GOITRE IN N.Z.

Press, Volume LXI, Issue 18415, 23 June 1925, Page 5

GOITRE IN N.Z.

ITS PREVENTION AND CURE. A VALUABLE REPORT. j USE OF lODISED SALT j RECOMMENDED. Tlic Health Department has received a valuable report on "Endemic Goitre in New Zealand" from Professor Hercus, with whom have been associated in this enquiry Professor W. N. Benson, Professor of Geology-, and Mr C. L. Carter, Lecturer on Chemistry. Research Programme. Other questions in regard to which medical research, is under way arc:— 1. An investigation into infantile paralysis—its origin, mode of spread, and measures which may be taken for its control. It will be remembered that, the Government reeeutly set aside a sum of £2OOO for this purpose, and that Dr. Hector, late pathologist of the Wellington Hospital, was appointed to undertake the work at the Ot.igo University Medical School, in conjunction with Professor Hercus. 2. The Government has authorised Dr. Renfrew White, Orthopoedic Specialist, Dunedin Hospital, to conduct an enquiry into rheumatoid arthritis and allied conditions, and has made him a grant for this purpose. 3. Arrangements are now in train for the commencement of an investigation into the cancer problem. A bequest of £IOO was recently made to the Wellington Hospital Board. The latter body has agreed to hand over this sum to the Health Department on the undertaking that it carries a subsidy of at least £ for £. This will finance a year's enquiry at the Otago Medical School into the cancer problem. The Health Department holds that the Otago Medical School is the obvious authority which should be entrusted with these investigations, on account of the fact that it is specially equipped and staffed for dealing with medical research problems of this nature. An Authority. Dr. E. McCarrison, who was in charge of the Deficiency Diseases Enquiry in England, and who is probably the most eminent British authority on the subject of goitre, in concluding a lecture on "Simple Goitre," recently said: — "I have been prompted to write this brief outline of our present knowledge of the causes of goitre, because this knowledge is now sufficiently definite to enable us to prevent and to cure this condition. The prevention of goitre is a matter of attention to food and water supply, to individual and to general hygienic conditions of life, and to the various needs of the body for iodine." As indicating the prevalence of goitre in New Zealand, it may be mentioned that the routine school medical inspection for 1924 shows that out of a total of 55,000 children examined goitre (of different degree) existed in 18.33 per cent., made up as follows: —Incipient, 12.53 per cent.; small, 5 per cent, medium, 7 per cent.; large, 11 per cent. Following is. in part the report of Professor Hercus and his associates: — New Zealand Health Advantages. The climatic advantages of New Zealand are accompanied by a relatively liigh standard of gcueral sanitation and of personal hygiene. Thero is a well-organised and active Department of Health, with Divisions of Public Hygiene, Infant Welfare, School Hygiene, Maori Hygiene, Dental Hygiene, and Pood and Drugs. These agencies combine to produce a reasonably satisfactory standard of\ general health, as is shown by such delicate indices as the infantile mortality rate (41.89), the typhoid morbidity Tate (.41), and the crude death rate (8.77) . . . . The high avorage health in New Zealand makes all the more noteworthy the presence of endoinic goitre t > marked extent among both the Maori and European population. It was only after an absence of, over five years from his native soil of Canterbury that one of us (Professor Hercus) realised the extent of its endemic goitre and endeavoured to determine with some degree of accuracy its incidence. This work was extended throughout tho country, and led to the chemical and geological studies which are here presented. Situation Demands Attention. The situation revealed by these studios is not of academic interest merely, but is of such significence to the Stat? as to demand attention. The experience of Switzerland and other countries where goitro had long been prevalent is too definite to be ignored. Endemic goitre is undoubtedly "the steppingstone "to cretinism, and already an occasional case of cretinism has occurrel in New Zealand in areas of high endeinicity. Other pathological conditions related to the thyroid gland, such as goitres clinically called "toxic" and mild degrees of myxodoema also occur to a moderate" degreo in the country; and all these conditions being so closely related would eventually respond to the same preventive measures. School Children: 31 Per Cent. Affected. As a result of flie studies here presented, we have established the fact that goitre is widely prevalent in Ne.w Zealand (31 per cent, of the' school children are affected by it), and that its incidence is in general roughly inversely proportional to the average amount of iodine in the soil, which determines tho amount, of iodine in the plant and animal food consumed by tho population of the district. Where exceptions t»> tliis occur, it has been shown that the required iodine is supplied in drinking rather than in foods. It may bo worthy of note that the majority of tho analyses were made bo • fore the sources of the samples were disclosed or ,the regional incidence of goi'ie ascertained. Any uuconseiou? bias on the part of the analysts his thus been practically eliminated. Causation of the Disease. This leads us to infer that so far as this country is concerned the most important factor in the causation of tho disease is an .iodine intake below the safety limit. We conclude', therefore, that in districts where the disease is endemic and where the soils and food have been shown to be deficient in iodine, the iodine should be supplied by adding minute quantities of the element to some widely-used article of diet. Evidence of the value and the harmle'ssness of this procedure is advanced in a discussion of prophylactic measures that are being investigated. Tho ""amount of iodine in the soil is the determining factor. Arising also from these studies is the question of the distribution of iodine in tho soils and waters in relation to the geological formations from which they are derived, and also the question ■ of the source of iodine in these formai tions. j Acknowledgments. I The chemical work has been subsi- , dised by a grant of £2OO from the Department of Health. For this grant and for many courtesies, we are indebt-

