A comparative epidemiological and anthropometric survey was conducted among Ibans, the largest indigenous ethnic group in Sarawak, in three regions where the endemicity of goitre exhibited marked differences , to assess the effect of endemic goitre on somatic growth. In the Ai river region the prevalence of goitre was 99.5%; 35% having grade 3 goitres, 55% grade 2 goitres and 9.5% grade 1 goitres. At Rubu the prevalence of endemic goitre was 74%; 3% having grade 3 goitre, 16% grade 2 goitre and 55% grade 1 goitre. In the Bajong region relatively few people were detected with goitre and most of these had migrated from other regions. Neurological cretinism was estimated at 3.6% in the severely goitrous Ai river population but was not detected in the other regions. Anthropometric data obtained from the three adult populations did not reveal any statistically significant differences in the following parameters: weight, height, weight/height ratio, height/sitting height ratios, head circumference, scapular skinfold thickness and left mid arm muscle circumference. The haemoglobin, serum total protein and serum albumin concentrations were similar in the three populations. It is concluded that endemic goitre occurs with a frequency of close to 100% in certain Iban populations which represents one of the highest incidences of endemic goitre in the world. Neurological cretinism is common in this population. Our observations suggest that body proportions and somatic growth do not vary among similar ethnic populations exhibiting greatly different endemicity of goitre. Although no iodine balance studies were performed, assessment of diets suggested that iodine deficiency is a significant contributory factor in the development of endemic goitre in Sarawak. Urgent attention to iodine supplementation is indicated to prevent the development of endemic goitre and neurological cretinism.
Four areas of differing remoteness were studied to determine the prevalence of goitre in the Keningau Division of Sabah. These areas were Keningau town, the Biah Resettlement Scheme, the Dalit subdistrict and the Pagalunggan subdistrict. The predominant ethnic group in these areas is the Murut. The overall endemicity of goitre for the study population was 76.5% for females aged 15 years and above. There was a significant correlation between the incidence of goitre and the remoteness of an area. The Dalit subdistrict has the highest incidence of goitre (82.6%) followed by the Pagalunggan subdistrict (77.8%), the majority of these goitre cases being classified as grade 2 (visible goitres). These were the two most remote areas in the study. In contrast, Keningau town, the least remote area has the lowest incidence of goitre (62.5%) with most of the goitres being relatively small. With regards to salt usage in the Dalit subdistrict, only 3.0% used iodised salt; 28.0% used fine salt; 3.6% used coarse salt and 65.5% used both fine and coarse salt. In the Pagalunggan subdistrict, all females used uniodised salt with 17.6% using fine salt, 20% using coarse salt and the remainder using both fine and coarse salt. As yet, there is no legislation for the iodisation of salt in Sabah. It is clear that all types of salt need to be iodised and adequately distributed to deprived areas, particularly inland areas.