Impact of Water, Sanitation, and Hygiene (WaSH) interventions on diarrhoeal infections among children in the tribal regions of Palghar: a quasi-experimental study

The Global Burden of Disease (GBD 2017), ranked diarrhoea as the fifth leading cause of child deaths among children under-five (GBD 2017 Diarrhea Collaborators 2019). Between 1990 and 2017 there was a significant decline in deaths due to diarrhoea per 100,000 people globally by 69.6% (63.1–74.6). As per the GBD (2017) analysis, improved sanitation, nutritional status among children, and an increase in the use of oral rehydration solutions significantly contributed to this success (Troeger et al. 2020). Despite this progress, enteric infections were responsible for 6.9 million DALY in 2019, of which 74.5 of the burden was in children under-five (GBD 2019 Child and Adolescent Communicable Disease Collaborators 2023). The pandemic distorted the progress and gastrointestinal (GI) symptoms were common among children that were life-threatening across nations (Poeta et al. 2022; Negsso et al. 2023). In certain regions, cholera cases increased during the rainy season, aggravating malnutrition risk amidst the pandemic (United Nations Children's Fund (UNICEF) 2020). The 2023 WHO report emphasizes improved Water, Sanitation, and Hygiene (WaSH) practices to prevent 1.4 million deaths globally (World Health Organization 2023).

According to GBD analysis, in India, access to unsafe water, hygiene, sanitation, and lack of resources to maintain hygienic practices emerged as the risk factors for diarrhoea (Behera & Mishra 2022). Spatial clustering of diarrheal prevalence using the National Family Health Survey (NFHS; IIPS 2021) across 707 districts identified 69 hot-spot districts mostly from Maharashtra, Bihar, Odisha, and Gujarat. The prevalence was concentrated among children under-five in the lower socio-economic settings (LES) (Ghosh Chakraborty & SenGupta 2023). This evidence comes when the NFHS 5, (the national health survey conducted in India) reported a decline in diarrhoea prevalence among children under-five from 9.2 to 7.3% (International Institute for Population Sciences (IIPS) & International Calverton (ICF) 2021). Furthermore, a high infant mortality rate was observed in states that recorded high diarrhoeal prevalence (NFHS 5). After adjusting for socio-demographic factors, ethnicity emerged as a major determinant, drawing attention to ethnic minorities (Bango & Ghosh 2023). In India, a higher prevalence of diarrhoea is reported in rural and tribal regions that are not reflected in national statistics. To progress towards Sustainable Development Goals (SDGs), India pledged its support for the Clean India movement (Swachh Bharat Abhiyan) (NITI Aayog 2020). Three years after the mission, significant differences between rural and urban areas in terms of resources and facilities were observed. The survey also showed that regardless of the efforts, households with better economic conditions had access to improved resources, while the poor had limited access to facilities (Prakash et al. 2022).

Despite the national economic growth, tribal regions in India have not progressed much. The state of Maharashtra is an example of this paradox, where regardless of being economically well placed, its tribal regions harbour a greater percentage of undernourished children. Palghar is one among the tribal districts that lack roads, and household water supply, and has poor access to healthcare and safe drinking water (Jain & Narnaware 2020). Cultural practices and taboos characteristic of tribal settings interfere with infant and young child feeding practices. This combined with household food insecurity, low literacy, and awareness about WaSH practices increases vulnerability to diarrhoea, undernutrition, and child deaths. Interventions that focus on stakeholder networking, and targeted and scaling up interventions have yielded no results and Palghar is often in the media for child deaths (Ghosh & Varerkar 2019; Jeyakumar et al. 2021b).

Our baseline assessment identified a high prevalence of undernutrition, diarrhoea, and poor WaSH indices. According to the composite index of anthropometric failure (CIAF), 66% of children showed at least one, and 40% showed more than one manifestation of undernutrition (Jeyakumar et al. 2021a). This is much higher than in urban and rural settings (Jeyakumar et al. 2024). The prevalence of diarrhoea among children was 33.4% (Jeyakumar et al. 2021b). WaSH indices studied in the baseline assessment included the Drinking Water Index (DWI), Household Sanitation Index (HSI), and Personal Hygiene Index (PHI). The details can be accessed in our previously published work (Jeyakumar et al. 2021a, 2021b). The risk factors of child undernutrition in Palghar are well documented in the literature. Among the factors poor complementary feeding practices, socio-economic environment, and diet diversity have been identified (Ghosh & Varerkar 2019; Jain & Narnaware 2020). The hilly terrain with solid rock formation affects the groundwater, rendering agricultural challenges. Ponds, wells, and other traditional water-conserving measures have not improved access to safe drinking water (Bombade & Gaikwad 2023). This, combined with poor access to healthcare with a difficult geographical terrain and long distances, increases the risk of infections and child mortality.

