Burden of Childhood Diarrhea and Its Associated Factors in Ethiopia: A Review of Observational Studies

Objectives: This systematic review and meta-analysis aimed to: i) determine the pooled prevalence of acute diarrhea; and ii) synthesize and summarize current evidence on factors of acute diarrheal illnesses among under-five children in Ethiopia. Methods: A comprehensive systematic search was conducted in PubMed, SCOPUS, HINARI, Science Direct, Google Scholar, Global Index Medicus, Directory of Open Access Journals (DOAJ), and the Cochrane Library. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The methodological quality of each included article was assessed using the Joanna Briggs Institute (JBI) quality assessment tool for cross-sectional and case-control studies. A random-effect meta-analysis model was used to estimate the pooled prevalence of diarrheal illnesses. Heterogeneity and publication bias were assessed using I2 test statistics and Egger’s test, respectively. The statistical analysis was done using STATA™ software version 14. Results: Fifty-three studies covering over 27,458 under-five children who met the inclusion criteria were included. The pooled prevalence of diarrhea among under-five children in Ethiopia was found to be 20.8% (95% CI: 18.69–22.84, n = 44, I2 = 94.9%, p < 0.001). Our analysis revealed a higher prevalence of childhood diarrhea in age groups of 12–23 months 25.42% (95%CI: 21.50–29.35, I2 = 89.4%, p < 0.001). In general, the evidence suggests that diarrheal risk factors could include: i) child level determinants (child’s age 0–23 months, not being vaccinated against rotavirus, lack of exclusive breastfeeding, and being an under-nourished child); ii) parental level determinants {mothers poor handwashing practices [pooled odds ratio (OR) = 3.05; 95% CI:2.08–4.54] and a history of maternal recent diarrhea (pooled OR = 3.19, 95%CI: 1.94–5.25)}; and iii) Water, Sanitation and Hygiene (WASH) determinants [lack of toilet facility (pooled OR = 1.56, 95%CI: 1.05–2.33)], lack handwashing facility (pooled OR = 4.16, 95%CI: 2.49–6.95) and not treating drinking water (pooled OR = 2.28, 95% CI: 1.50–3.46). Conclusion: In Ethiopia, the prevalence of diarrhea among children under the age of five remains high and is still a public health problem. The contributing factors to acute diarrheal illnesses were child, parental, and WASH factors. A continued focus on improving access to WASH facilities, along with enhancing maternal hygiene behavior will accelerate reductions in diarrheal disease burden in Ethiopia.


INTRODUCTION
Childhood diarrheal disease remains to be the existential threat to global public health scourge.According to the Global Burden of Disease Study 2019, diarrhea disease was listed among the top three most common problems causing a significant health burden in children [1].Evidence indicates that deaths from diarrheal disease among children under 5 are most prevalent in South Asia and sub-Saharan Africa, where access to healthcare, safe water, and sanitation remains limited [2,3].In Ethiopia, although there has been a reduction in the prevalence of diarrheal disease from 24% in 2000 to 12% in 2016, progress has not been sufficiently rapid to fully tackle this significant public health issue [4,5].
Despite the fact that diarrhea is largely preventable, it remains a public health problem in Ethiopia, and its burden is still a serious concern.Estimates of the burden of diarrheal disease and its associated factors in Ethiopia at the national level are not well known, masking the current status, a prohibitive factor to tracking progress and reducing morbidity.While it is known this to be an ongoing and significant public health issue needing current evidence, the most review evidence have been over 5 years old [37], which may not reflect the present situation.Additionally, preliminary studies that have recently been conducted throughout the country have reported inconsistent findings [7,12,13,26,31,33,34,[38][39][40][41][42][43][44], making it necessary to update the existing review in order to estimate the current nationwide and regional pooled prevalence of diarrheal diseases and associated factors.Therefore, this systematic review and meta-analysis provide updated results of pooled estimates of childhood diarrhea morbidity and summarized its associated factors in Ethiopia.The findings affirm the current status of diarrheal diseases and set a benchmark for tracking the words and sub-headings of keywords was generated and used to search articles from major databases including PubMed, SCOPUS, HINARY, Science Direct, Google Scholar, Global Index Medicus, Directory of Open Access Journals (DOAJ), and the Cochrane Library.Each database's or search engine's retrieved articles were added to an EndNote library.Additionally, articles from the retrieved bibliographies that met the inclusion criteria were added to be reviewed.We also used Google Scholar and Google to track citations.

