going beyond nutrition to understand child growth and development_laura smith_4.25.13
TRANSCRIPT
EE: Going Beyond Nutrition to Understand
Child Growth and Development
Laura Smith Rebecca Stoltzfus,Francis Ngure, Brie Reid,
Gretel Pelto, Mduduzi Mbuya, Andrew Prendergast, Jean Humphrey
Division of Nutritional Sciences
(Victora et al. 2010)
The “Window of Opportunity” for Improving Nutrition is very small… Pre-pregnancy until 18-24 months of age
What is causing all this stunting?
Cause #1: Malnourished Mother
• Malnourished mothers give birth to babies that are smaller and shorter than normal
• 50% of Guatemalan babies are born stunted (Ruel 2001)– Prevalence of stunting at birth not well documented– Good length data on newborns is very hard to get!
Estimates of 30-50% of stunting is due to intra-uterine factors. Effective macronutrient interventions for pregnant women are not
well established.
Cause #2: Poor Diet
• Systematic review of the efficacy and effectiveness of complementary feeding interventions in developing countries– Dewey & Adu-Afarwuah, 2008– 42 studies/programs, most published 1996-2006
• Children who received interventions gained:– 0.0 – 0.76 Z scores weight-for-age– 0.0 – 0.64 Z scores length-for-age
The best studies caused a 0.7 Z score improvement. BUT:the average growth deficit of African and Asian children is -2.0 Z
At best, diet solved 1/3 of the problem.
Cause #3: Diarrhea
• Between 6-18 months of age, children in developing countries have around 9 episodes of diarrhea.
• Many authors reported that diarrhea accounts for 10-80% of growth faltering
• But others contend that children grow at “catch-up rates” between episodes, and thus recover these deficits
The Lancet Nutrition Series (2008) concluded that by implementing sanitation and hygiene interventions with 99% coverage, child malnutrition would be reduced by only 2.4%
However:
Evidence exists that the effect of WASH interventions on linear growth is independent of its effect on diarrhea.
In several studies, WASH had a bigger effect on growth than it did on diarrhea
Peru: (Checkley, et al)
• Children assessed for diarrhea and growth from birth to 2 years
• Household sanitation and water assessed
• What predicted height deficit at 2 years?
16% explained by how much diarrhea the child had experienced
40% explained by the level of sanitation and water in child’s household
Rural Ethiopia: HH Hygiene Index was the variable most strongly associated with
stuntingAlive and Thrive baseline data; F Ngure (2013, in prep)
Cause #4: The Environmental
Enteropathy Hypothesis
• A subclinical condition of the small intestine, called environmental enteropathy (EE)
• Characterized by:– Flattening of the villi of the gut, reducing its surface area– Thickening of the surface through which nutrients must be absorbed– Increased permeability to large molecules and cells (microbes)
• Likely causes:– Too many microbes in the gut– Effects of toxins on the gut
Decreased nutrient absorption + Infiltration of microbes
Microbial translocation
Microbial products cross into blood stream
The lining of the gut is only one cell
thick
If the gut is injured and becomes permeable, gaps open up between cells
Chronic immune activation
Diverts nutrients from growth to infection-
fighting
EE is a major cause of post-natal stunting, anemia and immune competence
EE can be prevented or reduced by preventing infants and young children from ingesting human and animal feces through a package of interventions that improve sanitation and hygiene.
Environmental Enteropathy and Stunting Hypothesis:
Chronic immune activation
↑ pro-inflammatory cytokines
Immunosenescence (premature aging) of adaptive cell-mediated immune system
↑Hepcidin ↓Growth Factor (IGF-1)
Anemia StuntingImpaired response to vaccines and infections
HAZ changes over first 18 months in stunted and non-stunted infants
Birth 6wks 3mo 6mo 12mo 15mo9mo 18mo
IGF-1 and IGFBP3 were lower in stunted infants, beginning at 6 wk
P values for all time points 6 w to 12 mo, p<0.001
Values for healthy European children range from 54-170 ng/mL
P values for all time points 6 w to 18 mo, p<0.001
stunted stunted
Development of the WASH Intervention(Efficacy = “Proof of concept”)
WASH Goal:All infants never ingest any faeces between birth
to 18 months
Conventional WASH formative research (2008-2009)
Sanitation HIGHLY valued don’t have a latrine because lack money; a Blair VIP is a source of status
• Infant stools less offensive than adults’• Handwashing is seldom with soap• Frequently feed cold leftover food
• 6 hour observation of 20 babies, recorded what and how often went in the mouth and if visibly dirty
• Returned and collected samples of most frequent and dirtiest things mouthed for micro analysis
Baby Observation Study (2011)
Findings
Most frequent:38 time in 6 hours75% visiby dirty
DirtiestSoil (3 ate avg 11 bites)chicken faeces, stones
If allowed, toddlers consume poultry feces
Peruvian shantytown families:– Households who owned free-range poultry:
• Average ingestion of poultry feces by toddlers per 12-hour observation period was 3.9 times
– Marquis GM et al., Am J Public Health 1990
Rural Zimbabwe:– Not selected for poultry ownership:
• 3 of 7 toddlers directly ate chicken feces during a 6-hour observation period.
