Nutrition, Water quality, Sanitation and Hygiene Practices Associated with Children’s Health Status in Nepal. A Cross-sectional Study on Intestinal Parasitic Infections, Diarrhoea and Undernutrition


 Background: Providing universal access to safe water, sanitation and hygiene (WASH) in remote Nepal remains challenging. Efforts to improve WASH access in these areas are impeded by a dearth of information on the status of WASH conditions and its association with health and nutritional status of children in Nepal.
Methods: We investigated nutritional status, WASH practices, and their association with intestinal parasitic infections, diarrhoea, undernutrition and clinical signs of nutritional deficiencies (hereafter health outcomes) during March to May 2018. Data was collected through a cross-sectional survey of 1427 households, including questionnaires, observations, stool analysis, anthropometry, water quality measurements and assessment of clinical signs of nutritional deficiencies.
Results: We found that 55.5% had undernutrition, 63.9% had clinical signs of nutritional deficiencies, 51.1% of children were suffering from intestinal parasitic infections, and 52.2% had waterborne illnesses. Multivariate mixed logistic regression analysis revealed statistically significant associations (p<0.05) between aforementioned health outcomes and a better socioeconomic status (adjusted odds ratio (AOR)=0.43, 95% confidence intervals (CI)=0.25-0.75), caregivers who can read (AOR=4.07, 95% CI=1.00-16.5), own food production of food (AOR=0.67, 95% CI=0.46-0.97), providing food supplements to the children (AOR=0.57, 95% CI=0.38-0.84), intermittent water supply (AOR=2.72, 95% CI=1.18-6.31), source water quality (AOR=10.44, 95% CI=1.61-67.4), washing hands when they look dirty (AOR=0.47, 95% CI=0.32-0.71), no toilet at home (AOR=6.12, 95% CI=1.08-14.25), cleanliness of the available toilet (AOR=0.68, 95% CI=0.47-0.98), handwashing after going to toilet (AOR=0.37, 95% CI=0.13-1.02), cleanliness of caregivers hand (AOR=0.61, 95% CI=0.41-0.89), presence of earthen floor (AOR=2.29, 95% CI=1.20-4.37), animals inside the house overnight (AOR=1.71, 95% CI=1.17-2.51) and regular deworming of the children (AOR=0.44, 95% CI=0.20-0.94).
Conclusions: Findings suggest improvements in WASH services, along with household hygiene and nutritional interventions, may together reduce child morbidity and mortality in Nepal.
Keywords: Drinking Water Quality, Sanitation and Hygiene, Child Health, Diarrhoea, Undernutrition, Intestinal Parasitic Infections, Nepal.

[25]. Supine lengths were obtained for children younger than 2 years old using a Seca BabyMat 210.
For children aged between 24 months and 10 years, a height-measuring board and a digital scale (Seca 877;Hamburg,Germany) were used with precisions of 0.1 cm and 0.1 kg, respectively. Before each measurement, scales were calibrated with a standardized weight, and the children were measured barefoot [24]. Anthropometric indices were calculated using AnthroPlus (WHO; Geneva, Switzerland) in accordance with the World Health Organisation (WHO) guidelines [25,26]. Age in total months was recorded for each child and confirmed by an inspection of the birth certificate. Three anthropometric indices were expressed as z-scores (i.e. differences from the median in standard deviations): (a) weight for age (WAZ, underweight); (b) height for age (HAZ, stunting); and (c) body mass index for age (BMIZ, thinness) [4]. Z-scores of ≥ -2 were regarded as normal, those between < -2 and ≥ -3 as moderate undernutrition and those below < -3 as severe undernutrition [31,32].
Children were considered to be undernourished if at least one of the anthropometric indices indicated undernutrition.

