j.scitotenv.2021.146279

Article   ADS   CAS   PubMed   Google Scholar  

Fewtrell L, Kaufmann RB, Kay D, Enanoria W, Haller L, Colford JM (2005) Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis. Lancet Infect Dis 5(1):42–52. https://doi.org/10.1016/S1473-3099(04)01253-8

Foster MA, Hofmeister MG, Kupronis BA, Lin Y, Xia G-L, Yin S, Teshale E (2019) Increase in hepatitis A virus infections—United States, 2013–2018. MMWR Morb Mortal Weekly Rep 68(18):413–415. https://doi.org/10.15585/mmwr.mm6818a2

Gall AM, Mariñas BJ, Lu Y, Shisler JL (2015a) Waterborne viruses: a barrier to safe drinking water. PLoS Pathog 11(6):e1004867. https://doi.org/10.1371/journal.ppat.1004867

Gall AM, Shisler JL, Mariñas BJ (2015b) Analysis of the viral replication cycle of adenovirus serotype 2 after inactivation by free chlorine. Environ Sci Technol 49(7):4584–4590. https://doi.org/10.1021/acs.est.5b00301

Ghernaout D (2014) Coagulation and chlorination of NOM and algae in water treatment: a review. Int J Environ Monit Anal 2(6):23. https://doi.org/10.11648/j.ijema.s.2014020601.14

Ghernaout D (2017) Water treatment chlorination: an updated mechanistic insight review. Chem Res J 2:125–138

CAS   Google Scholar  

Gold K, Slay B, Knackstedt M, Gaharwar AK (2018) Antimicrobial activity of metal and metal-oxide based nanoparticles. Adv Ther 1(3):1700033. https://doi.org/10.1002/adtp.201700033

Article   CAS   Google Scholar  

Gullón P, Varela C, Martínez EV, Gómez-Barroso D (2017) Association between meteorological factors and hepatitis A in Spain 2010–2014. Environ Int 102:230–235. https://doi.org/10.1016/j.envint.2017.03.008

Gupta S, Satankar RK, Kaurwar A, Aravind U, Sharif M, Plappally A (2018) Household production of ceramic water filters in western Rajasthan, India. Int J Serv Learn Eng Humanit Eng Soc Entrep 13(1):53–66. https://doi.org/10.24908/ijsle.v13i1.11150

Gwenzi W, Sanganyado E (2019) Recurrent Cholera Outbreaks in Sub-Saharan Africa: moving beyond epidemiology to understand the environmental reservoirs and drivers. Challenges 10(1):1. https://doi.org/10.3390/challe10010001

Gwimbi P, George M, Ramphalile M (2019) Bacterial contamination of drinking water sources in rural villages of Mohale Basin, Lesotho: exposures through neighbourhood sanitation and hygiene practices. Environ Health Prev Med 24(1):33. https://doi.org/10.1186/s12199-019-0790-z

Haider MS, Shao G, Ahmad A, Imran SM, Abbas N, Abbas G, Hussain M, Kim HT (2019) Facile, single-pot preparation of nanoporous SiO 2 particles (carrier) with AgNPs at core and crust for controlled disinfectant release. J Saudi Chem Soc 23(7):828–835. https://doi.org/10.1016/j.jscs.2019.02.005

He Y, Ingudam S, Reed S, Gehring A, Strobaugh TP, Irwin P (2016) Study on the mechanism of antibacterial action of magnesium oxide nanoparticles against foodborne pathogens. J Nanobiotechnology 14(1):54. https://doi.org/10.1186/s12951-016-0202-0

Hoseinnejad M, Jafari SM, Katouzian I (2018) Inorganic and metal nanoparticles and their antimicrobial activity in food packaging applications. Crit Rev Microbiol 44(2):161–181. https://doi.org/10.1080/1040841X.2017.1332001

Ibrahim Y, Ouda M, Kadadou D, Banat F, Naddeo V, Alsafar H et al (2021) Detection and removal of waterborne enteric viruses from wastewater: a comprehensive review. J Environ Chem Eng 9(4):105613

Iwu CD, Okoh AI (2019) Preharvest transmission routes of fresh produce associated bacterial pathogens with outbreak potentials: a review. Int J Environ Res Public Health 16(22):4407

Javed A, Kabeer A (2018) Enhancing waterborne diseases in pakistan & their possible control. Am Acad Sci Res J Eng Technol Sci 49(1):248–256

Jeon I, Ryberg EC, Alvarez PJ, Kim JH (2022) Technology assessment of solar disinfection for drinking water treatment. Nat Sustain 5(9):801–808

Kallman EN, Oyanedel-Craver VA, Smith JA (2011) Ceramic filters impregnated with silver nanoparticles for point-of-use water treatment in rural Guatemala. J Environ Eng 137(6):407–415. https://doi.org/10.1061/(ASCE)EE.1943-7870.0000330

Kätzl K (2019) Anaerobic biochar filtration of municipal raw sewage for wastewater reuse (Doctoral dissertation, Ruhr-Universität Bochum)

Kiagho B, Machunda R, Hilonga A, Njau K (2016) Performance of water filters towards the removal of selected pollutants in Arusha, Tanzania. Tanzan J Sci 42(1):134–147

Kim JU, Ingiliz P, Shimakawa Y, Lemoine M (2021) Improving care of migrants is key for viral hepatitis elimination in Europe. Bull World Health Organ 99(4):280–286. https://doi.org/10.2471/BLT.20.260919

Khan A, Shams S, Khan S, Khan MI, Khan S, Ali A (2019) Evaluation of prevalence and risk factors associated with Cryptosporidium infection in rural population of district Buner, Pakistan. PLoS ONE 14(1):e0209188

Kumaravel V, Nair KM, Mathew S, Bartlett J, Kennedy JE, Manning HG et al (2021) Antimicrobial TiO 2 nanocomposite coatings for surfaces, dental and orthopaedic implants. Chem Eng J 416:129071

