Abstract
Diarrheal diseases are the second leading cause of child mortality worldwide, occurring in about one in every nine child deaths, and were associated with water, sanitation, and hygiene (WASH) access. In this study, we provided an overview of WASH indicators' evolution from 2000 to 2017 and their impact on the occurrence of diarrhea in children under 5 years old in Senegal. It was a retrospective cross-sectional study, in which we did a secondary analysis of data from the Joint Monitoring Program (JMP) for water supply and sanitation and from the Senegal Demographic and Health Survey 2018. Our results showed that access to safely managed services increased by 18.1 and 19.1%, respectively, for water and sanitation. The prevalence of diarrhea estimated at 18.16% was associated with straining water through a cloth (adjusted odds ratio (AOR) [95% confidence interval (CI)]: 1.21 [1.00–1.45]) and getting water supplies from a source not located in a dwelling (AOR [95% CI]: 1.59 [1.21–2.09]). The prevalence of diarrhea among children under 5 years old was still relatively high in Senegal and was significantly associated with a lack of WASH access. Although the latter continues to increase, additional efforts to make water safer to drink will significantly reduce the occurrence of diarrheal diseases among children under 5 years old in Senegal.
HIGHLIGHTS
WASH access has improved in recent years; however, the prevalence of diarrhea is still relatively high.
Diarrhea is associated with a lack of WASH access. Indeed, straining water through a cloth and getting water supplies from a source not located in a dwelling are associated with an excess risk of diarrhea among children under 5 years old.
Interventions to improve WASH are opportunities to save lives and are cost-effective measures.
Graphical Abstract
INTRODUCTION
Water is an essential resource for ecosystems and human activities. However, it can be the vehicle of biological hazards (viruses, bacteria, parasites, etc.) and responsible for relatively serious diseases in humans, like diarrhea (OMS & ONU-HABITAT 2018; OMS 2019). Children in developing countries are among the most vulnerable to the occurrence of diarrhea (OMS 1993; Ndiaye et al. 2010; Kabaré et al. 2017). It accounts for 8% of all deaths among children under 5 years old worldwide (UNICEF 2021) and is one of the leading causes of children under-five mortalities in sub-Saharan Africa (GBD 2019 Demographics Collaborators 2020). The significant effort included public health interventions and preventive measures such as improving the quality of drinking water, sanitation, and hygiene (WASH) has been made worldwide in recent decades to reduce the burden of diarrhea-related death among children (Fewtrell et al. 2005; GBD 2015 Mortality & Causes of Death Collaborators 2016). Indeed, the quality of water appears as a health requirement having regard to the foregoing and constitutes a key component of health protection policies. This explains the commitment of the international community, in particular, the declaration of Alma Ata on the importance of drinking water and healthy hygiene in health protection; the Millennium Development Goal 7 (MDG 7) aimed at halving the fraction of the population that does not have sustainable access to drinking water supply and basic sanitation; the Sustainable Development Goal 6 (SDG 6) focuses on the availability and sustainable management of water resources and sanitation for all; as well as the proclamation of 2005–2015, an international decade of action on the following topic: ‘water source of life’ (El Gamal 1990; UNICEF 2006; OMS & ONU-HABITAT 2018). This work is initiated with the aim of measuring the impact of access to WASH on the occurrence of diarrhea in children under 5 years old in Senegal, where the measurement is supplemented by an analysis of WASH indicators' evolution in recent years. The context described above justifies the interest of this study, which will support existing documentation on this subject.
METHODS
Setting and study design
We conducted a retrospective cross-sectional study, in which we did a quantitative secondary analysis on the seventh Demographic and Health Survey's database (DHS-7) to measure the impact of WASH access on the occurrence of diarrhea. This analysis was completed by a description of household's access to WASH between 2000 and 2017 using data from World Health Organization (WHO) and United Nations Children's Fund (UNICEF) Joint Monitoring Program (JMP) for water supply and sanitation. Data from DHS are available for researchers at https://dhsprogram.com/, on condition of briefly explaining the purpose for its use. As for the JMP, it has a database on WASH indicators for free access from https://washdata.org/data.
DHS sampling and data collection
DHS data collection used a stratified multi-stage cluster sample design in urban and rural areas. Enumeration areas (EAs) were identified in the first stage and then were drawn from the last census data. The second stage consisted of drawing a sample of households and an updated list of households in each EA selected. Participants in the survey include women aged 15–49 years, men aged 15–59 years, and children under 5 years old. Four questionnaires are used to collect data: household questionnaire, female questionnaire, male questionnaire, and biomarker questionnaire. The household questionnaire is used to collect information on household characteristics (the main source of drinking water, type of toilet, hand-washing equipment, etc.). It was also used to identify household members with some of their socio-demographic characteristics (age, sex, level of education, etc.) and to identify women, men, and children eligible for individual interviews and/or for biological tests and measurements. Male and female questionnaires are, respectively, intended to collect information concerning them, while a biomarker questionnaire is used to collect anthropometric data (weight and height) and those on anemia, malaria, and blood samples taken for human immunodeficiency virus (HIV) tests (ANSD & ICF 2018). Mothers were asked to respond, on behalf of their children, on their health status and demographic characteristics. Results presented in this paper are based on information on living children whose mothers were usual residents of the households where they were selected, i.e., a total of 10,851 children. The participation rate was, respectively, 98 and 96% for households and for women (ANSD & ICF 2018).
