|SCN News, Number 02 (UNSSCN, 1988, 12 p.)|
Iodine deficiency is generally associated with its most visible manifestation, goitre, an enlargement of the thyroid once regarded as a problem with few implications for general health. Recent field investigations have revealed, however, a broad spectrum of iodine deficiency disorders (or IDD) - mental and physiological effects which include stillbirths, congenital abnormalities and increased infant deaths. Concerned over estimates that some 800 million people in developing countries are at risk from these disorders, the ACC decided in October 1985 to accept the SCN proposal that priority attention should be given to prevention and control measures. In response, UN agencies, governments and NGOs have been asked to join and support a new ten-year programme aimed at eliminating cretinism and reducing goitre rates in vulnerable populations to below 10 percent before the turn of the century.
The programme, drawn up by WHO at SCNs request, was endorsed by the Sub-Committee at its annual session in March 1987. In presenting the programmes global strategy, WHO said iodine deficiency disorders were found mainly in areas where people consumed foods grown locally in soil depleted of its natural iodine content. IDD are most common in mountainous areas: the entire Andean chain is a major endemic region. More than 80 percent of the estimated 190 million people affected by goitre and cretinism are believed to live in Asia, with at least 40 million in Southeast Asia suffering mental and physical impairment. The disorder is also pronounced in at least 13 African countries. WHO said the spectrum of disorders ranged from abortion, stillbirth, increased infant and perinatal mortality, neurological cretinism to goitre and impaired mental functioning in adolescents and adults. However, undisputed evidence showed that IDD could be successfully and inexpensively prevented and controlled. Because the greatest risk from iodine deficiency was during brain development, the highest priority targets for preventive action were women of reproductive age, infants and school-age children.
Prevention and Control
Iodine supplementation has been shown to prevent goitre. The main approaches are the use of iodized salt and oil, fortification of foods, water and condiments, and distribution of iodine tablets. A single oral dose of iodized oil, for example, can correct severe iodine deficiency for three to five years, while an injection costing between $0.25 and $0.45 is believed to provide even longer protection. Salt iodization is less costly and carries less danger of toxicity than mass dose programmes, but also depends on efficient local level administration and, often, strong public education campaigns. In India, prevalence of goitre among those consuming fortified salt declined from 3 8 percent to 15 percent within five years, and fell to 3 percent after a decade. Researchers in Bolivia found that an iodized oil programme markedly reduced goitre after only two years and improved intellectual performance. In Central Java, Indonesia, large-scale injection campaigns are credited with having eliminated cretinism in new-born children.
The proposed ten-year programme will attempt to apply already extensive knowledge of IDD prevention through national prevention and control programmes supported technically and financially by the UN system and government and non-governmental bilateral agencies. While it will emphasize public health aspects of prevention, including the integration of national efforts into existing health system infrastructures, the programme will seek the active participation of such people as salt producers and traders, food processors and water distribution authorities. The programmes two main categories of activity are, first, situation assessment, motivation of authorities, development of action plans, training of personnel, public education, and development of educational materials; and, second, the provision of supplies (e.g. iodinated oil and potassium iodate), equipment and funding. WHO estimates the first group of activities to cost about $ 11 million a year during the first four years of the programme; the cost of salt iodization programmes and, on a smaller scale, iodine injections covering 800 million people is tentatively put at $42 million a year.
The SCN has formed an IDD Working Group with the task of monitoring the prevalence and severity of the deficiency, helping to mobilize international funding, and facilitating the launch of control programmes and monitoring their progress. The Working Group, which will report annually to the SCN, is linked to the International Council for the Control of Iodine Deficiency Disorders (ICCIDD), set up at a meeting in Kathmandu in March 1986. The council is composed of international experts, with representation from UNICEF, WHO and the World Bank, and is funded by UNICEF and Australia. In March 1987, the ICCIDD, UNICEF and WHO sponsored in Yaounde a Regional Seminar on Control of IDD in Africa attended by representatives from several African countries. After examining evidence that less was known about the extent of IDD in Africa than in any other major region, participants decided to set up a Task Force on IDD to be divided into three sub-regional groups.