Food hygiene has been largely neglected in the water, sanitation, and hygiene (WASH) sector. Traditional WASH interventions have focused on reducing exposure to fecal contamination through improved water supply, the use of household sanitation and hand washing (Cairncross et al. 2010; Luby et al. 2018; Null et al. 2018). Yet, recent research has demonstrated that traditional WASH interventions may not be sufficient to reduce diarrhea, particularly among infants and young children (IYC) living in environments heavily contaminated with feces (Cumming et al., 2019; Pickering et al., 2019; Clasen et al., 2012; Null et al., 2018; Kwong et al., 2021). Multiple transmission pathways exist that are specific to, or more extensive for, IYC. For example, as IYC explore their surroundings, they may eat (contaminated) soil, mouth dirty hands and objects, and, importantly, be fed contaminated food.

Contaminated Food is Unsafe 

Food can become contaminated in many different ways, including through the use of unsafe water to prepare the food, food preparation on contaminated surfaces, contaminated hands used for food preparation and feeding, use of dirty utensils and inadequate storage (figure 1). Research has shown that food fed to IYC to complement breastfeeding — a practice that generally starts around 6 months of age — poses a heightened risk because these foods tend to have high moisture levels, typically are stored at warm temperatures — a hospitable environment for bacterial growth — and are introduced at a critical time in child development (Islam et al. 2012; Saha et al. 2010). The habit of preparing food (e.g., porridge) in the morning and then storing it for later use has also been shown to increase fecal bacteria counts (Kung’u et al. 2009).

Multiple Transmission Pathways Require Multiple Interventions to Reduce Exposure

USAID’s Water, Sanitation, and Hygiene Partnerships and Learning for Sustainability (WASHPaLS) #2 project has set out to conduct research focused on interrupting contamination and transmission pathways that specifically threaten IYC health and growth. This work builds on findings from the original WASHPaLS project summarized in the 2022 USAID report Toward a hygienic environment for infants and young children: Limiting early exposures to support long-term health and well-being. 

Based on the evidence to date, given the multiple transmission pathways, no one intervention alone is biologically plausible to sufficiently reduce IYC exposure. The sector has only recently understood the significant role played by IYC and animal feces in fecal pathogen transmission — which involves a wide range of hygienic behaviors that need to be practiced and sustained in parallel — and the essential role of access to a variety of hardware items that could potentially facilitate behavior change. However, integrated programming around these multiple behaviors and practices is rare and complex. 

Evidence Gaps on Hand Washing and Food Hygiene are Substantial, But Mostly Addressed Separately

For example, it is understood that hand washing with soap is an important contributor to improved food hygiene and diarrhea reduction, but much less is known about how to stimulate and sustain caregiver hand washing and the relevant attributes of hand washing stations that support hand washing before and during food preparation and feeding. The WASH sector has focused on the construction and use of hand washing stations near latrines. But these hand washing stations will likely do little to facilitate hand washing before food preparation and child feeding as these behaviors are enacted in a different location. Social and behavior change (SBC) programming would also benefit from a more nuanced understanding of the behavioral drivers tied to food preparation and feeding for IYC, as these are not as well understood in comparison to drivers that promote hand washing after latrine use. 

While some studies in the nutritional field have shown success with the use of hardware, such as baby bowls and spoons or liquid soap, to help adopt and sustain new behaviors (Simiyu et al. 2020), more research is needed to apply these learnings to different contexts. The few studies on hygienic behaviors tend to separately examine food and hand hygiene. But addressing the interconnected ways that lead to food contamination requires intervention packages that target both hand washing with soap and food hygiene. 

Informing the USAID Hand Washing and Food Hygiene Research Agenda

A small number of implementation research studies have investigated hand washing and food hygiene interventions alone, together, and combined with other WASH interventions, testing the hypothesis that the combined interventions would yield greater benefits than each intervention alone (Briceño et al. 2017; Chidziwisano et al. 2020; Gautam et al. 2017; Morse et al. 2020; Prochaska et al., 2008). To date, the body of evidence from these studies is mixed. It suggests that integrated programming of WASH and food hygiene interventions may be beneficial but calls for more research to understand how interventions can be delivered at scale to lead to greater health benefits, particularly for IYC.

USAID is addressing some of the knowledge gaps. WASHPaLS #2 together with implementation partners and experts are gearing up to undertake a combined hand washing and food hygiene study that will explore feasible and desirable intervention packages to support caregivers’ improved performance of hand washing and food hygiene around complementary food preparation and feeding of IYC. Using Hazard Analysis of Critical Control Points (HACCP), WASHPaLS #2 will hone in on the most risky steps in the pathways of food preparation, feeding and storage, then develop and test interventions to reduce risk of exposure. This will include exploring the effect of the hand washing and food hygiene “enabling” hardware and the relative role of SBC messaging on caregivers’ behavior, and on food contamination levels and IYC health outcomes. 

The summary report of the WASHPaLS #2 desk review is entitled “WASHPaLS #2 Social and Behavior Change Research Agenda: Findings from a rapid desk review and stakeholder engagement”. It will be made available for download through www.globalwaters.com.