Effects of mothers’ water, sanitation and hygiene habits on diarrhoea and malnutrition among children under 5 years in Nepal

Abstract

Introduction

Diarrhoea and malnutrition (stunting, wasting and underweight) are major public health problems in developing countries, including Nepal. Improved water, sanitation and hygiene (WASH) may reduce the global disease burden by as much as 10.0%. This paper aims to examine the effects of the WASH components on diarrhoea and malnutrition rates among children under 5 years in Nepal.

Methods

The 2016 Nepal Demographic and Health Survey datasets were examined. The sample included children with outcome measures of diarrhoea (n=4846) and malnutrition (n=2363 for stunting, n=2360 for wasting and n=2370 for underweight). The study participants were mothers aged 15–49 with children under 5 years on the survey day. A multivariate logistic regression analysis was performed. The potential confounders were identified through Directed Acyclic Graphs software.

Results

Among children under 5 years of age, 7.6% were suffering from diarrhoea, 35.6% from stunting, 9.8% from wasting and 27.1% from underweight. The absence of a fixed place for handwashing was associated with diarrhoea (adjusted OR (aOR)=1.63; 95%CI 1.20 to 2.22). Having no access to an improved toilet arrangement was associated with stunting and being underweight (aOR=1.78; 95%CI 1.25 to 2.55 and aOR=1.45; 95%CI 1.03 to 2.06, respectively). Having no fixed place for handwashing was associated with wasting (aOR=1.52; 95%CI 1.00 to 2.30).

Conclusions

There is a significant relationship between diarrhoea and combined WASH facilities and mixed effects of an individual WASH components for malnutrition. A fixed place for handwashing can increase the rate of handwashing with soap practices. Importantly, combined WASH components can have positive effects on the control of diarrhoea but not necessarily on the prevention of malnutrition. Further, the results for individual WASH components in the prevention of malnutrition were also mixed. Therefore, further studies are needed to examine the association between combined WASH components and malnutrition.

WHAT IS ALREADY KNOWN ON THIS TOPIC

• It is well established that unimproved water, sanitation and hygiene (WASH) services contribute to diarrhoea, and children suffering from severe diarrhoea are at risk of malnutrition.

• The main risk factors for diarrhoeal diseases include inadequate access to and utilisation of WASH services by household members and carers.

• Improved WASH facilities can reduce diarrhoea by 50.0% and account for 50.0% of diarrhoeal diseases that occur among malnourished children.

WHAT THIS STUDY ADDS

• This study brings information to bear on outcomes of having limited or no access to improved water sources, improved toileting and handwashing with soap facilities.

• This study evaluates combined WASH components used by mothers and the diarrhoea and malnutrition outcomes for their children.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• This study highlights the need for research to prioritise communicable diseases such as diarrhoea and their relationship with malnutrition. This includes validating innovative health promotion models and evaluating integrated WASH strategies.

• Community engagement and behaviour change interventions are crucial for preventing diarrhoea and reducing malnutrition risks.

• Policymakers should develop a WASH policy to control communicable diseases and reduce malnutrition.

Introduction

Diarrhoea is one of the leading causes of morbidity and mortality among children under 5 years, worldwide.¹ Approximately 1.7 billion children experience diarrhoea each year, and of these, 443 832 deaths were reported by the WHO in 2024 as a result of diarrhoea.² Severe episodes of diarrhoea are most common in the South-East Asia Region (SEAR) and Sub-Saharan Africa (SSA), accounting for 26.0% and 50.0% of cases, respectively.³ The global mortality rate related to diarrhoea is around 27.0% among children under 5 years, with 90.0% of these deaths occurring in SEAR and SSA.¹ In Nepal, diarrhoea ranked among the top 10 disease burdens, affecting 10.4% of children under 5 years in 2022, with an increase to 11.5% in 2024.^{4 5} Several determinants contribute to diarrhoea, including demographic, sociocultural, economic and environmental factors, along with inadequate healthcare services.⁶ Children aged between 6 and 23 months⁷ and female children from low-income households are particularly vulnerable.^{8 9} Inadequate breastfeeding practices and malnutrition have been strongly linked to an increased risk of diarrhoea.¹⁰ Mothers with higher levels of education are more aware of effective preventive measures for diarrhoea.¹¹ Furthermore, cultural beliefs such as eating a banana during an episode of diarrhoea can delay access to professional medical treatment, increasing health risks and potential mortality.11,13 In rural communities of Nepal, some people believe that diarrhoea is caused by cold, fever and evil spirits, which can negatively impact health promotion practices, such as handwashing with soap.^{6 14} Others believe that diarrhoea can be caused by the eruption of teeth among children and can be cured by eating curd.¹⁵