Operational description of variables
Impact measurement has identified diarrhea as the dependent variable. The question asked by surveyors for this variable was ‘Had the child had any diarrhea during the last 2 weeks?’ and the possible responses were ‘Yes’ or ‘No’. WASH characteristics (main source of drinking water, type of toilet facility, hand-washing equipment, etc.) are defined as main exposure variables. We recoded several responses of these variables to fit the standard definitions of Sustainable Development Goals (SDGs) (UNSD 2022). Thus, possible responses to ‘Main source of water’ and ‘Type of toilet facility’ were recoded into ‘improved’ or ‘unimproved’ (Table 1). Some other variables such as children's specific characteristics (age, sex, and health status) and those of their mothers (educational level and age) and housing (place of residence and household wealth index) were also included in the analysis as potential confounding factors.
Recodes of ‘main source of water’ and ‘types of toilets’
Questions . | Possible answers/codes . | Recoded as . |
---|---|---|
The main source of drinking water for members of the household | Piped into dwelling; piped to yard/plot; public tap/standpipe; piped to neighbor; tube well or borehole; protected well; protected spring; rainwater; tanker truck; cart with small tank; bottled water; | Improved |
unprotected well; unprotected spring; river/dam/lake/ponds/stream/canal/irrigation channel; other | Unimproved | |
Type of toilet facility in the household | Flush to the piped sewer system; flush to septic tank; flush to pit latrine; flush, do not know where; ventilated improved; pit latrine; pit latrine with slab; composting toilet; | Improved |
Flush to somewhere else; pit latrine without slab/open pit; hanging toilet/latrine; bucket toilet; other | Unimproved |
Questions . | Possible answers/codes . | Recoded as . |
---|---|---|
The main source of drinking water for members of the household | Piped into dwelling; piped to yard/plot; public tap/standpipe; piped to neighbor; tube well or borehole; protected well; protected spring; rainwater; tanker truck; cart with small tank; bottled water; | Improved |
unprotected well; unprotected spring; river/dam/lake/ponds/stream/canal/irrigation channel; other | Unimproved | |
Type of toilet facility in the household | Flush to the piped sewer system; flush to septic tank; flush to pit latrine; flush, do not know where; ventilated improved; pit latrine; pit latrine with slab; composting toilet; | Improved |
Flush to somewhere else; pit latrine without slab/open pit; hanging toilet/latrine; bucket toilet; other | Unimproved |
As for the description of WASH access, the following definitions are also proposed for indicators:
‘Safely managed drinking water service’: Drinking water from an improved water source that is accessible on premises, available when needed, and free from fecal and priority chemical contamination.
‘Safely managed sanitation service’: Use of improved facilities that are not shared with other households and where excreta are safely disposed in situ or removed and treated offsite.
‘Basic drinking water service’: Drinking water from an improved source, provided collection time is not more than 30 min for a roundtrip including queuing.
‘Basic managed sanitation service’: Use of improved facilities that are not shared with other households.
‘Basic hygiene service’: Availability of a hand-washing facility with soap and water at home.
Statistical analysis
All statistical analyses to measure the impact of household WASH access on the occurrence of diarrhea were carried out using R software. The ‘survey’ package made it possible to weigh all observations in order to compensate for the oversampling of certain categories of respondents and to take into account the complexity of the sampling design. We did a frequency measurement to describe sample distribution and prevalence of diarrhea. The second phase of analysis was carried out by chi-squared (χ2) test and logistic regression with a significance threshold set at 5%. Univariate regression concerned variables significantly associated with diarrhea with regard to χ2 test p-value. Variables with a p-value less than 20% in univariate regression were subsequently included in a backward regression procedure to fit a multivariable model. Odds ratios (crude odds ratios (COR) and adjusted odds ratios (AOR)) were estimated as well as their 95% confidence intervals (95% CI).
RESULTS
Household's WASH access
Globally, WASH access has improved in recent years. Indeed, between 2000 and 2017, access to safely managed services increased from 65.2 to 83.3% and from 49.3 to 68.4%, respectively, for water and sanitation, respectively. As for hygiene, the proportion of households with basic services remained practically constant at 46% between 2013 and 2017 (Table 2).
