Applying nutrition science to public health. Wednesday, March 12, 14

Transcription

1 Applying nutrition science to public health

2 Malnutrition in Children

3 What is Malnutrition Malnutrition is defined as a pathological state resulting from relative or absolute deficiency of one or more essential nutrients. It is primary when there is deficiency of food available or secondary when food is available but the body cannot assimilate it for one or another reason. Malnutrition is common in children between age of 3 months and 3 years.

4 Intergenerational Cycle of Undernutrition The cycle of poor nutrition perpetuates itself across generations - supported by scientific evidence Childhood: Child growth failure, impaired mental development Fetal and Infant stages: Low birthweight baby Pregnancy Compromised nutritional status Adolescents: Low weight and height Adult: Small adult woman, lowered productivity

5 Infection-Malnutrition Synergism Weight loss Growth faltering Immunity lowered Inadequate dietary intake Disease Incidence Severity Duration Appetite loss Nutrient loss Malabsorption Altered Metabolism 5

6 Anthropometric Indices in Malnutrition Weight for age is the best screening tool. Weight for age below 2 Standard Deviation from median is taken as Malnutrition. It is used for mass screening of children to detect under nutrition. Weight for Height below the 5th Centile classifies the child as Wasted ( Acute Malnutrition). Height for age below the 5 th centile classifies the child as Stunted (Chronic Malnutrition)

7 Malnutrition in Pakistan 38% of Children are Low Weight for Age. (Shakirullah et el. JCN, 1999,vol.xii) 14% of Children are Wasted 36% or Urban and 44% of rural Children are Stunted. Malnutrition is responsible as underlying factor for 55% of Deaths in Children under 5 years of age. (Nelson textbook of Pediatrics, 16 th Ed. Saunders, 2001)

8 Nutrition, by definition, is a multi-sectoral issue. What limited implementation there has been is confined to health work and not coordinated across ministries

9 Etiology of Primary Malnutrition Failure of Lactation. Improper Weaning Practices Poverty Food Taboos 2 or more children under 5 years in household Death of Mother Incompetent/ Ignorant Mother. Lack of Family Planning

10 Etiology of Secondary Malnutrition Lack of Immunization Congenital Diseases: ASD, VSD, cleft palate etc. Malabsorption: Celiac Disease, Lactose intolerance, Giardiasis, Cystic Fibrosis Metabolic: Inborn errors of Metabolism, CRF, Renal tubular Acidosis etc. Infections: Tuberculosis ( very common in Pakistan)

11 Clinical features in Marasmus Marked muscle wasting and loss of subcutaneous fat. Monkey Facies Skin becomes loose and hangs in folds Abdomen protuberant due to hypotonic muscles Temperature is usually sub-normal Child is alert

12 Clinical features in Marasmus

13 Clinical features of Kwashiorkor Generalized Edema more marked in Lower Extremities. Apathy and Irritability Fine, sparse and discolored hair Anemia Usually Flaky Paint Dermatitis Enlarged Liver due to Fatty Changes

14 Clinical features of Kwashiorkor

15 Lab Investigations in Malnutrition Hemoglobin Associated dehydration hemoconcentration If there is no BCG Scar, do Diagnostic BCG and read after 72 hours. If more than 10 mm of induration, treat as Tuberculosis. Stool R/E and Urine R/E. Chest Xray in all cases of Malnutrition. Serum Pre-Albumin level. This is the most sensitive prognostic indicator in Kwashiorkor. Do on Day1, Day 5 and before discharge of the patient. Plasma Proteins and Serum Albumin level. These are usually very low in Kwashiorkor.

16 Complications of Malnutrition Hypothermia Hypoglycemia Cardiac Failure Infections Vitamin A Deficiency Severe Anemia Dermatosis

17 Treatment of Malnutrition Follow WHO Guidelines 1. Treat/prevent hypoglycemia 2. Treat/prevent hypothermia 3. Treat/prevent dehydration 4. Correct electrolyte imbalance 5. Treat/prevent infection 6. Correct micronutrient deficiencies 7. Initiate refeeding 8. Facilitate catch-up growth 9. Provide sensory stimulation and emotional support 10. Prepare for follow-up after recovery

18 Therapeutic Nutrition in Malnutrition Start slowly with F-75. If that is not available, give traditional easy to make, calorie rich foods. For those having severe anorexia, feed overnight with Milk given through NG tube, till appetite returns. Give Vitamin A, Vitamin D, Zinc, Magnesium, and folate to all children Treat Oral thrush, if present.