Landrigan PJ, Stegeman JJ, Fleming LE, Allemand D, Anderson DM, Backer LC, Rampal P (2020) Human health and ocean pollution. Ann Glob Health 86(1):151

Lantagne D, Klarman M, Mayer A, Preston K, Napotnik J, Jellison K (2010) Effect of production variables on microbiological removal in locally-produced ceramic filters for household water treatment. Int J Environ Health Res 20(3):171–187. https://doi.org/10.1080/09603120903440665

Lantagne D, Yates T (2018) Household water treatment and cholera control. J Infect Dis 218(suppl_3):S147–S153. https://doi.org/10.1093/infdis/jiy488

Lee EC, Kelly MR, Ochocki BM, Akinwumi SM, Hamre KES, Tien JH, Eisenberg MC (2017) Model distinguishability and inference robustness in mechanisms of cholera transmission and loss of immunity. J Theor Biol 420:68–81. https://doi.org/10.1016/j.jtbi.2017.01.032

Article   ADS   MathSciNet   PubMed   PubMed Central   MATH   Google Scholar  

Levy K, Smith SM, Carlton EJ (2018) Climate change impacts on waterborne diseases: moving toward designing interventions. Curr Environ Health Rep 5(2):272–282. https://doi.org/10.1007/s40572-018-0199-7

Li Y, Li J, Ding J, Song Z, Yang B, Zhang C, Guan B (2022) Degradation of nano-sized polystyrene plastics by ozonation or chlorination in drinking water disinfection processes. Chem Eng J 427:131690

Loomis D, Sobsey MD, Brown J (2008) Local drinking water filters reduce diarrheal disease in cambodia: a randomized, controlled trial of the ceramic water purifier. Am J Trop Med Hyg 79(3):394–400. https://doi.org/10.4269/ajtmh.2008.79.394

Loza K, Heggen M, Epple M (2020) Synthesis, structure, properties, and applications of bimetallic nanoparticles of noble metals. Adv Func Mater 30(21):1909260. https://doi.org/10.1002/adfm.201909260

Luby SP, Rahman M, Arnold BF, Unicomb L, Ashraf S, Winch PJ et al (2018) Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Bangladesh: a cluster randomised controlled trial. Lancet Global Health 6(3):e302–e315

Magana-Arachchi DN, Wanigatunge RP (2020) Ubiquitous waterborne pathogens. In: Waterborne pathogens, pp 15–42. Butterworth-Heinemann

Makvandi P, Wang C, Zare EN, Borzacchiello A, Niu L, Tay FR (2020) Metal-based nanomaterials in biomedical applications: antimicrobial activity and cytotoxicity aspects. Adv Func Mater 30(22):1910021. https://doi.org/10.1002/adfm.201910021

Manetu WM, Karanja AM (2021) Waterborne disease risk factors and intervention practices: a review. Oalib 08(05):1–11. https://doi.org/10.4236/oalib.1107401

McKee AM, Cruz MA (2021) Microbial and viral indicators of pathogens and human health risks from recreational exposure to waters impaired by fecal contamination. J Sustain Water Built Environ 7(2):03121001

Mohammed Sadiq I, Chandrasekaran N, Mukherjee A (2010) Studies on effect of TiO 2 nanoparticles on growth and membrane permeability of Escherichia coli , Pseudomonas aeruginosa , and Bacillus subtilis . Curr Nanosci 6(4):381–387. https://doi.org/10.2174/157341310791658973

Article   ADS   Google Scholar  

Montgomery MA, Elimelech M (2007) Water and sanitation in developing countries: including health in the equation. Environ Sci Technol 41(1):17–24. https://doi.org/10.1021/es072435t

Article   ADS   PubMed   Google Scholar  

Montufar Salcedo C (2018) Modification of the treatment protocol as a strategy in the control of the cholera epidemic in Haiti 2016–2017. Med Case Rep Rev 1(3):1–3

Mulugeta S, Helmreich B, Drewes JE, Nigussie A (2020) Consequences of fluctuating depth of filter media on coliform removal performance and effluent reuse opportunities of a bio-sand filter in municipal wastewater treatment. J Environ Chem Eng 8(5):104135. https://doi.org/10.1016/j.jece.2020.104135

Murei A, Mogane B, Mothiba DP, Mochware OTW, Sekgobela JM, Mudau M et al (2022) Barriers to water and sanitation safety plans in rural areas of South Africa—a case study in the Vhembe District, Limpopo Province. Water 14(8):1244

Mutuma BK, Shao GN, Kim WD, Kim HT (2015) Sol–gel synthesis of mesoporous anatase–brookite and anatase–brookite–rutile TiO 2 nanoparticles and their photocatalytic properties. J Colloid Interface Sci 442:1–7

Mwambete KD, Tairo VP (2018) Bacteriological quality of household drinking water and water disinfection practices in Kinondoni Municipality, Tanzania. Int J Health Sci 1:10

Nigay P-M, Salifu AA, Obayemi JD, White CE, Nzihou A, Soboyejo WO (2019) Ceramic water filters for the removal of bacterial, chemical, and viral contaminants. J Environ Eng 145(10):04019066. https://doi.org/10.1061/(ASCE)EE.1943-7870.0001579

Norton DM, Rahman M, Shane AL, Hossain Z, Kulick RM, Bhuiyan MI, Wahed MA, Yunus M, Islam MS, Breiman RF, Henderson A, Keswick BH, Luby SP (2009) Flocculant-disinfectant point-of-use water treatment for reducing arsenic exposure in rural Bangladesh. Int J Environ Health Res 19(1):17–29. https://doi.org/10.1080/09603120802272219

Obafunmi T, Ocheme J, Gajere B (2020) Oligodynamic effect of precious metals on skin bacteria. Fudma J Sci 4(3):601–608. https://doi.org/10.33003/fjs-2020-0403-334

Okoh EO, Miner CA, Envuladu EA, Mohammed A, Ugochi J (2020) Effect of household water treatment on microbiological quality of drinking water in rural communities of Plateau State, Nigeria: a comparative study of two treatment modalities

Paliwal I (2021) Detection of Trichomonas vaginalis , Giardia and Cryptosporidium spp. in remote indigenous communities in Canada using a point-of-care device

Parham S, Wicaksono DHB, Bagherbaigi S, Lee SL, Nur H (2016) Antimicrobial treatment of different metal oxide nanoparticles: a critical review. J Chin Chem Soc 63(4):385–393. https://doi.org/10.1002/jccs.201500446

Peterson KM, Diedrich DE, Lavigne DJ (2008) Strategies for combating waterborne diarrheal diseases in the developing world, 39.