Evolution of access to WASH between 2000 and 2017
Year . | Safely managed service (%) . | Basic service (%) . | |||
---|---|---|---|---|---|
Water . | Sanitation . | Water . | Sanitation . | Hygiene . | |
2000 | 65.2 | 49.3 | 59.9 | 38.9 | – |
2001 | 66.3 | 50.3 | 61.0 | 39.7 | – |
2002 | 67.3 | 51.4 | 62.2 | 40.4 | – |
2003 | 68.4 | 52.5 | 63.4 | 41.1 | – |
2004 | 69.6 | 53.6 | 64.6 | 41.9 | – |
2005 | 70.7 | 54.8 | 65.9 | 42.7 | – |
2006 | 71.8 | 55.9 | 67.1 | 43.5 | – |
2007 | 72.9 | 57.1 | 68.4 | 44.2 | – |
2008 | 74.0 | 58.2 | 69.6 | 45.0 | – |
2009 | 75.1 | 59.4 | 70.9 | 45.7 | – |
2010 | 76.2 | 60.5 | 72.1 | 46.5 | – |
2011 | 77.2 | 61.7 | 73.3 | 47.2 | – |
2012 | 78.3 | 62.8 | 74.6 | 48.0 | – |
2013 | 79.3 | 63.9 | 75.8 | 48.7 | 45.8 |
2014 | 80.3 | 65.1 | 77.0 | 49.4 | 45.9 |
2015 | 81.3 | 66.2 | 78.2 | 50.1 | 46.0 |
2016 | 82.3 | 67.3 | 79.5 | 50.8 | 46.2 |
2017 | 83.3 | 68.4 | 80.7 | 51.5 | 46.3 |
Year . | Safely managed service (%) . | Basic service (%) . | |||
---|---|---|---|---|---|
Water . | Sanitation . | Water . | Sanitation . | Hygiene . | |
2000 | 65.2 | 49.3 | 59.9 | 38.9 | – |
2001 | 66.3 | 50.3 | 61.0 | 39.7 | – |
2002 | 67.3 | 51.4 | 62.2 | 40.4 | – |
2003 | 68.4 | 52.5 | 63.4 | 41.1 | – |
2004 | 69.6 | 53.6 | 64.6 | 41.9 | – |
2005 | 70.7 | 54.8 | 65.9 | 42.7 | – |
2006 | 71.8 | 55.9 | 67.1 | 43.5 | – |
2007 | 72.9 | 57.1 | 68.4 | 44.2 | – |
2008 | 74.0 | 58.2 | 69.6 | 45.0 | – |
2009 | 75.1 | 59.4 | 70.9 | 45.7 | – |
2010 | 76.2 | 60.5 | 72.1 | 46.5 | – |
2011 | 77.2 | 61.7 | 73.3 | 47.2 | – |
2012 | 78.3 | 62.8 | 74.6 | 48.0 | – |
2013 | 79.3 | 63.9 | 75.8 | 48.7 | 45.8 |
2014 | 80.3 | 65.1 | 77.0 | 49.4 | 45.9 |
2015 | 81.3 | 66.2 | 78.2 | 50.1 | 46.0 |
2016 | 82.3 | 67.3 | 79.5 | 50.8 | 46.2 |
2017 | 83.3 | 68.4 | 80.7 | 51.5 | 46.3 |
Sample distribution by selected characteristics
In sum, 10,851 children aged 0–5 years were included in this study. The average age was 2 ± 1.41 years with 48.59% (girls) and 51.41% (boys). During the last 2 weeks preceding the interview, 18.16% of children had at least one episode of diarrhea. Moreover, more than half of the children (85.39%) had a low birth weight and 16.49% of them are stunted, and about their mother's level of education, 63.50% reported having no formal education. As for the area of residence and Combined Wealth Index, 63.03 and 24.45% of children, respectively, lived in a rural area and the poorest household. Regarding WASH characteristics, more than half of children live in households that mainly used an improved source of drinking water (80.17%) and improved toilet facility (66.17%), while less than half live in households where hand-washing facilities were observed (42.46%) (Table 3).
Sample distribution by children's selected characteristics including those of their mothers and housing
WASH characteristics . | Frequency (%) . |
---|---|
N = 10,851 . | |
Access to water | |
Main source of drinking water | |
Improved | 80.17 |
Unimproved | 19.83 |
Location of source for water | |
In own dwelling/yard/plot | 13.44 |
Elsewhere | 86.56 |
Water availability | |
Not interrupted for a full day | 50.7 |
Interrupted for a full day or more | 48.9 |
Do not know | 0.4 |
Anything done to water to make it safe to drink | |
Yes | 26.69 |
No | 73.22 |
Do not know | 0.10 |
Water usually treated by: boil | |
Yes | 0.25 |
No | 99.66 |
Do not know | 0.10 |
Water usually treated by: add bleach/chlorine | |
Yes | 12.7 |
No | 87.83 |
Do not know | 0.10 |
Water usually treated by: strain through a cloth | |
Yes | 16.72 |
No | 83.19 |
Do not know | 0.10 |
Water usually treated by: use a water filter | |
Yes | 0.63 |
No | 99.28 |
Do not know | 0.10 |
Water usually treated by: let it stand and settle | |
Yes | 1.10 |
No | 98.81 |
Do not know | 0.10 |
Access to Sanitation | |
Type of toilet facility | |
Improved | 66.17 |
Unimproved | 18.97 |
Bush/field | 14.86 |
Share toilet with other households | |
Yes | 24.09 |
No | 75.91 |
Location of toilet facility | |
In own dwelling/yard/plot | 96.96 |
Elsewhere | 3.04 |
Access to Hygiene | |
Place where household members wash their hands | |
Observed place | 42.46 |
Not observed place | 57.54 |
Presence of water at hand-washing place | |
Water is available | 60.37 |
Water not available | 39.63 |
Soap or detergent available at hand-washing place | |
Yes | 48.85 |
No | 51.15 |
Occurrence of diarrhea and other selected characteristics | |
Occurrence of diarrhea during the 2 weeks preceding the survey | |
Yes | 18.16 |
No | 81.84 |
Current age (in a year) | |
mean [±sd] | 2 [±1.41] |
Sex | |
Girl | 48.59 |
Boy | 51.41 |
Low birth weight infanta | |
Yes | 14.61 |
No | 85.39 |
Stunted child | |
Yes | 16.49 |
