Undernutrition: PEM, wasting, stunting and the link with infection
PEM shows as stunting (chronic), wasting (acute) and underweight. Infection and malnutrition feed each other in a vicious cycle, so immunisation also protects nutrition.
Forms of undernutrition in children
| Term | Measured as | Cut-off (WHO standards) | What it tells you |
|---|---|---|---|
| Underweight | Weight-for-age | Below −2 SD | A mix of past and present undernutrition |
| Stunting | Height (or length)-for-age | Below −2 SD | Chronic undernutrition, often starting in the womb; hard to reverse after age two |
| Wasting | Weight-for-height | Below −2 SD | Acute undernutrition: recent weight loss from hunger or illness |
| Severe acute malnutrition (SAM) | Weight-for-height, MUAC, oedema | Below −3 SD, or MUAC below 115 mm, or bilateral pitting oedema | High risk of death; needs urgent treatment |
| Low birth weight | Weight at birth | Below 2500 g | Mother's poor nutrition; the baby starts life undernourished |
Kwashiorkor vs marasmus
Wellcome classification (weight-for-age as % of reference): 60-80% without oedema = underweight; 60-80% with oedema = kwashiorkor; below 60% without oedema = marasmus; below 60% with oedema = marasmic kwashiorkor. Kwashiorkor was described by Cicely Williams in the 1930s in Ghana; the word means the illness of the child displaced from the breast by a new baby.
Causes and prevention (UNICEF framework)
| Level | Causes | Prevention |
|---|---|---|
| Immediate | Too little food (energy, protein, micronutrients); repeated infections such as diarrhoea, measles, pneumonia and worms | Exclusive breastfeeding, timely complementary feeding, ICDS supplementary nutrition, immunisation, ORS and zinc for diarrhoea, deworming |
| Underlying | Household food insecurity; poor care and feeding practices (late breastfeeding, diluted feeds); unsafe water, poor sanitation, poor health services | PDS grains under NFSA 2013, nutrition education, safe water and toilets, growth monitoring at the anganwadi |
| Basic | Poverty, illiteracy (especially of mothers), low status of women, large families, unemployment | Education and income for women, birth spacing, employment schemes, social protection |
| Treatment and rehabilitation | Children already severely malnourished | SAM with complications treated in Nutrition Rehabilitation Centres (NRCs); uncomplicated SAM managed in the community |
The malnutrition-infection cycle
- back to Poor diet
Scrimshaw, Taylor and Gordon (1968) called this synergism: malnutrition and infection together do more harm than either alone. Measles can tip a child into kwashiorkor and vitamin A blindness; hookworm causes anaemia.
Immunisation and why it matters for nutrition
| Age | Main vaccines (national schedule) | Nutrition link |
|---|---|---|
| Birth | BCG, OPV zero dose, hepatitis B birth dose | Protects the newborn while breastfeeding is established |
| 6, 10 and 14 weeks | OPV, pentavalent (DPT + hepatitis B + Hib), rotavirus; PCV and fractional IPV at set visits | Rotavirus vaccine prevents severe diarrhoea, a major cause of wasting |
| 9-12 months | Measles-rubella (MR) first dose; first vitamin A dose at the same visit | Measles can precipitate kwashiorkor and xerophthalmia |
| 16-24 months | MR second dose, DPT and OPV boosters; second vitamin A dose | Vitamin A then continues every 6 months up to 5 years |
| 5-6, 10 and 16 years; pregnancy | DPT booster; Td (tetanus and adult diphtheria); Td for the pregnant woman | Protects mother and newborn |
At the anganwadi, monthly growth monitoring spots a child whose weight is faltering before she becomes wasted. The worker checks the immunisation card, gives supplementary food and refers a SAM child with complications to the nearest NRC.
2 marks: “Differentiate stunting and wasting.” Stunting is low height-for-age (below −2 SD), showing chronic undernutrition. Wasting is low weight-for-height (below −2 SD), showing acute undernutrition.
5 marks: “Explain the relationship between nutrition and infection.” Synergism (Scrimshaw, 1968); malnutrition lowers immunity; infection worsens nutrition by appetite loss, malabsorption, raised needs and nutrient loss; draw the cycle; examples (measles, diarrhoea, hookworm); immunisation and the Universal Immunisation Programme (1985) break the cycle.
10 marks: “Discuss the etiology, clinical features and prevention of protein energy malnutrition.” Define PEM and its forms with NFHS-5 figures; kwashiorkor versus marasmus table; Wellcome classification; causes at immediate, underlying and basic levels; the infection cycle; prevention at each level, ICDS, immunisation and NRCs.
Stunted = short for age (chronic); wasted = thin for height (acute). Kwashiorkor has oedema; marasmus is 'skin and bones' with no oedema.