Influence of adjustment of universal salt iodization strategy on iodine deficiency disorders epidemic trend in Shanxi Province

Abstract

Objective To analyze the effect of adjustments of control strategy on epidemic trend of iodine deficiency disorders(IDD) in Shanxi Province after universal salt iodization(USI), and to provide basis for timely adopting targeted control countermeasure and scientifically adjusting intervention strategy. Methods A method of retrospective analysis was performed to collect data from IDD surveillance at national or province levels after 1995, and from iodized salt surveillance of the province after 2004. According to the statistics and analysis of children's goiter rate, median urinary, median and mean of salt iodine, coverage rate of iodized salt, qualified rate of iodized salt, consumption rate of qualified iodized salt and their relationship. Results Since 1995, the children's goiter rate by palpation and B-ultrasound showed a steady descending trend. The median salt iodine, mean salt iodine and children's median urinary iodine showed a trend of rise→decline→stable→decline. Namely: The three indicators began to rise year by year from 1995 (29.1 mg/kg, 31.7 ± 15.0 mg/kg, 199.3 μg/L), in 1999 (48.7 mg/kg, 53.4 ± 29.4 mg/kg, 407.5 μg/L) reached its climax; and then decreased, in 2001 (34.7 mg/kg, 36.2 ± 11.9 mg/kg, 282.1 μg/L) stoped; which were basically stable from 2001 to 2011; since 2013 (26.0 mg/kg, 26.5 ± 6.3 mg/kg, 192.0 μg/L), a significant decline began. The rate and edible rate of qualified iodized salt showed a trend of decline→rise→stable. Two indexes began to decline circuitously from 1995 (72.61%, 68.25%), and dipped to a low point in 1999 (44.80%, 43.67%); then began to rise, until 2002 (94.73%, 91.80%) reached basic stability; and remained steady from 2002 to 2013. Conclusions Following the process of prevention and treatment of IDD for more than 30 years in Shanxi Province, with the depth understanding of the range of adequate iodine nutrition, according to the monitoring-feedback mechanism, the strategy of salt iodization has been adjusted several times, the target of continuous elimination of IDD has achieved since 2000 and the levels of iodine nutrition in population are more reasonable. Salt iodization strategy should continue to adhere to. Key words: Iodine; Deficiency disorders; Epidemiology; Analysis