No | 83.51 |
Mother's age | |
Mean [±sd] | 29.90 [±7] |
Mother's educational level | |
Higher | 2.02 |
Secondary | 11.59 |
Primary | 22.84 |
No education | 63.50 |
Do not know | 0.5 |
Type of place of residence | |
Urban | 36.97 |
Rural | 63.03 |
Wealth Index Combined | |
Poorest | 24.45 |
Poorer | 21.92 |
Middle | 20.67 |
Richer | 17.09 |
Richest | 15.88 |
WASH characteristics . | Frequency (%) . |
---|---|
N = 10,851 . | |
Access to water | |
Main source of drinking water | |
Improved | 80.17 |
Unimproved | 19.83 |
Location of source for water | |
In own dwelling/yard/plot | 13.44 |
Elsewhere | 86.56 |
Water availability | |
Not interrupted for a full day | 50.7 |
Interrupted for a full day or more | 48.9 |
Do not know | 0.4 |
Anything done to water to make it safe to drink | |
Yes | 26.69 |
No | 73.22 |
Do not know | 0.10 |
Water usually treated by: boil | |
Yes | 0.25 |
No | 99.66 |
Do not know | 0.10 |
Water usually treated by: add bleach/chlorine | |
Yes | 12.7 |
No | 87.83 |
Do not know | 0.10 |
Water usually treated by: strain through a cloth | |
Yes | 16.72 |
No | 83.19 |
Do not know | 0.10 |
Water usually treated by: use a water filter | |
Yes | 0.63 |
No | 99.28 |
Do not know | 0.10 |
Water usually treated by: let it stand and settle | |
Yes | 1.10 |
No | 98.81 |
Do not know | 0.10 |
Access to Sanitation | |
Type of toilet facility | |
Improved | 66.17 |
Unimproved | 18.97 |
Bush/field | 14.86 |
Share toilet with other households | |
Yes | 24.09 |
No | 75.91 |
Location of toilet facility | |
In own dwelling/yard/plot | 96.96 |
Elsewhere | 3.04 |
Access to Hygiene | |
Place where household members wash their hands | |
Observed place | 42.46 |
Not observed place | 57.54 |
Presence of water at hand-washing place | |
Water is available | 60.37 |
Water not available | 39.63 |
Soap or detergent available at hand-washing place | |
Yes | 48.85 |
No | 51.15 |
Occurrence of diarrhea and other selected characteristics | |
Occurrence of diarrhea during the 2 weeks preceding the survey | |
Yes | 18.16 |
No | 81.84 |
Current age (in a year) | |
mean [±sd] | 2 [±1.41] |
Sex | |
Girl | 48.59 |
Boy | 51.41 |
Low birth weight infanta | |
Yes | 14.61 |
No | 85.39 |
Stunted child | |
Yes | 16.49 |
No | 83.51 |
Mother's age | |
Mean [±sd] | 29.90 [±7] |
Mother's educational level | |
Higher | 2.02 |
Secondary | 11.59 |
Primary | 22.84 |
No education | 63.50 |
Do not know | 0.5 |
Type of place of residence | |
Urban | 36.97 |
Rural | 63.03 |
Wealth Index Combined | |
Poorest | 24.45 |
Poorer | 21.92 |
Middle | 20.67 |
Richer | 17.09 |
Richest | 15.88 |
sd, standard deviation.
aLive births who were weighed at birth and were reported as weighing less than 2.5 kg; children who have a height-for-age indicator's z-score below two standard deviations (z-score ≤− 2).
Occurrence of diarrhea by selected characteristics and the χ2 test
Bivariate analysis shows that 20.44% of children with diarrhea lived in households that used an unimproved source of drinking water versus 17.60% of children who live in households that used an improved source, with a difference in proportion statistically significant (p = 0.013). The same is true for the location of the source (p = 0.003): 20.33% of children who suffered diarrhea live in households where drinking water comes from elsewhere, compared to 14.09% of children who come from households that have their drinking water source in their dwelling. Occurrence of diarrhea was also noted with significant differences in proportion with regard to the attempt to make water safe to drink (p < 0.001) and treating water with chlorine (p = 0.021), using a water filter (p = 0.005) or by letting it stand and settle (p = 0.015) and straining through a cloth (p < 0.001). About the latter, 22.11% of children with diarrhea live in households that practice it in order to make water safe to drink versus 17.39% of children residing in households that do not use this technique. Regarding access to sanitation, the highest proportion of diarrhea was noted among children who live in households where open defecation was practiced: 22.10 versus 20.58% (unimproved toilet) and 16.58% (improved toilet); p < 0.001. Differences in proportions were also significant with regard to sharing of toilets with other households (p = 0.024) as well as the location of toilet facilities (p = 0.015). As for access to hygiene, although differences in proportion noted between children who live in households that had hand-washing equipment (18.58%) and those living in households without (17.85%) are not significant, differences were significant regarding the presence of water (p = 0.026) and soap (p < 0.001) at hand-washing place (Table 4).