19 Prevention of Malnutrition Primary Prevention Health Education to mothers about good nutrition and food hygiene through Lady Health Workers Immunization of children. Growth monitoring on Growth Charts specially of all children under 3 years of age Secondary Prevention Mass Screening of high risk populations, using simple tools like Weight for age or MUAC. Tertiary Prevention Good Nutritional Care, supplementary feedings and rehabilitation, counseling of mothers.

20 Prevention of Malnutrition Breastfeeding Complementary feeding Mother s nutrition Vitamin A and iron Sick/severe cases Iodized salt

21 INFANT FEEDING Exclusive breast feeding (EBF) for first 4-6 months Those not EBF have double the infant mortality rate as breast fed infants in developing countries Breast milk Sterile with multiple anti-infective mechanisms Nutrients tailored to needs and developmental stage of infant Promotes brain and visual development Growth-stimulating factors of digestive tract Psychological benefits for maternal infant pair Few safe alternatives in poor countries and among HIV positive mothers. Enhances child spacing called lactational ammenorrheä (Suppresses ovulation but imperfectly)

22 WEANING CHALLENGE FEEDING THE TODDLER NEED TO ADD SOLID FOODS TO SUPPLY MORE ENERGY 6> MONTHS, PROTEIN, IRON, AND OTHER MICRONUTRIENTS AFTER ONE YEAR, CHILD OUTGROWS THE MILK SUPPLY Need for energy-dense food (small stomachs!) with high-quality complete protein, energy, essential vitamins and minerals Iron, zinc, iodine, calcium, vitamins A, C, B, D, esp. B12 Supplied by local legumes, cereals, dairy products, and need for modest amounts of animal foods; i.e., meat, fish, fowl For vitamins C and A, use of green and orange fruit and vegetables. NOTE: Death rates around weaning time fold higher in developing countries than in rich nations, due to combination of malnutrition and infection

23 Public health approaches to modifying intake in the prevention and control of micronutrient deficiencies Food-based (esp in poor countries) Dietary diversification Home gardening Nutrition education Development of high carotenoid varieties Raising of small animals (including fish) for milk, meat, and eggs for household consumption Greater sustainability through food-based approaches than relying on micronutrient distribution by pills, etc. particularly to rural and isolated communities

24 Micronutrient Fortification (where feasible and affordable) Sugar, flour, margarine, edible oils, noodles, condiments i.e. soy, etc. Supplementation (particularly in developing countries) National immunization days and micronutrient distribution days Distribution through health centers, including mothers and children Postpartum supplementation Vitamin A capsule distribution programs in developing countries (mega-doses every 6 months for children under 5)

25 Nutrition transition in developing countries Double burden of malnutrition and over-nutrition and obesity in urban areas of developing countries Change in lifestyle and shift to cash economy, with movement to urban areas No longer grow own food in cash economy, and relying on high-fat, street foods and fast foods No longer access to fruits and vegetables, and milk produced on own homesteads Decreased physical labor and physical activity in urban settings Accompanying cardiovascular diseases with obesity, causing high mortality and morbidity among adults Increased stress and alcohol consumption

26 Fetal programming and origins of adult chronic disease The Barker Hypothesis (seen globally) Intrauterine malnutrition with low-birth weight in numerous epidemiological studies, associated with increased risks of coronary heart disease, stroke, hypertension, and type II diabetes in surviving adults Associations seen globally Effects may be due to fetal programming, presumably due to insult at critical, sensitive periods in fetal development, with permanent adverse effects on structure, physiology, metabolism, and hormonal function Adaptations invoked by maternal placental failure of nutrient supply to meet fetal demand. Maternal body composition and nutrient balance before and during pregnancy of key importance, and under active research Barker Hypothesis has stimulated large number of studies on possible intrauterine mechanisms

27 Indicators of nutritional status

28 Categories of Nutrition Indicators Nutritional status Breastfeeding practices Complementary feeding practices Micronutrient supplements/fortified foods Household food security; vulnerability to food and nutrition insecurity

29 Most Common Indicators Nutritional status Weight-for-age and/or height-for-age Body Mass Index in women Anemia prevalence Vitamin A deficiency Infant and young child feeding practices Timely initiation of breastfeeding Exclusive breastfeeding rate Complementary feeding rate Extra feeding for malnourished/recently sick children

30 Most Common Indicators Micronutrient Interventions Vitamin A supplementation Iron supplementation Coverage with iodized salt, other fortified foods Household Food Security/Vulnerability Daily meal frequency of family/individuals Perceived inadequacy of food reserves in community