The Integrated Child Development Services (ICDS) provide nutrition-specific interventions like supplementary nutrition and other services for child growth and development. In addition, nutrition-sensitive interventions such as WaSH are implemented to complement existing services to prevent diarrhoea among children. Major water technology initiatives, construction of toilets, and wells, and small-scale interventions such as water wheel projects to improve access have been tested. However, the improvements are slow and lack sustainability due to the hilly terrain (Department of Science & Technology 2021). Some of the challenges in these difficult-to-dwell settings were wells drying up within months due to lack of land water, and non-functional toilets without water. While most of these interventions relate to water access or physical facilities, WaSH interventions with particular emphasis on diarrhoea prevention in Palghar and its impact on health are less studied. The high prevalence of diarrhoea and poor WaSH indices in the tribal regions have been identified as major concerns that require urgent attention. Our study, therefore, aimed to assess the effect of WaSH interventions on knowledge, awareness, practices (KAP), and diarrhoeal infections in children in the tribal regions of Palghar.

To test the effect of the WaSH kit combined with awareness creation, we performed a quasi-experimental study. Prior to intervention, knowledge attitude and practices related to WaSH were elicited. Following the needs assessment, the intervention arm received the WaSH Kit along with education, while the control group solely received the WaSH kit.

Open design was chosen as in a community trial: (a) blinding was not possible and (b) the researchers did not have expectations or preferences that would favour the research or the researcher. For instance, the objective was not to test the effect of the water tablets in disinfecting the water. (c) Non-blinding reduced the risk of non-participation.

The intervention was performed in the tribal regions of Mokhada, Palghar, in Maharashtra state, India.

Cluster random sampling was used to select and assign villages to the control and intervention arm. Palghar district has a total of eight tehsils. Of these, one taluka, that is, Mokhada, was selected as the study site as prevalence of malnutrition was high. There are a total of 59 villages in Mokhada of which six villages, namely Chas, Ghoshali, Khoch, Gonde Khurd, and Washala, were randomly selected for the study. The allocation of the intervention and control groups between the six villages was done purposively to prevent information exchange between the participants. The research team coordinated with the team of public health officers in Palghar (Medical Officers and Child Development Project Officers) for this trial. With the help of the community health and anganwadi workers, households were selected for intervention from the selected villages. As per the administrative divisions' tribal Villages were selected, to ensure similar resources such as child and healthcare facilities, and WaSH resources.

The research team obtained a list of children enrolled in the anganwadi (government preschool) centers from the selected villages. Eligible participants were selected by meetings arranged in the anganwadi centers. Mothers with children under-five registered in the anganwadi centers, free of chronic diseases, who were part of the baseline survey and who will not migrate for work in the next 8 weeks, were recruited after obtaining informed consent. The households were purposively selected to minimize the risk of contamination between clusters (i.e., households with less likelihood to visit the other households or preschool centers).

Considering a prevalence of 33.4% of diarrhoea (Jeyakumar et al. 2021b), assuming a 50% reduction in the prevalence, the formula for comparing proportions (Smith 2015) was used. With an error factor of 1.3 at 95% CI, a sample of 96 was required in each arm. With the challenges of recruiting samples in community settings, the final sample recruited in each group was n = 90.

The control arm received only the WaSH kit, while the intervention arm received education along with the WaSH kit. In both groups, the households were selected based on the information collected in the baseline survey. This was done to ensure the initial comparability of the groups. During pre-intervention, participants in the control/intervention group were encouraged to utilize the services provided by the government health system in case of an episode of diarrhoea. Multiple visits were made, one each at baseline, intervention, and follow-up. Thus, the intervention group had an additional visit. Post-test and delayed post-tests were performed for both the control and intervention arms. One additional visit for the intervention group to (i) explain two posters followed by (ii) a demonstration was performed to observe water droplets through a frugal microscope from the drinking water sources, and (iii) use of water tablets to treat specific volumes of water. Thus, six visits for the intervention group and five visits for the control group were made. Each intervention session lasted for 45–60 min.

