EPIDEMICS.

Hawera & Normanby Star, Volume XLII, Issue XLII, 6 January 1923, Page 4

EPIDEMICS.

SCIENTIFIC EXPERIMENT. (By a Physician.) There is at present being carried on in London one of tne most remarkable experiments which science has ever conceive. This is the study of epidemics - of disease in a lar^e "population— of mice. Just as the problems of designing a great ship are wor_ed out of a tiny model, so the problems of vast waves of disease, affecting whole continents, are being studied in a room or two. Dr. W. W. C. Topley, whose idea the "mouse population" is, has already come upon some remarkable new facts'. By far the most interesting of these is the strange effect on the mouse colony of immigration into it. As soon as a number of new mice arrive trouble may be expected. The reason, apparently, is that a population which does not move about establishes a kind of "working agreement" with its besetting sicknesses. These are present, but they do not attack. But the moment newcomers arrive the agreement is upset. For these newcomers are not exactly the same phy- ' sical condition as the natives; some of , them, at any rate, are more liable to in- j fection. If they fall ill they begin to spread ' their illness at once, because the disease grows more active and dangerous with each new individual it attacks. Very soon a great part of the population is "down." " i Then, provided no fresh arrivals take ! place, a new "working agreement" is ; reached and the epidemic passes away. \ Here, obviously, is a real explanation at last of the outbreaks of disease which ■ always accompany a war". No matter what care may be taken by the army doctors, epidemics are sure*, sooner or later, to arise when vast bodies of men 1 , are "on the move." - j The importance of this work for far- ! j mers and stockbreeders is obvious At I present they suffer great losses which, I it would seem, knowledge of these studies of mice might save them. Incidentally we are learning how very ' complicated is the problem of defence ; against disease. The old idea that if we could rid the world of germs we should be safe is seen now to belong to | the "Walrus and the Carpenter" period of bacteriology, when: "They wept like anythins to see Such quantities of sand." Germs are everywhere in numbers greater even than thousands of the sea. But they are not dangerous except in ' certain special conditions. Only when man grows restless and begins to move . in his thousands across the face of th~e , earth does disease obtain power anel its ' opportunity. I , At present we are without light on s the means of avoiding these 01 con«e- , quences of our migrations. But this study is still only in its infancy.