Praveena SM, Aris AZ (2015) Application of low-cost materials coated with silver nanoparticle as water filter in Escherichia coli removal. Water Qual Expo Health 7(4):617–625. https://doi.org/10.1007/s12403-015-0167-5

Quang DV, Sarawade PB, Hilonga A, Kim J-K, Shim YH, Shao GN, Kim HT (2012) Synthesis of silver nanoparticles within the pores of functionalized-free silica beads: the effect of pore size and porous structure. Mater Lett 68:350–353. https://doi.org/10.1016/j.matlet.2011.10.073

Raghunath A, Perumal E (2017) Metal oxide nanoparticles as antimicrobial agents: a promise for the future. Int J Antimicrob Agents 49(2):137–152. https://doi.org/10.1016/j.ijantimicag.2016.11.011

Rayner J, Luo X, Schubert J, Lennon P, Jellison K, Lantagne D (2017) The effects of input materials on ceramic water filter efficacy for household drinking water treatment. Water Supply 17(3):859–869. https://doi.org/10.2166/ws.2016.176

Reece SM, Sinha A, Grieshop AP (2017) Primary and photochemically aged aerosol emissions from biomass cookstoves: chemical and physical characterization. Environ Sci Technol 51(16):9379–9390.

Rehman AU, Nazir S, Irshad R, Tahir K, ur Rehman K, Islam RU, Wahab Z (2021) Toxicity of heavy metals in plants and animals and their uptake by magnetic iron oxide nanoparticles. J Mol Liq 321:114455

Sawai J, Himizu K, Yamamoto O (2005) Kinetics of bacterial death by heated dolomite powder slurry. Soil Biol Biochem 37(8):1484–1489. https://doi.org/10.1016/j.soilbio.2005.01.011

Shailemo DHP, Kwaambwa HM, Kandawa-Schulz M, Msagati TAM (2016) Antibacterial activity of Moringa ovalifolia and Moringa oleifera methanol, N-hexane and water seeds and bark extracts against pathogens that are implicated in water borne diseases. Green Sustain Chem 06(02):71–77. https://doi.org/10.4236/gsc.2016.62006

Shao GN, Engole M, Imran SM, Jeon SJ, Kim HT (2015) Sol–gel synthesis of photoactive kaolinite-titania: effect of the preparation method and their photocatalytic properties. Appl Surf Sci 331:98–107. https://doi.org/10.1016/j.apsusc.2014.12.199

Shao GN, Imran SM, Jeon SJ, Engole M, Abbas N, Salman Haider M, Kang SJ, Kim HT (2014) Sol–gel synthesis of photoactive zirconia–titania from metal salts and investigation of their photocatalytic properties in the photodegradation of methylene blue. Powder Technol 258:99–109. https://doi.org/10.1016/j.powtec.2014.03.024

Sobsey MD, Brown J (2012) Boiling as household water treatment in Cambodia: a longitudinal study of boiling practice and microbiological effectiveness. Am J Trop Med Hyg 87(3):394–398. https://doi.org/10.4269/ajtmh.2012.11-0715

Syafrudin M, Kristanti RA, Yuniarto A, Hadibarata T, Rhee J, Al-onazi WA, Algarni TS, Almarri AH, Al-Mohaimeed AM (2021) Pesticides in drinking water—a review. Int J Environ Res Public Health 18(2):468. https://doi.org/10.3390/ijerph18020468

Thill A, Zeyons O, Spalla O, Chauvat F, Rose J, Auffan M, Flank AM (2006) Cytotoxicity of CeO 2 nanoparticles for Escherichia coli . physico-chemical insight of the cytotoxicity mechanism. Environ Sci Technol 40(19):6151–6156. https://doi.org/10.1021/es060999b

Tsao NH, Malatesta KA, Anuku NE, Soboyejo WO (2015) Virus filtration in porous iron (III) oxide doped ceramic water filters. Adv Mater Res 1132:284–294. https://doi.org/10.4028/www.scientific.net/AMR.1132.284

Ubomba-Jaswa E, Navntoft C, Polo-López MI, Fernandez-Ibáñez P, McGuigan KG (2009) Solar disinfection of drinking water (SODIS): an investigation of the effect of UV-A dose on inactivation efficiency. Photochem Photobiol Sci 8(5):587. https://doi.org/10.1039/b816593a

UN (2019) The United Nations world water development report 2019: leaving no one behind

Vargas-Reus MA, Memarzadeh K, Huang J, Ren GG, Allaker RP (2012) Antimicrobial activity of nanoparticulate metal oxides against peri-implantitis pathogens. Int J Antimicrob Agents 40(2):135–139. https://doi.org/10.1016/j.ijantimicag.2012.04.012

Vega-Jiménez AL, Vázquez-Olmos AR, Acosta-Gío E, Álvarez-Pérez MA (2019) In vitro antimicrobial activity evaluation of metal oxide nanoparticles. Nanoemulsions Prop Fabr Appl 78812(2):1–18

Verma S, Daverey A, Sharma A (2017) Slow sand filtration for water and wastewater treatment—a review. Environ Technol Rev 6(1):47–58

Waddington H, Snilstveit B (2009) Effectiveness and sustainability of water, sanitation, and hygiene interventions in combating diarrhoea. J Dev Eff 1(3):295–335. https://doi.org/10.1080/19439340903141175