Parasitological survey
On the day following the household survey visit, caregivers were asked to provide a fresh morning stool sample without urine contamination from the participating child. The samples were processed on the same day by two experienced laboratory technicians. Each stool sample was analysed using direct wet-mount and formalin-ether concentration techniques to detect intestinal protozoa and helminths following standard guidelines [27][28][29]. In addition, a duplicate Kato-Katz thick smear was prepared for the diagnosis of helminths [30]. The presence of infection by any worm species was defined by the detection of one or more eggs on either slide [7]. Children were considered positive if at least one of the diagnostic techniques revealed an infection. The infection intensity of helminths was calculated according to criteria defined by the WHO and multiplied by 24 to reach the total number of eggs per gram (EPG) of stool. Infection intensities were then classified as light, moderate, and heavy as per the thresholds set by the WHO [5,31].

Signs and symptoms of nutritional deficiencies
During the household survey, the children were screened by the certified medical assistants using a standard checklist for clinical signs and symptoms of nutritional deficiencies: wasted appearance (protein deficiency), loss of hair pigment and easy pluckability (protein deficiency), Bitot's spots (vitamin A deficiency), dry and infected cornea (vitamin A deficiency), oedema (thiamine deficiency), several types of dermatitis (niacin deficiency), spongy bleeding gums (vitamin C deficiency), pale conjunctiva (iron-deficiency anaemia), red inflamed tongue (riboflavin deficiency), sub-dermal haemorrhage (vitamin C deficiency), bowed legs (vitamin D deficiency), and goitre (iodine deficiency) [32].

Drinking water quality examination
Water samples were collected from the household's main drinking water source and from the container used for drinking water transport and storage. The sample at the source was taken after letting the water run for 60 seconds from the tap, and then filling a sterile Nasco Whirl-Pak bag. The caregivers were requested to bring fresh drinking water from the point of collection to the household in the same container they usually use to fetch their drinking water [33]. A second water sample was taken by pouring water from the transport container into another sterile Nasco Whirl-Pak bag. All water samples were stored inside cooler bags and analysed at the field site using the membrane filtration technique: 100 ml water samples were passed through sterile 0.45 µm millipore cellulose membrane filters with sterilized filtration equipment. The filter pads were plated on Nissui Compact Dry Coli-scan plates and incubated for 24 hours at 35 +/-2°C [15]. A solar-powered electrical system was set up to run a low-power incubator at the field site. Colony-forming units of total coliforms and Escherichia coli (E. coli) were counted after 24 hours of incubation.

Data management and statistical analysis
Data cleaning was performed daily during the survey, and if any values were missing or inconsistent, the respective household was consulted the following day. Readings of intestinal parasite and nutritional deficiency screenings were double entered into an Excel 2010 spread sheet (Microsoft; Redmond, USA) and cross-checked. Numerical variables were described by means and standard deviations if normally distributed and by medians and interquartile range otherwise. Categorical variables were described by absolute and relative frequencies. We employed χ 2 statistics to assess the differences in distribution for categorical variables between the study areas. Household socioeconomic status was characterized by factor analysis of reported household assets, such as the availability of electricity, radio, television, solar panel, mobile phone, bicycle, motorbike, fridge, watch, own house, and land ownership. Three factors reflecting three socioeconomic domains were retained and divided using the k-means procedure into three categories: (a) low, (b) medium, and (c) high [34]. The same procedure was applied to create one variable for the hygiene of containers used for transport and storage of drinking water, latrine hygiene, cleanliness of the household environment and kitchen, and personal hygiene. For each of these variables, three factors were retained and categorized, indicating (a) low, (b) medium, and (c) high status.
We assessed four health-related outcome variables: (a) intestinal parasitic infection; (b) diarrhoea; (c) undernutrition including stunting, underweight, and BMIZ (thinness); and (d) clinical signs and symptoms of nutritional deficiencies. The associations between the outcome variables and risk factors were first assessed by conducting univariate mixed logistic regression analyses with random intercepts of the study areas. Since only a few undernutrition cases were severe, the cases were pooled into a binary variable of stunted/non-stunted, and underweight/non-underweight for the subsequent analysis. Similarly, there was a low prevalence of parasites such as T. trichiura, E.
vermicularis and Ancylostoma duodenale, so all reported intestinal parasitic infections were pooled into a binary variable of parasite infection/no infection to maximize statistical power. The clinical signs of nutritional deficiencies and diarrhoea outcomes were coded into binary variables for the subsequent comparative analysis.
We assessed associations between the binary outcome variables and hypothesized risk factors using logistic regression models with random study site intercepts and controlling for potential confounders with the demographic variables of age, sex, and socioeconomic status. First, the associations between outcome variables and risk factors were assessed using univariate models. Variables with p-values < 0.2 were retained for the maximal model. The final model was then obtained using backward selection with the same level of 0.2 [35]. Odds ratios were reported and the associations were considered as statistically significant if p-values were < 0.05. The statistical analysis was performed with STATA version 14 (STATA Corporation, College Station, TX, USA).

