Background
Globally, diarrheal disease is the 9th largest cause of death among all ages and the 4th leading cause of mortality among children under the age of 5 years [
1]. Over 40% of all-age deaths and more than 60% of under-5 mortality occurs in sub-Saharan Africa [
1]. In 2015, in Kenya, childhood diarrheal disease accounted for 122 deaths per 100,000 children and over 790,000 disability-adjusted life years (DALYs)—almost one half of DALYs attributed to diarrheal diseases for Kenyans of all ages [
1].
According to some estimates, poor water, sanitation, and hygiene (WASH) are responsible for approximately 58% of diarrheal-related deaths per year [
2]. Other studies suggest the burden of disease associated with poor WASH may be even higher than those previously estimated [
3]. Poor water, sanitation, and hygiene are particularly critical health concerns for people living in informal settlements where high population densities combined with a lack of formal waste management strategies, inadequate or absent sewers and storm drainages, and inconsistent and often contaminated water supplies increase residents’ risk of direct exposure to human feces and consumption of unsafe water [
4]. Studies exploring the prevalence of diarrheal diseases in Kenya, especially, have found higher rates for children in urban areas, particularly informal settlements, than in other settings [
5]. For example, statistics suggest that over 30% of children in informal settlements in Nairobi had experienced diarrheal episodes within the prior 2 weeks compared to about 13% in other parts of Nairobi and 17% in Kenya as a whole [
6,
7]. In Kenya, 60% of Nairobi’s population lives in informal settlements [
8]; yet, there is a paucity of research exploring the relationship between characteristics of residents’ sanitation and hygiene environments in these settlements and their health outcomes.
The few studies exploring the environmental and socioeconomic factors associated with prevalence of diarrhea in informal settlements in low- and middle-income countries have found important links between several WASH-related factors and the prevalence of diarrheal diseases in these settings. Several studies, for example, have found links between diarrheal infection in children and household drinking water sources [
9,
10]; access to and conditions of sanitation [
11,
12]; and caregiver knowledge and practices associated with hygiene and sanitation for diarrhea prevention [
7,
9,
13].
Despite the growing body of literature suggesting important links between WASH-related factors and prevalence of diarrhea around the world, there is still a paucity of empirical research focused on these issues in informal settlements in East Africa, particularly Kenya. In addition, most research focuses exclusively on diarrhea cases in young children. While children under 5 years are the most affected by diarrheal-related morbidity and stunting, diarrhea is a health concern for residents of all ages, especially women [
1]. Findings from a recent study in rural Kenya, for example, suggest that female adults have higher incidence of hospitalizations due to diarrheal infections than males [
14].
Numerous studies in developing countries have suggested that women, as the managers of household WASH and the primary caretakers of children and elderly and disabled family members, play a critical role in ‘breaking the chain of contamination’ within their households [
15‐
17]. As the primary caretakers of the home, women are responsible for supplying water for drinking, cooking, bathing, hygiene, and other domestic tasks [
16]. Women are also primarily responsible for raising and educating children with regards to WASH and, frequently, for taking care of sick members of the household [
16]. These roles and responsibilities put women in a critical position for establishing and maintaining safe and hygienic spaces within the household, ensuring that children form hygienic health- and sanitation-related habits, and helping to minimize illness from preventable diseases [
16]. For example, findings from several studies suggest that women’s sanitation behaviors and their ability to access sanitation is linked to their children’s sanitation behaviors, especially for young children [
18,
19]. Findings from a 2016 qualitative study suggest that one of the factors that influences women’s sanitation behaviors in informal settlements in Nairobi is the need to set an example and/or be a role model for their children’s sanitation practices [
19]. Other studies report that women with small children often take their children with them when they leave the home to access sanitation and/or collect water [
20‐
22]—suggesting that the mother’s WASH-related behaviors may be linked to their children’s exposure to different environments and, consequently, their health [
16,
18]. Additionally, if a woman lacks the ability to pay to use a public toilet for herself, she is also unlikely to be able to pay for her children to use the public facility—suggesting that both she and her children have to find alternative methods of disposal, such as the use of bags/buckets in the home or open defecation (OD), to meet their sanitation needs [
18,
23]. Lastly, women are typically responsible for two other potential sources of household diarrhea: cooking and handling of food and collecting and managing household water supplies [
24]. Despite suggestions of a link between women’s WASH-related environments or behaviors and household health, there are few studies focusing on this phenomenon. This study is a step towards filling a piece of this gap by examining associations between characteristics of women’s sanitation and hygiene knowledge, behaviors and environments and occurrences of household diarrheal disease in an informal settlement in Nairobi, Kenya.