Socioeconomic status plays an important role in supporting good health; households with adequate incomes can more easily access nutritious food, improved water, sanitation and hygiene (WASH) facilities and quality healthcare services, thereby reducing the incidence of diarrhoea and enhancing overall health.¹⁶ Conversely, children from low-income households, marginalised populations and those with limited access to improved WASH facilities are varyingly affected by diarrhoea.¹⁷ Therefore, a multilevel examination of the components of WASH is warranted, as highlighted in previously published papers focusing on mothers and caregivers at the household level in Nepal.^{18 19} The relationship between diarrhoea and WASH practices is well documented,²⁰ with improved WASH significantly reducing the incidence of diarrhoea.^{21 22} A study conducted in Pakistan showed that improved WASH can reduce malnutrition by 36.0%.²³ This reduction is primarily attributed to decreased rates of diarrhoea and other infections caused by poor WASH, which in turn helps improve nutritional status, particularly among children under 5 years. Malnutrition remains a major public health problem, measured by indicators such as height-for-age (stunting), weight-for-height (wasting) and weight-for-age (underweight), particularly affecting children under 5 years.²⁴ In 2022, the global prevalence of stunting among children under 5 years was 22.0%, wasting was 7.0%²⁵ and underweight was 12.3%.²⁶ Fifty per cent of deaths among children were due to malnutrition.²⁷

Factors affecting child malnutrition include child age, sex, dietary habits, breastfeeding practices, healthcare access, maternal weight, education, employment and economic status.28,33 Unimproved WASH practices are linked to poor childhood growth and development due to frequent infection, such as diarrhoea, and the resulting high mortality is well established.^{34 35} Malnutrition and diarrhoea are bidirectional and interrelated.³⁶ Diarrhoea can lead to malnutrition, and malnourished children are more susceptible to diarrhoea.³⁷ Fifty per cent of all child deaths are associated with malnutrition,³⁸ with similar rates observed in children with diarrhoea due to unimproved WASH.^{39 40} In Nepal, approximately half of the total under-five mortality is associated with malnutrition exacerbated by recurrent diarrhoea and other infections.³⁰ Given the lack of mothers’ knowledge gaps, particularly combined WASH facilities and diarrhoea and malnutrition at home yet to be studied. This paper aims to assess the effects of WASH on diarrhoea and malnutrition in children under 5 years of age in Nepal. This study will explore the relationship between WASH facilities and the incidence of diarrhoea and malnutrition among children under 5 years in Nepal. It will highlight the critical role of improved WASH practices in reducing both conditions. The findings will provide evidence to policymakers to support the implementation of effective WASH interventions.

Methods

Study design and setting

A cross-sectional study was performed using quantitative data from the Nepal Demographic and Health Survey (NDHS) of 2016, which provided detailed information on mothers’ and children’s health and household characteristics. The sampling frame was the National Population and Housing Census records of 2011. With regards to the sample design, seven provinces comprising 75 districts were divided by rural-urban setting and by three ecological zones during the period of this study. Two districts were further divided into two additional districts during the redesigning process of the country following the new constitution of Nepal in 2015. The survey included 383 wards and 217 municipalities as eligible survey study areas.⁴¹

Sampling technique, data source and study participants

The 2016 NDHS used a multistage cluster sampling technique, selecting 383 wards proportionally as a cluster. A household listing was conducted in each selected cluster, resulting in the identification of mothers from these households (n=11 040). A total of 12 862 mothers were interviewed. After excluding mothers whose children had died within a year of birth (n=177), the unweighted sample included 4861 mothers. Using the ‘svy’ command in STATA, a weighted sample of 4887 mothers was created. Following this, the final weighted sample sizes were 4846 mothers (after excluding 41 participants with missing data) for the outcome diarrhoea; 2363 mothers (after excluding participants with missing measurements) for stunting; 2360 mothers (after excluding participants with missing measurements) for wasting; and 2370 mothers (after excluding participants with missing measurements or implausible measurement errors) for underweight (figure 1). These were measured using an anthropometric approach, which involved the systematic measurement of children’s physical properties. Identified study variables were taken from the children record (KR) and the household record (HR) files of the 2016 NDHS. The HR file was merged into the KR file. The study participants were households’ usual resident mothers, aged 15–49 years, with children under 5 years. The weighted sample for this study was 4887 once women with only deceased children were excluded.

