PREVALENCE OF IODINE DEFICIENCY DISORDERS AMONG SCHOOL-CHILDREN OF DELHI

Background. iodine deficiency disorders (IDDs) are an important cause of mental handicap and poor educability of children, Though Delhi does not lie in the classical Himalayan goitre belt, it has been shown tha t IDD was endemic in Delhi, Studies of school children in Delhi report ed a total goitre rate of 55% which indicates severe endemicity, The s ale of uniodized salt has been banned in Delhi since July 1989, This s tudy was done five years later to assess the impact of this measure on IDD prevalence in Delhi. Methods. A cross-sectional study was done am ong class VI students studying in government schools of Delhi, A compl ete list of government middle schools in Delhi was obtained and 30 wer e selected on the basis of 'probability proportion to size', A sample size of 1200 was decided based on an expected prevalence of 50% with 5 % error and design effect of three, All children in class VI of each s chool were clinically examined by a trained doctor for the presence of goitre and casual urine samples were collected in capped plastic tube s, The urinary iodine estimation was done by the wet ashing method. Re sults. The total goitre rate was 20.5%, If the results were limited to children in the age group of 10-12 years it was 19.7%. The urinary io dine was less than the recommended 100 mu g/L of urine in 23.6% of the children; 7.6% had no iodine in the urine, It is possible that some c hildren could have substituted water in place of urine, The median uri nary iodine level was 198 mu g/L of urine. Conclusion. The study showe d that IDD continues to be prevalent in mild endemic proportions. Comp ared to the results of previous surveys, the IDD rates have declined i n the last few years, However, it continues to be an important public health problem in Delhi, It is essential to monitor the iodine content of salt on a regular basis, IDD control activities should be strength ened in Delhi and repeat surveys should be done every 3-5 years to mon itor the progress achieved in eliminating IDD.