– Ngure F et al., submitted, 2012
% HH with E coli + sample
E coil/Per gram
Average E ColiPer Day
Infant Food 0% 0 0
Drinking Water54% 2 800
Soil in laundry area 60-80% 70 1,400
Chicken feces100% 10,000,000 10,000,000
Clearly, kids must stop eating dirt and chicken poop!
24
Babies are fed on *Ground in the yard (60-80% E coli+) or *Kitchen floor
(81% E coli+)
Source: World Bank, accessed 6.23.11http://web.worldbank.org/WBSITE/EXTERNAL/TOPICS/EXTWAT/EXTTOPSANHYG/
Geophagia, dirty hands
LaundryWater
Nappy Handling
Protective Play Space
for babies!
A new way of thinking about WASH in the first 1000 days
• Protective play space, to protect developing child from contaminated soil and animal feces (especially chickens)
• Infant handwashing with soap, when outside of protective play space.
• Caregiver handwashing with soap after fecal contact and before preparing/serving food
• Safe disposal of feces—especially of children
• Water treatment
• Avoid feeding leftovers, or reheat
BABY WASH
Control
Infant Feeding: Education + Nutributter
WASH:Integrated Water,
Hygiene & Sanitation
WASH+
Infant Feeding
2x2 Factorial Design
ObjectiveTo measure the independent and combined effects of
WASH and infant nutrition on stunting and anemia among children from birth to 18 months of age
And, on a sample of 1600 infants, measure the hypothesized “causal pathway” of EE
1000 HIV- mothers600 HIV+ mothers
Protective play space
Goal: Culturally-acceptable, economical product that could be locally fabricated, which protects babies and toddlers from ingesting soil while allowing physical and cognitive development
Engaged a marketing expert (Malinda Sanna, Spark) for consumer research
Design process led by team from Cornell’s Department of Design and Environmental Analysis and Human Development
Early Childhood
Development
Nutrition
Stimulation Social Protection
Hygiene
Programmatic approaches for nutrition, stimulation and social protection are well developed.
UNICEF 2006 Programming Experiences in Early Childhood Development
Lancet 2011 Child Development Series
Hygiene for babies (Baby WASH)
needs to be further developed and tested
Environmental Protection?
SHINE Investigators:
MoHCWGoldberg Mangwadu – Director of Environmental Health, MoHCW (Co-PI)Cynthia Chasokela – Director of Nursing
ZvitamboJean Humphrey (Co-PI) Mduduzi Mbuya, Naume Tavengwa, Kuda Mutasa, Robert Ntozini
Johns Hopkins Bloomberg School of Public HealthLarry Moulton, Jim Tielsch (J Humphrey)
CornellRebecca Stoltzfus
University of LondonAndrew Prendergast
University of British ColumbiaAmee Manges
FundingGates, DFID, CIDA,
NIH,Wellcome Trust,
UNICEF
Zimbabwe SHINES
Zimbabwe Sanitation Hygiene Infant Nutrition Efficacy Study
Observation: babies with healthier guts and less inflammation grow better.
Biological hypothesis: babies who are protected from fecal ingestion will grow better.
Randomized trial hypotheses: babies whose households receive a comprehensive Water Sanitation & Hygiene (WASH) intervention will grow better.
WASH Intervention
Reduced fecal
ingestion
Better Growth
San & HygBehaviors
Healthier Gut& Less
Inflammation
WASH + Nutrition will have more benefit than either alone.
Community-basedTwo entire rural districts
total popn: 180,000K
Standard Care 1. Revived VHW network2. Strengthened PMTCT care3. EBF Promotion 4. Latrine at end of study
Infant Nutrition1. Standard care 2. Promote optimal use of local foods
for complementary feeding3. 20 g Nutributter daily provided for
infants (6-18 mo)
Sanitation/Hygiene1. Standard care2. VIP latrine 3. 2 Tippy Taps and soap4. Water Guard5. Protected play area6. Promote safe feces disposal hand
washing, water Rx, hygienic infant feeding
Infant Nutrition & Sanitation/Hygiene
1. Standard care2. All Nutrition interventions3. All Sanitation/Hygiene interventions
Implementation
• Enroll 4,800 pregnant women at 10-12 weeks gestation and follow them until their babies are 18 months old.
• Interventions delivered by 360 Village Health Workers on bicycle and Oxfam
• Outcomes measured by 34 Research Nurses on motorbike
Outcomes
• Among all 4800 infants assess growth, anemia, intervention uptake, relevant behaviors
• Among 1600 infants, assess causal pathway (indicators of EE) at 3, 6, 12, 18 months
The context: IO study
Laundry area
Bare soil and animal waste
Micro team
Results: IO phase summary
• Barely no HW for infants:
21 times (in 13/23 HH) in 130 hours
HWWS 6/21: all as part of a bath.• Adult caregivers’ HWWS after contact with stool-
7.5 % (4 HWWS/53 opportunities)• 9/23 (39 %) infants took:
3 infants- active soil ingestion
2 took chicken feces
4 took stones from the dirt
Results: Micro phase summaryA one year old ingesting chicken feces, soil and
400 ml of contaminated water:On average 10 million E. coli counts/g of
Chicken feces
Frequency of E. coli: 22/22 HH (100 %)69 E. coli counts/g of wet shaded area soil:
Frequency: 18/22 HH (82 %)800 E. coli counts from water.
