Abstract
An assessment of the severity of iodine-deficiency disorders and of the iodized salt programme in Laos was undertaken in 1996 through a field study among 957 schoolchildren in seven schools of different regions in Laos. Urinary iodine concentrations in 225 samples were remarkably lower in schools from the north than in those from the south, a finding similar to that from a national survey in 1993. However, in 1996 the median concentrations of urinary iodine were much higher than in 1993:85 versus 5 μg/L in the northern sites and 195 versus 22 μg/L in the southern sites. the prevalence of consumption of iodized salt, introduced only six months to one year before, had increased from 69% to 91%, levels that could explain the nearly normal and normal urinary iodine concentrations. the wide range of mild to very severe iodine-deficiency disorders found by palpation of goitre most likely reflected a delay in the regression of the thyroid gland due to the rather recent introduction of iodized salt and due to the varying severity of iodine-deficiency disorders in the different sites before the start of the programme. in one of the six salt production plants with moderate capacity in Laos, the consistency of the salt-iodization process was checked and found to be good. the iodine concentration was 15 to 45 ppm in 90% of the salt lots sampled, as compared with the criterion of 30 ppm. At consumption 82% of the salt samples were also found to be adequately iodized, with an iodine concentration of 15 ppm or more. These data reflect the initial success of the iodized salt programme in Laos, but they also emphasize the need for an evaluation of the iodine-deficiency disorder situation in different demographic and social settings, as well as for the systematic monitoring of the iodized salt programme at the production, distribution, and consumption levels, accompanied by sufficient social marketing to maintain attention on this public health problem.