Characterizing Potential Risks of Fecal–Oral Microbial Transmission for Infants and Young Children in Rural Zambia

Abstract

Undernourished children in low-income contexts often suffer from environmental enteric disorder-damage to the intestines probably caused by chronic exposure to bacterial pathogens from feces. We aimed to identify strategies for reducing infants and young children's (IYC) exposure to human and animal feces in rural farming families by conducting direct observation of 30 caregiver-infant dyads for 143 hours and recording water, sanitation, and hygiene (WASH)-related behaviors to identify possible pathways of fecal-oral transmission of bacteria among IYC in rural Zambia. In addition to mouthing visibly dirty hands, toys, sibling's body parts, and food, 14 IYC actively ingested 6.1 ± 2.5 (mean ± standard deviation [SD]) pieces of soil and stones and one ingested animal feces 6.0 ± 0 times in the span of 5 hours. Ninety-three percent (21 of 30) of mothers reported observing the index-child eating soil and 17% (5 of 30) of mothers reported observing the index-child eating chicken feces. Adult and child handwashing was uncommon, and even though 70% (28 of 30) of households had access to a latrine, human feces were found in 67% of homestead yards. Most animals present in the household were un-corralled, and the highest observable counts of feces came from chickens, pigs, and cattle. To protect IYC in low-income communities from the exploratory ingestion of feces and soil, Baby WASH interventions will need to interrupt fecal-oral microbial transmission vectors specific to IYC with a focus on feasibility, caregiver practices, and local perceptions of risk.

Exposure to Livestock Feces and Water Quality, Sanitation, and Hygiene (WASH) Conditions among Caregivers and Young Children: Formative Research in Rural Burkina Faso

“…Direct ingestion of soil within household courtyards, where poultry frequently scavenge and defecate, was observed among 45% of households. This is more frequent than what was observed in rural Zimbabwe (13%) 15 and about the same as in Zambian households (47%) 15 (albeit, in-depth observation periods were substantially longer in these other contexts). Direct soil ingestion by young children has also been observed in low-income contexts in rural Bangladesh, 20,21 peri-urban Peru, 22 and rural Kenya.…”

“…1 However, domestic animal excreta are an important and underemphasized source of fecal contamination. 15–17 Moreover, formative research suggests young children often directly ingest animal feces or contaminated dirt (geophagy), which have extremely high concentrations of bacteria. 16,17 It has been hypothesized that ingestion of animal feces might also contribute to EED and ultimately child stunting, perhaps even through nonpathogenic bacteria.…”

“…16,17 Although handwashing could minimize ingestion of fecal pathogens, it is poorly carried out and less common in many low-income settings. 15–17 It is also unclear how effective these traditional WASH measures are in disrupting other pathways outlined in the F-diagram, linking animal feces to young children health and nutrition outcomes.…”

Risk factors and transmission pathways associated with infant Campylobacter spp. prevalence and malnutrition: A formative study in rural Ethiopia

“…In the same study 35.0% of infants directly ingested floor surface material and poultry faeces was directly ingested by two infants (10.0%) [50]. Other studies have also recorded infants frequently ingesting poultry faeces from the floor during normal exploratory play [27,80,81].…”

A localized sanitation status index as a proxy for fecal contamination in urban Maputo, Mozambique

“…Human excreta is more likely to spread infection via multiple interacting pathways when safely managed sanitation is absent [3]. There is increasing interest in soil as an important environmental transmission pathway for enteric pathogens, especially among children who may mouth contaminated hands or objects, or directly ingest soil [4–8]. The pathways through which human excreta spreads to the environment further suggests that soil serves as a sink for enteric pathogens [3,9].…”