Epidemiology of endemic cretinism in Sikkim, India.

A survey was conducted in Sikkim to determine the prevalence of endemic cretinism in the state. A household was the basic sampling unit. Villages were selected randomly in the state and from these households were selected randomly using the electoral lists. All members of the households were studied. Total of 17,837 individuals from 3,197 households from 249 villages were studied. There were 8,953 males and 8,884 females. A total of 617 endemic cretins were identified: 316 males and 301 females. The overall prevalence of endemic cretinism was 3.46%: (males 3.53% and females 3.39%). Endemic cretinism was observed in 194 (77.9%) villages studied. Neurological cretinism was the predominant form (98.7%). Deaf-mutism was the most salient neurological feature seen in 472 (76.5%) subjects. Motor system examination revealed proximal spasticity and brisk reflexes, both more marked in the lower limbs. Recording of daily life activities revealed 14.1% of the cretins to be totally dependent and another 23% to be requiring considerable assistance for their daily routine activities. The overall prevalence of goitre found in this survey was 54%. Urinary iodine concentration was estimated from a representative sample of the population; mean 4 micrograms/dl (SD 2.68). This survey shows the existence of severe iodine deficiency in Sikkim.