Figure 1. Flow diagram of participants included in the study.

Inclusion and exclusion criteria 

Mothers aged 15–49 years with a child under 5 years were included in the analysis. Children who were present during the survey and had their heights and weights recorded were included; while visiting mothers, children who were not weighed or measured were excluded. Data were also excluded if incomplete (eg, unknown date of birth) and/or measurements were out of range or invalid (eg, children with height-for-age z-scores below −6 SD or above +6 SD; with weight-for-age z-scores below −6 SD or above +5 SD; or with weight for height z-scores below −5 SD or above +5 SD).

Outcome variables 

The outcome variables were diarrhoea and malnutrition among children under 5 years. Diarrhoea was measured based on mothers’ reports of their child passing watery stools more than twice in 24 hours over the last 2 weeks. Malnutrition was calculated using measured heights and weights and calculating z-scores for stunting (height for age), wasting (weight for height) and underweight (weight for age), with a cut-off point of SD/Z-score <-2. The outcome variables were binary (yes/no).

Exposure variables

Exposure variables for this study included water sources (improved/unimproved), toilet facilities (improved/unimproved), handwashing place (fixed/mobile), availability of soap and water (available/not available) and provision of combined WASH, such as the integration of water sources, sanitation facilities and the availability of water, soap and handwashing stations (available/not available). Water source data were self-reported and toilet facilities, handwashing places and availability of soap and water data were observed.

The definitions for improved and unimproved water sources and toilet facilities are provided below:

• Improved water source: piped water, public taps, standpipes, tube wells, boreholes, protected dug wells and springs, water delivered via a tanker truck and bottled water.

• Unimproved water source: water from an unprotected dug well or unprotected spring and surface water (river/dam/lake/pond/stream/canal/irrigation channel).

• Improved toilet facilities: non-shared facilities that flush to a sewer system, septic tank or pit latrine, as well as ventilated improved pit latrines, slab pit latrines and composting toilets.

• Unimproved toilet facilities: flush to a known location but not to a sewer system or septic tank, along with open defecation.

Identification of confounders 

Potential confounding variables (covariates) for the diarrhoea outcome were the child’s age in months (<12, 13–24,25-36, 37–48,49-59), mother’s and father’s education (no education, primary, secondary and school leaving certificate and above), mother’s occupation (no work, agriculture, non-agriculture), wealth index (low, middle and high), caste and ethnicity (Brahmin, Janajati, Scheduled/Untouchable and Others), current breastfeeding (yes, no), media exposure (no exposure and exposure), residence (rural and urban), ecology (plains, hills and mountains), province (Koshi, Bagmati, Madhesh, Gandaki, Lumbini, Karnali and Sudurpakshim), distance to the water source (≤30 min and >31 min) and attendance at health mother groups (not available, available, and do not know). The health mother groups refer to the community groups for women aged 15–49, who meet monthly to discuss topics related to safe motherhood, maternal and child health, nutrition, family planning, WASH and other relevant topics.⁴² For the malnutrition outcome, the same potential confounding variables were used, with the exception of how mother’s age in years was categorised. For this model, the age group categorisation was 15–24, 25–34 and older than 35. This differed from the categorisation used for the diarrhoea outcome, as childbirth at a younger maternal age might influence malnutrition but not diarrhoea. Confounders were identified using directed acyclic graphs (DAG)⁴³ and adjusted in multivariate analyses based on a p value of less than 0.05 and existing knowledge. The minimal sufficient adjustment sets for estimating the total effect of WASH on diarrhoea and malnutrition are illustrated in the given circle (online supplemental figure 1).

