Subscribe to E-Bulletin Donate to CEGA

Preschool Deworming: Impacts on Child Health and Education in India

Development Challenge

Nearly 40% of children in Africa and Asia suffer from iron deficiency anemia (IDA), which can result in weakness, stunted physical growth, and a compromised immune system. Intestinal helminths (worms) cause chronic intestinal blood loss which contributes to iron deficiency anemia. Worms are prevalent among children in developing countries and are believed to have a negative impact on education, impacting child cognitive and physical development as well as school attendance. Estimates suggest that the impact of iron deficiency anemia—through both physical and cognitive channels—could be as large as 4% of GDP on average in less developed countries, yet there is little rigorous work by economists on the effects of anemia on economic development.


Like other developing nations in the region, iron deficiency anemia and Vitamin A deficiency affect many of India’s children. Over 69% of preschool aged children in urban Delhi are anemic and 30% suffer from intestinal worms, contributing to the high prevalence of malnutrition. In 2005, 46% of children were found to be underweight, and 38% were found to have stunted growth. Children in this study typically came from families of poor migrant laborers, and have a particularly high risk of anemia and other nutritional deficiencies. 

Evaluation Strategy

This study evaluated the impact of NGO Pratham’s preschool nutrition and health project in the slums of Delhi, India. The program delivered a package consisting of iron and Vitamin A supplementation and deworming drugs to 2-6 year old children through an existing preschool network.

Two hundred preschools with a total of 2,392 children were randomly divided into three treatment groups, which were gradually phased into the program over two years. The deworming drugs were taken at "health camps" held at the preschool approximately every three months. Preschool teachers in treatment schools were instructed to administer daily iron doses for thirty school days following each health camp. Children in both treatment and comparison groups were also administered Vitamin A supplements, which in addition to other health benefits, promotes the absorption of iron.

Results and Policy Implications

Child Weight Gain: Large gains in child weight—roughly 0.5 kg on average—were found in the treatment schools relative to comparison schools over the two-year study period. No gains in average child height were found, but this pattern makes sense from a clinical standpoint: iron supplementation is thought to reduce acute malnutrition in the short-run by improving the absorption of micronutrients and increasing appetite, but improvements in chronic malnutrition are not expected over short periods.

Impact on School Attendance: Average preschool participation rates increased sharply by 5.8 percentage points among treated children, reducing preschool absenteeism by roughly one fifth.

Given the low cost of the intervention (averaging approximately US$1.70 per additional year of schooling induced for one child), these results suggest that the package of iron, Vitamin A and deworming drugs is a highly cost-effective means of improving child school participation and health in a poor urban setting where anemia and worm infections are widespread.

The results of this study largely confirm the Kenya Primary School Deworming Project findings that child health gains translate into higher school participation. A robust demonstration that a nearly identical relationship holds in another geographic setting (urban India), with a younger age group, and a different health intervention provides additional confidence that there does indeed exist a relationship between child nutrition, health, and school participation in poor countries.


2001 - 2002