!ed to Sir Maui Pomare, Minister or Health, and to Dr. T. H. A. Valintine, Director-General of Health. To tlio officers of tlio School Medical Servico Ave are deeply indebted for the assistance given jn determining tl-e goitre incidence in the various districts. We would like to mention particularly the Director, Dr. Ada Paterson; Dr. Eleanor Baker, who assisted in the original survey in Canterbury, and has controlled the' Prophylactic work: and Dr. R. J. R. Maeredy, especially for his studies in the Otago and Auckland provinces. To our colleagues, Dr. Drennan and Dr. Carmalt Jones, Professors of Pathology and Medicine respectively, we are indebted for much helpful information and criticism. "Wo _ have also received the greatest assistance from the various medical officers of health, and others (whose names are mentioned 1 ). It is always a matter of difficulty to determine the exact incidence of a disease in n community. Endemic goitre is no exception, in spite of the comparative ease of diagnosis. Factors of age and sex, of diet and infection, of race aud exact locality, all combine to complicate the task. Military Recruits Rejected. The first figures indicating the distribution of endemic goitre in New Zealand were supplied from the returns of recruits examined by military medical boards during a period when conscription was in operation, from November, 191G, to November, 1018. These figures can lie regarded as a rough index only, confined as they were to an examination of males between the ages of 20 and 45, and to goitres sufficiently marked to render the recruits unfit for active service. One hundred and thirty-five thousand two hundred and eighty-two men were examined, and of these lijSl were declared unfit for active service on account of thyroid enlargement. Sixty-three per cent, of these rejects came from the Canterbury military district, Otago coming next with 19 per cent. In April, 1920, one of us, assisted by Dr. Eleanor Baker, of the School Medical Service, set out to establish accurately tho extent to which thyroid enlargement prevailed amongst tho school children of Canterbury and Wcstlaud. The majority of the children examined were in tho age group of five to fourteen years. Results Summarised. The results may bo summarised as follows: —14,916 children examined, 39 per cent, were found to have normal, and 61 per cent, enlarged, thyroids. .... Goitre was also found in many species of animals in the district. An account is also given of an extension of the survey of goitre throughout New Zealand, including the Maoris in the Urewera Country. Approximately, 18 per cent, of the Maoris there were found to bo affected. Chapters follow giving detailed results of examinations of: (1) "The iodine in soils, waters, fertilisers, and commercial salt in New Zealand.'' (2) "Previous investigations of the_ distribution of iodine in rocks, minerals, soils, and water," etc. Amount of lodine in Soil. In order to ascertain if possible the geographical factors (including the geological) influencing the incidence of goitre, we have divided the country into 33 districts of varying size, each more or less uniform in regard to its geographical conditions, and have determined the average amount of iodine in a representative series of soils from each. In each district also has been determined the average incidence _ of goitre as determined by the examination of school children by the State medical officers. Incidence of Goitre in School Children in Relation to Amount of lodine in the Boil. Percentage Crudo Incidenco Average of of lodine