Data analysis

Data were analysed using STATA 15 software.⁴⁴ The sociodemographic characteristics were analysed descriptively and shown as numbers and percentages. The prevalences of diarrhoea and malnutrition were calculated by percentage through univariate analysis. The weighted sample was used for consistency across regions and clusters. Bivariate analysis was performed, and after careful identification of confounding variables using a DAG, an adjusted OR at a 95% CI with 0.05 significance levels was calculated. Bivariate and multivariate logistic regression analysis was applied to examine the effects of the WASH components on diarrhoea and malnutrition among children under 5 years. The Strengthening the Reporting of Observational Studies in Epidemiology checklist was completed (online supplemental table 1).

Results

Characteristics of study participants by diarrhoeal disease status and malnutrition types

The overall prevalence of diarrhoea among children under 5 years was 7.6% (online supplemental table 2). Of the mothers who participated, 51.3% of them were aged 25 to 34 years, and 52.6% of their children were males. A total of 34.1% of mothers and 14.8% of their husbands had no education. The highest percentage of mothers in the workforce was in the agricultural profession (45.3%). The majority of mothers had a low household wealth index score (42.2%). Eighty-five per cent of mothers identified as being of the Hindu religion and the remainder were of non-Hindu religions (Buddhism, Islam, Kirat and Christianity). A higher rate of diarrhoea occurred among children whose mothers were not exposed to newspaper (80.9%). A total of 59.2% of children from rural residences reported diarrhoeal infection compared with 40.8% of children from urban residences. The province with the highest rate (30.2%) of diarrhoea among children under 5 years was the Madhesh Province. Approximately one-third of participants reported existing health mother groups in the community.

The prevalence of stunting was 35.8%, wasting was 9.8% and underweight was 27.1% among children under 5 years. Of the children who experienced stunting, 17.0% were also underweight and 3.0% experienced wasting. Of the children who experienced wasting, 4.0% were also underweight and 3.0% experienced stunting. Of the children who were underweight, 17.0% also experienced stunting and 4.0% experienced wasting, while 3.0% experienced both wasting and stunting (figure 2).

Figure 2. Venn diagram of the distribution of stunting, wasting and underweight.

Online supplemental table 2 shows that children aged 25–36 months had the highest rate of stunting (23.8%), and 23.1% of children of this age were underweight. However, the age group with the highest rate of wasting was children younger than 12 months, at 38.5%. The rates of stunting and underweight were higher among children whose mothers and/or fathers were uneducated. When examining the impact of income, 42.3% of children in the low wealth index, 22.3% in the middle wealth index and 35.4% in the high wealth index experienced malnutrition. In relation to caste and ethnicity, study participants had the highest representation from those identifying as Brahmin and Janajati (27.9% and 38.0%, respectively), while scheduled (untouchable or Shudra caste) had the lowest representation (13.6%).

The highest rate of stunting, wasting and underweight was among children of mothers in the under 20 years age group. More than one-quarter of mothers who participated in this study were breastfeeding their child during the survey period. The children of participants who were not exposed to media (newspaper and/or radio and/or television) had higher rates of malnutrition compared with children of mothers who were exposed to media at least once a week (figure 3).

Figure 3. Bar diagram of the child malnutrition by maternal media exposure.

Stunting, wasting and underweight were more common in rural settings compared with urban ones. Children from mountainous regions had the highest rates of stunting, while plain regions had the highest rates of wasting and underweight. Children from Madhesh mothers who did not have access to a health mother group had higher rates of stunting, wasting and underweight compared with mothers who had an available health mother group.

This study found that children under 5 years whose mothers used an unimproved water source had a higher prevalence of stunting (43.1%), wasting (9.7%) and underweight (31.4%) compared with children of mothers who had access to an improved water source. Children of mothers with no access to an improved toilet had higher rates of stunting (49.7%), wasting (13.1%) and underweight (41.0%) compared with children of mothers who had access to an improved toilet. Children of mothers with a mobile handwashing station had higher rates of stunting (40.8%), wasting (14.1%) and underweight (33.4%) compared with children of mothers who had a fixed handwashing station. Children under 5 years whose mothers did not have soap and water available at the handwashing place experienced higher rates of stunting (42.2%), wasting (11.1%) and underweight (33.1%) compared with children whose mothers had soap and water available. Children of mothers’ access with to combined WASH services had lower rates of stunting (40.0%), wasting (11.0%) and underweight (32.3%) compared with children of mothers who did not have access to combined WASH services at home.

