Sustainable universal salt iodization in low-income countries - time to re-think strategies?

OBJECTIVE: Sustained iodine deficiency control requires sustainable mechanisms for iodine supplementation. We aim to describe the status of salt iodation machines, salt producers' experiences and quality of salt produced in Tanzania. METHODS: Qualitative and quantitative data was collected from the factory sites, observations were made on the status of UNICEF-supplied assisted-iodation machines and convenience samples of salt from 85 salt production facilities were analysed for iodine content. RESULTS: A total of 140 salt works visited had received 72 salt iodation machines in 1990s, but had largely abandoned them due to high running and maintenance costs. Locally devised simple technology was instead being used to iodate salt. High variability of salt iodine content was found and only 7% of samples fell within the required iodation range. CONCLUSION: Although iodine content at factory level is highly variable, overall iodine supply to the population has been deemed largely sufficient. The need for perpetual iodine fortification requires reassessment of salt iodation techniques and production-monitoring systems to ensure sustainability. The emerging local technologies need evaluation as alternative approaches for sustaining universal salt iodation in low-income countries with many small-scale salt producers.

Iodine deficiency persists in the Zanzibar Islands of Tanzania.

BACKGROUND: Iodine is an essential micronutrient for normal human growth and development. It is estimated that more than 1.6 billion people live in iodine-deficient environments, yet there are still some countries and areas where the prevalence of iodine-deficiency disorders is unknown. OBJECTIVE: To establish the prevalence of iodine-deficiency disorders in the Zanzibar Islands, a community assumed to have ready access to iodine-rich seafoods. METHODS: In a cross-sectional study, 11,967 schoolchildren were palpated for goiter prevalence, a subsample was evaluated for urinary iodine concentration, and the availability of iodated salt was assessed at the household and retail levels. RESULTS: The mean total goiter prevalence was 21.3% for Unguja and 32.0% for Pemba. The overall median urinary iodine concentration was 127.5 microg/L. For Unguja the median was 185.7 microg/L, a higher value than the median of 53.4 microg/L for Pemba (p < .01). The household availability of iodated salt was 63.5% in Unguja and 1.0% in Pemba. The community was not aware of the iodine-deficiency problem and had never heard of iodated salt. CONCLUSIONS: The inadequate intake of iodine documented in the Zanzibar Islands belies the common assumption that an island population with access to seafood is not at risk for iodine-deficiency disorders. We urge health planners to implement mandatory salt iodation and education efforts to alleviate the situation.