Occurrence of diarrhea by children's selected characteristics including those of their mothers and housing and association measurement using the χ2 test
WASH characteristics . | Occurrence of diarrhea (%) . | χ2 test's p-value . |
---|---|---|
Access to water | ||
Main source of drinking water | ||
Improved | 17.60 | 0.013 |
Unimproved | 20.44 | |
Location of source for water | ||
In own dwelling/yard/plot | 14.09 | 0.003 |
Elsewhere | 20.33 | |
Water availability | ||
Not interrupted for a full day | 17.85 | 0.946 |
Interrupted for a full day or more | 17.43 | |
Do not know | 19.01 | |
Anything done to make water safe to drink | ||
Yes | 21.06 | < 0.001 |
No | 17.13 | |
Do not know | 3.07 | |
Water usually treated by: boil | ||
Yes | 13.36 | 0.345 |
No | 18.19 | |
Do not know | 3.07 | |
Water usually treated by: add bleach/chlorine | ||
Yes | 20.71 | 0.021 |
No | 17.83 | |
Do not know | 3.07 | |
Water usually treated by: strain through a cloth | ||
Yes | 22.11 | < 0.001 |
No | 17.39 | |
Do not know | 3.07 | |
Water usually treated by: use a water filter | ||
Yes | 6.30 | 0.005 |
No | 18.25 | |
Do not know | 3.07 | |
Water is usually treated by: let it stand and settle | ||
Yes | 29.05 | 0.015 |
No | 18.06 | |
Do not know | 3.07 | |
Access to sanitation | ||
Type of toilet facility | ||
Improved | 16.58 | < 0.001 |
Unimproved | 20.58 | |
Bush/field | 22.10 | |
Share toilet with other households | ||
Yes | 20.03 | 0.024 |
No | 16.67 | |
Location of toilet facility | ||
In own dwelling/yard/plot | 17.28 | 0.015 |
Elsewhere | 23.58 | |
Access to Hygiene | ||
Place where household members wash their hands | ||
Observed place | 18.58 | 0.507 |
Not observed place | 17.85 | |
Presence of water at hand-washing place | ||
Water is available | 16.85 | 0.026 |
Water not available | 21.22 | |
Soap or detergent available at hand-washing place | ||
Yes | 15.55 | < 0.001 |
No | 21.47 | |
Current age (in years) | ||
< 1 | 22.28 | < 0.001 |
1–2 | 27.63 | |
2–3 | 18.98 | |
≥ 3 | 10.40 | |
Sex | ||
Female | 17.94 | 0.642 |
Male | 18.37 | |
Low birth weight infanta | ||
Yes | 18.88 | 0.684 |
No | 18.11 | |
Stunted child | ||
Yes | 20.38 | 0.033 |
No | 17.91 | |
Mother's age | ||
< 18 | 24.77 | < 0.001 |
18–25 | 21.88 | |
25–35 | 17.50 | |
≥ 35 | 16.22 | |
Mother's educational level | ||
No education | 19.06 | 0.033 |
Primary | 16.73 | |
Secondary | 17.27 | |
Higher | 10.40 | |
Do not know | 8.89 | |
Wealth index combined | ||
Poorest | 20.98 | < 0.001 |
Poorer | 20.35 | |
Middle | 19.64 | |
Richer | 15.55 | |
Richest | 11.70 | |
Type of place of residence | ||
Urban | 15.97 | 0.003 |
Rural | 19.45 |
WASH characteristics . | Occurrence of diarrhea (%) . | χ2 test's p-value . |
---|---|---|
Access to water | ||
Main source of drinking water | ||
Improved | 17.60 | 0.013 |
Unimproved | 20.44 | |
Location of source for water | ||
In own dwelling/yard/plot | 14.09 | 0.003 |
Elsewhere | 20.33 | |
Water availability | ||
Not interrupted for a full day | 17.85 | 0.946 |
Interrupted for a full day or more | 17.43 | |
Do not know | 19.01 | |
Anything done to make water safe to drink | ||
Yes | 21.06 | < 0.001 |
No | 17.13 | |
Do not know | 3.07 | |
Water usually treated by: boil | ||
Yes | 13.36 | 0.345 |
No | 18.19 | |
Do not know | 3.07 | |
Water usually treated by: add bleach/chlorine | ||
Yes | 20.71 | 0.021 |
No | 17.83 | |
Do not know | 3.07 | |
Water usually treated by: strain through a cloth | ||
Yes | 22.11 | < 0.001 |
No | 17.39 | |
Do not know | 3.07 | |
Water usually treated by: use a water filter | ||
Yes | 6.30 | 0.005 |
No | 18.25 | |
Do not know | 3.07 | |