Children of mothers without access to health mother groups, improved water sources or improved toilets had higher rates of stunting, wasting and underweight. Additionally, those with mobile handwashing places and without soap and water also experienced higher rates of malnutrition.

Effects of water, sanitation and hygiene (WASH) on diarrhoea and malnutrition among children under 5 years

Table 1 shows the effects of WASH components with other explanatory variables on diarrhoea rates among children under 5 years. Children of mothers without access to a fixed place for handwashing were more likely (adjusted OR (aOR)=1.63; 95%CI 1.20 to 2.22) to experience diarrhoea, relative to children of mothers with a fixed place for handwashing at their home. Compared with those with combined WASH facilities, children under 5 years of mothers without combined WASH services were more than twice as likely to contract diarrhoea (aOR=2.12; 95% CI 1.06 to 4.29).

Table 1. Bivariate and multivariate logistic regression analysis on the effects of WASH on diarrhoea, stunting, wasting and underweight among children under 5 years (de facto or guest mothers were excluded in the analyses).

Variables	Diarrhoea*		Stunting†		Wasting†		Underweight†
	Bivariate	Multivariate	Bivariate	Multivariate	Bivariate	Multivariate	Bivariate	Multivariate
	COR (95%CI)	aOR (95%CI)	COR (95%CI)	aOR (95%CI)	COR (95%CI)	aOR (95%CI)	COR (95%CI)	aOR (95%CI)
Source of water
Improved	1	1	1	1	1	1	1	1
Unimproved	1.01 (0.57 to 1.80)	0.70 (0.31 to 1.56)	1.36 (0.90 to 2.04)	1.21 (0.77 to 1.89)	0.67 (0.3 to 1.41)	0.69 (0.29 to 1.61)	1.27 (0.83 to 1.94)	1.30 (0.83 to 2.05)
Types of toilets
Improved	1	1
Unimproved	1.47 (1.00 to 2.18)	1.01 (0.62 to 1.67)	2.10 (1.59 to 2.76)	1.78 (1.25 to 2.55)	1.65 (1.18 to 2.29)	1.05 (0.69 to 1.62)	2.41 (1.82 to 3.19)	1.45 (1.03 to 2.06)
Fixed place for handwashing
Available	1	1	1	1	1	1	1	1
Unavailable	1.57 (1.21 to 2.04)	1.63 (1.20 to 2.22)	1.31 (1.04 to 1.64)	0.77 (0.57 to 1.04)	1.74 (1.22 to 2.47)	1.52 (1.00 to 2.30)	1.61 (1.24 to 2.09)	0.93 (0.68 to 1.27)
Soap and water
Available	1	1
Unavailable	1.34 (0.96 to 1.88)	0.64 (0.35 to 1.15)	2.16 (1.75 to 2.68)	1.53 (0.90 to 2.59)	1.53 (1.11 to 2.11)	0.83 (0.39 to 1.77)	2.50 (1.95 to 3.20)	1.62 (0.96 to 2.74)
Combined WASH services
Available	1	1
Unavailable	1.67 (1.26 to 2.21)	2.12 (1.06 to 4.29)	2.19 (1.73 to 2.7)	1.00 (0.56 to 1.77)	1.64 (1.17 to 2.32)	1.39 (0.60 to 3.22)	2.69 (2.04 to 3.55)	0.99 (0.55 to 1.81)

Bold values are statistically significant.

^*Adjusted for covariates including child’s age, mother’s and father’s education, mother’s occupation, wealth index, caste and ethnicity, breastfeeding, media exposure, residence, ecology, province, distance to the water source and health mother group for the diarrhoea outcome.

^†Adjusted for covariates including child’s age, mother’s age, mother’s and father’s education, mother’s occupation, wealth index, caste and ethnicity, breastfeeding, media exposure, residence, ecology, province, distance to the water source and health mother group for the stunting, wasting and underweight outcome.

WASH, water, sanitation and hygiene.

As shown in table 1, children of mothers with unimproved toilet facilities were more likely to experience stunting (aOR=1.78; 95%CI 1.25 to 2.55) compared with those with improved toilets, after adjusting for identified confounding variables. Underweight was also associated with unimproved toilet facilities after adjusting for potential confounding variables (aOR=1.45; 95%CI 1.03 to 2.03) compared with children whose mothers had access to improved toilet facilities. Mothers without a fixed place for handwashing were more likely to have children who were wasting (aOR=1.52; 95%CI 1.00 to 2.30) compared with mothers who had a fixed place for handwashing. 

