我国碘缺乏病高危地区重点调查结果分析

目的 调查我国碘缺乏病高危地区新发地方性克汀病(地克病)和地方性甲状腺肿(地甲肿)的流行现况,了解高危地区碘盐覆盖率较低的原因,有针对性地提出防治对策.方法 以县为单位,在西藏、青海、新疆、甘肃、宁夏、四川、海南、重庆、云南、广西、内蒙古11个省份的碘盐监测盲区(高危县)采取单纯随机抽样方法选择调查乡,在其他高危县按照典型调查原则以乡为单位选取调查点,进行10岁以下新发地克病病例搜索;对8～10岁儿童采用B超法检测甲状腺大小,采用中国瑞文测验(农村修订版)检测智商;对育龄妇女开展人户调查和采集家中盐样,盐碘测定采用半定量法,统计居民户碘盐覆盖率;采集8～10岁儿童和育龄妇女尿样,尿碘测定采用砷铈催化分光光度法;全部结果采用Epi Iinfo 6.0软件进行分析.结果 在101个高危县中搜索出地克病线索病例4122人,其中确诊地克病249例.儿童甲状腺肿大(甲肿)率为8.28%(4434/53 541),44个县儿童甲肿率在5%～20%,5个县儿童甲肿率在>20%～30%,3个县儿童甲肿率>30%.儿童智商均值为85.44,智商<70的儿童占16.52%(8713/52 745).儿童尿碘中位数为154.69;μg/L、尿碘<50μg/L的比例为17.26%(9069/52 558),有25个县的儿童尿碘中位数<100μg/L;育龄妇女尿碘中位数为107.14μg/L、尿碘<50μg/L的比例为27.50%(3722/13 534),有46个县家庭主妇尿碘中位数<100μg/L.居民户的碘盐覆盖率为77.85%(13 150/16 891),西藏、海南、青海碘盐覆盖率较低,分别为52.80%(1585/3002)、44.72%(631/1411)、72.82%(1850/2506).西藏、四川、海南、甘肃、青海居民户中>10%的人认为购买碘盐不方便,有71.39%(7652/10 719)的家庭食用土盐,土盐每公斤的平均价格(0.30～1.20元)低于碘盐(1.20～3.00元).结论 碘缺乏病高危地区存在发生地克病和地甲肿的危险,应在这些地区开展碘缺乏病监测,降低碘盐价格,提高碘盐覆盖率,对特需人群要尽快实施应急补碘,建立消除碘缺乏病的长效机制.

Analysis of field survey results for iodine deficiency disorders in high-risk areas of China

Objective To investigate the occurrence of new cretinism cases and the prevalence of endemic goiter, and the reason of lower coverage rate of iodized salt in the iodine deficiency disorders(IDD) high-risk areas of China, so as to put forward target prevention measures for these areas. Methods A hundred and one counties from 11 provinces(autonomous regions, municipality), such as Tibet, Qinghai, Xinjiang, Gansu, Ningxia, Sichuan, Hainan, Chongqing, Yunnan, Guangxi, Inner Mongolia, were chosen into the survey by simple random sampling. In the counties of high risk, typical sampling principle was used. In the selected townships, searching for new cretinism cases were carried out in the children under 10 years old, the thyroid volume of children aged 8-10 years old were determined by B-ultrasonography methods and their urinary iodine (UI) were determined by As3-Ce<'4+> catalytic spectrophotometry, the intelligence quotient(IQ) values of children aged 8-10 years old were measured by the combined Raven Test in China. In the household survey, the housewives were asked to fill in the questionnaire, the iodized salt coverage rates and the UI levels of child-bearing age women were investigated, the salt iodine content was determined using self-quantitative kit. Epi Info software was used to analyze the determination results. Results In the 101 high-risk counties, 249 were diagnosed as new cretinism cases from 4122 suspected cases searched. The goiter rate of children aged 8-10 years old by B-ultrasound was 8.28% (4434/53 541), 44 counties had goiter rates in the range of 5%-20%, 5 counties had goiter rates in the range of 20%-30%, and 3 counties had goiter rates of 30%. The mean IQ of children was 85.44, and the percentage of IQ value less than 70 was 16.52%(8713/52 745). The median urinary iodine(MUI) of children was 154.69 μg/L, the percentage of UI less than 50 μg/L was 17.26% (9069/52 558). Twenty-five counties had a MUI of children less than 100 μg/L. The MUI of housewives was 107.14 μg/L, the percentage of UI less than 50 μg/L was 27.50% (3722/13 534). MUI of housewives in 46 counties were less than 100.0 μg/L. The coverage rate of iodized salt at household level was 77.85%(13 150/16 891). The coverage rate of iodized salt was 52.80%(1585/3002), 44.72% (631/1411) and 72.82% (1850/2506) in Tibet, Hainan and Qinghai, respectively. More than 10% residents of Tibet, Sichuan, Hainan, Gansu and Qinghai complained that iodized salt was not convenient to buy. There were 71.39%(7652/10 719) of observed people ate crude salt. The average price of crude salt price(0.30-1.20 Yuan/kg) was lower than iodized salt(1.20-3.00 Yuan/kg). Conclusions In these IDD high-risk areas, the risk of endemic goiter and cretinism prevalence is threatening. The IDD monitoring should be carried out successively in these high-risk areas. The prevention measures, increasing iodized salt coverage rate and establishing the sustainable mechanism for eliminating IDD should be strengthened. Emergent iodine fortification measure for high risk region people should be implemented as soon as possible, a long term effective mechanism of eliminating IDD should be established.