Water is usually treated by: let it stand and settle | ||
Yes | 29.05 | 0.015 |
No | 18.06 | |
Do not know | 3.07 | |
Access to sanitation | ||
Type of toilet facility | ||
Improved | 16.58 | < 0.001 |
Unimproved | 20.58 | |
Bush/field | 22.10 | |
Share toilet with other households | ||
Yes | 20.03 | 0.024 |
No | 16.67 | |
Location of toilet facility | ||
In own dwelling/yard/plot | 17.28 | 0.015 |
Elsewhere | 23.58 | |
Access to Hygiene | ||
Place where household members wash their hands | ||
Observed place | 18.58 | 0.507 |
Not observed place | 17.85 | |
Presence of water at hand-washing place | ||
Water is available | 16.85 | 0.026 |
Water not available | 21.22 | |
Soap or detergent available at hand-washing place | ||
Yes | 15.55 | < 0.001 |
No | 21.47 | |
Current age (in years) | ||
< 1 | 22.28 | < 0.001 |
1–2 | 27.63 | |
2–3 | 18.98 | |
≥ 3 | 10.40 | |
Sex | ||
Female | 17.94 | 0.642 |
Male | 18.37 | |
Low birth weight infanta | ||
Yes | 18.88 | 0.684 |
No | 18.11 | |
Stunted child | ||
Yes | 20.38 | 0.033 |
No | 17.91 | |
Mother's age | ||
< 18 | 24.77 | < 0.001 |
18–25 | 21.88 | |
25–35 | 17.50 | |
≥ 35 | 16.22 | |
Mother's educational level | ||
No education | 19.06 | 0.033 |
Primary | 16.73 | |
Secondary | 17.27 | |
Higher | 10.40 | |
Do not know | 8.89 | |
Wealth index combined | ||
Poorest | 20.98 | < 0.001 |
Poorer | 20.35 | |
Middle | 19.64 | |
Richer | 15.55 | |
Richest | 11.70 | |
Type of place of residence | ||
Urban | 15.97 | 0.003 |
Rural | 19.45 |
Impact measurement by logistic regression
From the full multivariate model obtained by introducing all variables significantly associated with the occurrence of diarrhea with regard to the χ2 test, the backward selection procedure made it possible to retain the following variables: Wealth Index Combined, the current age of the child, water treatment by straining through a cloth, and location of the drinking water source. Excess risks associated (AOR [95% CI]) to the latter two were estimated at 1.20 [1.00–1.45] and 1.55 [1.19–2.03] for, respectively, households treating their drinking water by straining through a cloth and those getting their supplies from a source not located in dwelling. These risks remained significant after adjusting for gender and place of residence: 1.21 [1.00–1.45] and 1.59 [1.21–2.09] (Table 5).
Multivariate logistic regression models estimated between the occurrence of diarrhea and children's selected characteristics including those of their mothers and housing
. | Full model . | Backward model . | |
---|---|---|---|
– . | with forced variables . | ||
Selected characteristics . | COR [95%CI] . | AOR [95%CI] . | AOR [95%CI] . |
Wealth Index Combined | |||
Richestref | – | ||
Poorest | 2.62 [0.98–6.97] | 1.94 [1.02–3.68] | 2.03 [1.08–3.80] |
Poorer | 2.17 [0.85–5.55] | 1.78 [0.92–3.45] | 1.84 [0.97–3.50] |
Middle | 1.99 [0.88–4.49] | 1.81 [0.94–3.49] | 1.73 [0.92–3.27] |
Richer | 2.14 [0.88–5.21] | 1.48 [0.68–3.20] | 1.38 [0.66–2.94] |
Current age (in years) | |||
≥ 3ref | – | – | – |
< 1 | 2.98 [1.92–4.63] | 2.90 [2.35–3.56] | 2.92 [2.37–3.59] |
(1–2) | 3.63 [2.39–5.52] | 3.47 [2.85–4.22] | 3.48 [2.86–4.23] |
(2–3) | 1.92 [1.25–2.93] | 2.37 [1.89–2.96] | 2.38 [1.90–2.98] |
Water usually treated by: strain through a cloth | |||
Noref | – | – | – |
Yes | 1.96 [0.86–4.46] | 1.20 [1.00–1.45] | 1.21 [1.00–1.45] |
Location of source for water | |||
In own dwelling/yard/plotref | – | – | – |
Elsewhere | 2.01 [1.43–2.84] | 1.55 [1.19–2.03] | 1.59 [1.21–2.09] |
Type of place of residence | – | ||
Urban | – | – | |
Rural | 0.69 [0.43–1.11] | 0.79 [0.60–1.03] | |
Sex of child | – | ||
Maleref | – | – | |
