Tanzania national survey on iodine deficiency: impact after twelve years of salt iodation.

Background: In many low-income countries, children are at high risk of iodine deficiency disorders, including brain damage. In the early 1990s, Tanzania, a country that previously suffered from moderate to severe iodine deficiency, adopted universal salt iodation (USI) as an intervention strategy, but its impact remained unknown.

Methods: We report on the first national survey in mainland Tanzania, conducted in 2004 to assess the extent to which iodated salt was used and its apparent impact on the total goitre prevalence (TGP) and urinary iodine concentrations (UIC) among the schoolchildren after USI was initiated.

Remaining challenges in Tanzania's efforts to eliminate iodine deficiency.

Objective: To determine iodine levels in salt and iodine deficiency prevalence in school-aged children in 16 districts in Tanzania with previous severe iodine deficiency.

Design: A cross-sectional study in schoolchildren. Systematic probability sampling was used to select schools and subjects for goitre assessment and urinary iodine determination.