China : leading the way in sustained IDD elimination

s 20 ICCIDD GLOBAL NETWORK IDDNEWSLETTER VOLUME 42 NUMBER 2 MAY 2014 China: leading the way in sustained IDD elimination 2 IDD NEWSLETTER MAY 2014 CHINA Program management and implementation – past and present Since its inception, China’s salt iodization program has been one of the most successful in the world (Box 1). The national standards for the production, wholesale, and inspection of salt and iodized salt have been defined in a series of regulatory documents on edible salt monopoly, iodine content, and production/wholesale quality management. Only designated salt producers may iodize salt if they are judged to meet these standards. Stringent internal and external quality assurance testing is undertaken at both the production and wholesale levels. As a result, almost all salt is iodized, except in areas with high levels of iodine in the drinking water, where policy requires that non-iodized salt be provided. The IDD Elimination Program is supported by the Chinese Surveillance System of Iodine Deficiency Disorders (CSSIDD), a broad-based system of complementary mechanisms to evaluate and monitor (i) the quality of salt throughout production and at the wholesale and retail levels, (ii) the household coverage of adequately iodized salt at the sub-national and national levels, Box 1 : Key factors contributing to China’s success • High and sustained levels of political commitment and leadership, including sufficient funding and prioritization of IDD elimination on the social and economic development agenda • Multisectoral cooperation • National monopoly that prohibits sale of non-iodized edible salt and relevant systems for law enforcement, plus substantial investment in the salt industry, and industry commitment to iodization • Strategic support to high-risk areas • Frequent, well-coordinated, and highquality surveillance and quality assurance that provides accurate information on the IDD situation and the impact of the program. Together they form the basis for policy development, guide program implementation, and enable modification • Consolidation of achievements for sustained IDD elimination and (iii) the population’s iodine status at the sub-national and national levels. The health-associated aspects of salt iodization (household coverage of iodized salt and iodine status in the population) are monitored under a trial National IDD Surveillance Plan that is currently being implemented. The four components of the plan include: 1. National salt monitoring – Coverage at household level is evaluated annually to identify regions that may be at high risk of lower coverage, but also to monitor the coverage of non-iodized salt in iodine excess areas (with high levels of iodine in water). 2. National IDD Survey – Carried out every 2 to 5 years, it evaluates the population’s iodine status based on three indicators: children’s urinary iodine excretion, household iodized salt coverage, and thyroid volume (goiter). Pregnant women were included in the survey for the first time in 2011, and the next survey is due in 2014. Karen Codling Regional Coordinator for Southeast Asia and the Pacific, ICCIDD Global Network and USI Consultant, UNICEF; Zupei Chen ICCIDD Global Network Board Director and Chairman of the National IDD Advisory Committee; Shen Hongmei Executive Director of the Center for Endemic Disease Control, National Health and Family Planning Commission; Mu Li ICCIDD Global Network Board Director, School of Public Health, The University of Sydney; Yunyou Gu Director of the National Reference IDD Laboratory, National Health and Family Planning Commission; Zhen Xin Lu Country Director, GAIN China; Chang Suying Nutrition Specialist, UNICEF China In the early 1990s, over 700 million people in China were iodine deficient. In 1993, China adopted salt iodization as its principal control strategy. By 2000, USI had virtually eliminated IDD. This review celebrates this remarkable achievement and describes how the program is adapting to the ‘changing landscape’ of iodine nutrition, to ensure sustainability. IDD NEWSLETTER MAY 2014 CHINA 3 3. High-risk area monitoring – It was added to the CSSIDD in 2008. Its objective is to monitor iodine levels and IDD epidemic situations in regions where iodized salt coverage is below 80% and where cases of endemic cretinism have been recorded. If necessary, remedial actions can follow quickly, including emergency supplementation with iodized oil capsules and free distribution of iodized salt to populations at risk. 4. IDD Laboratory Quality Control Network – Implemented by the National Reference Laboratory (NRL), the network aims to standardize the operating procedures and test the proficiency of laboratory technicians to ensure that all laboratories responsible for testing urinary and salt iodine levels provide scientific and reliable data. Their certification is renewed annually. In addition to the above, the Endemic Disease Control Center and the Institute of Nutrition and Food Safety of the Chinese Center for Disease Control and Prevention have undertaken a number of special investigations or studies of specific issues to provide supplementary information to the surveillance system: • In 2005, an investigation of iodine excess identified 109 counties in 9 provinces as being high water iodine areas. Regions with iodine excess lie in the former flood plain of the Yellow River, and are often ‘embedded’ in areas with inadequate or deficient water levels of iodine. This investigation was later used to formulate a national strategy on IDD prevention and control in high iodine areas. • In 2007, a survey of high-risk areas identified 40 counties as high risk, with 249 new cases of cretinism, and a prevalence of goiter >5%. In all cases, the cause of iodine deficiency was access to raw salt (from local salt lakes and salt deposits). Easy access makes law enforcement and prevention of illegal salt entering the market more difficult. • A survey of four coastal provinces in 2009 investigated whether their populations were consuming excessive iodine through a combination of iodized salt and seafood. Contrary to expectations, iodized salt was the main source of dietary iodine, and iodine nutrition was found to be adequate in general, with some women showing borderline or mild deficiency. This analysis contributed to a peer-reviewed study investigating the variability of iodine intake across China, published in 2012 (1). • From 2011 to 2012, a study project evaluated the status of interventions in high water iodine areas with the aim of making recommendations for an updated ‘prevention and control strategy’ in high water iodine areas (2). Sustaining the achievements at national and sub-national level The National Plan for the Control and Prevention of Key Endemic Diseases has foreseen several phases of IDD Elimination. Based on the global WHO/UNICEF/ ICCIDD indicators (3), the target of sustained elimination of IDD has been met: national coverage with adequately iodized salt has been sustained above 90% since 2005, and the MUIC of school-age children is currently >100 μg/L (Figure 1). There are no provinces with a median UIC below the deficiency threshold of 100 μg/L, and the goiter rate (measured by ultrasound) has fallen steadily over the years and currently stands at 2.4%. Despite its tremendous success at national level, the evaluation of the program in 2010 concluded that discrepancies in iodine nutrition still persist across the regions. Therefore, the objectives of the ongoing phase (2011– 2015) are as follows: F IGURE 1 Regular monitoring and adjustment of salt iodine content ensures adequate iodine intakes in children in China. Data: Q Ming, ICCIDD GN Regional Coordinator for China and East Asia