Female | 0.91 [0.78–1.07] | 0.91 [0.78–1.07] | |
Main source of drinking water | – | ||
Improved | – | ||
Unimproved | 0.86 [0.56–1.33] | ||
Anything done to make water safe to drink | – | ||
Yesref | – | ||
No | 0.86 [0.36–2.08] | ||
Water usually treated by: add bleach/chlorine | – | ||
Noref | – | ||
Yes | 1.21 [0.80–1.84] | ||
Water usually treated by: use a water filter | – | ||
Noref | – | ||
Yes | 1.84 [0.56–5.99] | ||
Water usually treated by: let it stand and settle | – | ||
Noref | |||
Yes | 0.66 [0.15–2.77] | ||
Type of toilet facility | – | ||
Improvedref | – | ||
Unimproved | 1.33 [0.89–1.98] | ||
Share toilet with other households | – | ||
Noref | – | ||
Yes | 1.29 [0.89–1.86] | ||
Location of toilet facility | – | ||
In own dwelling/yard/plot | – | ||
Elsewhere | 1.28 [0.59–2.76] | ||
Presence of water at the hand-washing place | – | ||
Water is availableref | – | ||
Water not available | 0.68 [039–1.17] | ||
Soap or detergent available at the hand-washing place | – | ||
Yesref | – | ||
No | 1.45 [0.88–2.42] | ||
Stunted child | – | ||
Noref | – | ||
Yes | 0.92 [0.65–1.29] | ||
Mother's age | – | ||
≥ 35 | |||
< 18 | 1.66 [0.48–5.72] | ||
18–25 | 0.93 [0.64–1.35] | ||
25–35 | 0.90 [0.63–1.29] |
. | Full model . | Backward model . | |
---|---|---|---|
– . | with forced variables . | ||
Selected characteristics . | COR [95%CI] . | AOR [95%CI] . | AOR [95%CI] . |
Wealth Index Combined | |||
Richestref | – | ||
Poorest | 2.62 [0.98–6.97] | 1.94 [1.02–3.68] | 2.03 [1.08–3.80] |
Poorer | 2.17 [0.85–5.55] | 1.78 [0.92–3.45] | 1.84 [0.97–3.50] |
Middle | 1.99 [0.88–4.49] | 1.81 [0.94–3.49] | 1.73 [0.92–3.27] |
Richer | 2.14 [0.88–5.21] | 1.48 [0.68–3.20] | 1.38 [0.66–2.94] |
Current age (in years) | |||
≥ 3ref | – | – | – |
< 1 | 2.98 [1.92–4.63] | 2.90 [2.35–3.56] | 2.92 [2.37–3.59] |
(1–2) | 3.63 [2.39–5.52] | 3.47 [2.85–4.22] | 3.48 [2.86–4.23] |
(2–3) | 1.92 [1.25–2.93] | 2.37 [1.89–2.96] | 2.38 [1.90–2.98] |
Water usually treated by: strain through a cloth | |||
Noref | – | – | – |
Yes | 1.96 [0.86–4.46] | 1.20 [1.00–1.45] | 1.21 [1.00–1.45] |
Location of source for water | |||
In own dwelling/yard/plotref | – | – | – |
Elsewhere | 2.01 [1.43–2.84] | 1.55 [1.19–2.03] | 1.59 [1.21–2.09] |
Type of place of residence | – | ||
Urban | – | – | |
Rural | 0.69 [0.43–1.11] | 0.79 [0.60–1.03] | |
Sex of child | – | ||
Maleref | – | – | |
Female | 0.91 [0.78–1.07] | 0.91 [0.78–1.07] | |
Main source of drinking water | – | ||
Improved | – | ||
Unimproved | 0.86 [0.56–1.33] | ||
Anything done to make water safe to drink | – | ||
Yesref | – | ||
No | 0.86 [0.36–2.08] | ||
Water usually treated by: add bleach/chlorine | – | ||
Noref | – | ||
Yes | 1.21 [0.80–1.84] | ||
Water usually treated by: use a water filter | – | ||
Noref | – | ||
Yes | 1.84 [0.56–5.99] | ||
Water usually treated by: let it stand and settle | – | ||
Noref | |||
Yes | 0.66 [0.15–2.77] | ||
Type of toilet facility | – | ||
Improvedref | – | ||
Unimproved | 1.33 [0.89–1.98] | ||
Share toilet with other households | – | ||
Noref | – | ||
Yes | 1.29 [0.89–1.86] | ||
Location of toilet facility | – | ||
In own dwelling/yard/plot | – | ||
Elsewhere | 1.28 [0.59–2.76] | ||
Presence of water at the hand-washing place | – | ||
Water is availableref | – | ||
Water not available | 0.68 [039–1.17] | ||
Soap or detergent available at the hand-washing place | – | ||
Yesref | – | ||
No | 1.45 [0.88–2.42] | ||
Stunted child | – | ||
Noref | – | ||
Yes | 0.92 [0.65–1.29] | ||
Mother's age | – | ||
≥ 35 | |||
< 18 | 1.66 [0.48–5.72] | ||
18–25 | 0.93 [0.64–1.35] | ||
25–35 | 0.90 [0.63–1.29] |
ref, reference category.
