25 MARCH 1922, Page 20

THE PREVENTION OF MALARIA.*

THERE is in medicine no more romantic story than that of the fight against malaria, the scourge not only of the white man living in the tropics, but, as Dr. Watson shows in this fascinating book, of the yellow and darker skinned races as well. In this fight British investigators have played an honourable part ; the work of such -men as Patrick Manson and Ronald Ross rendered possible thegreat success of anti-malarial measures. Although much still remains to be done, the result of well- planned anti-malarial work has already had a profound effect on the health of communities living in malarial districts and has enabled work, such as the construction of the Panama Canal, to be carried to completion which, without such anti- malarialmeasures, would have been extremely difficult or, indeed, wellnigh impossible. Not only are the works of peace impeded by malaria, but the operations of war may suffer in like manner. The problem of the Balkan campaign was to a great extent the problem of malaria, while in East Africa this disease cost us many lives and greatly increased the difficulties of an arduous campaign.

This intermittent fever is not a disease only of modem times. Sir Clifford Allbutt, in his learned FitzPatrick Lectures on Greek Medicine in Rome, recently reviewed in the Spectator, tells us that by 500 B.C. malaria had already established itself in Greece, Sicily and the southern part of the Italian peninsula, that Sophocles gives an unmis- takable description of an attack, while in Aristotle's time Greece had become highly malarious. The following words of the lecturer are worthy of attention. Speaking of the infectious diseases which so frequently devastated Rome he says: "The first of them, that to which the minds of my hearers will turn at once, is malaria, not merely for its medical importance but also for its remarkable bearings on history " ; and he proceeds 'to suggest that the ruin of Greece, and later of Rome, was in no small degree due to the debilitating, enervating and devastating effects of malaria.

The problem of the origin and control of this terrible scourge naturally exercised the minds of the Roman citizens, and it is remarkable how near they got to its elucidation. Thus Varro

• The Prevention of Malaria in the Fate:aged Malay States. By Malcolm Wateon, M.D., C.M., D.P.H. Second Edition, with contributions by P. S. Hunter,

X.A., N.B., D.P.H., and A. E. Wellington, M.E.C.S., D.T.M. a H.; and a Preface by Sir Ronald Koss, K.C.B., K.C.M.G., D.P.H.,

D.Se., P.R.S., Nobel Laureate. London : John Murray. [116e. net.] (210-116 a.c.) warns against expending money on pestilential lands, for " tiny, even invisible, animals are bred in , marshes which enter by the mouth and nostrils " ; and Dr. Watson recalls that Sir Patrick. Manson suggested that the , infected mosquito carried the malarial, parasites to water, which when drunk by man infected him. Again, Columella, at the beginning of the Christian era, wrote : " Nor, indeed, must there be, a marsh near the buildings nor adjoining a public highway, for a marsh always throws up noxious and poisonous steams during the heats, and breeds animals armed with mischievous stings, which fly upon us in exceeding thick swarms." , Sir Clifford Allbutt further records that in the fifth century B.C. the city of Selinus, in Sicily, struck a beautiful coin in honour of Empe- doeles, recording how he stopped an endemic of fever by draining a certain marsh. Thus the ideas of the parasite, the mosquito and drainage of marshy ground had all occurred to these ancient investigators, yet their truth was not established till the close of the nineteenth century. First, in 1880, the Italian investi- gator Laveran discovered the malarial parasite in the blood of patients ; then Manson, who had proved that Filatia nocturne, the organism responsible for elephantiasis, was present in certain mosquitoes, suggested that the malarial parasite infected a mosquito, and Rosa, taking up this suggestion in 1898, proved that the parasites are taken up from infected patients by mosquitoes (anopheles), where they undergo a cycle of develop- ment and are later reinjected into man.