Socio-demographic characteristics of the study participants
The sociodemographic and socioeconomic characteristics of the households interviewed are provided in Table A in supplementary materials. Caregivers aged 25-40 years of age constituted the largest group (57.9%) of interviewees, whereas those aged >40 years constituted the smallest group (13.9%). More than 80% of the caregivers could both read and write. Agriculture was the main (60.6%) occupation of the household heads. A total of 59.7% of the households kept animals inside the home overnight. A majority (84.1%) of the households had earthen floors. The majority of children (99.1%) included in the study were between 6 months and 5 years of age, while 0.9 % were age 6 to 10 years. Around 52.7% of the households across the study sites had access to electricity.
Water handling, water quality, sanitation, hygiene, and WASH promotion Tables 1 and 2 and Table B in supplementary materials describe water handling, water quality, sanitation, and hygiene practices, WASH infrastructure, WASH promotion, and WASH-related psychological factors in the households in the four study sites. Some 75.5% of the respondents depend on a communal village tap for drinking purposes, 20.7% have access to piped water in the house or yard, and the remaining respondents use open water sources (2.0%) and unmanaged pipe systems (0.3%). More than half (54.4%) of the respondents were confident about the safety of their available drinking water. Just 16.5% of the households reported treating their water at the point of use. One third (33.7%) of the respondents reported disliking the taste of treated water (Table 2 &   Table B in supplementary Materials).
We found that the vast majority of water samples from the point of collection and point of use were contaminated with E. coli (93.6% and 95.3%, respectively) and total coliform bacteria (99.4% and 98.8%, respectively). Five percent of water samples at the point of consumption met the WHO's guidelines for microbial safety of drinking water (<1 CFU E. coli/100 mL), 16% were in the low risk category (1-10 CFU E. coli/100 mL), 51% in the intermediate risk category (10-100 CFU E. coli/100 mL), and 28% in the high or very high risk categories (>100 CFU E. coli/100 mL) [36]. Further details of the microbial water quality at the source and the point of use are presented in Table 2.
We found that 6.3% of the households did not have latrines, and 93.7% of the households had traditional pit latrines. Almost half of the latrines (48.7%) were in a poor hygienic state. Three quarters (76.0%) of the respondents reported having washed their hands with soap less than five times per day prior to the day of survey. The overall hygiene conditions were very low or low in 64.0% of the surveyed households. Only 10.9% of the respondents reported having received information on water treatment and hygiene. Among those, 89.7% reported that this information changed their WASH behaviour, such as using soap more often for washing hands (Table 3). Table C in the supplementary materials shows the percentage distribution of child health records, health-seeking behaviours, and risk awareness of the causes of diarrhoea and of perceived vulnerability by study site. A total of 49.9% of the children from under age 6 months to 5 years were reported to have been sick within 7 days prior to the survey. Respiratory illnesses and fevers were most common (both 40.4%) followed by diarrhoea (16.5%). For respondents not seeking health care services, the main reason was a feeling of non-requirement (61.9%), followed by financial constraints (21.2%), preference for self-treatment (7.1%), and lack of accessibility (1.8%) ( Table C in supplementary materials).