Short-term WaSH interventions have shown significant improvements in health outcomes, and utilization of services, perceptions, and capacity of stakeholders. Long-term strategies aim to promote safe hygienic practices in a sustained manner. Awareness creation is a long-term strategy and needs to be tested to inform policy. Testing combinations of short- and long-term strategies would provide directions for expanding scope and scale.

• (a) WaSH kit: To provide evidence-based short-term WaSH intervention, a kit was prepared and distributed to both arms (control and intervention). The kit comprised of the following: (i) water treatment tablets; (ii) handwash; (iii) soap; and (iv) nail cutter (Environmental Health Unit WHO 2015; Piper et al. 2017). As per the WHO evaluation of household water treatment technologies (World Health Organization 2016, 2019), it is categorized as a chemical disinfectant that meets the performance targets for at least two classes of pathogens. Accordingly, water tablets (effervescent chlorine tablets with sodium dichloroisocyanurate (NaDcc)) were distributed to purify water and prevent water-borne diseases. The usage of water treatment tablets was demonstrated and distributed to participants to treat specific volumes. A standard volume of handwash and a nail cutter was distributed. The participants were taught to use nail cutters as they had not seen or used them before.

• (b) WaSH education: The intervention arm received WaSH education along with the WaSH kit. The researchers were trained in communication using two posters developed on WaSH practices and diarrhoea prevention. The details of the poster design, content, and evaluation have been published previously (Jeyakumar et al. 2020). Poster 1 described the numbers to highlight diarrhoea as a killer disease, its causes, prevention, and management. Poster 2 focused on the WaSH for the prevention of diarrhoea. The posters used mostly nonverbal communication principles with more pictures and fewer words. Also, the slides of contaminated water samples from their drinking water sources were prepared for the participants to observe through a frugal tool (foldscope) (Cybulski Clements & Prakash 2014; Jeyakumar et al. 2021c). Contaminated water as a risk factor for diarrhoea was communicated through the poster and was experimentally and visually reinforced using the foldscope.

Thus, our intervention tried to address the knowledge gaps, provided essential resources for maintaining hand hygiene, and created awareness about the reasons why it is important to take preventive measures for diarrhoea. In addition to this, the second poster addressed the important aspect of preventing diarrhoea and dehydration through simple public health measures. Participants and investigators were not blinded to the intervention. The duration of the intervention was 4 weeks.

Data on pre (t0), post (t1), and delayed post-test (t2) was collected using a semi-structured questionnaire, which included questions specific to the intervention. The knowledge domain had questions about water, its source, and ill health due to unsafe water. The awareness domain had questions related to open defaecation, household hygiene and sanitation, hand washing, breastfeeding, and healthcare services available for the management of diarrhoea. The practices domain included questions on hygienic practices such as filtering, treating, and storing water, disposal of garbage and excreta, washing hands before having food and after defaecation with soap and water, and administration of ORS during diarrhoea. In all the KAP consisted of 17 questions, five for knowledge and awareness, and seven for WaSH practices (KAP). The maximum possible score (MPS) for knowledge and awareness was 5 each, and the practices domain was 7. The total MPS for KAP was 17 and the minimum possible score was zero. The questions in the tools were pretested and validated in our earlier work (Jeyakumar & Ghugre 2017). Data were collected using EpiCollect version 5 software through face-to-face interviews. This prevented printing and enabled geo-tagging to the study setting.

The outcome variables studied were (1) change in knowledge, awareness, (2)WaSH practices as measured by the utilization of WaSH kit, and (3) difference in the number of children with diarrhoea between intervention and control groups.