" Such was the state of our knowledge when early in January, 1901, I found myself in Kiang, in the Federated Malay States," writes Dr. Watson. A great advance surely in twenty years, yet it is not to be supposed that the old theories of a mimeo would be quickly cast aside by the public ; moreover, the practical application of the newly ascertained facts had yet to be demonstrated. Dr. Watson approached his task with an enthusiasm and zeal which is beyond praise. His attention to details was extraordinary, but had it not been for this attention the wonderful success which has attended his efforts would have been impossible. The methods to be adopted required careful consideration. The Italians were in favour of the free use of quinine and protection by mosquito netting, and Koch also favoured the regular administration of the drug. Fortunately, Dr. Watson chose the method of destruction of the breeding places of the anophelenes, but, as later work showed, luck had no little to do with the choice of the first area to be dealt with, the town of Kiang. At the time the scheme for dealing with Kiang had been inaugurated the knowledge of the species of mosquitoes carrying malaria was very imperfect. "The Malay Peninsula may from the malarial standpoint be divided into several zones, which may conveniently be distin- guished as the Mangrove Zone, the Coastal Plain; the Coastal Hills, the Inland Plain and the Inland Hills." Now, different species of mosquitoes breed in these zones, and each species, at least each of the two main species of malaria carriers, namely anopheles umbrosus and anopheles maculatus, require quite different measures for their extermination. In the Mangrove Zone, and in that of Coastal Plain and low Coastal Hills, anopheles umbrosus has its sway, and destruction of the surrounding jungle, combined with drainage of the marshy ground, eradicates the pest. Kiang is in this area, and the steps taken resulted in instant success. But in the jungle of the Inland Hills umbrosus does not breed, and opening up the jungle results in developing breeding places for maculates, and the better drained the area and the cleaner the hill stream, the more suitable does it become for this mosquito. So that if, as was at one time possible, the initial experiment had been made in the town of Seremban, situated among the Inland Hills, it is conceivable and, indeed, highly probable, that matters would have been made worse instead of better, with disastrous results to the development of anti-malarial measures in the Federated States. With success attending the first experiment Dr. Watson and his associates were encouraged to proceed and to battle. with the new problems that the extension of their efforts encountered. Anopheles maculatus was dealt with by carrying the drain pipes under- ground, no light task in the steep ravines, and this was later supplemented by " oiling " with petroleum. The success which has attended these various measures has been truly remarkable. Previously the death-rate among the imported Indian labourers was .simply appalling. Thus, on the Seafield estate it was in 1911, the year a drainage scheme was started, no less than 144 per thousand. This, by 1919, had been reduced to- 37. The spleen rate- —i.e., the number of ewe of

enlarged spleen among the surviving children—was equally favourably influenced. The women used to say : " We cannot have children here, and the children we bring die " ; but now this is all changed, children are born on the estate and live free from malaria, so that Dr. Watson with justifiable pride is able to include in his book an excellent photograph of the mothers and children on the Seafield Estate.

But the saving of life has not been the only benefit to the Federated Malay States from all this anti-malarial work, although this life saving alone would have been sufficient justification for the expenditure of the necessary funds. Finan- cially, the benefits have been stupendous. Dr. Watson estimates that the measures taken have resulted in the saving of millions of pounds in addition to saving approximately 100,000 lives. It is advisable to ponder well these words of the writer : " if we estimate the wealth of a country by what its inhabitants produce, the saving of these lives and the value of their work lead our thoughts into figures that stagger us ; but only do so because we rarely count the cost of disease, and have not yet realized the value of medical research and the prevention of disease. As a nation, are we really practical ? " Words applicable not only to the malaria problem.

Sir Ronald Ross says in the short preface that Dr. Watson " has thrown into the work a degree of energy and enthusiasm which has not been exceeded in any anti-malaria campaign which has been carried out since we learned the manner in which it is carried from man to man," and the book is worthy of the man thus eulogized. Practical, well written, excellently illus- trated, and containing chapters contributed by other workers in the anti-malaria campaign, it is all that such a book should be.