Survey of prevalence of iodine deficiency disorders and iodine nutrition in high-risk areas of Inner Mongolia in 2007 and 2008 / 中国地方病学杂志

ABSTRACT

Objective To investigate new cases of endemic cretinism in high-risk areas of Inner Mongolia, the prevalence of endemic goiter, the implementation of comprehensive measures, and to provide scientific basis for developing control strategies against iodine deficiency disorders (IDD). Methods In 2007 and 2008, a search for new cretin cases was conducted among children under the age of 10 in 11 historical serious epidemic cretinism prevalent areas of Songshan district, Keshiketeng qi, Kalaqin qi, Zhalaite qi, Zhuozi county,Liangcheng county, Qingshuihe county, Helin county, Dongsheng district, Zhungeer qi and Yinjinhuoluo qi. Three to 5 towns were selected in each qi(county, district) and 3 to 5 village primary schools were selected in each town.One hundred and twenty to 200 children aged 8 to 10 were selected in each school to inspect thyroid by B ultrasound and palpation and to test intelligence and urinary iodine. Two villages were selected in each town and 30 households were selected to determine urinary iodine of housewives and salt iodine. Results A total of 56 cases of suspected cases of endemic cretinism were found from the 11 counties but no case was confirmed. The goiter rate of children aged 8 to 10 was 5.2% (309/5922) by palpation and 4.3% (252/5922) by B-ultrasound. The median urinary iodine of children aged 8 to 10 was 241.5 μg/L, and urinary iodine was 100 to 300 μg/L, accounted 65.9%(3901/5920). Median urinary iodine of the 9 Qis(counties, districts) was in the range of 200 and 300μg/L.Higher than 5% of the 11 Qis(counties, districts) with urinary iodine lower than 50 μg/L was zero. Higher than 10% of the 11 Qis(counties, districts) with urinary iodine lower than 100 μg/L was 1. The median urinary iodine of housewives was 225.6 μg/L, and lower than 50 μg/L accounted for 2.2%(35/1597). Higher than 10% of the 11 Qis(counties, districts) with urinary iodine lower than 100 μg/L was 4. A total of 2109 households were investigated and 97.45%(2055/2109) of them ate iodized salt and 2.55%(54/2109) of them ate non-iodized salt. Conclusions In the 11 investigated counties, goiter rate of children has decreased to less than 10%, and no new cretin was found. It could be concluded that the fulfillment of prevention and control of IDD is effective. The iodine nutrition of children and women of childbearing age is in an adequate level. The coverage rate of iodized salt has maintained at a higher level, the sales network is sound, the salt price is reasonable and salt is easy to get and the children's intelligence is protected effectively. But, the health education about IDD is still weak, need to be reinforced.