Before the commencement of the study, the research team underwent training to ensure consistency in data collection procedures and reporting. The training included the following features: (i) to select similar geographical sites, settings to match the environment, and age groups of children to ensure that the characteristics of the test and the control villages were similar. Accordingly in both groups, all selected villages were categorized under the tribal administrative division and children were recruited from anganwadis. (ii) The anganwadi workers, community health workers, and supervisors were oriented to the objectives of the project and served as facilitators. The team was monitored by the project coordinating team, to resolve problems or questions during the study. Every phase of the study was supervised. (iii) Roles and responsibilities such as selection of villages, and enrolment of participants were assigned to the research team. Data sheets were prepared in Google Forms, and weekly data updates were monitored. The data sheets had the household numbers, the distribution of kits, follow-up visits, and data gathered during follow-up. The following measures were taken to maintain data quality management and internal validity. The treatments were assigned to the villages by the researchers. Each household received 30 water treatment tablets and 300 ml of handwash. Participants' compliance with the use of WaSH kits was monitored at regular intervals. The project was monitored by tracking the progress of the weekly tasks completed against the predefined milestones. The records of everyday travel, utilities consumed, and intervention kits distributed were monitored to study the progress of work. Site visits and weekly meetings were organized to update progress address challenges and check the quality of interventions.

Two researchers trained in Public Health conducted the study. Information was elicited from participants through face-to-face interviews using Epi-collect software. The researchers were trained in using the Epi-collect software, anthropometry, explanation of the posters in the local language, demonstration of water treatment, and displaying the contaminated water through the foldscope by slide preparation from the locally collected water sample. To minimize variation between the researchers one of them explained the posters and the other performed the demonstration in all the villages. Quality assessment of the collected data and the delivery of interventions were monitored by internal and external monitors, respectively.

Cross-tabulations and summary statistics were performed to describe the study population. Simple frequencies, summary measures, tables, and figures were used to present the data. Mean scores of KAP at baseline (t0) and change in scores from baseline were computed to study the effect on KAP post-intervention (t1) and 1 month after intervention (t2). Percentage changes in diarrhoeal cases before and after intervention were computed. The analysis was done using the Statistical Package for the Social Sciences (SPSS) for Windows Version 21.0 for data management and advanced analysis (International Business Machines Corporation-IBM Corp., Armonk, New York).

Before the commencement of the study, ethics approval was obtained from the institutional ethics committee of Savitribai Phule Pune University (Ref No: SPPU/IEC/2020/04). The procedures followed aligned with the requirements of ICMR. Informed consent was obtained from participants before recruitment. Their participation in the study was voluntary and they were free to withdraw at any time during the study period. The anonymity of the participants and the confidentiality of data were ensured. Participants screened for diarrhoea were referred to a public health facility. In this study, no adverse reactions were reported after consuming treated water.

Table 1 describes the socio-demographic, maternal, and child characteristics of participants. The data for the baseline characteristics was extracted from the cross-sectional survey performed prior to the intervention (Jeyakumar et al. 2021b). The reported mean age of the mothers selected in our study was 25.81 ± 2.99. About three-fourths of the mothers did not receive any formal education (71.1%) and only about 30% were engaged in income-generating activities. The mean age of children was 30.99 ± 17.11 months. Both male and female children were equally represented in the study. The average family size of the participants was 6.48 ± 2.59 individuals. The mean birth weight of the children was 2.64 kg ± 0.44 and more than 85% had received age-appropriate immunization. Greater than 90% of the households were below the poverty line (BPL) and over 10% of the households did not possess a ration card indicating the high risk of food insecurity. The geographical location that limits access to basic needs, the high levels of illiteracy, and the prevailing food insecurity underscore the vulnerability of the study population.

Table 2 compares the overall and separate KAP scores of intervention and control groups at the t0, t1, and t2 timelines. The mean scores of the knowledge domain which elicited information about the quality of water and health scored the lowest at baseline (less than 2.5, (50%) out of 5). The practices score related to hand washing, household hygiene, etc., and the awareness scores were above 50% of MPS in both the control and intervention groups at baseline. The average overall KAP score of the intervention group increased significantly from 8.54 ± 1.65 to 11.89 ± 1.60 (p < 0.001), between pre-intervention (t0) and 4 weeks after intervention (t2). All the individual scores (i.e., knowledge, awareness, and practice) in the intervention group also increased significantly, between pre-intervention (t0) and 4 weeks after intervention (t2). In the control group, the average overall KAP score between t0 and t2 assessments also increased but was not statistically significant (8.39 ± 1.72 to 8.74 ± 1.76) (p = 0.764). Comparable to the overall KAP score, individual scores in the control group also showed no significant change.