Searching Strategy
The following combination of keywords and other MeSH words was used in the search: diarrhea [MeSH Terms], Diarrhea [Text Word], Diarrhoea [All Filed], Prevalence [Text Word], Factor*, determinant*, child [MeSH Terms], infant [MeSH Terms], under-five children, and Ethiopia.The search terms were used separately and in combination using Boolean operators like "OR" or "AND."A detail searching strategy was provide in the Supplementary Material S2.The electronic database search was supplemented with gray literature searches via Google Scholar and Google searches.A secondary search method known as "footnote chasing" was also used to identify further and relevant articles.Reference lists of included studies were manually searched for additional relevant articles.Moreover, preprint articles from the MedRxiv, BioRxiv, and Research square databases were also accessed to ensure wider coverage.The related systematic review and meta-analysis published in 2017, in which the subjects from the included studies were mostly enrolled before 2017.In this review, all papers published from first of November 2017 to June 30th , 2022, were considered.All papers published until the June 30th, 2022 were considered.An initial search was conducted on June 1st , 2022 and later repeated on June 30th, 2022 to identify articles.

Study Selection Process
In accordance with predetermined inclusion and exclusion criteria, two investigators (BS and DA) independently screened and identified relevant articles by title, abstract, and full text.The screened articles were compiled by the two authors (BS and DA), and any disagreements between them were settled through discussion.Duplicate articles were then removed from the review after all the searched articles were exported into the EndNote ™ version X8 software.After reading the complete texts of the remaining articles, we retained studies that met the inclusion criteria.Based on the eligibility requirements, BS and DA independently reviewed the full text of the articles based on the study eligibility criteria.

Data Extraction
Microsoft ™ Excel was used to extract the data.The primary author, publication year, study design, study area, sample size, prevalence of diarrhea, number of children, age of children, sampling techniques, and factors associated with diarrhea were included in the summary of the studies that were included in the review.

Risk of Bias Assessment of the Studies
The quality of the included studies was evaluated using the Joanna Briggs Institute (JBI) method for quality evaluation.We used the JBI checklist for case-control studies and observational studies were used [47].Two reviewers independently evaluated the included studies' quality (BS and DA).There are eight and ten parameters in the evaluation tools for cross-sectional and case-control studies, respectively.When the information provided was insufficient to make a decision, we decided to assess a 1 rating for the specific item (a failure to satisfy a specific item or unclear/not applicable).Bias risks were divided into three categories: low (0-2), moderate (3 or 4), and high (total score of 5 or higher).Disagreements are usually remedied through discussion until consensus is reached.However, for the current study, there was no disagreement in selecting the potential research (Supplementary Material S3).

Synthesis of Results
The prevalence of diarrhea and/or associated factors were used in reporting the findings of each study.Where available, 95% CI for reported diarrhea was obtained from the eligible studies.Based on published studies, 95% CI were calculated using available data where the full text of the eligible studies did not report diarrheal estimates.Narrative methods including text and table were used as a tool for associated factors data presentation.The heterogeneity among included studies was assessed by I 2 statistics and the Cochran Q-test.The included studies exhibited significant high heterogeneity (I 2 = 94.9%,p < 0.001), which led us to compute a random effect meta-analysis model to estimate the pooled prevalence of diarrhea.The pooled prevalence of diarrhea and their corresponding 95% CI were presented using a forest plot.Subgroup analyses were performed to investigate the observed heterogeneity, based on the subregions of Ethiopia.Further statistical analyses, such as univariate meta-regression, was also performed to identify possible sources of heterogeneity.
We used a qualitative approach to summarize the factors associated with diarrhea and synthesize the relevant information based on the objectives of the study.We did not perform a meta-analysis for all identified factors due to the considerable heterogeneity of the included studies.We have discussed identified associated factors and estimates descriptively.For some variables, however, the adjusted odds ratios (AOR) were pooled using the generic inverse variance method, which involved converting the adjusted odds ratio to a logarithmic scale and then calculating standard error based on the 95% confidence intervals [48].The Cochran Q-test and Haggin I 2 statistics were used to assess the presence and degree of heterogeneity among included studies [49].

Publication Bias
In this meta-analysis, the presence of publication bias was evaluated using funnel plots and Egger's weighted regression test at a significance level of less than 0.05.

Sensitivity Analysis
To identify the source of heterogeneity, a leave-one-out analysis was employed.Sensitivity analysis using a random-effects model was performed to assess the influence of a single study on the overall pooled prevalence estimate.

Study Selection
Overall, the searches identified 707 articles (i.e., identification of studies via databases and registers).Of the initial articles, 444 articles were excluded due to duplication.We screened the titles and abstracts of 263 articles and obtained 91 full text articles, of which 53 studies met the inclusion criteria and were included in the final systematic review and meta-analysis.Of the included 53 studies, 44 studies were eligible for meta-analysis (Figure 1).

