PUBLIC RECORD OFFICE
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Reference :-
TTTTTC.O. 885
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO
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RECORD OFFICE, LONDON
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stomach and intestinés, the contents of which are mixed with blood, and enlargement and discoloration of the mesenteric glands.
In sheep the symptoms and post mortem appearances are almost the same, except that the enlargement of the spleen is not so well pronounced.
In the horse the lesions resemble those of cattle, with the following differences. There is a large oedematous swelling around the throat, often extending half way down the neck. The stomach, bowels, and mesenteric glands are inflamed, but the swelling of the spleen is not constant.
Microscopic diagnosis of the disease. If a drop of blood is taken immediately after death from one of the small veins of the ear or tail, and examined micro- scopically, it will be found to contain numerous large non-motile bacilli. On making a cover glass preparation from the same source and staining it with a watery solution of methylene blue, the characters of the bacilli can be readily made out. They stain dark blue, and between them is seen a reddish-purple or violet granular material. This is diagnostic of anthrax, as in no other disease will methylene blue give this purple hue.
Local peculiarities of the disease.-Before discussing methods of prevention there are certain local conditions to consider which slightly modify the measures one would suggest for ordinary outbreaks.
It has been pointed out that the disease occurs only during the early rains. Furthermore, it is only seen in cattle that graze on the marshes by the sides of the river and creeks. When the rains are well established the outbreak ceases. I could find no trace of horses, sheep or goats dying of the disease and they are grazed just as much as cattle, but only around the villages. Horses are not numerous in the Gambia, and sheep and goats require very little water, so that it is not necessary to send them to the marshes. At the beginning of the year there is only a limited It is at this time quantity of food and water near the villages and in the bush. they begin to go to the low land near the river. Here there is a tremendous growth of tall, coarse grass, patches of which are burnt. A week or so afterwards a crop of sweet, young grass makes its appearance, which is readily eaten by the cattle. By the end of May or the beginning of June most of the rank herbage has been burnt, and the marsh appears as a huge plain. During these months there is continuous brilliant sunshine and no rain, the temperature in the open varying from 140° to 160° F. These combined factors are most unfavourable to the life of the When the bacillus, and might account for the absence of the disease at this time. first rains come, however, the sky becomes cloudy, the temperature drops to between 90° and 100° F., the surface of the marsh is soft and damp, and a great deal of sub- On land tainted by deaths from anthrax for genera- soil is brought up by worms. tions, this combination of moisture and moderate heat is most favourable to the recurrence of the disease.
The Fullahs, who own by far the greatest number of cattle in the Protectorate, are in the habit of slaughtering their animals as soon as they present symptoms of anthrax or any fatal disease. If an animal is found dead it is cut up and the flesh is eaten. The hide is dried in the sun and eventually sold to the traders on the river. The remarkable part of this proceeding is that the people do not appear to suffer in the least from skinning, handling, or eating the flesh. The medical officers of the Protectorate cannot trace a single case of a native having ever suffered from any form of anthrax, and some thousands of cases of sickness of all kinds have passed through their hands.
Although it appears to be harmless in this respect, the greatest mischief is done to the land by the shedding of the blood which occurs when the carcase is cut up.. If the dead animal is left intact the germs die during the process of putrefaction, but when the blood is exposed to the air the bacilli germinate and form spores, which persist indefinitely in the soil. The blood, which is teeming with bacilli, is trampled on by man and beast, and dispersed broadcast, forming fresh centres for future outbreaks. The Mandingoes are cleaner feeders than the Fullabs, and will not touch the flesh of an animal that has died. Several told me it was their custom to burn fires over cattle that die suddenly. When the rains have well set in, it is not necessary to graze on the marshes, which become swampy and impassable, and this puts an end to anthrax for another year. A few years ago, when cattle were not so numerous, some of the more intelligent Fullahs used to send their animals to fresh ground to graze during this dangerous period, but now all such suitable land is
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occupied. Cattle have increased in numbers tremendously, and were it not for the marshes they would die of starvation.
Preventive Measures.-In many parts of France anthrax is enzootic, and thousands of cattle are successfully vaccinated against it annually. If the disease was responsible for much mortality in this Colony after ordinary precautions had been tried, inoculation of all herds in infected districts would be indicated, but from what has been said of the customs of the people it will be seen that much might be done towards the suppression of the disease in other ways. Furthermore, the number of deaths from the disease in ordinary years does not justify inoculation on a large scale.
The natives require instruction and advice about the disease in simple language, and to this end I suggest that the chief and headmen of every district should be called together every year just before the rainy season, when the nature and method of spread of the disease could be explained to them.
Notification. It should be compulsory for an owner of cattle to report all sudden deaths, during the early part of the rainy season, to the headman of his village who, in turn, should notify the chief. The Commissioner would, on his tour round the district, be informed by the chiefs of the number of deaths, and so obtain some idea of the extent of the disease.
Isolation. The infected herd should be isolated as much as possible, and not allowed to associate with others for seven days. The period of incubation is very short, and this time would be ample to determine whether any of the isolated animals were infected or not. From conversations I had with various natives, I could see that any restriction on other people's cattle that would keep away disease from their own appealed to them not a little, and I think they could be entrusted to keep their eyes on a herd which they knew to be dangerous.
Disposal of the carcase.-Special attention should be given to this. With the abundance of wood there is in the bush the best and safest method to dispose of the carcase would be to burn it on the spot where the animal has died. Failing this, should be buried and dry grass, leaves, and shrubs burnt on the ground to destroy any blood that may have escaped from the nostrils or anus. The dragging of the Great stress should be laid on the carcase over the ground should be avoided. damage done by skinning and cutting up the dead animal, which is the surest way to spread the disease. Experience has shown that when a carcase is buried intact and ordinary precautions taken, the disease frequently ceases after the death of one animal.
If it is afterwards found that the disease persists in certain districts and is responsible for many deaths, inoculation can be tried. This would have to be done one month before the rains commence. Two inoculations are necessary, an interval of ten days elapsing between each. No protection is afforded till a week or 30 after the second inoculation. The immunity conferred lasts on an average for twelve months, so that the inoculation must be repeated every year. The vaccines are attenuated cultures of the anthrax bacillus, and they give the animal a very mild form of the disease.
Exportation of hides. With a view of preventing danger to the Europeans of the Colony and infected hides being exported, I recommend that traders should be advised not to buy the hides of cattle that have died during any part of the rainy season. The dipping to which the hides are subjected in Bathurst previous to exportation is to preserve them against attacks from insects. No known dip will destroy the germs of anthrax in a hide without making the leather valueless. European employees should be advised to wear gloves when handling hides.
If natives act on the advice given regarding the prevention of the disease, no infected hides would find their way to the traders. Cattle very seldom die from any other disease at this particular time, and so very few are killed for food- except at places like McCarthy-that there would be little interference with trade in this respect. All buildings where hides are stored should be disinfected in a most thorough manner once a year, and exposed to the sun as much as possible. The trading cutters and boats on the river should receive the same attention.
In conclusion, I take this opportunity of expressing my sincere thanks to His Excellency Sir George Denton, K.C.M.G., the Governor, for facilitating my work in every possible way; to Mr. W. B. Stanley, the Commissioner of the Upper River, for much valuable aid and for the interest he took in the investigation; to
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