Yellow fever and malaria : evidence given before the Royal Commission / by William Osler.

  • Osler, William, Sir, 1849-1919.
Date:
[1908?]
Catalogue details

Licence: In copyright

Credit: Yellow fever and malaria : evidence given before the Royal Commission / by William Osler. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    o As the fever has disappeared in Havannah, map I ash whether the special stegomyia mosquito has also disappeared ?—No, they have made an active warfare against it, but J think the mosquito itself has not disappeared. But if the mosquito is capable of transmitting the disease ■during its existence, after it has bitten a patient suffering from the disease, how can you get rid of the disease, so long as the mosquito lives?—That is only a matter, I think, of 8 or 9 months. I do not know definitely what the life of a mosquito is. I do not think it is more than over the succeeding winter. Is there anything further you wish to add about yellow fever ?— No, I think not. The work in Brazil lately has shown that even in large centres, like Rio, by the mosquito brigades thoroughly carrying out measures such as were introduced in Havannah by G-orgas, the reduction in mortality and in the number of cases has been very striking. By taking steps to prevent the breeding and multiplication of mosquitoes ?—Yes, and by carefully reporting and carefully isolating the very earliest cases I look forward to the total abolition of yellow fever within five years, and that, from the commercial standpoint alone, will revolutionise the trade of those districts. Every few years that a terrible epidemic arrives and spreads, New Orleans and the Southern States, and the commerce of the whole oountry, has been paralysed lor long periods. How do you account for the epidemic's rise and fall, because the mosquitoes were ahuays there, and the yellow fever on which they feed is always there ?—That is the difficult point ; it is not easily explained. It depends very much upon how large the immune population is. The greater the proportion of non-immunes, the heavier will the epidemic be, because in a city like Havannah every non-immune within a year of his arrival there took the disease— he could not escape. How that you have discovered that the mosquito is the cause, how do you ensure protection against it ?—By screening the houses properly and scouring out all the pools and protecting the water tanks. By destroying the habitat of the insect ?—Yes, and particularly in Havannah, by covering up and protecting the water tanks, and by the active energetic fight against the mosquito which has been made so successfully. Then the object is the extirpation of the mosquito ?— Yes. The mosquito does not fly very far, I suppose 1—Some of them go long distances, particularly when carried by the wind. Then of course, they are carried by ships, and get into the holds, and get from one country to another in this way. Is it not the case that in the mosquito which is connected ivith yellow fever the changes from the