Discussion
The purpose of this study was to examine associations between characteristics of women’s sanitation and hygiene knowledge, behaviors and environments and recent cases of diarrhea in the Mathare Valley informal settlement in Nairobi, Kenya. Diarrhea is one of the leading causes of death among children under 5 years and a serious contributor to the global burden of disease for people of all ages, especially in informal settlements in sub-Saharan Africa. Results of this study provide important information for developing better and more targeted intervention and policy strategies to prevent diarrhea in these rapidly expanding settlement environments.
Several findings from this study are consistent with evidence from other studies exploring factors associated with recent diarrheal infections in urban and peri-urban informal settlements. For example, women who reported that their toilets were clean in this study had lower odds of reporting recent diarrhea in the household. This is consistent with findings from other studies [
11,
12] suggesting that the cleanliness of toilets is a key factor associated with diarrhea. Studies suggest this is particularly true in informal settlements where toilets are often shared between many families and the locus of responsibility for cleaning these toilets is not often clearly defined [
35].
Primary water source—another common factor associated with diarrheal disease—was also associated with recent household diarrhea in this study. Women who reported using taps inside their buildings, plots, or houses had higher odds of recent household diarrhea than women who rely primarily on public wells or taps. Recent literature suggests that while public water kiosks and taps are usually operated by formally licensed providers in informal settlements in Nairobi and, consequently, are regulated, private vendors, e.g. households and/or landlords who supply water to their tenants in plots or buildings, are usually unregulated [
36]. In light of literature focused on water providers in informal settlements in Kenya, the findings from this study may suggest that private water sources, e.g. those within households, plots, or buildings, may not be regulated and, consequently, unsafe for drinking.
Several previous studies have also found that the number of children in a household increases the risk of recent diarrhea [
5,
10,
37,
38]. Findings from this study suggest that women
with children had higher odds of reporting at least one case of diarrhea in the household in the preceding 2 weeks, but, when controlling for other factors, the
number of children did not have a significant association (results not shown).
Women in sanitation profile 2—those who rely primarily on toilets for defecation during the day, but use bags, buckets, and OD for urination during the day and for urination and defecation at night—had significantly higher odds of reporting acute diarrhea by at least one member of their household in the preceding 2 weeks. While it is difficult to determine precisely why women in this sanitation profile had higher odds of recent diarrhea among members of their household, it could be related to the type of facility these women use. All but one of the women in this profile, for example, rely on public toilets for defecation during the day (99.2%). In order to test this hypothesis, we ran a separate logistic regression model (results presented in
Appendix) to examine the relationship between women who relied on public toilets at least once in a 24-h period and recent diarrhea in the household. Findings from this analysis suggest that women who use public toilets have higher odds of reporting recent diarrhea in the household compared to women who do not use public facilities (OR = 2.3, 95% CI = 1.54–3.3,
p = 0.001). The magnitude and significance of the other covariates and WASH-related factors in the model were similar to those in the primary logistic regression (See
Appendix).
Interestingly, the number of people sharing women’s toilets/sites for urination/defecation was not significantly associated with recent diarrhea in the family in the regression analysis, which is inconsistent with evidence from previous studies [
11,
38]. The association between use of public toilets, the majority of which are used by more than 100 people in Mathare (77%), and recent household diarrhea may indicate that the type and management of a toilet and the relationship between the people using it may be of more importance than just the number of people sharing it. Finally, results from this study also suggested that distance (walk time) to reach a toilet was associated with higher odds of recent diarrhea—a finding that is consistent with other studies [
11]. Walk time or distance to a toilet may also be an indication of the type of toilet facility on which women are relying. For example, mid-range walk times likely indicate the use of plot/building toilets or nearby public toilets while longer walk times likely indicate use of further public toilets or OD.
Interestingly, women in this study who relied exclusively on OD and/or bags or buckets in their homes and disposing of feces in open drainages outside their homes, i.e. those in sanitation profile 5, did not have higher odds of reporting recent diarrhea compared to women using toilets as all times (sanitation profile 1) as has been found in previous studies [
12]. This finding, however, may point to an important disconnect between individual- and public-health when it comes to sanitation. According to McGranahan [
39] an individual’s sanitation strategies can, in principal, be more clean, hygienic, safe, and private than other alternatives from the user’s perspective, but still impose a heavy health burden onto others and the community as a whole. For example, women in Mathare may feel that OD and/or use of bags/buckets is a safer, more manageable, cleaner, or even hygienic option than a public or shared toilet; however, as soon as the raw sewage is left in the open or emptied into open drainages, everyone in the community is likely to be at greater risk. While exclusive use of OD or bags/buckets in the home may not increase the odds of individuals in that household getting diarrhea because, for example, women may work hard to ensure that the process is as hygienic as possible, women who rely exclusively on these strategies also do not show significantly lower odds of household diarrhea compared to women who utilize toilets at all times. This could be because the health burden of disposing of raw sewage in the environment is shared, more or less equally, by all in the local community.