Child health, health-seeking behaviours, and KAP survey
A majority (82.7%) of the respondents knew that contaminated water can cause diarrhoea and that children are particularly vulnerable (74.4%). However, a majority (78.9%) of the respondents had never heard about intestinal parasites. The proportions of caregivers who were aware that handwashing with soap (11.1%), wearing shoes (5%), drinking clean water (16.6%), and undergoing regular deworming treatment (11.1%) might prevent intestinal parasitic infections were low (Table C, Supplementary materials). Table 3 presents the association of risk factors with diarrhoea. A total of 16.5% of children less than 5 years suffered from diarrhoea within 7 days prior to the survey. The results from the multivariate regression analysis indicated that children above the age of 5 years showed significantly lower odds of diarrhoea (AOR = 0.39; 95% CI: 0.26-0.57; p = 0.01) than their younger counterparts. The children from the households experiencing a service interruption of more than 1 week to their main drinking water source at the time of visit had 2.87 higher odds of diarrhoea (AOR = 2.87; 95% CI: 1.24-6.61; p = 0.01) than children from households not experiencing an interruption. The children of caregivers who were aware of the need for handwashing during critical times, such as after using the latrine, were significantly better protected against diarrhoea (AOR = 0.37; 95% CI: 0.14-1.10; p = 0.05) than were children whose caregivers were unaware. Households with clean latrines were significantly better protected against diarrhoea (AOR = 0.66; 95% CI: 0.45-0.95; p = 0.03) than were households with dirty latrines. Similarly, the children with visually clean hands without spots of dirt were significantly better protected against diarrhoea than were children with dirty hands (AOR = 0.63; 95% CI: 0.41-0.98; p = 0.04). Children living in households with a floor made of earth painted with animal dung had 2.29 times higher odds of suffering from diarrhoea than children living in households with a cement floor (AOR = 2.29; 95% CI: 1.20-4.37; p = 0.01).

Prevalence of intestinal parasites and associated risk factors
Tables 4 and 5 show the prevalence of intestinal parasitic infections in the study population and the associated risk factors. The overall prevalence of intestinal parasitic infection is 51.1%. The prevalence of intestinal parasitic infections, stratified by sex, age group, and study site, are summarized in Table 4. The predominant helminth species infecting the children was Ascaris lumbricoides (21.1%), followed by Hymenolepsis nana (4.6%), Ancylostoma duodenale (3.2%), Enterobius vermicularis (2.7%), and Trichuris trichiura (0.7%). Polyparasitism and co-infection were not common. Infections with all types of helminths were of light intensity. About 23.4% of the children were infected with Giardia intestinalis (Table 4).
Multivariate analysis showed that the odds of infection with intestinal parasites among children in households where the caregivers could only read were four times higher than the odds among children whose caregivers could both read and write (AOR = 4.07; 95% CI: 1.00-16.55; p = 0.05).
Children in households relying on a simple pit latrine for defecation had six times higher odds of being infected with intestinal parasites than those in households with a pour flush pit latrine (AOR = 6.12; 95% CI:1.57-23.9; p = 0.01). Children with caregivers having clean hands were significantly better protected from intestinal parasitic infection (AOR = 0.61; 95% CI: 0.41-0.89; p = 0.01) than were children of caregivers with dirty hands (Table 5).

Child-feeding practices and household food security
Almost all caregivers (99.6%) reported having breastfed the participating child until the age of 6 months. Complementary feeding in addition to breastfeeding before the age of 6 months was only provided to 3.0% of children. The dietary diversity scores were low, with only 11.2% of the households having consumed all nine listed food groups in the previous 7 days (Table 6 and Table D, supplementary materials). The consumption of milk or milk products and eggs at least once per week was low (9.2% and 5.3%, respectively; Table D, supplementary materials). About 60% of the households do not produce their own food. Among those producing their own food, 20.8% reported self-sufficiency throughout the entire year. Table 7 shows the percentage distribution of undernutrition in the study sample by sex, age group, and study area. The prevalence of undernutrition was 55.5%, while the prevalence of stunting was 44.5%, thinness (BMIZ) 11.2%, and underweight 29.9%. Table 8 provides an overview of the association between undernutrition and the caregiver's socioeconomic status, nutrition and health awareness, intestinal parasitic infections, hygiene status, and water quality of the households in univariate and multivariate regression analyses. Children living in a household of higher socioeconomic status showed lower odds of undernutrition (AOR = 0.43; 95% CI: 0.25-0.75; p = 0.01) than in households with lower socioeconomic status. Children of caregivers with sound knowledge about the importance of regular deworming had lower odds of undernutrition (AOR = 0.44; 95% CI = 0.20-0.94; p = 0.03) than did children whose caregivers had no such knowledge. Children receiving supplementary food were at significantly lower odds of being undernourished (AOR = 0.57; 95% CI: 0.38-0.84; p = 0.01) than were the children without supplementary food. Similarly, households producing their own food were at significantly lower risk of being undernourished (AOR = 0.67; 95% CI: 0.46-0.97; p = 0.03) than were households without agricultural production.