Wang Z, Lee Y-H, Wu B, Horst A, Kang Y, Tang YJ, Chen D-R (2010) Anti-microbial activities of aerosolized transition metal oxide nanoparticles. Chemosphere 80(5):525–529. https://doi.org/10.1016/j.chemosphere.2010.04.047

Wen X, Chen F, Lin Y, Zhu H, Yuan F, Kuang D et al (2020) Microbial indicators and their use for monitoring drinking water quality—a review. Sustainability 12(6):2249

Weststrate J, Dijkstra G, Eshuis J, Gianoli A, Rusca M (2019) The sustainable development goal on water and sanitation: learning from the millennium development goals. Soc Indic Res 143:795–810

World Health Organization (2006) Guidelines for drinking-water quality: First addendum to the third edition, volume 1: recommendations

World Health Organization (2022) Guidelines for drinking‑water quality: Fourth edition incorporating the first and second addenda (4th ed + 1st add + 2nd add). World Health Organization. https://apps.who.int/iris/handle/10665/352532

World Health Organization (2020) State of the world’s sanitation: an urgent call to transform sanitation for better health, environments, economies and societies

Yekta R, Vahid-Dastjerdi L, Norouzbeigi S, Mortazavian AM (2021) Food products as potential carriers of SARS-CoV-2. Food Control 123:107754

Download references

Acknowledgements

We acknowledge Mkwawa University College of Education (MUCE) for material support

Author information

Authors and affiliations.

Department of Chemistry, Mkwawa University College of Education, University of Dar es Salaam, P.O. Box 2513, Iringa, Tanzania

Godfrey Michael Shayo, Elianaso Elimbinzi, Godlisten N. Shao & Christina Fabian

You can also search for this author in PubMed   Google Scholar

Contributions

GMS participated in designing, writing, and submitting the manuscript. GNS originated the water purification system idea and conducted research relating to chemical contaminants in water and final approval of the version to be submitted. CFP involved in organization of the manuscript, editing of the manuscript, and revision of the manuscript critically for important intellectual content. EE was a major contributor to the manuscript's writing and interpretation of the relevant literature. All authors have read and approved the manuscript.

Corresponding author

Correspondence to Godfrey Michael Shayo .

Ethics declarations

Ethics approval and consent to participate, consent for publications, competing interests.

The authors declare that they have no competing interests.

Additional information

Publisher's note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ .

Reprints and permissions

About this article

Cite this article.

Shayo, G.M., Elimbinzi, E., Shao, G.N. et al. Severity of waterborne diseases in developing countries and the effectiveness of ceramic filters for improving water quality. Bull Natl Res Cent 47 , 113 (2023). https://doi.org/10.1186/s42269-023-01088-9

Download citation

Received : 05 May 2023

Accepted : 17 July 2023

Published : 24 July 2023

DOI : https://doi.org/10.1186/s42269-023-01088-9

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Waterborne diseases
• Developing countries
• Drinking water
• Water contaminants
• Water-filtration strategies
• Water quality

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

The PMC website is updating on October 15, 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• Int J Environ Res Public Health

Narrative Review of Primary Preventive Interventions against Water-Borne Diseases: Scientific Evidence of Health-EDRM in Contexts with Inadequate Safe Drinking Water

Emily ying yang chan.

1 Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response, Hong Kong, China; [email protected]

2 Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK

3 JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China; kh.ude.khuc.knil@9207515511 (K.H.Y.T.); [email protected] (C.D.); kh.ude.khuc@miKHJ (J.H.K.); kh.ude.khuc@kowkokk (K.O.K.)

4 GX Foundation, Hong Kong, China; moc.oohay@dcmaraik

5 Accident & Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China

Kimberley Hor Yee Tong

Caroline dubois, kiara mc donnell, jean h. kim, kevin kei ching hung, kin on kwok.

6 Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong, China

7 Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, China

8 Hong Kong Institute of Asia-Pacific Studies, The Chinese University of Hong Kong, Hong Kong, China

Associated Data

Not available.

Waterborne diseases account for 1.5 million deaths a year globally, particularly affecting children in low-income households in subtropical areas. It is one of the most enduring and economically devastating biological hazards in our society today. The World Health Organization Health Emergency and Disaster Risk Management (health-EDRM) Framework highlights the importance of primary prevention against biological hazards across all levels of society. The framework encourages multi-sectoral coordination and lessons sharing for community risk resilience. A narrative review, conducted in March 2021, identified 88 English-language articles published between January 2000 and March 2021 examining water, sanitation, and hygiene primary prevention interventions against waterborne diseases in resource-poor settings. The literature identified eight main interventions implemented at personal, household and community levels. The strength of evidence, the enabling factors, barriers, co-benefits, and alternative measures were reviewed for each intervention. There is an array of evidence available across each intervention, with strong evidence supporting the effectiveness of water treatment and safe household water storage. Studies show that at personal and household levels, interventions are effective when applied together. Furthermore, water and waste management will have a compounding impact on vector-borne diseases. Mitigation against waterborne diseases require coordinated, multi-sectoral governance, such as building sanitation infrastructure and streamlined waste management. The review showed research gaps relating to evidence-based alternative interventions for resource-poor settings and showed discrepancies in definitions of various interventions amongst research institutions, creating challenges in the direct comparison of results across studies.

1. Introduction

Water-borne diseases (WBDs) are infectious diseases, such as cholera, shigella, typhoid, hepatitis A and E, and poliomyelitis, that are transmitted to humans through contaminated water [ 1 ]. These infections are caused by a number of bacterial, viral, and parasitic organisms where there is inadequate sanitation, hygiene, and safe water for drinking, cooking and cleaning [ 2 ]. There is a high prevalence of WBDs in low- and middle- income countries in tropical and subtropical regions. The major etiological agents for WBDs in such contexts are Rotavirus and Escherichia coli . Bacteria Shigella and parasite Cryptosporidium are also major agents globally [ 1 ]. A list of pathogens transmitted through water can be found in Appendix A . According to the World Health Organization (WHO), WBDs account for an estimated 3.6% of the total disability-adjusted life year global burden of disease and are the leading causes of human morbidity and mortality worldwide, causing approximately 1.5 million deaths annually [ 1 ]. Furthermore, diarrheal disease is the second leading cause of death in children under five years old [ 2 ]. It is estimated that children under three years old in low-income countries experience an average of three episodes of diarrhea annually, which can in turn, lead to malnutrition, severe dehydration and increased risk of developing deficiency disorders [ 3 ].