Table 3 compares the outcome variables between the intervention and control groups. Personal hygiene variables such as cut nails (39%) and clean hands (46%) showed better percentages in the intervention group as compared to the control group (28 and 34%, respectively). Also, there was a higher uptake of water purification tablets (remaining tablets: 1.71 ± 1.95) and handwash (remaining handwash: 122.33gm ± 12.25) as compared to the control group (7.68 ± 3.75 and 149.00gm ± 19.50 respectively). The number of children reported to have diarrhoea in the intervention group decreased from 31 to 24% at t2 but the decrease was not statistically significant. Whereas in the control group, it remained unchanged from 35 to 33%, between the t0 and t2 assessments. The percent reduction in diarrhoeal cases in the intervention group was 22% compared to a 6.5% reduction in the control group.

In summary, the WaSH kits were better utilized by the intervention group followed by significant improvements in KAP scores, and a reduction in the number of diarrhoeal cases. The results confirm the combined effect of awareness and improved WaSH resources in preventing diarrhoea in children.

The district of Palghar is situated between the west coast of the Arabian Sea and Sahyadri mountains. Most of the areas of Palghar are categorized as scheduled areas which indicate the predominance of tribal population. The isolated geographical settings, hilly terrain, difficulty in agriculture, food insecurity and lack of development reflect in high prevalence of childhood illness and undernutrition.. Our study identified higher levels of illiteracy, poverty, and a lower percentage of women involved in income-generation activities similar to other studies in tribal settings (Ministry of Tribal Affairs 2016; Reddy B et al. 2017). In resource-poor settings, lack of education and awareness combined with poverty increases the risk of childhood diarrhoea and mortality. Our work evaluated the effect of comprehensive WaSH intervention to improve safe WaSH practices and reduce diarrhoea in children under-five.

The uniqueness of the intervention was the comprehensive use of short- and long-term interventions that included health education using an origami microscope to raise awareness about diarrhoea prevention and a WaSH kit to follow simple public health practices such as washing hands, cutting nails, and treating water. The intervention was designed after a thorough need assessment performed for 2 months in the tribal community (Jeyakumar et al. 2021b). Literature evidence emphasizes needs assessment as a preliminary step to design interventions to ensure the successful translation of knowledge to action (Romney et al. 2022; Wolfenden et al. 2022). Our intervention also focused on the WaSH practices, than just theoretical knowledge. Metacognitive skills can be learned through practice and are crucial for lifelong learning. The use of a frugal tool in our study for creating awareness is a novel strategy to translate science in such settings. Live demonstrations to observe contaminated water and demonstration of water treatment were unique communication methods used to enhance the learning and problem-solving process. Such learning techniques enable people to adapt and improve their learning (Sáiz Manzanares et al. 2019). Also, in households with children who have had an episode of diarrhoea the perceived benefits of the intervention are likely to be the highest (White et al. 2020). The 22% percent reduction in diarrhoeal cases in the intervention group in our study is a clear pointer to the effect of creating awareness among the population while providing WaSH resources. Literature evidence supports our findings where improved availability and affordability of WaSH resources and investment in behaviour change communication have emerged as key factors in the reduction of diarrhoeal burden (Takele 2023; Bisimwa 2022).

The delayed post-test showed significant retention of knowledge, which confirmed the observed improvement in knowledge and awareness was not by chance. In public health interventions, multiple observations over time can potentially reduce observation bias. Our delayed post-test thus enhanced the quality of our observations. Quite a few Indian studies have assessed and reported the prevailing poor access to WaSH conditions in tribal settings (Jana & Bhowmick 2003; Kuberan et al. 2015; Reddy B et al. 2017). However, to the best of our knowledge, ours is the first effort to provide awareness on safe WaSH practices and diarrhoea prevention through customized and tested information, education, and communication (IEC) material in the much-isolated regions of Palghar.