Prevalence of nutritional deficiencies and associated risk factors
A total of 63.9% of the children in the study suffered from at least one sign of a nutritional deficiency.
About one third (35.9%) of the children suffered from pale conjunctiva, followed by Bitot's spots (19.8%), red inflamed tongue (18.3%), spongy bleeding gums (16.3%), wasted appearance (13.8%), dry and infected cornea (13.2%), loss of hair pigment (10.7%), sub-dermal haemorrhage (4.6%), oedema (2.7%), bowed legs (2.6%), and goitre (0.6%) ( Table 9). The children >5 years had twice the odds of having nutritional deficiencies compared to their younger counterparts (AOR = 1.84; 95% CI: 1.30-2.62; p = 0.01). Children whose caregivers washed their hands after cleaning a baby's bottom were at lower odds of having nutritional deficiencies (AOR = 0.60; 95% CI = 0.40-0.92; p = 0.02) compared to children whose caregivers did not follow this practice. Children from households producing their own food were significantly better protected against nutritional deficiencies (AOR = 0.51; 95% CI: 0.35-0.76; p = 0.01) than were children from households without their own food production. Children from households in the higher category of latrine hygiene were at lower odds of nutritional deficiencies than those living in households with low latrine hygiene (AOR = 0.61; 95% CI: 0.41-0.91; p = 0.01). Children living in houses where animals were kept inside overnight had 1.71 times higher odds of having signs of nutritional deficiencies (AOR = 1.71; 95% CI = 1.17-2.51; p = 0.01) than children from households not keeping animals inside the home overnight. Being in the lower category of personal hygiene increased a child's odds for clinical signs of nutritional deficiencies by 1.84 (AOR = 1.90; 95% CI: 1.17-3.10; p = 0.01) over being in the higher category. Children from households with coliform bacteria in their drinking water sources had 10.4 times higher odds of having signs and symptoms of nutritional deficiencies (AOR = 10.4; 95% CI: 1.61-67.42; p = 0.01) than children from households with an uncontaminated water source (Table 9).

Discussion
Our findings highlight that the alarming health conditions of children in remote areas of rural Nepal are associated with insufficient nutrition, with unhygienic conditions in the household environment and inappropriate personal hygiene, including inadequate handwashing, inappropriate sanitation, and lack of access to regular and safely managed drinking water supply. While more than half of the surveyed children were infected with parasites and suffered from undernutrition or nutritional deficiencies, the prevalence of diarrhoea of 16.5% was slightly lower. Our analysis identified specific risk factors for each of these health outcomes.