Frequency: 12/ 22 HH (55 %) Other bacteria population
Key messages
• Chicken feces and soil ingestion are predominant pathways
• Exploratory soil ingestion and geophagia could be more prevalent in rural Zimbabwe than observed for 23 HH - 2 FGDs indicated this.
• Water contamination is significant.• Infants HW barely practiced.
Key messages
• Caregiver’s HWWS after fecal contact is not common.
• WASH interventions need to focus more on protecting infants from eating earth and chicken feces
• The idea of a washable mat or playing pen as a WASH intervention input
IYCF Intervention
Promote optimal use of locally available foods, responsive feeding, nutrient density, feeding during illness
Provide 20 g/d Nutributter 6-18 mo
Prior to Trial Launch
Village Health Worker Revitalization
Full complement recruited, trained (8 months) Provide tools (bike, kit, uniforms)
Campaign to promote Exclusive breastfeeding for all to 6 months
1. Health worker training
2. Social marketing
Implement WHO 2010 Prevention of Mother to Child Transmission of HIV and Infant Feeding Guidance
EE is caused by environmental exposure
• Fetuses and newborns do not have it
• People acquire it moving into developing country and lose it moving out
• Widely believed:
Result of high exposure to fecal contamination in an environment of poor sanitation and hygiene
• EE is a major cause of child stunting
• EE can be prevented or reduced by preventing infants and young children from ingesting human and animal feces through a package of interventions that improve sanitation and hygiene.
Environmental Enteropathy and Stunting Hypothesis:
Fecal contaminationEnvironment
Altered bacterial load, composition and/or timing of colonisation
Intestinal inflammation and reduced surface area
Increased intestinal permeability
Microbial translocation
Microbiome
Intestinal pathology
Microbial translocation
StuntingAnemia
Activates innate immune system
proinflammatory cytokines
Immune activation
Activates adaptive immune system
Immunosenescence
Impaired responses to vaccinations and
infections
IGF-1 Hepcidin Erythropoiesis
Iron absorption and mobilization
IGF-1
• 70 amino acid polypeptide• Mostly produced by liver• Mediates the effects of growth hormone • Important in fetal and postnatal growth• Endocrine function (paracrine, autocrine)• Highly protein bound
– 6 binding proteins– Mostly IGFBP3– Acid labile subunit
Inflammatory markers were higher in stunted infants
P values for all time points 6 w to 12 mo, p<0.001
P values from multivariate models that included maternal education, MUAC, sex, birth weight, and mixed feeding.
P=0.007 P=0.064
NSP=0.023
stunted
Mean 95.9 Mean 114.3
P=0.02
R=0.50P<0.001
R=-0.39P<0.001
R=0.52P<0.001
Maternal and infant values were correlated at birth
Intestinal Fatty Acid Binding Protein (I-FABP)
• Very small (15kD) cytoplasmic protein• Found in enterocytes• Involved in intracellular transport of LCFA• Rapidly released into blood after cellular damage• Predominantly expressed in cells at tips of villi in
small intestine• Elevated in celiac disease compared to healthy
contols Derikx JP, J Clin Gastroenterol 2009
High I-FABP levels in stunted and non-stunted Zimbabwean infants
6 months 12 monthsMedian 859 Median 978 Median 1148Median 1070
Healthy controls 172.7 pg/mL (±20.2) – mean age 22 yrs (range 1-61 yrs)Coeliac disease Median 784.7 pg/ml (±145.5)Advanced HIV (adults) 174.4 pg/mL
P=0.36 P=0.13
I-FABP was higher in stunted infants
stunted
P value from multivariate model that included maternal education, MUAC, sex, birth weight, and mixed feeding.
P=0.030
Summary
• Growth hormone axis is perturbed very early in life in apparently healthy Zimbabwean infants with poor linear growth.
• Small intestinal damage and low-grade inflammation are evident post-natally and associated with stunting by 18 mo of age
• Diarrhea (measured by clinic visits) was not associated with stunting.
• Circulating levels of pro-inflammatory mediators and IGF-1 in mother-infant dyad at birth are associated with in utero growth.
Zimbabwe SHINES
Zimbabwe Sanitation Hygiene Infant Nutrition Efficacy Study
Observation: babies with healthier guts and less inflammation grow better.
Biological hypothesis: babies who are protected from fecal ingestion will grow better.
Randomized trial hypothesis: babies whose households receive a comprehensive Water Sanitation & Hygiene (WASH) intervention will grow better.
WASH Intervention
Reduced fecal
ingestion
Better Growth
San & HygBehaviors
Healthier Gut& Less
Inflammation