According to literature, caregiver knowledge related to WASH and health can be an important protective factor to prevent diarrhea [
7,
9]; yet, evidence of the association between WASH and health knowledge and diarrhea are sometimes mixed [
40,
41]. Some studies suggest, for example, that high levels of overall WASH and health knowledge do not always lead to better diarrheal prevention behaviors [
40,
41]—findings which are consistent with findings in this study. For example, over two-thirds of the women in this study identified OD and/or use of bags and buckets (emptied into open drainages) as a primary cause of diarrhea and 70% said avoiding OD and/or use of bags and buckets was a key diarrhea prevention strategy; yet, close to 69% of the women reported that they rely on bags or buckets for urination/defecation at night and an additional 6% reported defecating in the open at night. One explanation for this findings might be, as evidence from other studies corroborates [
42,
43], that there is a knowledge-behavior gap when it comes to issues of WASH. Women may know, for example, that use of OD and/or bags and buckets is linked to poor health outcomes, but abandoning these practices may be hindered by additional more-pressing factors that prevent women, and their children and family members, from accessing clean water, safe sanitation, and or products for safe hygiene [
17,
44]. For example, several recent studies have provided evidence that women in sanitation-poor environments, e.g., informal settlements, often face a number of gender-specific barriers to access sanitation such as lack of privacy and dignity [
18,
45,
46] and sexual violence and harassment associated with having to rely on community toilets or sites for OD at night or during menstruation [
22,
45‐
48]. In this study, for example, 80% of women reported that it is not safe to go alone to a toilet at night—a barrier that may need to be addressed if women and, more than likely, their children are to consider abandoning the use of OD or bags and buckets, especially at night. An alternative explanation might be that women’s WASH and health knowledge influences their decisions to use methods in their homes because they perceive them to be more hygienic than the alternatives. Literature suggests that shared sanitation in informal settlements may be associated with poor health outcomes, e.g. diarrhea [
31,
35,
49‐
51]; women may be using bags, buckets, or OD in or near the home not out of ignorance of the health risks, but rather because they perceive such practices to be healthier options than using shared sanitation facilities regardless of any greater environmental or public health implications.
Overall, findings from this study suggest that a number of characteristics of women’s sanitation and hygiene knowledge, behaviors and environments are associated with recent cases of household diarrhea in Mathare. Findings suggest that women in this settlement are knowledgeable about WASH and health and adopt reasonable sanitation-management strategies in light of the numerous challenges they face in these settlements. Some of their sanitation-management strategies, e.g. relying on OD or using bags and buckets that are subsequently emptied into open drainages, may have serious public and environmental health implications; thus, it is critical to consider reasonable solutions to help women have more and better options for sanitation management. Given that findings from the research suggest women in Mathare are knowledgeable about WASH and health, solutions to sanitation issues in this settlement should focus on addressing other external factors that continue to limit women’s ability to access sanitation, e.g. safety and privacy. A growing number of sanitation interventions have been implemented in Mathare in recent years, such as Sanergy’s Fresh Life toilets, Grand Challenge Canada’s funded Banza toilets, and/or National Youth Service’s (NYS) slum improvement project toilets, to name a few, but little is known about the effect of these interventions on women’s ability to consistently access sanitation throughout a 24-h period, changes in women’s sanitation management strategies or on sanitation-related health outcomes like diarrhea. Findings from a recent article focused on women’s solutions to sanitation challenges in Mathare, suggest that strategies aimed at supporting women’s efforts for collective action around issues of sanitation and co-production efforts between landlords and governments may help women have more and better options to manage household sanitation more safely and, consequently, to reduce household diarrhea [
23]. These collective action and co-production strategies are also in-line with the WHO’s recent Guidelines on Sanitation and Health, which encourage sanitation strategies and interventions that combine government leadership, oversight, monitoring, and potential funding with locally delivered services [
52].
There were several limitations to this study. For example, we relied on a self-reported measure of diarrhea provided by only one female resident of each household. While self-reported measures of two-week diarrhea provided by the primary caregiver (usually the mother) are common in studies assessing the prevalence of diarrhea among children under the age of 5 years, this study neither focused exclusively on under-5 children nor did it require that the female study participant be the primary caregiver in the household. Thus, the women in this study may not have been able to provide an accurate account of diarrhea for all members of the household, nor are their reported sanitation practices necessarily the same as those of other members of the household. Second, while this study included many of the common socio-economic, environmental, and WASH factors assessed in similar diarrhea prevalence studies, the list is not comprehensive. We did not, for example, include factors such as water quality measures, observed hygiene measures (e.g., presence of flies in house/on food/in toilets, observed feces in toilet facilities or in open drainages, sewage conditions, or garbage disposal methods), or medical factors (e.g., fever, stunting, and dehydration)—variables that have shown to be important risk or protective factors in other studies [
10‐
12].