2011年全国碘缺乏病病情监测结果分析

National iodine deficiency disorders： an analysis of surveillance data in 2011

目的 了解全国碘缺乏病防治工作现状,评估我国31个省份及新疆生产建设兵团（简称兵团）持续消除碘缺乏病进展.方法 2011年,在我国的31个省份及兵团按人口比例概率抽样法进行抽样,每个省份及兵团各抽取30个抽样单位.在除外水碘含量＞ 150 μg/L的乡镇后,采用单纯随机抽样方法,从上述每个抽样单位中抽取1所小学,每个小学抽取40名8～ 10岁儿童,检测儿童甲状腺容积;在40名儿童中抽取12名儿童检测尿碘,并检测儿童家中食用盐盐碘及家庭人均日食盐摄入量.在小学校所在地附近选择3个乡（镇、街道）,每个乡（镇、街道）抽取5名孕妇和5名哺乳妇女,检测孕妇和哺乳妇女尿碘.在调查地所在村按东、西、南、北、中各抽取1份饮用水水样,如为集中式供水地区,则采集2份末梢水水样进行水碘测定.儿童甲状腺检查采用B超法,依据《地方性甲状腺肿诊断标准》判定;尿碘测定采用砷铈催化分光光度法（WS/T 107-2006）;水碘测定采用国家碘缺乏病参照实验室推荐方法;盐碘测定采用制盐工业通用试验方法（GB/T13025.7-1999）中的直接滴定法,川盐及其他强化食用盐采用仲裁法;儿童家庭人均日食盐摄入量采用3日称量法.判定标准：①尿碘：儿童尿碘＜ 100μg/L为碘不足,100～199 μg/L为碘适宜,200～299 μg/L为大于适宜量,≥300 μg/L为碘过量;②碘盐（GB 5461-2000）：合格碘盐含碘量为（35±15） mg/kg,＜5 mg/kg为非碘盐,5～＜ 20 mg/kg或＞50 mg/kg为不合格碘盐.采用全国第六次人口普查的总人口数对统计数据进行校正.结果 全国31个省份及兵团平均儿童甲状腺肿大率为2.4％,明显低于国家碘缺乏病消除标准（＜5％）.碘盐覆盖率为98.0％、合格碘盐食用率为95.3％,达到了国家碘缺乏病消除标准（≥95％、＞90％）.盐碘中位数为30.2 mg/kg.儿童、孕妇、哺乳妇女尿碘中位数分别为238.6、184.4、174.4 μg/L,其中儿童尿碘水平处于大于适宜量水平,孕妇、哺乳妇女在适宜量范围内.25个省份的水碘中位数为5.6 μg/L,23个省份及兵团人均日食盐摄入量为10.1 g.结论 我国以食盐加碘为主的碘缺乏病综合防治措施成效显著,在国家水平上处于消除碘缺乏病状态.

Objectives To understand current situation in national prevention and control of iodine deficiency disorders （IDD）,and to evaluate the progress in eliminating IDD in 31 provinces and Xinjiang Production and Construction Corps （Corps） in China.Methods In 2011,30 units were sampled in each of 31 provinces and Corps in China based on the sampling method of Probability Proportional to Size.After excluding townships of water iodine level higher than 150 μg/L,1 primary school was chosen in each unit,by the randomized sampling method,40 students in cach school were sampled for examining their thyroid volume,among them,12 students were tested for their urinary iodine level and for their household salt iodine level and per capital daily salt intake.Near the location of these primary schools,3 townships were chosen,5 pregnant women and 5 lactating women in each township were sampled to test their urinary iodine level.Besides,1 water sample was sampled according to the location in each village （east,west,south,north,and middle） in non-central water supplying villages,and 2 tap water samples in central water supplying villages.The ultrasound was used to detect goiter size according to the diagnostic criteria for endemic goiter; As3＋-Ce4＋ catalytic spectrophotometry using ammonium per sulfate digestion （WS/T 107-2006） was used to test the urinary iodine level; the testing method recommended by the National Iodine Deficiency Disorders Reference Lab was applied to test the water iodine level,the direct titration method among the generic methods of iodide testing for salt production industry （GB/T 13025.7-1999） was used to determine the salt iodine level; and the arbitration method was adopted for quantitative determination in case of well salt or special salts and the salt intake was estimated based on three-day weighed food record.Evaluation standards are as follows：urinary iodine level of children：deficient is the median of urinary iodine （MUI） less than 100 μg/L,adequate is MUI at 100-199 μg/L,more than adequate is MUI at 200-299 μg/L,and excessive is MUI equal to or greater than 300 μg/L;salt iodine：definition of qualified iodized salt is （35-± 15） mg/kg; non-iodized salt （GB 5461-2000） is iodine less than 5 mg/kg; definition of unqualified iodized salt is iodine between 5-＜ 20 mg/kg or higher than 50 mg/kg.The total population of the sixth national census was used for statistical data correction.Results Among 31 provinces and Corps,children＇s goiter rate was 2.4％,which was obviously lower than the IDD elimination standard at the national level （＜ 5％）; the national iodized salt coverage rate was 98.0％ and the consumption rate of qualified iodized salt was 95.3％,both figures had achieved the national standard （the iodized salt coverage should be greater than 95％ and the consumption rate of qualified iodized salt greater than 90％）.The median of salt iodine was at 30.2 mg/kg; the MUI of children,pregnant women and lactating women was 238.6,184.4 and 174.4 μg/L,respectively.Urinary iodine of children was higher than adequate level,of both pregnant women and lactating women were at adequate level.The surveillance results of water iodine in 25 provinces revealed that the median was at 5.6 μg/L; the salt intake surveillance results among students＇ households in 24 provinces and the Corps revealed that the daily intake was 10.1 g per person a day.Conclusions National IDD prevention and control strategy integrated with universal salt iodization as a key measure has achieved remarkable impacts.IDD has been eliminated at the national level.