In many developing regions, WBDs are associated with physical water scarcity, defined as the lack of available water resources as well as economical water scarcity, defined as the lack of investment in water infrastructure for available water use [ 4 , 5 , 6 ]. It is estimated that 56% of the world’s population have unsafe sources of water, contaminated by sewage, septic tanks, latrines, or other sources [ 2 ]. In areas of water scarcity, or unsafe sanitation, populations are prone to poor hygiene practices. Specifically, there are four main transmission routes for WBDs: (1) water-borne, exposure to pathogen through ingestion of contaminated water; (2) water-washed, exposure to pathogens through a person-to-person or fecal-oral route due to poor personal hygiene; (3) water-based, exposure to pathogen through skin contact with contaminated water that has passed through an aquatic animal; and (4) water-related, insect vectors that breed near the water [ 7 ]. Worldwide, 150 million people still rely on surface water sources (i.e., lake water, ponds and springs) that possess high risk of contamination [ 8 , 9 ]. The lack of access to water, sanitation and hygiene (WASH) in these communities is one of the world’s most urgent public health issues, with 2.2 billion people lacking safely managed drinking water and 4.2 billion people lacking safely managed sanitation in 2015-2018 [ 1 , 9 ].

Socioeconomic factors can determine an individual’s access to and use of clean water, as those with lower income and educational level may be unaware to the consequences of using unsafe water and inadequate sanitation practices or infrastructure or have access to the resources necessary for improvement [ 5 ]. Other factors could further exacerbate the disease burden of WBDs in rural communities such as lack of WASH policies; poor maintenance of sanitation facilities; environmental discharges of untreated waste; and water scarcity associated with climate change [ 1 , 9 ]. Furthermore, WBDs can cause economic burdens and be a barrier to the socioeconomic development of communities. Loss of household income can result from cost of care and treatment, or loss of economic productivity due to sickness. The actual economic burden of WBDs is difficult to estimate due to lack of health professional capacity, under-reporting of illness in the case of asymptomatic or self-limiting infections, and non-binary diagnostic parameters [ 10 ]. However, a study conducted by the WHO Regional Office for Africa in 2005 estimated that the total economic loss due to cholera could be up to 156 million USD in the WHO African region that encompasses 47 member states [ 7 ].

The WHO Health Emergency and Disaster Risk Management (health-EDRM) Framework [ 11 ], developed in line with the Sendai Framework for Disaster Risk Reduction 2015-2030 [ 12 ], refers to the structured analysis and management of health risks brought upon by emergencies and disasters. These hazardous events can include biological hazards, such as WBDs [ 11 , 12 ]. The health-EDRM focuses on disease prevention through hazard and vulnerability reduction, preparedness, and response and recovery interventions, emphasizing community involvement in mitigating the burden of hazardous events. Under the health-EDRM framework, hazard preventive interventions can be implemented at three levels: primary, secondary, or tertiary prevention levels [ 11 ]. Primary prevention aims to reduce health risks and the onset of disease through health promotion, education, and awareness; secondary prevention aims to stop disease progression by screening and identifying infected individuals, while tertiary prevention focuses on treatment of disease [ 13 ]. Primary prevention, and interruption to reduce transmission, is the most cost-effective method in reducing the burden of infectious disease per capita in populations with poor access to healthcare [ 13 , 14 ]. Effective bottom-up approaches from an empowered community, along with top-down governance and policy, allow successful implementation of primary prevention and behavioral modification throughout the disaster management cycle: prevention, mitigation, preparedness, response and recovery [ 11 , 12 , 13 ]. Interventions that aim to improve access to WASH are main bottom-up approaches for reducing risks of WBD in endemic rural areas [ 15 ].

The United Nations Sustainable Development Goals 2015-2030 (SDG) aims to eradicate poverty and achieve a more sustainable future for all [ 16 ]. The alleviation of the burden of WBDs globally will have a cross-cutting impact on several SDGs [ 16 ]. This review examines the available published literature on primary preventive interventions against WBDs, the strength of evidence behind these interventions, and the feasibility or barriers of successfully applying health-EDRM approaches for WBD prevention in contexts with inadequate safe drinking water, or resource-poor settings.

2. Materials and Methods

A literature search on studies with interventions designed to reduce transmission of WBD was conducted.

2.1. Search Strategy

PubMed, Science Direct, Web of Science, Medline, and Scopus databases were searched in March 2021 using the MeSH key words: water, sanitation, hygiene, WASH, waterborne disease, intervention, prevention, primary prevention, measures, health-EDRM, unclean water, inadequate safe drinking water, population and community Boolean operators then combined the key words by similarity of definition into a search term: ((water AND sanitation AND hygiene) OR WASH) AND (waterborne disease) AND (intervention OR prevention OR primary prevention OR measures OR health-EDRM) AND (unclean water OR inadequate safe drinking).

2.2. Inclusion and Exclusion Criteria

The search was limited to human studies in international peer-reviewed journals, online reports and electronic books published in English. The search included any studies relating to any WBDs, with no distinction between causative agent or symptoms. Eligible studies were retrieved, and their bibliographies were checked for further relevant publications. To obtain the most relevant literature for this review, the titles and abstracts were screened against the inclusion and exclusion criteria.

Inclusion criteria:

• English-language based article.
• Published between 1 January 2000 and 24 March 2021.
• Effectiveness of primary prevention methods against waterborne diseases mentioned in the abstract.