Although improvement in knowledge and uptake of WaSH messages have been studied in low-and middle-income counties in varied settings (Olukann et al. 2014; Taylor et al. 2015), not all interventions show improvement in practices following the intervention. A study in Kenya showed low knowledge acquisition following the intervention, however significant change in attitude was observed (Wasonga et al. 2014). On the contrary, studies showed improved practices but no improvement in knowledge after incorporating curricular changes in schools for WaSH education (Patel et al. 2012). Thus, in a spectrum ranging from the organized sector (educational institutions) to the isolated settings, the need to design feasible and successful interventions emerges (van Lieshout et al. 2016). Reinforcement of knowledge through multiple mediums can enhance retention of knowledge. Following up and monitoring would enable better compliance with healthy practices.

Our study was performed in a setting where limited access to safe drinking water and poor hygienic conditions increased the risk of diarrhoea and undernutrition (Luby et al. 2011). This combined with poverty and lack of education limits exposure to information. Caste hierarchy as a deterrent to awareness has been documented in previous research in tribal settings (Einarsdbttir et al. 2001). The results of our intervention showed a significant improvement in individual and total KAP scores among the intervention group. Educating mothers about simple public health practices such as washing hands before and after food and after defaecation has proven to be a successful strategy for risk reduction in vulnerable settings in earlier research (Luby et al. 2011). Setting-specific interventions are therefore likely to improve results.

The challenges in multicomponent interventions lie in changes in a few indicators with little or no change in others. In our study too, improvements were seen in hand hygiene and WaSH kit utilization (usage of water tablets, and handwash), among the intervention group. Yet the percentage of participants who followed safe WaSH practices was less than 50% in any observation. Under such situations, reinforcement of health messages at regular intervals to improve compliance has shown positive results (Humphrey 2019). Also, the availability of water to follow safe practices could have affected the study results, which was documented in our earlier work (Jeyakumar et al. 2020). In addition to the reinforcement of knowledge, need-based interventions appeal to the community and ensure adherence to practices. For instance, in our intervention, water tablets were utilized by more than 90% in both groups as they offered ease of use in any season (as burning wet firewood could be cumbersome during monsoons) and did not alter the taste and smell as reported in other interventions (Roberts et al. 2001).

Health awareness as a standalone approach is not likely to yield results. Ours was a combination of short- and long-term strategies that are proven to result in behaviour change, where WaSH kits met their need for resources. The utilization of the kit served as a proxy indicator that could be measured for behaviour change in our study. WaSH resources when combined with improved awareness resulted in a reduction of diarrhoeal infection in the intervention group.

From a public health perspective providing WaSH kits is not cost-effective, but health education is. However, as per evidence, low-cost WaSH interventions or improved awareness alone may not be sufficient to reduce high contamination and improve health outcomes in resource-poor settings, emphasizing a critical need to improve resources (Gera et al. 2018).

Systematic reviews and meta-analyses conducted recently have demonstrated that interventions focusing on WaSH can effectively reduce the incidence of diarrhoea and mortality among children under the age of five (Darvesh et al. 2017; Sharma Waddington & Cairncross 2021; Wolf et al. 2022). Additionally, other studies have also documented improvements in knowledge that are consistent with the findings of our study (Joshi & Amadi 2013; Mushota et al. 2021). However, the meta-analysis identified significant gaps in system-related interventions. While short-term strategies have been tested, the need for sustainability of WaSH interventions through the public health system needs to be studied.

Despite positive results, our work is not free from limitations. The inherent limitations of a quasi-experimental design in a community setting could not be avoided. The lack of randomization affects the representativeness of the sample and is likely to have introduced bias in the selection of villages. It further prevented ascertaining causality. Resource constraints limited outcome measurements, where the mothers' verbal confirmation of episodes of diarrhoea was not clinically confirmed. Utilization of water tablets was used as a proxy indicator of water treatment and water samples were not tested for quality in the laboratory. Although the study was conducted during the same period to avoid the influence of seasonal variability in the disease pattern, household variables such as exposure to the quality of diet, safety of food, and family support in childcare could have influenced our study results. During pre-intervention participants from the control group were asked about the diarrhoeal infection among children in their households and were also given WaSH kits. This could have influenced their behaviour towards the utilization of the kit material, which in turn could have affected the real difference in utilization and led to the underestimation of risk reduction in the intervention group. Although kits were provided, the researchers could not ensure access to water, which could have resulted in poor compliance. Environmental changes could have also contributed to the reduction in the prevention of diarrhoea which was not documented in our work. Improved awareness of healthcare access following intervention could have contributed to increased use of ORS and zinc supplements. This in turn could have contributed to the observed decrease in the number of diarrhoeal cases in the intervention group. This was not monitored in the study. The lack of improvement in the control group points to the need to improve awareness. While our work assessed the effect of WaSH kit, the individual effects of the different components could be varied, and this was not measured. Diarrhoea cases were self-reported and not clinically confirmed. Non-adherence to specific WaSH practices in our study could have been better explored using qualitative techniques. Further, an open trial comes with limitations of contamination and bias in observations. To overcome this, the villages selected had safe distances that could not be easily reached and a delayed post-test was performed to minimize bias. However, the delayed post-test could not be performed after a longer interval post-intervention due to time constraints. In addition, our short-term intervention does not address sustainability issues that are essential features for public health interventions. Raising awareness without resources would be a futile effort to lead behaviour change. It is therefore imperative to provide access to safe drinking water and low-cost resources through the public health system to overcome the key economic barriers.