Diarrhoea
In line with previously reported findings, the prevalence of diarrhoea was highly associated with the age of the children, with older children being less susceptible [37,38]. Surprisingly, water quality was not associated with diarrhoea prevalence, but we found significant associations with factors relating to handwashing, personal hygiene, kitchen hygiene, and the type of toilet. A very strong association was observed between diarrhoea incidence and the family living in a house with a floor made of mud [39,40]. This risk factor needs further attention, because people living in the surveyed area have the practice of painting the mud floors in houses with animal dung. We hypothesize that this practice leads to a high load of diarrhoea-causing pathogens in the household environment, orders of magnitude higher than concentrations found in drinking water, thus masking the impact of clean drinking water on children's health. Children playing on the floor inside or around their houses are at high risk of ingesting pathogens [41,42]. This assumption is confirmed by several studies that associate the contamination of the floor with E. coli with the disposal of faeces and the presence of animals close to the households. Kwong et al. reported that 35% of children put their hands in their mouths after touching soil particles, putting them at risk of contamination [40]. Additionally, we observed that animals were often kept in or near the home and brought indoors overnight. Such practices have been shown to increase exposure to faecal contamination in the household environment in other rural settings [15]. Other studies conducted in India and Bangladesh highlighted the importance of faecal contamination of animal origin in the domestic environment, including source and stored drinking water, hands, and soil [43,44]. A strong association was also found between diarrhoea and interruptions of the water supply. Caregivers who reported their water supply system being interrupted for more than 7 days had 2.7 times higher odds of having children with diarrhoea. Underlying reasons might be the subsequent lack of water for hygienic practices or that intermittent water services present an increased risk of bacterial contamination in the system, or it might be that the risk of pathogen infiltration is greater during such low-pressure events in the piped network [45,46]. Similar results were reported in a study conducted in low-and middle-income countries, which reported that the provision of high-quality piped water, sewer connections, and the use of water filters were associated with considerable reductions in diarrhoea [47].

Intestinal parasitic infections
The high prevalence of intestinal parasitic infections among children in our study is similar to or higher than the rate reported in studies conducted in other parts of Nepal [16,18,48]. The higher infection rates may be explained by the fact that our study areas were located in extremely remote rural and hilly areas with difficult access and a lack of infrastructure, which together result in a low level of access to basic health and WASH services [16,18,48]. Our analysis showed that children from households without latrines had a four times higher odds ratio for developing an intestinal parasitic infection than did those without latrines. This indicates that the poor hygienic status observed in the pit latrines used by more than 94% of the households and the lack of water for flushing toilets is a major risk factor in the transmission of intestinal parasites. The effect of inadequate sanitary conditions on intestinal parasitic infections was also documented in a systematic review and meta-analysis [49].
The cleanliness of caregivers' hands was identified as a significant risk factor for children's parasitic infections, suggesting that caregivers' hands play a critical role in transferring parasites from the household environment to their children. We observed poor handwashing conditions, with 59.9% of households not having adequate infrastructure for washing their hands and a limited presence of soap and water at the handwashing stations. The importance of clean hands to preventing parasitic infections is in agreement with previous studies conducted in eastern Nepal, which found not using soap after defecation to be significantly associated with intestinal parasitic infection [16,50]. There is strong evidence a high load of pathogens in the household environment and inadequate handwashing increase the numbers of pathogens on caregivers' hands [42]. The association between critical sanitation, hygiene factors and infections with intestinal parasites was also documented by studies conducted in other parts of Nepal [16,48,51] .
Surprisingly, despite the low quality of the water consumed, we did not find any association between drinking water quality and parasitic infections in the study households. We hypothesize that the transmission of pathogens through drinking water was minor compared to the high load of pathogens existing in the household environment. In contrast to this, two other studies recently conducted in Nepal identified the consumption of untreated water as a risk factor for infection with Giardia species [18,48]. However, these studies may well have been conducted in different, hygienically less challenging contexts.

Undernutrition
One reason for the high prevalence of undernutrition in our study sites could be high poverty rates and their location in food-scarce regions where agricultural activity has been affected by such impacts of climate change as untimely heavy rainfall, droughts, and hailstorms. Against expectations, undernutrition was linked less to hygiene-related risk factors and more to a low socioeconomic status of the household and poor nutrition. These findings are in line with the results of recent evaluations of WASH and nutrition interventions that found an effect of nutrition on reducing child stunting or thinness but no effect of improved WASH [52][53][54]. An indirect link to the importance of hygienic conditions in reducing undernutrition could be observed through the significant association with a lack of regular deworming activities. Although the relation between undernutrition and parasitic infections is not well understood, undernutrition may be caused by recurring infections in the gut, which limit the proper absorption of calories and nutrients [55,56]. Our findings on the association between undernutrition and intestinal parasitic infection are in agreement with studies conducted elsewhere [56,57]. However, in contrast to findings from a study conducted in Bangladesh, our study did not identify recent diarrhoea infection as a risk factor for undernutrition [58]. Because we collected data during a cross-sectional survey, we do not have any longitudinal information on the frequency and severity of diarrhoea cases occurring in the study population. We think that there is a high chance that chronic diarrhoea and environmental enteropathy are linked with undernutrition at our study sites, but our data only refers to one point in time and, thus, cannot be confirmed [54,59,60].
We observed that unsafe water was used to wash feeding and storage containers, unhygienic kitchen cloths were used to dry children's utensils, caregivers did not wash their hands with soap while preparing food and feeding children and food was not hygienically stored. In addition, 76.8% of the households had flies indoors and in their surroundings. The recurrent food-borne infections are likely to have resulted in nutritional deficiency, environmental enteropathy, and consequent undernutrition [54,56,61,62]. Similar observations of unsafe WASH practices and inadequate food hygiene were reported in a study conducted in other parts of Nepal [63].