Discussion

This paper aims to assess the effects of WASH on diarrhoea and malnutrition in children under 5 years of age in Nepal. In this study, the prevalence of diarrhoea, 7.6%, is higher than the findings of Nepal’s first micronutrient status survey conducted in 2016, which showed diarrhoea prevalence was 6.0% among children between 6 and 59 months of age.⁴⁵ The difference in rates of diarrhoea between the 2016 micronutrient status survey and the present study is likely due to a difference in sample size and the exclusion of children under 6 months from the 2016 micronutrient status survey. A study conducted in an urban slum area of the Tansen Municipality, Palpa, Nepal, showed the prevalence of diarrhoea was 40.0% among children under 5 years.⁴⁶ In India, the prevalence of diarrhoea among children under 5 years was 9.2% in 2015–2016, 19.0% in Pakistan in 2016–17 and 4.9% in Bangladesh in 2017–2018.47,49 A single cross-sectional study in Ethiopia found the prevalence of diarrhoea among children of the same age was 13.6% in 2019, and the pooled prevalence of diarrhoea from 31 studies was 22.0% in 2018.^{50 51} The discrepancies rates of diarrhoeal diseases could be due to the reasons of sample size, data collection season, geography and local context. The morbidity of diarrhoea varied by geography, location, population size and nature, seasons, mothers’ education, occupation and wealth index, and WASH-related services.

This study’s findings suggest that having a designated handwashing place encourages positive WASH practices among mothers and their children. A study conducted in India concluded that diarrhoea can be prevented with adequate handwashing with soap practices.⁵² However, in the current study, there was no significant difference in diarrhoea prevalence with the improved water sources, availability of soap and water, and improved toilet facilities after adjusting for possible confounders.

Unlike previous studies,^{46 53 54} breastfed children in this study had a higher prevalence of diarrhoea. Some possible explanations for this unexpected finding may include poor hygiene and environmental factors that might overshadow the protective effects of breastfeeding, or the differences may be due to a difference in the definition of breastfeeding, given that participants in our sample may not have been exclusively breastfeeding.

Another unexpected finding was that access to an improved water source was not associated with any of our measured outcomes. An improved water source alone did not effectively prevent diarrhoea in the absence of improved toilet and hand hygiene facilities. This finding has demonstrated the importance of combined WASH facilities in reducing childhood diarrhoea. A systematic review conducted by Alan et al in 2021 suggested that a single component of WASH, such as handwashing alone, is not associated with childhood malnutrition, which is consistent with this current study. However, in their review, the safe disposal of children’s faeces was found to reduce the risk of malnutrition.⁵⁵ Previous studies have found that handwashing with soap reduces the risk of diarrhoea.^{6 56} This study found that ensuring access not only to handwashing but also to all components of WASH is important for reducing diarrhoea among children under 5 years. This result is similar to findings of a systematic review published in 2019 that reported the provision of combined WASH contributed to the protection of children from diarrhoea.⁵⁷

This current study’s findings concerning stunting, wasting and underweight in relation to maternal WASH habits raise critical public health concerns. The stunting, wasting and underweight rates among children between 6 and 59 months of age in this study were consistent with those of the 2016 micronutrient status survey, where the results were found to be 35.0%, 11.3% and 29.0%, respectively.⁴⁵ The global figures from the United Nations Children’s Fund (UNICEF), reported in 2018, stated that 21.9% of children under 5 years were categorised as stunted and 7.3% of children as wasting, whereas this study’s results were higher than the global prevalence.⁵⁸ When compared with the results of a study conducted in India in 2017, where the prevalence of stunting among children under 5 years was at 39.9%, wasting was at 19.0% and underweight was at 32.7%, the results of this current study are almost identical, except for a lower prevalence of wasting.⁵⁹ A study conducted in the Banke district of Nepal in 2015 found a higher proportion of stunting (55.7%), wasting (18.6%) and underweight (41.4%) than this study.⁶⁰ The different rates of stunting, wasting and underweight were due to the different socioeconomic status and the homogeneity of study participants.