Characteristics of Included Studies
The descriptive summary of included cross-sectional and casecontrol studies were presented in Table 1.Of the included 53 studies, 9 were case-control studies, 12 comparative crosssectional studies, and 32 cross-sectional studies by design.A total of 27,458 under-five children were included as participants in the current systematic review and meta-analysis.In the current review, the sample size varied from small (n = 191) [61] to large (n = 2,030) [6].In this review, the lowest prevalence of diarrhea (9.4%) was found in a study conducted in Bahir Dar, northwest Ethiopia Amhara region [14], while the highest prevalence (36.5%) of diarrhea was reported in a study conducted at west Guji zone, Oromia region [62].
We performed subgroup analysis based the studies' geographical settings (i.e., region of the country).Accordingly, the highest proportion of acute diarrhea was observed in Gambella region with a prevalence of 33 2).
We conducted a stratification analysis on prevalence, considering age groups and gender.Our findings revealed that the prevalence of diarrhea among male under-five children in Ethiopia was 19.73% (95% CI: 15.39-24.07,I 2 = 94.1%,p < 0.001), a rate comparable to that of female children.Additionally, our

Publication Bias
In this meta-analysis, possible publication bias was visualized through funnel plots and using Egger's weighted regression test.Asymmetrical large, inverted funnel resembled the absence of publication biases (Figure 3).The Egger's tests were also not statistically significant for the estimated prevalence of diarrhea in Ethiopia, with a p-value of 0.06.

Sensitivity Analyses
To detect the influence of one study on the overall meta-analysis estimate, sensitivity analysis was conducted using a randomeffects model.There was no evidence for the influence of a single study on the overall pooled result of diarrheal morbidity in Ethiopia (Supplementary Material S5).

Meta-Regression
We conducted a univariate meta-regression analysis by considering publication year, sample size, and quality score as covariates to identify the possible sources of heterogeneity across primary studies, but none of these variables was found to be a statistically significant source of heterogeneity.The results of meta-regression analysis also showed no significant relationship between prevalence of diarrheal disease and sampled size (p = 0.084) and publication year (p = 0.729).
Supplementary Material S4A-F presents the pooled odds ratios of the association between child age, the child's sex, and childhood diarrhea in Ethiopia.As depicted in Supplementary Material S6A, there is no statistically significant difference in the odds of experiencing childhood diarrheal disease between male and female children under the age of five (pooled OR = 0.61; 95% CI: 0.35-1.07,I 2 = 88.0%,p < 0.001).
Mothers' history of diarrheal episodes in the previous 2 weeks before the study was also identified as a risk factor for childhood diarrheal disease [7,11,17,19,20,26,27,35,39,60,64].The overall result of the meta-analysis revealed that children whose mothers had a history of diarrhea in the previous 2 weeks were three times more likely to develop diarrhea than children without a history of maternal diarrhea in the previous 2 weeks (pooled OR = 3.19, 95%CI: 1.94-5.25,n = 13).We used a random effect meta-analysis model to estimate pooled OR because the included studies had high heterogeneity (I 2 = 79.4%,p-value = 0.006) (Supplementary Material S7B).Since two studies [28,54] used different reference categories, we pooled the odds ratios separately.Likewise, the odds of diarrhea was reduced in children whose mothers had not recently experienced any diarrheal episode (pooled OR = 0.49, 95% CI: 0.35-0.68,I 2 = 0.0%, p = 0.901, n = 2).
The pooled result of this meta-analysis indicated that children from households that lacked handwashing facilities near the toilet         The meta-analysis results of ten studies that reported confounder adjusted association between household water treatment and childhood diarrhea.The overall result showed that, children from households that did not use treated drinking water at home were two times higher odds of having diarrheal disease compared to children living in households that used home treated drinking water (pooled OR = 2.28, 95% CI: 1.50-3.46,I 2 = 64.5%,p = 0.003, n = 10) (Supplementary Material S7E).