Deficiency of lodine. "Finally wo come to the hypothesis that the disease is primarily due to deficient iodine- intake. There is no more fascinating cnnpocr in the history of medicine than that which follows the gradual steps by which was established the knowledge o± the intimate relationship which exists between iodins and the.thyroid. (The writers give a sketch of the discoveries referred to.) Wo havo shown that the greatest incidence in- New Zealand is in the regions where the soil is very deficient in iodine, particularly o« the recei't alluvium of river valleys, from which such iodine as may be set free fronthe gravel and by weathering processes is quickly bleached out of the ' soil, which, containing but little clayey matter, has small power of ab sorbing arid retaining the iodine. The incidence of goitre we havo also shown to be very low indeed in tho regions underlain by igneous rocks yielding clayey soils rich in iodine. Borderline of Safety. Anv deficiency of iodine in the soil is reflected in the vegetables grown therein, and as the latter constitute our principal source of iodine, it is evident that in such regions the iodine intake falls to the borderline of safety or below it. In the former case the thyroid may remain of normal size until sonicincreased demand is made upon it This demand may bo a physiological one, such as menstruation or pregnancy, or it may be due to infection or to an unbalanced dietary; but the end resiilt is always the same, namely, thyroid enlargement. In the districts where tho iodine intake is definitely below the minimum requirements of the gland no increased demands upon the thyroid are necessary to deterroino a high incidence of goitre. The fundamental cause, underlying all other secondary factors, is therefore a deficient iodine intake. The Prevention of Goitre. Assuming that the fundamental factor in the causation qf_£oitre in a deficient intake of iodine, the prevention of the disease should be a comparatively simple problem In 1917 Marine and Kimball renewed the attempt abandoned on the Continent to apply iodine prophylaxis to man. I». the endemic district of Ohio they worked on 1000 school girls of tho ago period when thyroid enlargement is most frequently developed, using adequate controls. They gave four grammes of sodium iodide in 0.2 gramme doses daily for ten* consecutive school days during the spring and autumn terms. Their results were extremely good. Thus- at the end of thirty months 28$ normal girls who had taken the iodine showed ho cases of goitre, whereas "otrt of 205 normal control girls who had not taken the treatment, 68 showed definite aigns

of goitre. In Switzerland also the prophylaxis of goitre amongst school children has been extensively practised with extremely good results. Prophylaxis Amongst School Children. In April, 1921, prophylaxis was commenced in two schools in Christehureh. Tho results of one year's treatment were encouraging, but were in no way comparable to those of Marine. Thus, of 258 children of both sexes with normal thyroids, 162 received no treatment, and 80, or 55 per cent., of them developed thyroid enlargement during ' that period, while of tho 96 who received treatment 38, or 39 per cent, showed thyroid enlargement —a difference of 16 per cent, in favour of the prophylactic treatment. The therapeutic result was slightly better; 15 per cent, of the untreated children with goitre showed a decrease, in size, as against 35 per cent, in the treated. In February, 1924, we re-examined the children who had continued the treatment since 1921. The total number of children of both sexes originally normal was now 224. Thirty-three per cent, of those who had received no treatment showed thyroid enlargement, as against 11 per cent, of those who had received the treatment. On the therapeutic side, of the 622 children remaining, 206 had not taken treatment, and 17 per cent, showed increased enlargement, while 38 per- cent, showed a decrease in measurement, whereas of the treated children, 416 in number, only 23, or 3 per cent., showed increased enlargement, and 244, or 39 per cent., showed decrease. Three Years' Test. It will thus be seen that the result at the end of three years is distinctly better than after one year from the point of view of both prevention and cure. Similar results are also given of treatment in a school at Timaru. ' In a farm in the Clutha Valley where as many as 39 calves had had to be destroyed in one year on account of congenital goitre, it was sufficient to allow the cattle access to rock-salt containing iodine, to eradicate the disease. The body requires an adequate daily supply of iodine throughout life for normal thyroid activity. To recognise I the deficiency and to supply it during t the school period only subject to the caprice of the parent, is unsound. No country confronted with an endemic goitre problem can afford to adopt a drift policy in the supply of a deficiency so important as this. Switzerland has not only provided the world with an object-lesson of tho consequences which attend the neglect of 1 endemic goitre, but latterly she has demonstrated the success which will at- '■, tend the supply of the deficient iodine. | . lodised Salt. ! In February, 1922, the Canton Appenzell, Switzerland, introduced a stan-

