SCOURGE OF MALARIA.

New Zealand Herald, Volume LXVI, Issue 20367, 23 September 1929, Page 13

SCOURGE OF MALARIA.

SEARCH FOR A REMEDY*

SIR RONALD ROSS'■ LABOURS.: ]

EXPERIMENTS ON MOSQUITOES*

The prevalence of malaria in many) parts of the Empire makes it of imports aiico to British subjects the world over, and 'the scientific history of the disease shows that British investigators have played a predominating part in elucidatn ing most of the baffling problems which! malaria presents.

Tho name of Sir Ronald Ross is justlyj honoured in connection with tho earliest! work on the malarial parasite, says thff medical correspondent of the Morninjj Post.

Malaria is caused by a parasite which! lives in tho blood of the infected indi-i vidual and is conveyed from patient td patient by a species of mosquito. Earlier workers had discovered tho parasite in the human subject, but it was Ross who* after a long series of patient observations,; found evidence of its existence in the! mosquito. This work was reported in 1895, and in 1898 Ross published an account of further work by which he had been able to trace a form of malarial infection in birds, which was transmitted by mosquitoes.' This work on malaria in birds was carried out in India in most difficult circumi stances. Sir Ronald Ross records that} the bulk of his investigations were dona with an old microscope with a cracked eye-piece, while tumblers and bottles served for apparatus. Even at tho "laboratory" which wa» provided for him later he had to supply; his own microscopes and even pay his own assistants, while books of any kintj could rarely be obtained. Yet with the*i« poor facilities the whole of the very; difficult technique of the experiments oa; mosquitoes was established. The methods of keeping tho mosquitoes alive, of feeding them, of dissecting them and examining them were worked out so fully that with this information about! malaria in birds available it was a com* paratively easy step to carry out parallel observations on human malaria. This Sir Ronald Ross would undoubtedly have done had not his duties sent him to investigate another disease elsewhere, and conse-i quently his work was carried out in the first place by Professor Grassi and hi* colleagues in their well-equipped labora-t tories in Rome.

The "cold storage" of British troopi in India—the withdrawal of as many ai possible from malarious stations to the hills during the infective season—is the new method employed to lessen malaria attacks in the country. Lieutenant-Colonel •T. Mackenzie, who was director of hygiene and pathology at army headquarters in India, and who has written al book on "Army Health in India," states that throughout the civilisation of thai past the "captain of the armies of disease" had taken incalculable toll of human life and treasure, , destroyed armies, depopulated cities, arrested the development) of vast territories, and brought empires to decay. The number of his victims was beyond computation. In India alone 100,000,000 were attacked every year, and the annual toll of the dead was from ona and a-half to two millions.

A study of the statistics of the last 100 3'ears led irresistibly to the conclusion that, allowing for certain factors, the out* line of the medical history of the BritisfaJ Army in India was, in the main, the curv<( of malaria incidence. Cholera had comal and gone, enteric fevers had risen and declined ; malaria remained.. . "Cold storage"—introduced in 1925, 'and partial mosquito-proofing, carried out in 1926» had, however, shown that the problenl was not insoluble.