Persistence of iodine deficiency 25 years after initial correction effortsin the Khumbu region of Nepal

Aims. To assess the current status of, and understanding about iodine defic iency disorders among Sherpa residents of the Kbumbu region of Nepal, 25 ye ars after the introduction of iodised oil injections. Methods. Several groups of Khumbu Sherpas were studied and goitre rate, uri nary iodine level and cretinism prevalence were measured as indicators of i odine deficiency. Subjects were also questioned in detail about their food consumption, with particular reference to salt use, and about their underst anding of the causes and treatment of iodine deficiency disorders. Results. The prevalences of goitre, deaf-mutism and cretinism were 21%, 1.3 % and 0.5% respectively (compared to 92%, 4.7% and 5.9% in 1966). No cretin s had been born since 1966. The median urine iodine concentration was 35 mu g/L. Most people preferred uniodised Tibetan rock salt, although 44% regul arly consumed iodised salt. All granulated salt tested from the local marke t contained adequate amounts of iodine. Only 11% of those surveyed knew tha t goitre was caused by iodine deficiency Conclusions. Although prevalences of iodine deficiency disorders are much l ess than 30 years ago, iodine deficiency continues to be a major problem in Khumbu and demands a clear control strategy, combining ongoing iodine supp lementation and education. Iodised salt is usually the best approach to con trol of iodine deficiency disorders for most regions of the world but the K humbu experience shows that local cultural and commercial factors can sever ely limit its impact. To be successful, control programme for iodine defici ency disorders also needs assessment of the salt trade, monitoring, educati on and occasional targeted interventions with iodised oil or other suppleme nts.