dard iodised salt. The results after two j years' use are remarkable. The per-, centage of babies with congenital goitre has dropped from. 50 per cent. ■ ; to nil, and the number of goitre operations diminished by 75. per cent. In February, 1924, over 700,000 inhabitants of Switzerland were using standard salt daily. The salt is used in the kitchen, as well as by bakers, butchers, butter and cheese manufacturers, etc. In America, Marine has recommended the use of table salt containing 0.2 per cent, of iodine in districts where ■ endemic goitre prevails to a mild extent. Many districts in Canada and America have adopted Marine's recommendation. lodised Salt in New Zealand. In October, 1923, one of us (Professor Hercus) obtained permission _ to introduce the use of iodised salt into the orphanage of St. Vincent de Paul, in Dunedin, where 54 out of 76 children showed thyroid enlargement—27 per cent, incipient, 24 per cent, small, 9 per cent, medium, and 9 per cent, large. Eighteen months later, during which period the iodised salt was used regularly,' the children were re-examined. None of the children who were goitre free at the previous examination had developed goitre, and 25, or 69 per cent., of the remaining 36 children who had had goitre showed an average' decrease of .3 inch. The remaining li children snowed a slight increase in measurement. Some of the therapeutic results were most encouraging, goitres which had previously been classified tis largo being now small or incipient. One girl showed a decrease in measurement of .63 inches. BJVT.A. Becommendations. At the annual congress of tho New Zealand branch of the British Medical Association in February, 1924, a resolution was passed uring the Government to introduce the use of iodised salt into endemic areas. The Health Department inserted in its Food and Drug Regulations definitions for iodised salt and - medicated salt. These regulations came into force in June, 1924, but so far uo iocliiod or medicated salt conforming , them has appeared on the market. The B.M.A. Congress supported the opinion that the situation demands a .•rmpulsory clause. We suggest that salt for use in endemic area 3 should conform to such a definition as this (here follows the chemical definition). We understand that the Department: of Public Health is considering the advisability of such a regulation, but is awaiting the results of this and other investigations now in progress. Other Methods. There are other methods which havebeen suggested and utilised from time

to time, but they all have, in our opinion, serious limitations or difficulties. Thus, very minute amounts of iodine have been supplied in the water supply in Eochester, New York, with good ro suits. This method, however, is limited in application and extravagant, and in an artesian area such as Christchurch, it would requiro to be carried out by the individual householder. The use of foods naturally rich in, iodine would be of distinct preventive value, but would bo difficult to control. Tlio Japanese are said to use seaweed as a food, and to be free from goitre in consequence. The use of oysters, lobsters, and shrimps, which are all rich in iodine, -could be encouraged, and marine fish generally could replace butchers' meat several times a week. Tho fresh stem of ordinary .kelp is edible and attractive, either raw , or roasted, and is generally regarded as -1 delicacy by children, while the young fresh leaves of " dulse" make-good eating. In a sea-girt country like Ne\i Zealand there should bo no difficulty in maintaining constant supplies. If the primary deficiency is in tho I soil, and if,, as our work suggests, the soil promptly reflects in plants grown upon it any addition in iodine, the use of manures rich in iodine should give good results. Guano, Chilean or perhaps seaweed, might be used in deficient soils. These measures are, however, expensive, and as a means of supplying the iodine, to foods infinitely less economical and efficient than tho use of iodised salt, and an extensive educational campaign would be necessary to establish their use. and Conclusions. The incidence of goitre among school children in New Zealand has been determined by the examinations made by one of us (Professor Hercus) and by the officers of the School Medical service, of over 80,000 children. The proportion of men of military age who were unfitted for active" service on account of goitre was ascertained during the examination of over 135,000 recruits by the Military Medical Boards in the years 1916-18. Additional information has also been derived from hospital records, by the number of operations for goitre. The amount'of iodine has been determined in nearly 500 samples of soil, obtained from all parts of New Zealand, together with samples of a number of waters from mineral springs and town supplies. In order to ascertain whether any relation exists.between the amount of iodine in the soil of any district (considered as a soil of plant food, and therefore indirectly of human food), we have divided the Dominion into 33 districts, each homogeneous as far as possible in its geological and geographical