DISCUSSION
WASH access constitutes a key domain of intervention in humanitarian and international political agendas because of its determining role in the development and occurrence of several pathologies including diarrhea. In order to facilitate monitoring of progress in the WASH sector, objectively measurable indicators have been defined, as well as monitoring mechanisms such as the joint WHO/UNICEF monitoring program for water supply and sanitation (JMP) and DHS program, which also provides information on populations’ health status. This work was initiated with the aim of measuring the impact of WASH access on the occurrence of diarrhea in children under 5 years old in Senegal, which measurement is supplemented by a description of WASH access in recent years. Indeed, the link between poor conditions of hygiene, sanitation, access to drinking water, and the occurrence of diarrhea among children under 5 years old is widely documented; however, in Senegal, few studies have focused on this issue. We conducted a cross-sectional secondary analysis study using the JMP and DHS databases. Overall, results show a good improvement in access to WASH in households over the past few years. Indeed, between 2000 and 2017, access to safely managed services increased by 18.1 and 19.1% for, respectively, water and sanitation. The same was observed in the WHO/UNICEF report on progress in WASH. Respectively, a 10 and 17% increase in the global population with access to safely managed water and sanitation services has been noted between 2000 and 2017 (OMS & UNICEF 2019). Regarding diarrhea, 18.16% of children had at least one episode during the last 2 weeks preceding the interview, with no major difference between boys (51.41%) and girls (48.59%). This prevalence is slightly lower than in the 2015 report (19%) (ANSD & ICF 2015). This could be explained by the recent improvement in access to a quality source of water, especially in the urban areas which represent 48.1% of the total population (ANSD & ICF 2015). However, this prevalence is higher than what was reported by the Nigeria Demographic and Health Surveys which was 11% (NPC & ICF 2014). Another study conducted in the slum of Addis Ababa also reported an occurrence of diarrhea estimated at 11.9% (Adane et al. 2017) among children aged 0–50 months, which is also lower compared prevalence noted in Senegal. Among other factors explaining the diarrhea were the wealth index of the household, the age of the child, the use of a water purification technique, and the use of drinking water from a source not located in dwelling. Indeed, the last two characterize the access to water in households and were associated with an excess risk of diarrhea. More than half of children live in households that used an improved source of drinking water (80.17%), which is mainly not located in dwelling (86.56%). In addition, only 26% of households used a water treatment technique to make it safer to drink, and in most households, water was filtered by straining through a cloth (16.72%). A higher proportion (58%) of households practicing a treatment technique for their drinking water was found within a Nepalese community and for most of these households, water was treated by boiling (52.6%) (Shrestha et al. 2021). Moreover, compared to a Tanzanian community, the proportion (12%) of households treating their drinking water by straining through a cloth was slightly higher in Senegal (Kakulu 2012). Bivariate analysis showed that 20.33% of children presenting with diarrhea lived in households where drinking water came from elsewhere versus 14.09% of children who came from households that have their drinking water source in their dwelling, the difference in these proportions was statistically significant (p = 0.003). A study in Malawi documented a proportion of 17% of households that have their source of drinking water on premises, whose proportion is slightly above that noted in Senegal (Moon et al. 2019). Occurrence of diarrhea was also noted with significant differences in proportions (p < 0.001). About households that strain water through a cloth (22.11%) compared to those not practicing this technique (17.39%), a higher rate of diarrhea (52.5%) was noted among children who lived in households that practiced water treatment compared to those that did not treat their drinking water (Shrestha et al. 2021). This could be explained by the inadequate implementation of available techniques. Indeed, straining water through a cloth can be a source of water contamination if the cloth used is not sterile. This situation was more likely to occur when the person performing this technique had not been schooled and has no basic understanding of the water contamination mechanism. The excess risks (AOR [95% CI]) associated with water purification technique and location of the main source of drinking water were estimated at 1.20 [1.00–1.45] and 1.55 [1.19–2.03] for, respectively, households treating their drinking water by straining through a cloth and those who obtain their supply from a source not located in the dwelling. These risks remained significant after adjusting for gender and place of residence: 1.21 [1.00–1.45] and 1.59 [1.21–2.09]. Similar results were reported by other research works. The odds of suffering from diarrhea were 1.6 [1.217–2.343] as high among children who lived in households with a lack of access to clean water (He et al. 2018). It was also found that in households that used drinking water with detectable microbes like fecal coliforms, children were 21 times more likely to develop diarrhea (Kakulu 2012); however, the non-availability of water source in dwelling exposed to a higher risk of contamination during transportation. Indeed, the risk of contamination will be even lower when the water source is located near the dwelling. Thus, 30 min or more time taken to get to the water source showed 1.184 times [1.045–1.342] higher than the water source on the premises (Moon et al. 2019). Moreover, concerning water treatment by straining through a cloth, beyond the probable risk of contamination from which it may be a source, it does not ensure decontamination as satisfactory as the other methods. Indeed, bacterial contamination of water varies according to the potabilization technique applied; however, a study counts 89.5% of samples treated by straining through a cloth and presenting contamination beyond the acceptable limit versus 80%, 71.7%, and 66.2% of samples respectively treated with chlorine, by letting it stand and settle, and by boiling it (Kakulu 2012). About the latter, a study revealed that 39.7% of water samples infected with coliforms and treated by this technique versus 86% of contaminated and untreated samples, the lack of water treatment being significantly associated with the presence of coliforms and incidence of diarrhea (Wani et al. 2022).
This work faced some difficulties related to the availability of estimates of access to hygiene for certain years. In addition, this was a cross-sectional study which is a design not allowing us to conclude on a causal inference about our findings, because this design does not take into account the temporal sequence of events. In addition, data were obtained from the DHS survey, participants in this survey self-reported the occurrence of diarrhea and other factors. Therefore, it is difficult to eliminate some biases such as over-reporting or under-reporting. Furthermore, preventive measures and development programs in Senegal are changing rapidly and findings from the earlier study might not reflect the reality of today. However, DHS provides data that are representative of the population at the national and sub-national levels, and the survey is conducted in all the 14 medical regions of Senegal.
CONCLUSION
Overall, WASH access indicators have improved significantly in recent years. However, given the involvement of straining water through a cloth and water source not located in dwelling in the occurrence of diarrhea, and in view of the burden of this in child mortality, additional efforts to improve WASH access need to be implemented. Government and partners could focus on interventions aimed at guaranteeing access to water sources located in the housing. The government could also conduct a national campaign to raise public awareness of the risks of water contamination associated with straining water through a cloth.
DATA AVAILABILITY STATEMENT
All relevant data are available from an online repositories (https://washdata.org/data and https://dhsprogram.com/).
CONFLICT OF INTEREST
The authors declare there is no conflict.