Our work adds to the evidence that implementing WaSH interventions at the community level significantly improved KAP and prevented diarrhoea. The findings of the study are limited to isolated tribal settings and therefore cannot be generalized to other settings. The potential impact of these interventions on the nutritional status of children warrants further investigation. However, to ensure the sustainability of interventions, it is imperative to test their integration with health services. Frugal technology should be utilized to its maximum potential to translate science in these settings.

In the resource-constrained settings of tribal regions of Mokhada, our WaSH intervention that tested the combined effect of awareness creation and providing WaSH resources significantly improved practices and reduced the number of diarrhoea cases. This comprehensive intervention included the development of communication materials focused on safe WaSH practices, the use of a frugal tool like the origami microscope (foldscope) to observe unsafe water, and the distribution of WaSH kits. To further the positive results of this research incremental improvements need to be planned after achieving the initial goals of behaviour change. The short- and long-term strategies for WaSH practices appear promising for integration into public health policies and programmes. For instance, integration of this intervention with an Integrated Child Development Programme could be tested for effectiveness, where Anganwadis could serve as the point of distribution of the WaSH kits. Frugal innovations are known to be sustainable and improve outcomes specifically in community settings (Sahid et al. 2023). They enable the achievement of objectives through substantial cost reduction compared to traditional tools. The foldscope drew the attention of the younger members of the households. The enhanced appeal for foldscope needs further thrust, for integration into school programmes, which will engage young children in efforts to improve WaSH practices. Partnerships with community agencies and integrating interventions with public health programmes are suggested strategies for the sustainability of interventions. Furthermore, this intervention is well-aligned with the government's Swachh Bharat mission, and the locally feasible strategies could be accommodated with regional programmes in similar resource-deprived settings. In the long run, these experiences can provide valuable inputs for WaSH policies for the nation, specifically for tribal regions. Essentially, we recommend intensified efforts to improve resources in tribal settings such as access and availability to water for basic human needs, to improve behaviour change.

Transport was a challenge during data collection. The households were situated away from each other and not clustered together. To address this, a three-wheeler was hired for an entire day throughout the data collection period, to travel to and from the place of stay. With the help of the health workers and the local leaders, the participants were brought together. The study setting was 290 km away from the University, therefore, the researchers stayed in the tribal regions during the data collection period. Prior arrangements were made for their stay with the help of medical officers and NGOs in Palghar. Seasonal migration was a common feature in Palghar. The study was therefore planned during the sowing season when migration is minimal. Overall, without the valuable inputs and assistance of local personnel, health workers, NGOs, and community leaders the data collection efforts would not have been possible. It is implicit that strategies that invest in collective efforts with the community yield better results in public health interventions. Another challenge specific to the intervention was the water tablets. As the tablets varied in size the team selected a common size and number, for each household, for a specified duration for the ease of monitoring and trained them to use for specific volumes.

We thank the Department of Biotechnology (DBT) for funding this study. Medentech, Ireland donated Aquatabs for this research. We also thank the medical officer, anganwadi workers in Palghar, Maharashtra, and the participants of the study for their cooperation during the study period.

This work was supported by the Department of Biotechnology (DBT), Government of India (GOI) grant [Grant number: BT/IN/Indo-US/Foldscope/39/2015]. The funders did not have any influence on the design or outcome of the study.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.