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.

  • 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

Graphical Abstract
Graphical Abstract

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.

Setting and study design

Senegal is a francophone country located on the West African coast and shares borders with five other countries (Mali, Guinea, Mauritania, Gambia, and Guinea-Bissau). The total population of Senegal is estimated at 15.3 million people (in 2017) unequally distributed in 14 medical regions with an annual growth rate of 2.7% (Republique du Senegal 2016). Almost one-quarter of the population lives in the capital region of Dakar. In 2018, 42.7% of the total population were less than 15 years old, and 50.8% of them were female (Republique du Senegal 2016; ANSD 2019). Senegal is classified as a lower-middle-income country with a growing economy based on agriculture, fishing, and tourism (Republique du Senegal 2016), see the administrative map of Senegal (Figure 1).
Figure 1

Administrative map of Senegal (ANSD 2018).

Figure 1

Administrative map of Senegal (ANSD 2018).

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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.

Table 1

Recodes of ‘main source of water’ and ‘types of toilets’

QuestionsPossible answers/codesRecoded 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 
QuestionsPossible answers/codesRecoded 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).

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).

Table 2

Evolution of access to WASH between 2000 and 2017

YearSafely managed service (%)
Basic service (%)
WaterSanitationWaterSanitationHygiene
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 
YearSafely managed service (%)
Basic service (%)
WaterSanitationWaterSanitationHygiene
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).

Table 3

Sample distribution by children's selected characteristics including those of their mothers and housing

WASH characteristicsFrequency (%)
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 characteristicsFrequency (%)
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).

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 characteristicsOccurrence 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 characteristicsOccurrence 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).

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 modelBackward model
with forced variables
Selected characteristicsCOR [95%CI]AOR [95%CI]AOR [95%CI]
 Wealth Index Combined    
  Richestref    
  Poorest 2.62 [0.986.97] 1.94 [1.023.68] 2.03 [1.083.80] 
  Poorer 2.17 [0.855.55] 1.78 [0.923.45] 1.84 [0.973.50] 
  Middle 1.99 [0.884.49] 1.81 [0.943.49] 1.73 [0.923.27] 
  Richer 2.14 [0.885.21] 1.48 [0.683.20] 1.38 [0.662.94] 
 Current age (in years)    
   ≥ 3ref    
   < 1 2.98 [1.924.63] 2.90 [2.353.56] 2.92 [2.373.59] 
  (12) 3.63 [2.395.52] 3.47 [2.854.22] 3.48 [2.864.23] 
  (23) 1.92 [1.252.93] 2.37 [1.892.96] 2.38 [1.902.98] 
 Water usually treated by: strain through a cloth    
  Noref    
  Yes 1.96 [0.864.46] 1.20 [1.001.45] 1.21 [1.001.45] 
 Location of source for water    
  In own dwelling/yard/plotref    
  Elsewhere 2.01 [1.432.84] 1.55 [1.192.03] 1.59 [1.212.09] 
 Type of place of residence    
  Urban   
  Rural 0.69 [0.431.11] 0.79 [0.601.03] 
 Sex of child    
  Maleref   
  Female 0.91 [0.781.07] 0.91 [0.781.07] 
 Main source of drinking water   
  Improved  
  Unimproved 0.86 [0.561.33] 
 Anything done to make water safe to drink   
  Yesref  
  No 0.86 [0.362.08] 
 Water usually treated by: add bleach/chlorine   
  Noref  
  Yes 1.21 [0.801.84] 
 Water usually treated by: use a water filter   
  Noref  
  Yes 1.84 [0.565.99] 
 Water usually treated by: let it stand and settle   
  Noref  
  Yes 0.66 [0.152.77] 
 Type of toilet facility   
  Improvedref  
  Unimproved 1.33 [0.891.98] 
 Share toilet with other households   
  Noref  
  Yes 1.29 [0.891.86] 
 Location of toilet facility   
  In own dwelling/yard/plot  
  Elsewhere 1.28 [0.592.76] 
 Presence of water at the hand-washing place   
  Water is availableref  
  Water not available 0.68 [0391.17] 
 Soap or detergent available at the hand-washing place   
  Yesref  
  No 1.45 [0.882.42] 
 Stunted child   
  Noref  
  Yes 0.92 [0.651.29] 
 Mother's age   
   ≥ 35  
   < 18 1.66 [0.485.72] 
  1825 0.93 [0.641.35] 
  2535 0.90 [0.631.29] 
Full modelBackward model
with forced variables
Selected characteristicsCOR [95%CI]AOR [95%CI]AOR [95%CI]
 Wealth Index Combined    
  Richestref    
  Poorest 2.62 [0.986.97] 1.94 [1.023.68] 2.03 [1.083.80] 
  Poorer 2.17 [0.855.55] 1.78 [0.923.45] 1.84 [0.973.50] 
  Middle 1.99 [0.884.49] 1.81 [0.943.49] 1.73 [0.923.27] 
  Richer 2.14 [0.885.21] 1.48 [0.683.20] 1.38 [0.662.94] 
 Current age (in years)    
   ≥ 3ref    
   < 1 2.98 [1.924.63] 2.90 [2.353.56] 2.92 [2.373.59] 
  (12) 3.63 [2.395.52] 3.47 [2.854.22] 3.48 [2.864.23] 
  (23) 1.92 [1.252.93] 2.37 [1.892.96] 2.38 [1.902.98] 
 Water usually treated by: strain through a cloth    
  Noref    
  Yes 1.96 [0.864.46] 1.20 [1.001.45] 1.21 [1.001.45] 
 Location of source for water    
  In own dwelling/yard/plotref    
  Elsewhere 2.01 [1.432.84] 1.55 [1.192.03] 1.59 [1.212.09] 
 Type of place of residence    
  Urban   
  Rural 0.69 [0.431.11] 0.79 [0.601.03] 
 Sex of child    
  Maleref   
  Female 0.91 [0.781.07] 0.91 [0.781.07] 
 Main source of drinking water   
  Improved  
  Unimproved 0.86 [0.561.33] 
 Anything done to make water safe to drink   
  Yesref  
  No 0.86 [0.362.08] 
 Water usually treated by: add bleach/chlorine   
  Noref  
  Yes 1.21 [0.801.84] 
 Water usually treated by: use a water filter   
  Noref  
  Yes 1.84 [0.565.99] 
 Water usually treated by: let it stand and settle   
  Noref  
  Yes 0.66 [0.152.77] 
 Type of toilet facility   
  Improvedref  
  Unimproved 1.33 [0.891.98] 
 Share toilet with other households   
  Noref  
  Yes 1.29 [0.891.86] 
 Location of toilet facility   
  In own dwelling/yard/plot  
  Elsewhere 1.28 [0.592.76] 
 Presence of water at the hand-washing place   
  Water is availableref  
  Water not available 0.68 [0391.17] 
 Soap or detergent available at the hand-washing place   
  Yesref  
  No 1.45 [0.882.42] 
 Stunted child   
  Noref  
  Yes 0.92 [0.651.29] 
 Mother's age   
   ≥ 35  
   < 18 1.66 [0.485.72] 
  1825 0.93 [0.641.35] 
  2535 0.90 [0.631.29] 

ref, reference category.

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.

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.

All relevant data are available from an online repositories (https://washdata.org/data and https://dhsprogram.com/).

The authors declare there is no conflict.

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