This is likely due to a lack of dietary intake of iodine, which is richly found in seafood. Once the problem was found to be an iodine deficiency, an effort was made to prevent this disease by iodizing salt. It could be that certain geographic areas of the world, lack sufficient sources of iodine from local diets and the salt is not iodize. It is a very preventable condition with supplementation of one’s diet with iodized salt.

Pete