This study shows WASH components have mixed effects on malnutrition among children under 5 years in Nepal. It is evident the establishment of a fixed handwashing station has positive effects on the prevention of wasting. A fixed place for handwashing is also a primary indicator of the standard of living and health of children under 5 years and their mothers. Mothers with children under 5 years should have access to proper handwashing facilities with soap, clean toilets, and safe and clean water sources. Poor WASH practices may lead to diarrhoea, which can progress to further infection, resulting in malnutrition from chronic diarrhoea

Strengths and limitations

This study has several strengths, such as the sample being highly representative of the population, with the NDHS 2016 data collected from different parts of provinces and clusters across the diverse geography of Nepal. The NDHS data are valid and have appropriate ethical approval from the Inner-City Fund and Nepal Health Research Council. The data were analysed after validated weights were applied, which helped to minimise errors that might occur due to the sample distribution. Furthermore, this study analyses mother- and child-specific data, which provides subpopulation study results, fulfilling the lack of mothers’ knowledge gap found in previous studies. A further strength of this study was the stringent method used to capture child heights and weights. The DHS programme uses best practice measures for the collection of anthropometric data using the WHO-UNICEF guidelines.²⁴ These data provided accurate measures for the stunting, wasting and underweight outcomes. Furthermore, this study considered single and combined WASH outcomes to provide further evidence for each study outcome. This approach offers a comprehensive framework to better analyse the positive impact of how WASH interventions impact on public health. Nonetheless, some limitations of this study have been identified. Data were not available for all children of interviewed mothers as children may have been absent at the time of data collection or may have refused to provide anthropometric measurements. Also, the study data cannot be used for the analysis of mothers’ and children’s WASH behaviour over time, due to the cross-sectional study design. While the findings cannot be generalised to the broader population, they are representative of the specific subsection of the Nepalese population. While the weighted sample provides a close representation of the population, the random sampling technique may have resulted in sampling biases. The current WASH status and diseases prevalence may differ from those reported in this study, as the data were collected more than 8 years ago.

Implications

Communicable diseases remain a public health challenge in Nepal, and most current efforts target non-communicable diseases. Health promotion programmes and interventions that focus equally on communicable diseases can benefit a large portion of the world’s population, especially in developing countries like Nepal, compared with countries with more resources where such diseases are often less prioritised. This study focuses on the important role of mothers’ WASH practices in reducing diarrhoea and malnutrition, highlighting the significance of addressing mothers’ WASH issues in a timely manner, as mothers are the first teachers for their children. The roles of males such as father, husband and grandfather in supporting WASH facilities at home significantly contributed to improved household WASH, which in turn benefited the mother and child. It is recommended that strategies for reducing diarrhoea and malnutrition should be prioritised, in conjunction with the provision of combined WASH facilities. Such initiatives should be practised by all individuals, with support from various stakeholders. International health promotion best practices should be applied to address the challenges in Nepal, helping to overcome existing obstacles in service delivery.⁶¹ The government of Nepal recently (June 2025) decided to recruit public health officers in all rural and urban municipalities for the first time on this large scale, which is expected to use this paper’s findings as a resource material to support improving household level WASH facilities and reducing communicable diseases through new public health (health promotion) approaches.⁶²

Conclusions

This study confirmed that the lack of fixed places for handwashing is significantly associated with diarrhoea and wasting, as soap and water in the home are often not used if not conveniently placed. A fixed handwashing station encourages proper handwashing practices by all family members. Similarly, the use of unimproved toilets is associated with stunting and underweight, indicating good sanitation improves the health and well-being of children and reduces malnutrition. The utilisation of combined WASH facilities is important for preventing diarrhoea, but findings were inconclusive for malnutrition. Therefore, policymakers should develop WASH strategies that support combined WASH services to prevent infectious diseases like diarrhoea. Ensuring access to improved handwashing facilities will help to enhance child health in a cost-effective manner. Both WASH and nutrition programmes must be integrated throughout the country. Further research, including intervention studies, is recommended to explore the impact of individual and combined WASH components on child health, especially for malnutrition. It is recommended that further research be undertaken with the consideration of the United Nations’ Sustainable Development Goals, 2016–2030, and beyond.

Data availability statement

Data are available upon reasonable request. All data relevant to the study are included in the article or uploaded as supplementary information.