Exclusion criteria:

• Abstracts that did not mention primary prevention methods against WBD.
• Papers studying only foodborne and/or airborne diseases.
• Papers studying secondary and/or tertiary level prevention.

Full texts of potential papers were assessed and excluded if the effectiveness of the primary prevention intervention was not reported. Through a snowballing method, further texts were identified through the references of the identified publications that fit into the inclusion criteria.

The identified papers were then categorized according to the Oxford Centre for Evidence-Based Medicine (OCEBM) 2009 Levels of Evidence ( Table 1 ) which determines the strength of evidence of a piece of research according to its study design and methodology [ 17 ]. The papers obtained from each database were collected and consolidated, and duplicates were removed.

The Oxford Centre for Evidence-Based Medicine (OCEBM) 2009 Levels of Evidence [ 17 ].

The process of identifying relevant publications is outlined in Figure 1 . The initial database search identified 994 search records, of which 64 were removed due to duplication. This was refined to 140 records following the screening of titles and abstracts, after which the full-texts were read and assessed for inclusion. From these results, 32 full texts were included, in addition to 56 identified through the snowballing method. The total number of studies included in this review are 88 [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 ].

Flowchart showing the search results and exclusion process, according to databases searched, duplicates removed, publications screened, and the final number of studies included in this literature review.

3.1. Strength of Evidence of Identified Studies

Each of the 88 identified studies were assessed in strength of evidence of their studies, according to the OCEBM Levels of Evidence ( Table S1 ) [ 17 ].

The included studies were categorized according to the type of intervention studied, which resulted in a group of eight common bottom-up, non-pharmaceutical, primary preventive interventions, based on the health-EDRM framework. These were: two “personal” protective practices (regular handwashing, intake of prophylactic supplements), four “household” practices (household water treatment, household water storage, maintain household cleanliness, household waste management) and two “community” practices (build community infrastructure, conduct community education) were identified. 13% of the studied literature was associated with personal practices, 65% with household practices and 22% with community practices. The review of evidence was disaggregated according to the eight preventive interventions, and categorized according to OCEBM Levels of Evidence [ 17 ], which can be found in Table 2 .

Overview of Health-EDRM Primary Prevention Approaches against Waterborne Diseases in the reviewed articles, categorized by the Levels of Evidence based upon Oxford Centre for Evidence-Based Medicine (OCEBM) criteria [ 17 ]. (Please see Table S1 for details).

1 Of the 88 publications reviewed, some included findings on more than one prevention measure, and are counted more than once.

The comparison of the strength of evidence of the reviewed literature ( Table 2 ) showed that the largest proportion (35%) of identified publications fell into Level 1B classification, which includes randomized controlled trials with narrow confidence interval and the majority of these studies investigated the effects of water treatment for WBD prevention. Level 4 studies, including cross-sectional mixed-method studies and case series studies, accounted for 17% of the identified publications, which mainly evaluated the possible association between perceptions, WBD prevalence and preventive interventions in targeted populations with interviews, questionnaires and surveys. Among the 88 studies, no systematic review of case-control studies and only one systematic review of cohort studies was identified. Level 3B studies, including case-control studies, only accounted for 3% of the identified publications. There was more literature on preventive interventions at household levels (65%) with a significantly stronger study design, compared to interventions at community (22%) and personal levels (13%). Regarding individual primary preventive interventions, high-strength evidence is most available concerning the practice of water treatment, and lacking at different levels in practices of household waste management (6%) and household cleanliness (7%), with only one study available for chemoprophylaxis (0.6%).

3.2. Overview of Studies Included for Analysis

Table 3 , Table 4 , Table 5 and Table 6 summarize each of the 8 primary preventive interventions against WBDs at personal, household and community levels. Without distinction by causative agent, disease symptomology, or therapy, the tables are a compilation and comparison of each preventive methods, according to their potential health risk, desired behavioral changes, potential health co-benefits, enabling and limiting factors and strength of evidence available in published literature. The tables also identify suggested alternative measures for each intervention, which are variations of the action that have the intention of achieving a similar result, but may be implemented differently, for example, if the materials or resources required to undertake the intervention are not available or accessible.

Personal protection practices as primary preventive interventions against WBDs: regular handwashing and intake of prophylactic supplements.

Household practices as primary preventive interventions against WBDs: household water treatment and household water storage.

Household practices as primary preventive interventions against WBDs (continued): household cleanliness and household waste management.

Community practices as primary preventive interventions against WBDs: community infrastructure and community education.

The majority of the reviewed studies demonstrated positive relationship between primary preventive interventions on diarrhea incidence and disease transmission by addressing WBD associated health risks, however, there is a lack of assessed literature that quantifies the extent of the efficacy of such interventions on disease reduction. In the case of water treatment, many studies conferred a well-established link between less contaminated household drinking water and reduction in diarrhea risk, but not the effectiveness of WBD reduction and associated health outcomes, such as mortality, within the community [ 29 , 41 , 51 , 55 , 59 , 64 , 70 , 71 , 83 , 85 , 100 , 101 ].

4. Discussion

This narrative review examined evidence of eight primary preventive interventions against WBDs. The interventions share certain enabling and limiting factors that affect the success of proposed preventative interventions when applied to the health-EDRM framework: resources accessibility and affordability, accommodating community health facilities, correct understanding of WBD associated health risks, sustainable behavioral change, cultural relevance, and cross-sector collaboration with top-down contribution from policy makers. By contrast, socioeconomic barriers, geographical location and cultural incompetence were noted as key limiting factors.

4.1. Top-Down, Capacity Building, Cultural Relevance and Post-Intervention Monitoring

Many of the primary preventive interventions examined in this review were complex interventions that relied upon a combination of enabling factors to reduce WBD. For instance, a large proportion of interventions required access to material resources, ranging from simple soap to materials for constructing facilities. However, in very low-resource settings, contributions from authorities and policy-makers are also essential in order to provide these material resources. For instance, in order to ensure sustainable delivery of safe water supply and waste management systems in low income areas, multi-sectoral collaboration and coordination from local and national-level authorities is necessary. Furthermore, in order to successfully implement behavioral interventions such as the appropriate use of prophylactic supplements, government support and capacity within health system is often required. Policy makers should, therefore, re-prioritize the delivery of sustainable water and sanitation services as the importance of safe water access to reduction in WBD incidence has been reinforced in this review.