31 Monitoring & evaluation (M&E) in nutritional epidemiology

32 Data Collection Systems Routine Sentinel food and nutrition surveillance Institutional health records- clinics, schools Feeding & cash or food transfer programs records- daily/weekly/monthly attendance Non-routine Population-based surveys Emergency appraisals, rapid assessments Experimental and operational research

33 Anthropometric Measures (1) Children: Weight-for-age (underweight) Reflects chronic or acute malnutrition or both Height-for-age (stunting) Reflect chronic (prolonged, cumulative) malnutrition Weight-for-height (wasting) Reflects acute and recent malnutrition

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35 Detecting Low Weight-for-age Option A Growth Chart Girls Cut-Off Points Low Weight-for- Age Boys Age mths Age mths Low wt/age Low wt for age below this line below this line

36 Detecting Low Weight-for-age Option A Growth Chart Option B Table of weight-for-age cut off points Girls Cut-Off Points Low Weight-for- Age Boys Age mths Age mths Low wt/age Low wt for age below this line below this line

37 Anthropometric Measurements (2) Adults: Body Mass Index (BMI) Low weight-for-height ( kg/m2) reflects chronic &/or acute Mid-upper arm circumference (MUAC) Thin reflects chronic &/or acute

38 Data Sources for Anthropometry MCH programs/clinic records School feeding- school heights. Food and nutrition, epidemiological surveillance Poverty mapping/school height census - heights for chronic, weights for current Reports from emergency/refugee programs

39 Statistical Presentation of Anthropometric Indicators Prevalence Percent below a cut-off, such as <-2SD or < -3 SD Mean Z-score values (in SD units) Z score refers to how far and in what direction the measure deviates from the median of the NCHS/WHO international reference standard

40 Exercise: Interpreting Standard DHS Nutrition Status Tables If low HFA is 50%, WFA is 30%, WFH is 15%, which is the worst problem? Why? Which child is more vulnerable to die: a -sd wasted or a -3sd stunted child? Why? In which age group? Which characteristics are more important for program targeting: rural/urban, region, sex, age, or birth order?

41 Feeding Practices: M&E Considerations Proportion of infants aged 0-5 months who were exclusively breastfed in the last 24 hours, Proportion of infants less than 12 months of age who were put to the breast within one hour of delivery, Proportion of infants aged 6-9 months receiving breast milk & complementary foods, Mean number of food groups eaten in the last 24 hours by children 6-23 months of age,

42 Appropriate Complementary Feeding Percentage of infants and young children 6-23 months of age who receive appropriate complementary feeding 6 to 8 months of age : Breast milk + other food at least 2-3 times per day + variety of food groups 9 to 11 months of age : Breast milk + other food at least 3-4 times per day + variety of food groups 12 to 23 months of age : Breast milk + other food at least 3-4 times per day + variety of food groups

43 Coverage Indicators for Micronutrient Programs Proportion of children aged 6-59 months who received a high dose of vitamin A in the last 6 months, Proportion of households consuming adequately iodized (i.e. 15+ ppm of iodine) salt, Proportion of pregnant women who received the recommended number of iron/folate supplements during pregnancy,

44 Choices in Program M&E Design Which age groups to measure Anthropometry, infant and young child feeding, How to obtain valid measurements Anthropometry; micronutrients; infant and young child feeding Timing Trends; seasonality Evaluation design

45 Examples of Flaws in Nutrition Evaluations No comparison groups No pretest or baseline No control for age, e.g. < 6 mo.,< 2 and 3+ yrs Not accounting for confounding factors Seasons not comparable Not controlling for mortality reduction Non-representative samples, small samples Pilot projects, not replicable

46 Economic Analysis in Nutrition M&E Cost-effectiveness analysis compares two or more alternatives for achieving coverage or scale or behavior change, or a process outcome such as training to build capacity Answers the question which is the more efficient option? Used more in evaluations Cost-benefit compares the resources required to achieve impact and the monetary value of that impact Answers the question is the investment worthwhile? Based on many assumptions with limited empirical evidence

47 Challenges of M&E Multisectoral programs (attributing outcome?) Clinical Indicators May need large samples (e.g. xerophthalmia) May be sensitive to enumerator training (e.g. goiter) Measurement of iron deficiency (lack of specificity) Selection bias (institution based sample)

48 Challenges: Comparisons & Trends Sample design Sample size Cutoff points & standards Seasonality

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