DISCUSSION
Childhood diarrheal disease can cause significant morbidity and remain a significant public health issue across the world.This systematic review and meta-analysis aimed to estimate the pooled prevalence of diarrhea disease and summarize the potential associated factors among under-fives in Ethiopia.The pooled prevalence showed that one in every five children under the age of 5 years in Ethiopia experienced diarrheal disease.Overall, early childhood, poor child nutrition status, use of unimproved sanitation, lack of hand washing facilities, maternal diarrhea illness in previous 2 week, inadequate maternal hygiene knowledge and behavior, and improper domestic solid waste disposal were important factors associated with diarrheal disease.
The meta-analysis findings from the included 44 studies indicated that 20.8% of children under five in Ethiopia experienced diarrheal diseases.The results are comparable with the 2016 Ugandan Demographic and Health Survey (DHS) that reported the prevalence of diarrhea among children <5 years in Uganda to be 20% [65].Our finding was in line with the prior pooled prevalence estimates of diarrhea 22% [37].Although the results showed a relatively lower prevalence, this figure seemed to imply that the prevalence of diarrheal disease has not dropped significantly.As such, it would be reasonable to argue that diarrheal disease was still a significant public health concern of high magnitude in Ethiopia.On the other hand, our finding showed that the diarrheal disease prevalence was higher than the overall prevalence of diarrheal disease among under-fives in sub-Saharan Africa 15.3% [66] and the East Africa pooled estimate 14.28% [67].The observed higher prevalence of diarrheal disease in this review compared to the East Africa regional estimate could be due to the differences in methodological approaches.The DHS sampling, design, and setting were very different from the type of analysis that was used in the current study.The results of DHS reports are based on primary data collection, whereas we reviewed and used prevalence measurements from previously conducted primary studies from different areas, populations, and seasons.
The top three regions with the highest prevalence of diarrhea were observed in the Gambella region, 33.0%, SNNPR region 24.21%, and Dire Dawa city administration 23.0%, according to the subgroup analysis of this study.The Sidama region had the lowest proportion of diarrheal disease, at 14.24%.Regional estimates could differ due to differences in basic sanitation, household behavioral characteristics, and access to healthcare facilities.The high prevalence of diarrheal disease in the Gambella region could also be due to the inclusion of a single comparative cross-sectional study in sub-group meta-analysis, which was limited to a single area and did not represent the entire region.Corresponding to the Ethiopia DHS 2016 report, the Gambela region had the highest diarrheal morbidity in Ethiopia (14.5%), followed by the SNNP region (13.9%)[4].
The findings of our review suggest that there is no significant difference in the prevalence of childhood diarrheal disease between male and female children under the age of five.This observation aligns with previous studies that have also failed to identify gender as a significant risk factor for diarrheal illness [68].Our study adds to the body of evidence indicating that diarrheal disease does not exhibit a gender-specific pattern among young Ethiopian children.Our review also highlights a  [69].The current study found lack of exclusive breastfeeding to be associated with a higher likelihood of diarrheal disease in children [14][15][16][17].Evidence showed that breastfeeding is an ideal food for infants and young children and it prevents nearly half of all diarrheal episodes and 72% of diarrheal-related hospitalizations [70,71].Breast milk is safe, clean, and contains antibodies which help to protect children against many common childhood illnesses [72].A meta-analyses of eighteen studies showed that not breastfeeding resulted in an excess risk of diarrheal mortality in comparison to exclusive breastfeeding among infants 0-5 months of age and to any breastfeeding among children aged 6-23 months [70].This study identified significant association between being underweight [26,27] and wasting [14] and childhood diarrhea.The relationship between child undernutrition and diarrheal illnesses was clearly shown [73] as diarrheal disease and malnutrition being bidirectionally related, meaning that: diarrhea causes malnutrition, and malnutrition worsens the course of diarrheal disease [74].
Across the studies, lack of maternal education was consistently associated with higher odds of childhood diarrheal [6,11,23,24,26,62], which is consistent with research conducted in Nigeria [75].The educational attainment of mothers influences hygienic practices, child feeding, weaning, and sanitation practices, all of which are crucial factors against the onset of childhood diarrheal disease.Primary studies identified mothers' poor handwashing practices [7,12,13,26,31,33,34,[38][39][40][41][42][43][44] and mothers' history of diarrheal episodes in the previous 2 weeks [7,11,17,19,20,26,27,35,39,60,64] as potential factor associated with childhood diarrhea.The result of this meta-analysis revealed that, the odds of childhood diarrhea was three times higher among children whose mothers did not practice hand washing at critical times.Likewise, the odds of childhood diarrhea among children whose mother had a history of diarrhea in the previous 2 weeks was three times higher than their counterparts.The importance of proper handwashing at critical times with appropriate handwashing agents has long been established in the reduction of diarrheal disease with handwashing with soap reducing the burden significantly [76][77][78].For instance, a recent systematic review, handwashing promotion in communities prevents one-quarter of diarrhea episodes in Low and Middle-Income Countries (LMICs) [79].The pooled result of this metaanalysis indicated that children from households that lacked handwashing facilities near the toilet were four times more likely to have diarrheal morbidity as compared to their counterparts.This finding supports previous studies which have identified lack of a handwashing station as predictors of diarrheal disease [12,38,56,60].This finding was not surprising as several studies explore strong link between handwashing and childhood diarrhea [80].A systematic review of the literature by Shah et al. also reported handwashing are effective strategy for preventing all causes of diarrheal disease [81].
Children living in households that used untreated drinking water and those collecting water from unimproved drinking water sources were at a higher risk of diarrheal disease.Several studies provided evidence that improving access to safe drinking water reduces the risk of diarrheal disease in children [25,82].In our meta-analysis, the odds of developing childhood diarrhea in households that did not use treated drinking water at home were two fold higher compared to children used home treated drinking water, and that improved water quality was generally is an effective strategy in preventing diarrheal disease [83].Although evidence exists that improved sanitation is one of the key factors in the reduction of diarrheal diseases [52,84], however, to establish the effect of improved latrines on diarrheal disease prevention in the absence of universal or at least adequate latrine coverage in a given community is controversial and difficult as indicated in the recent cluster-randomized controlled trial on sanitation interventions reporting that improved latrines had no protective effect against childhood diarrheal prevalence [85,86].However, other systematic review and meta-analysis have shown that both improved neighborhood sanitation conditions and household sanitation are associated with reduced diarrheal illness [87].

