Goiter rate prevalence

In mild and moderate ID, the prevalence rate of circulating thyroid autoantibodies in the population is also high (Laurberg et ai, 1998 Pedersen et aL, 2003). In such areas, non toxic and toxic multinodular goiters are prevalent and overall hyperthyroidism is more common than hypothyroidism (Laurberg et ai, 1999). Results from areas with severe ID are fimited and might, in some cases, be influenced by the general immunosuppressive effect of malnutrition, which may occur simultaneously (Salabe et al., 1982). 

Surveys on goiter in schoolchildren and on the iodine content of drinking water were conducted for the first time in four representative counties, namely, Houghton, Wexford, Midland and McComb. The prevalence of goiter was 38.6% among the 65537 school children studied. Salt containing potassium iodide (1 part in 5000) was introduced, and by 1929 the prevalence rate was reduced to 9% (Kimball, 1937). Brush and Airland (1952) conducted follow-up surveys on 53785 subjects in the same counties and found only 1.4% goiter prevalence. 

AP is still required because of its fast impact, especially at lower rates of goiter prevalence. 

Suzuki and Mashimo (1973) Observational study Japan Association of increased goiter rates with higher consumption of kelp in coastal districts compared with an inland city decrease in goiter prevalence following reduction in kelp intake... 

It was neither necessary nor feasible to monitor goiter incidence continuously. This was to be evaluated by repeated investigations of cohorts (the DanThyr Cohort Study), including the iodine status of the population as to intake of an iodine-rich diet and supplements, the prevalence rate of subclinical thyroid disease, and possible confounding factors that might influence the occurrence of thyroid abnormalities independent of iodine intake. 

Since the iodization of salt, there has been an increase in the daily consumption of iodine among the population, leading to a decrease in the prevalence of iodine deficiency disorders. In a survey (Toteja et ai, 2004) carried out on 1 45 264 children aged 6—12 years in 15 districts in India in 1997—2000, the goiter rate was found to have decreased to 4.78% as compared to a previous report of 21% in 1984—1986 (IGMR, 1989). Follow-up surveys carried out in the same region of the country over the period have shown a decrease in the prevalence of goiter over the years, as exemphfied by data from the National Capital Territory of Delhi (Table 87.1). 

However, despite the decrease in the overall goiter rate in India, the prevalence of goiter, albeit at a lower rate, continues. This partial persistence of goiter in the country and its possible causes have been discussed elsewhere in this book. These may include incomplete correction of iodine deficiency, ingestion of goitrogens, or the presence of autoimmune thyroid disease. 

Note Decrease in the prevalence of goiter rate in the National Capital Territory of Delhi after salt iodization. Source Pandav etal., (1980) Sharmaeta/., (1988) Pandavef a/., (1996) Kapil etal., (2004) Gopalakrishnan etal., (2006). 

The presence of goiter in Italy has been known since the ancient Roman Age. In recent years, several surveys have shown high rates of the prevalence of goiter and low urinary iodine excretion. Active prophylaxis has been very hmited (Aghini-Lombardi et ai, 1998). Before 2005, prophylaxis with iodized salt in the country was performed on a voluntary basis. For this reason, iodized salt consumption in Italy still accounted for approximately 3%... 

The Department of Health of the Ministry of Public Health is the main office responsible for implementing intervention programs on IDD alleviation. The pilot project for salt iodization was first launched in 1965 in one of the northern districts where the prevalence of goiter rate had been very high. Later in 1968, the salt iodization program was expanded to all affected areas in the country (Figure 126.3). 

Mali is a landlocked country in West Africa, and is one of the poorest countries in the world. Iodine deficiency disorders (IDD) have been prevalent in several areas of the country, especially in the southern part. This chapter provides a historic overview of the changes in IDD over time, and of the various strategies that have been implemented to combat IDD. While the national total goiter rate was estimated to be 30% in 1974, a nationwide survey in 2005 found a total goiter rate of 8%, with 88% of the households using iodized salt. The latest figures indicate that Mali still suffers from iodine deficiency, and that efforts must continue in order to reach the goal of universal salt iodization. 

While goiter rates also decline with iodine supplementation, several reports suggest the persistence of endemic prevalence of goiter several years after iodine supplementation. The exact cause for this has yet to be elucidated although an increase in thyroid autoimmunity and the influence of other environmental goitrogens remain possible explanations. 

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