This review noted that primary interventions for reducing WBDs also often require addressing pervasive misconceptions, attitudes and social norms. For instance, WASH- education campaigns were successful in teaching participants to associate contaminated water and poor hygiene with diarrhea-related illnesses [ 26 , 28 , 50 , 77 , 80 , 99 , 105 ]. These campaigns were successful in increasing positive change in disease prevention behaviors at an individual level, as well as improvements in the hygiene practice of pupils in health education campaigns [ 35 ]. Addressing misconceptions (the perception that boiling is sufficient in killing all waterborne microbes [ 29 ]), cultural traditions (painting of mud floors with animal dung [ 47 ]) and religious beliefs (WBD outbreak as a result of ancestral curse and witchcraft [ 21 ]), allows individuals to develop understanding of the rationales behind the preventative interventions. Education and the transfer of knowledge should be delivered in a culturally-sensitive manner, whilst accounting for language needs and health literacy of the target population to guarantee accurate uptake of information [ 32 , 102 ]. The implementation of other primary prevention initiatives should therefore follow the health-EDRM framework with emphasis on capacity building and cultural relevance to prompt long-term positive behavioral changes [ 11 ], allowing the evaluation of the real-life impacts and feasibility of interventions. We noted in addition to cultural relevance, intervention adherence requires contextual relevance (improved buckets for water collection were more popular amongst refugee camp inhabitants despite lower effectiveness in water quality protection compared to proper chlorination, as improved features, such as small handle and lid, were more appreciated within the culture [ 43 ]). However, this review noted that in some cases, the WBD interventions lacked long-term impacts such as improvements in child health (no difference in prevalence of child diarrhea in post-intervention follow-up [ 76 ]), and improvements in hygiene practices (no difference in self-reported handwashing behavior [ 76 ], lack of adoption of water treatment into regular household routines despite distribution of filters and soap [ 21 ]). These findings may indicate decreasing compliance with interventions with time and the necessity of post-intervention small-scale monitoring to ensure sustainable positive behaviors. Hence, continued behavioral monitoring, such as regular inspection of chlorine levels in house-hold stored water, may be necessary to improve baseline water quality levels and maintain household capacity building.

4.2. Long-Term Sustainability and Long-Term Co-Benefits

Many It is important to note that the effect and impacts of preventive interventions are cross-cutting. The uptake of one intervention should not impede the practice of another, and despite the mixed evidence regarding the cost-effectiveness of multi-intervention programs compared to single intervention [ 19 , 28 , 30 , 34 , 35 , 39 , 45 , 46 , 47 , 56 , 58 , 59 , 77 , 87 , 95 , 99 , 104 , 105 ], different interventions could be promoted in rural communities to maximize the potential positive health impacts from improved water, sanitation and hygiene behavior. For instance, the construction of community infrastructures, such as filtration system that delivers clean water to storage tanks or directly to homes [ 54 , 95 ], and sewer system that allows safe waste disposal [ 67 ], did not only improve access to safe water but also allowed more effective uptake of certain personal and household interventions that rely on adequate baseline water quality in the community. Despite the higher costs in constructing community infrastructure, it has been shown to influence positive behavioral changes within a community (increase in the number of households with hygiene enabling facilities and proper use and maintenance of toilets and sewers [ 27 , 67 ]). This could reduce future expenditures on the prevention of disease outbreak or medical costs for individuals and households. Additionally, lowered medical expenses from reduced incidence of diarrheal illness can allow for greater ability to purchase resources, such as firewood and purifiers, to maintain water quality [ 26 , 48 , 62 ]. Sustainable and continuous implementation is required for all interventions to ensure maximum efficacy, and alternatives to such behavior should also be explored. Certain interventions, for example, waste management and handwashing, also exert co-benefit in reducing risks from other biological hazards under the health-EDRM framework, such as food-borne, vector-borne and droplet-borne diseases [ 111 , 112 , 113 ].

4.3. Research Gaps Identified in Current Published Literature

This review has identified six major research gaps in the literature relating to health-EDRM primary preventative interventions for WBDs.

First, current studies focus on reducing exposure to hazards, such as contaminated water. A total of 73% of the studies in this review proposed interventions, such as improved water treatment, water storage and waste disposal in household and community settings. There is little evaluation on the efficacy of managing other causal factors of in WBD. Future studies can examine interventions that target hazard preparedness and risk-reduction within exposed populations.

Second, research outcomes are skewed towards reduction in diarrhea incidence, with lack of evidence on the reduction of other WBD-associated symptoms, such as vomiting and stomach cramps [ 26 , 35 , 38 ]. Diarrhea is a leading cause of mortality and morbidity, especially in children under five years of age, however, it is not the sole indicator of WBD. Nor are WBDs the only cause of diarrhea, as symptoms can be associated with infectious diseases that transmit through other mechanisms, such as HIV and Ebola [ 114 , 115 ]. The observed reduction in incidence of solely diarrhea from an intervention does not necessarily represent the true risk reduction as related to WBDs. The impact of the intervention on WBD prevention is at risk of being overestimated if other diseases are present or underestimated if other symptoms are not considered. Future studies that evaluate the efficacy of primary prevention interventions should consider evaluating non-diarrheal symptoms such as vomiting and stomach cramps along with diarrhea, to strengthen the accuracy and validity of such methods as WBD preventative behavior, particularly in vulnerable or resource-poor communities.