circumstances, and have ascertained the average amount bit iodine in Mil* the average incidence of goitre among school children within each, district. utilising certain defined methods of ant analysis and diagnosis of goitre. It is prove! that the following lemtiokis approximately true throughout:—*■*• centago incidence of goitre among school children is equal to 6 phis 360 divided by the amount of iodine in tea million parts of soil, so as '.tiis does not exceed 50. When the aoU is x. abnormally rich in iodine the constant 6 must be diminished. \ Approximately, therefore, tho incidence of the disease is inversely jao* portional to the amount of iodinf in the soil. Farther, where, though tho incidence of goitre is low, the amount of iodine in the soil is abnonnaßy-Jew, we have proved that it is nresent ia the water supply in greater amosmts than usual, and the dairy intake of iodine among the inhabitants of.snob a district is thereby maintained. Tatther, regions in which the average amount of soil iodine is low those in which goitro is most frequently seen amongst the domestic animals. What the Tacts Show. Though there aro certain points as yet unexplained, the whole body of facta is too large and 'the relationship too consistent to be fortuitous. We ; believe, therefore, that the hypothesis that goitre is caused by a deficiency of iodine in the diet has been folly maintained by the present investigation. Seasons liavo been deduced also for believing that a similar relation holds between the incidence of goitre and the distribution of geological formations la Switzerland, and perhaps in fetter countries. .-- ': • ' Further, a study has bees nude of the prophylactic treatment of school children in New Zealand by administering small amounts of iodine weekly. Tliis has hitherto had fairly good results. - The Best Method. We believe that the best method of prophylaxis, considered on physiological grounds, as well as those of efficiency and economy, would be derived from daily ingestion of minute amounts of iodine, by the utilisation for all culinary and table purposes of an. iodised salt, in which one nut of potassHsn iodide had been added to IWMMO of sodium chloride—the method which has been attended by such satisfactory results in Switzerland. This wonld afford. the minimum amoant of .Olmg per day, which seems necessary for the functional requirements -of the thyroid gland, while it wonld be far too small to have any ill-effects in the production of hyperthyroidism.

Goitre. an Sou. Stewart Island .. - — 87 Bluff . . , • • 2t 20 Invcrcargill and Southland 35 20 « 4 Waimea Plains 31 Olutha Valley 40 Taieri Valley and Milton. .., JJunedin . . ■• •■■ North Otaso <- . . , • • no 19 17 G 33 13 South Canterbury '... G2 3 Christchurch. . * *» 64 9 Banks Peninsula • • 31 9 North Canterbury .< 58 6 Marlborough .. • * 38 17 Nelson ' 29 West Coast .... 52 40 16 24 Wellington ••.. '• • 25 Hutt Valley . • ■ • 41 Wnifarapa and Dannevirke 20 Hawkc's Bay Gisborne • • • • Horowhenua .. 1.5 1.4 4 1 13 137 9 8 166 Palmerston and Mnrton .. 15.5 Wanganui and Patea i .. 44 4 Taranaki Main Trunk Line S5 14 Taumarunui ' • -,_,..•• West Coast and Te Kulti . . 59 25 Watkato and Plako Valley 70 55 io Taupo and Rotorua 69 1 fl Bav of Plenty 20 * 1J. 158 Cape Colville Peninsula ;: 2 Auckland .. ;; 3 53 North Auckland