The aetiology, prevention and treatment of simple goitre.

Introduction Simple goitre has afflicted mankind since the earliest times. It was known to the Chinese about 1500 B.C., to the ancient Greeks and to the Romans. Humbolt, in I824, observed it among the natives of the Andes and Livingstone among those of Central Africa. Two thousand years ago sea salt was known to be beneficial and burnt sea sponge was a remedy in use from the times of the ancient Greeks to the early part of the igth century. Unknown to the users, these substances are rich in iodine. The distribution of simple goitre is world-wide. It occurs in all races, in all climates and at all inhabitable altitudes. It arises sporadically, occasionally in epidemics and in certain areas it is endemic. While most of the endemic districts are mountainous, there are numerous exceptions. Goitre is rare in Iceland, in the main islands of Japan, amongst the Esquimaux and usually along the sea coast, the reason being that in these districts the diet of the inhabitants consists largely of sea food which is rich in iodine. The goitre areas of the world are shown in Fig. I: those readers who require fuller information on the prevalence and geographical distribution of endemic goitre should consult the excellent and exhaustive review of the subject by Kelly and Snedden.14 The number of goitrous people in the world is unknown, but the total is not far short of 200 million.14 In large areas endemic goitre is associated with cretinism, myxoedema, deaf-mutism, sterility, mental deficiency and physical incapacity and it also predisposes to cancer of the thyroid gland. The disease is thus a major problem of public health, but in those countries enjoying a rising standard of living and possessing an enlightened outlook concerning hygienic living conditions and the prophylactic use of iodized salt the incidence has substantially declined during the past 30 years.