PUBLIC RECORD OFFICE
Reference :-
C.O. 885
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO
22 PUBLIC RECORD OFFICE, LONDON
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3. I approve this proposal, and an officer of the West African Medical Staff Reserve will be posted to Southern Nigeria forthwith, to augment the establishment for the purpose indicated. On his arrival an officer of the medical establishment will no doubt be assigned to the Institute for a definite period.
4. I will take a suitable opportunity of communicating the Committee's sugges- tion to the other dependencies.
5. In regard to the proposal of the Director that a Medical Dispensary should be opened in the vicinity of the Institute to supply a public want and to furnish material for the exact study of common native disorders, it was pointed out by Dr. Langley that there is already a dispensary at Ebute Metta, and that there is a lunatic asylum within a very short distance of the Institute. Dr. Graham should be told that it appears to nie that it will be sufficient if he makes full use of the opportunities afforded by the asylum, and the Medical Officer in charge of the asylum should be instructed to give Dr. Graham suitable access for the purpose.
13480
No. 12.
I have, &c.,
L. HARCOURT.
MEMORANDUM REGARDING THE RETURNS OF VARIOUS COLONIES AND PROTECTORATES ON MOSQUITO-BORNE DISEASES. BY PROFESSOR SIR RONALD ROSS, K.C.B., F.R.S. (Received May 2, 1912.)
1. Historical.
CONTENTS:
2. Nature of the Return.
3. Explanation of Abstracts I. and II.
4. The Returns for 1910 in Detail.
5. Other Communications on the Subject.
6. Summary.
7. Remarks.
8. Suggestions.
9. Abstracts I. and II.
1. Historical-About the middle of last century many parasites were proved to be common to two species of hosts. In 1858, Filaria bancrofti, a parasite of man, was shown to be connected with a small fresh-water arthropod, (Cyclops; and in 1877, Filaria bancrofti of man was found to have a similar development in mosquitoes. In 1898-9, the parasites of malaria were shown to be carried by other species of mosquitoes; and during the last days of last century yellow fever was proved to be transmissible in the same way. In 1902, dengue was also brought under the same insect- law; and many other diseases of men and animals have now been traced to carriers."
There are three obvious methods of combating all these diseases, namely: (1) by reducing the carriers; (2) by reducing the parasites; and (3) by reducing the frequency of contact between the two species of hosts. In 1899, the general sanitary measure of mosquito-reduction was fully and accurately described in Sierra Leone; and in 1901 an object lesson in the method was given in that Colony. In the latter year the Americans commenced their campaign against malaria and yellow fever by this means in Havana; and similar work was started then and later in Italy. Lagos, Ismailia, the Federated Malay States, Hong Kong, Panama, Durban, and elsewhere. In the meantime, the second and third methods mentioned above were often tried and elaborated; and by 1902 there was nothing to prevent all the measures being adopted, at least in the principal towns affected by the diseases under con- sideration.
Four years later, in May, 1906, Major Seely, M.P., asked the Under-Secretary of State for the Colonies in the House of Commons," whether he can grant a return showing the measures taken in the Crown Colonies and Protectorates to eradicate malaria fever, and the results as shown by the health statistics of the inhabitants:" In consequence, the Secretary of State for the Colonies (Lord Elgin) issued a letter dated the 6th June, 1906, to the Governors of all Colonies, &c., not possessing
C:
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responsible Government, and the High Commissioner of Cyprus," asking for the suggested return. He desired that yellow fever and other mosquito-borne diseases should be included; required a concise account of the nature and cost of all the measures taken; wished for accurate figures as to the results; and directed that the reports on the subject should be utilised in the Annual Reports of the Advisory Committee for the Tropical Diseases Research Fund.
This circular, together with replies from 10 Colonies and extracts from the medical reports of 11 others, was published in the Annual Report of the Advisory On the 22nd July, 1908.* Committee for the year 1907 [Cd. 3992], pages 7-34.
I wrote, by permission, to Colonel Seely, then Under-Secretary of State for the Colonies, a review of all these documents, in which some were commended and others criticised. My letter was laid before the Advisory Committee, which, as I was informed in a letter from the Colonial Office dated the 11th December, 1908,† while it did not accept all my conclusions, readily admitted that much remained to be done, and urged that medical officers appointed to Tropical Colonies should duly appre- ciate the importance of the measures referred to.
The succeeding Annual Reports of the Advisory Committee for the years 1908. 1909, and 1910, contain further reports, letters, and extracts on the subject. In 1909, I was appointed a member of the Advisory Committee, and was asked to review the correspondence again. In a note published in the Annual Report for 1910 ([Cd. 5514), pages 20-24, I expressed my general conclusion that, to judge from most of the reports received, the details of the information required had not always been understood; and I therefore submitted for consideration a draft return which I suggested might be sent to the Colonies to be filled in every year. This was approved by the Committee, and accepted by the Right Honourable the Secretary of State (page 20). The returns for the year 1910 have now been received (by me) from 21 Colonies, and are, for the most part, published in the Annual Report of the Advisory Committee for 1911.§ I now propose to discuss them, as requested.
It should be added that in 1909 an Advisory Medical and Sanitary Committee for Tropical Africa was formed at the Colonial Office, and that it has advised a model Annual Medical and Sanitary Report, which largely covers the same subject (in greater detail) for the African Colonies.
2. Nature of the Return.-This was discussed in the Annual Report of the Committee for 1910, page 21. The return aims at giving a brief record (a) of the frequency of mosquito-borne diseases in each Colony; and (b) of the efforts made against them.
The first five headings give the name, the area, the population, and the total births and deaths of the Colony.
Headings 6 and 7 attempt to indicate the frequency of the mosquito-borne diseases. A good rough measure is given by comparing the total attendances at all hospitals and dispensaries with the attendances for mosquito-borne diseases, and calculating the percentage of the latter to the former. We should observe, however, that this indicates merely the proportion of mosquito-borne diseases among persons who are ill enough to come to hospital, and not the total number of infected persons in a place; and the latter figure can be ascertained only by difficult medical and statistical enquiries.
It is still more difficult to estimate accurately the frequency of deaths due to malaria. The returns of deaths ascribed to malaria are generally worthless unless death certificates are signed by medical men-which is not often demanded in the tropics. But by Meldrum's law the excess of the mortality during the malarious months over that during the non-malarious months may often be ascribed to malaria, or at least to seasonal diseases; and for applying this law it is necessary to have These are given under tables of the monthly deaths and the monthly rainfall.
The deaths due to filariasis and dengue can headings 14, 15, and 16 of the return. scarcely be estimated accurately by any method; but those for yellow fever, per pumber of cases recognised, are generally well known.
Heading 9 gives the proportion of school children which attend school every day on the average-a figure which tends to vary, ceteris paribus, with the healthi- ness of the locality.
Heading 10 indicates the healthiness of indentured labourers and the ascribed
No. 42 in Miscellaneous No. 221.
‡ [Cd. 4176], [Cd. 4999], and [Ca. 5514].
t No. 69 in Miscellaneous No. 221. § [CU, 6024] ¡African No. 959.