Clinical signs of nutritional deficiencies
The prevalence of having at least one clinical sign for a nutritional deficiency was high. Because of the dearth of studies conducted on children with clinical signs of nutritional deficiencies in Nepal and other similar contexts, our results cannot be compared with other studies. The most frequently encountered nutritional deficiency, pale conjunctiva, which was found in 36.0% of children, can be related to the lack of animal proteins in diets.
In contrast to our findings on risk factors associated with undernutrition, clinical signs of nutritional deficiencies were significantly associated with water quality and various hygiene factors. Our analysis identified a significant protective association with handwashing, improved latrine cleanliness, better hygiene in the kitchen, and the household's own production of food. A higher risk for a nutritional deficiency was associated with poor water quality, keeping animals inside the house overnight, and the low personal hygiene of caregivers and of children. Further in-depth research is required to provide more insight into these issues.
Our study has several limitations. First, the findings presented in our study cannot be generalized to all other rural areas of Nepal, as the study was conducted in an extremely remote setting characterized by exceptionally low access to basic services. Second, an anthropometric survey has certain limitations related to the inaccuracy of children's dates of birth. Although we checked birth certificates to validate the reported ages, these certificates were not always available. Third, only one stool sample per participating child was examined by a double Kato-Katz thick smear, which likely led to an underestimation of the true prevalence of parasitic infections due to the low sensitivity of this technique.

Conclusion
More than half of the children living in remote hilly areas of Nepal suffer from an impaired nutritional status, nutritional deficiencies, intestinal parasitic infections, and to a lesser degree from diarrhoea.
Better nutritional status of children was highly associated with higher economic status and improved nutrition provided to the child. The regular receipt of deworming tablets was equally important to better nutritional status. This indicates an indirect association between a better nutritional status and improved hygiene, because parasitic infections were highly associated with lacking sanitation and dirty hands. The presence of animal faeces in houses, caused by keeping animals in the household overnight and by painting mud floors with animal dung, was highly associated with diarrhoea and nutritional deficiencies in addition to hand hygiene and sanitation-related factors. Consequently, interventions to reduce the load of pathogens transmitted by animals into the household environment could be promising for improving children's health and call for further investigation.
Children's health status in remote areas in Nepal is alarming. Addressing this, our findings suggest interventions providing improved nutrition and promoting improved hygiene practices, including a reliable water supply to provide sufficient water for these. Declarations interpretation of the data, manuscript writing, and revisions. All authors read and approved the final manuscript.

Funding
This work is supported by the Swiss Agency for Development and Cooperation and the REACH project.
The donors had no role in study design or data collection or analysis or the preparation of the manuscript or the decision to publish the manuscript.

Availability of data and material
The dataset and the questionnaire supporting the conclusions are available from the corresponding author on reasonable request.

Ethical approval and consent to participate
The study protocol was approved by the Stellungnahme der Kantonalen Ethikkommission, Zurich in participation was emphasized, and caregivers were informed that they could withdraw at any time without obligations. A unique identifying code was assigned to each household. Results were communicated with the caregivers, and when the child was found to be positive for either intestinal parasites or nutritional deficiencies or malnutrition, they were referred to the collaborating government health facilities, where they received treatment free of charge.

Consent to publication
Not applicable Sanitation, hookworm, anemia, stunting, and wasting in primary school children in