Third, there is limited research on alternatives of preventive interventions for implementation in resource-poor or material-scarce settings. For example, the beneficial effect of handwashing with soap is consistent across various studies, but there is little evidence to support the use of alternatives, such as ash in communities where soap is not available [ 2 , 116 ]. The efficacy of such alternatives has been demonstrated in averting the transmission of droplet-borne and vector-borne, but not in waterborne diseases [ 112 , 113 ]. As almost 80% of all illnesses and deaths in low and middle-income countries are linked to poor water and sanitation conditions, further evidence-based and scientifically-rigorous studies should be conducted to better inform public health interventions in these contexts where financial and material resources are lacking [ 117 ]. The scientific merits of such alternatives should, therefore, be further evaluated and used to build effective strategies in regions that experience physical and economic water scarcity [ 6 ].

Fourth, there is inconsistency in the recommendations by research institutions for certain preventive interventions between research institutions. For handwashing interventions, the time required for washing to ensure proper hand hygiene was not specified in most studies [ 19 , 20 , 35 , 38 , 42 , 45 , 46 , 47 , 60 , 61 , 68 , 72 , 73 , 78 , 79 , 80 , 104 , 105 ]. On the other hand, while the WHO defines improved sanitation as better access to sanitation facilities [ 114 ], many of the reviewed studies did not specify what measures can be put in place in a household to achieve improved sanitation. There is also lacking evidence in the ways to maintain appropriate use and cleanliness of household and community facilities. This creates challenges in assessing the competitiveness of results.

Fifth, there is little evidence on the efficacy of chemoprophylaxis against WBD. Only one study included prophylactic supplements in their intervention, where a diarrhea pack with water purification sachet was distributed within the community [ 56 ]. Comparative evaluation for variation of preventive interventions, such as different types of prophylactic supplements and types of water storage containers are useful in the planning of cost-effective interventions and should be implemented in future studies. The use of the more economical regular soap is now favored in most handwashing campaigns as similar reduction in diarrheal incidence has been observed with the use of regular soap and anti-bacterial soap [ 68 , 72 ]. Due to the search strategy and key words used, vaccination was not identified as an intervention. However, it must be acknowledged immunization has been regarded as one of the most effective primary prevention methods against viral illnesses with observed effects in food-borne and vector-borne diseases [ 111 , 112 ]. Vaccines against typhoid, hepatitis A and cholera are recommended by the WHO to travelers visiting areas of increased WBD risks [ 118 ]. Cholera vaccination is also included in routine childhood vaccination programs in many countries worldwide where risk is high, although the high costs of procurement, delivery, and program implementation, coupled with gaps in community education and awareness, are barriers to vaccine delivery in low-income countries where WBD is most prevalent [ 115 ].

Sixth, there was limited evidence in comparative evaluation for variations of primary preventive interventions, such as efficacy of the different water storage containers, or different materials to maintain household cleanliness. Strengthening the available evidence in the above-mentioned areas will allow development of strategies for protecting against WBDs in low-resource settings.

This study summarized the most common eight primary prevention interventions identified in WASH-related literature and the strengths and limitations of their implementation to improve Health-EDRM outcomes in low-resource communities. There is value in subsequent studies assessing the risks of WASH at multiple levels as pertaining to these interventions through a number of alternative frameworks, including the WASH cluster strategic operations framework and other ecological models.

4.4. Study Strengths and Limitations

There are some limitations to this review. The review excluded non-English-based literature, non-electronically accessible civilian-published literature, grey literature or any publications before 2000. The review also excluded annual reports from specialized organizations, United Nations reports, or reports by national governments. The eight preventative interventions identified in this review do not constitute all of the non-pharmaceutical preventative behavior that is available in the mitigation of WBD. Moreover, this review has not disaggregated findings by pathogen, for example difference in efficacy of interventions between viral, bacterial, and parasitic diseases. This area warrants further research, in order to review predictive success of interventions across different areas with particular disease patterns.

Despite the limitations, this review was able to identify valuable behavioral interventions for the planning and implementation of health policies that prevent water-borne biological hazards. Preparedness in communities facing specific vulnerabilities could be reinforced through multi-faceted and multi-sectoral collaboration, with an emphasis on four key areas (risk understanding, governance, preparedness and resilience) as suggested by the primary prevention model for disaster risk reduction in the Sendai Framework for Disaster Risk Reduction [ 12 ].

5. Conclusions

WBD-associated health risks will remain an ongoing biological hazard to the rapidly globalized world, which highlights the importance of sustainable strategies. In order to meet the SDGs by 2030 [ 16 ], multi-sectoral, multi-level capacity building will be needed for sustainable health-EDRM practices, with research for the effectiveness of alternative methods to WBD prevention in low resource settings. The implementation of policies such as early warning systems to inform the associated health risks of seasonal outbreaks and community education that focuses on early symptom identification with subsequent health-seeking behaviors could allow for better prevention and control of unexpected outbreaks. Such policies would also be beneficial in the case of the recent COVID-19 pandemic as low-resource communities are more likely to be affected by the pandemic. Evidence-based research must be translated into feasible and effective actions for disaster risk mitigation and risk reduction.

Supplementary Materials

The following are available online at https://www.mdpi.com/article/10.3390/ijerph182312268/s1 , Table S1: Relevant interventions, study design, relevant key findings, and conclusion of each utilized reference, Table S2: Coding for each type of intervention in Table S1.

Pathogens transmitted through drinking water are diverse in causative agent, characteristics, and health significance. Table A1 shows pathogens that are globally significant for water safety and supply management [ 119 ].

Pathogens associated with water-borne diseases, by global significance of incidence and disease severity.

Author Contributions

Conceptualization, E.Y.Y.C. and C.D.; methodology, C.D. and K.M.D.; formal analysis, K.M.D. and K.H.Y.T.; writing—original draft preparation, K.H.Y.T. and C.D.; writing—review and editing, E.Y.Y.C., J.H.K., K.K.C.H. and K.O.K.; supervision, E.Y.Y.C. All authors have read and agreed to the published version of the manuscript.

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Data availability statement, conflicts of interest.

The authors declare no conflict of interest.

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.