Limitations
First, in the majority of the included studies diarrheal disease was based on self-reported screening and was not further clinically confirmed.Second, our study could lack representativeness at a country level as we did not find a study from some regions of Ethiopia.Third, there was high heterogeneity between included studies, as indicated by the I 2 statistic.Fourth, we were unable to pool all the adjusted odds ratio as a number of the included studies showed significant heterogeneity and used different reference category.As a result, this work only summarizes the findings as described in the study protocol.Fifth, because the studies in this review were all observational in design, it is possible that other confounding variables could influence the identified associated factors.Sixth, the majority of included articles were observational studies (i.e., cross-sectional studies), so causality cannot be inferred.Last but not least, because our search was restricted to publicly accessible databases, we were unable to include databases like EMBASE.

Conclusion
Our study indicated that approximately one in five under-five children in Ethiopia experienced diarrheal disease during the 2 weeks, and there were regional variations in diarrheal prevalence among under-five children.The key contributing factors to childhood diarrheal were related to child, parental, and WASH factors (such as poor handwashing practices, use of untreated drinking, household that lacked handwashing facility near the toilet facility, and lack of toilet facility).To address diarrheal disease and achieve the Sustainable Development Goals and the 2030 agenda [88], Ethiopia must strive to strengthen current strategies and consider the identified factors.To reduce diarrheal disease among children under the age of five, priority should be given to strengthening interventions that focus on improving household WASH facilities and raising awareness about the importance of handwashing, proper sanitation, and hygiene practices.

Table 3
demonstrates the summary of the studies included in this review.The factors associated with acute diarrheal disease have

TABLE 1 |
(Continued)Descriptive summary of studies included in this systematic review and meta-analysis of the prevalence and risk factors of diarrhea among under-five children in Ethiopia(Ethiopia, 2017(Ethiopia,  -2022)).
CS: cross-sectional study; CCS: comparative cross-sectional study; CC: case-control study.Int J Public Health | Owned by SSPH+ | Published by Frontiers June 2024 | Volume 69 | Article 1606399 6 Sahiledengle et al.Childhood Diarrhea in Ethiopia FIGURE 2 | Forest plot of the pooled prevalence of diarrhea among under-five children in Ethiopia, (Ethiopia, 2017-2022).

TABLE 2 |
Subgroup analysis of acute diarrhea among under-five children in Ethiopia(Ethiopia, 2017(Ethiopia,  -2022)).beendivided into categories of child, parental, and WASH and environmental factors.

TABLE 3 |
Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).
(Continued on following page) Int J Public Health | Owned by SSPH+ | Published by Frontiers June 2024 | Volume 69 | Article 1606399 9

TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).
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TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).
• (Continued on following page) Int J Public Health | Owned by SSPH+ | Published by Frontiers June 2024 | Volume 69 | Article 1606399 11

TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).

TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).
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TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).

TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).

TABLE 3 |
(Continued) Summary of risk factors and there strength of association of acute diarrhea among under-five children in Ethiopia,(Ethiopia, 2017(Ethiopia,  -2022)).prevalence of diarrheal disease among children aged 12-23 months.Several factors may contribute to the heightened susceptibility in this age group, including increased mobility and exploratory behavior, which lead to greater exposure to contaminated environments Int J Public Health | Owned by SSPH+ | Published by Frontiers notably high