EXPEDITION TO THE RIVER NIGER
DURING THE YEARS 1841-2.
HISTORY OF THE FEVER.
Sequences of the Fever.
Under this head I shall principally confine my observations to the illustration of a fact in the pathology of the fevers of Africa, more especially of those contracted in rivers, which does not seem to have engaged much attention. I mean the existence of an irritability and great susceptibility of disease in the mucous lining of the bowels, for a long time after the cessation of the primary attack. The colicky, dysenteric and other symptoms, so common among men who have suffered from fever in Africa, depend, I believe, in the majority of instances, upon lesions of the mucous membrane of the bowels that come on during the fever. This opinion I formed while serving on the coast of Africa some years since, and my late experience has tended to confirm it.
Previous to my joining H.M.S. Scout, under the command of Captain Robert Craigie, in 1838, the crew of that vessel had suffered from fever contracted in the river Bonny; and a prize crew had suffered from the same disease at Sierra Leone, whither they had been sent in a slave vessel. Several deaths took place; of those who recovered some were invalided, and a few continued in the ship. The latter were quite free from disease while the vessel was at the Cape of Good Hope. In the less temperate climate of the Mauritius, they were troubled with diarrhoea, and on the return of the ship to the West coast, they all were attacked with intermittent, dysentery, or affections of the liver or spleen. At this period it was necessary to invalid some of the cases for a change of climate; and two cases proved fatal, one from intestinal hemorrhage, and the other from colic, followed by symptoms of inflammation of the bowels.
Of the diseases that are likely to be produced after fever, acute inflammation of the bowels may be shortly noticed. The lining membrane of the bowels may be for a long time even ulcerated, without any great complaint or marked suffering, until from some cause acute inflammation is set up. In one of the cases in which disease of the bowels was consequent on the fever, and which proved fatal, the patient had symptoms of colic which passed into those of enteritis. On dissection, the lower end of the ileum and the colon were found studded with old ulcers, around which were marks of recent inflammatory action.
Colic. This complaint is common among crews on the west coast of Africa, more especially among those who have suffered from fever. Indeed it may be safely asserted that few convalescents from fever will escape an attack of colic unless extreme caution be used. I have seen it produced by very slight infringement of strict rules of diet. An almost imperceptible change in the temperature or hygrometrical condition of the atmosphere, will also bring on colicky symptoms, in persons who have had African fever, so sensible in them are the bowels of impressions made on the skin. As irritating matter in the bowels often causes colic in healthy persons, we may fairly suppose that it will bring it on still more readily in those whose bowels are in a morbid condition from fever, whether this condition be that of mere tenderness, of chronic inflammation, or ulceration of the membrane. Colic in its' milder or severer form, is likely to ensue from the action of acrid bile and other morbid secretions, as well as by irritating substances taken into the stomach.
Hematemesis and hemorrhage from the bowels are much less frequent as sequences of fever than colic; but they sometimes occur as such. I saw one case of hematemesis, at Ascension hospital, which terminated in recovery; and one of hemorrhage from the bowels, after fever, which proved fatal, on board ship: in this last case there were ulcerated patches low down in the ileum and in the colon: the liver was enlarged and indurated, and the spleen was in a state of congestion. I inferred that the activity of the hemorrhage in this case was owing to the condition of the liver, which, by obstructing the portal circulation, caused the blood to be extravasated at the ulcers, the weakest points in the surface of the mucous membrane. Hemorrhage may, however, take place from mucous membranes, without any discoverable breach of surface.
Dysentery. Diarrhoea and dysentery are also frequent among those who have suffered from African fever; and further evince the morbid susceptibility of the bowels induced by that disease: this was remarked in the former expedition up the Niger. Mr. M'Gregor Laird, who accompanied Lander, informed me that two persons, Dr. Briggs and a seaman, on board the Quorra, died of dysentery after recovery from the fever: Dr. Briggs died in the river, and the seaman at sea some months afterwards. Dr. Briggs had so far recovered as to be able to go out shooting, and suffered only from occasional intermittent. Mr. Laird himself had a severe attack, from which he recovered, under the care of a native doctor. Of those in the Albert who had fever in the Niger, and who did not at once leave the coast, few escaped bowel complaints, which often assumed the form of dysentery. Dr. Vogel, botanist to the Expedition, died of this disease at Fernando Po, ten weeks after he got rid of the river fever. Many of the men were troubled with it, three months after the Albert left the Niger. At the hospital of Ascension a private marine died of dysentery, complicated with abdominal dropsy, ten months subsequent to a severe attack of fever contracted in the Niger. Dysentery may be an immediate sequence of the fever, or it may come on long after the fever has passed.
Hepatic disease will not unfrequently occur, as a result of these affections of the gastro-enteric lining. The mode by which inflammation is propagated from the gastro-intestinal mucous surface to the liver has not, so far as I am aware, been satisfactorily explained: whether this takes place by sympathetic irritation, by being spread by continuity of surface along the biliary ducts, or by being conveyed along the internal coat of the vena portae, I am unable to say; but feel confident that I have met with several well-marked cases, in which hepatitis, in various forms, followed chronic disease of the gastro-enteric mucous membrane.
The period during which the lesions of the intestines are inactive or latent. There seems reason to believe that the morbid susceptibility of the bowels consequent on fever may, for a time, be latent, and that chronic inflammation, enlargement of the follicles, softenings and even ulcerations may exist without producing constitutional disturbance. The duration of this period of inaction will vary according to circumstances. A change from a warm humid atmosphere to a drier and more bracing one, with proper attention to diet, clothing, and the avoidance of all causes likely to produce a determination from the surface to the abdominal organs, may not only destroy the morbid sensibility of the bowels consequent on fever, but even cure some of the worst forms of disease produced by it. Due regard must also be paid to the state of the bowels, so as to prevent acrid bile, or any other secretion from fretting the already irritable surface.
It often happens that the disorders referrible to the bowels do not appear, until convalescence from fever has considerably advanced. This is the period at which the patient is apt to throw off restraint. He neglects precaution as to clothing, and becomes less careful in his diet. The liver and other organs become deranged, the morbid secretions are poured out on the tender surface of the mucous membrane of the bowels, and disease in various forms is thus lighted up.
Intermittent Fever. It is, I believe, generally admitted that remittent fevers are only severer grades of the same pathological states as constitute intermittents. Remittent fever occurred in six out of seven whites, who returned to the Niger in the Wilberforce, and during the same voyage two blacks had slight agues. On board the Albert none of those who had fever in the Niger, and were not at once sent to England, escaped intermittent. Five who suffered severely were invalided at Ascension, nearly nine months after the vessel left the Niger. In the Wilberforce nine cases of ague, following Niger fever, occurred during the passage to Ascension. The severity of the intermittent did not always bear a relation to the intensity of the primary remittent. Commander Fishbourne was affected by the remittent in a comparatively mild form, but he was many months afterwards as violently visited by intermittent as any one in the Expedition. Nearly twelve months after recovery from remittent, and after about eight months of freedom from intermittent, I was three days confined to bed, with the latter complaint, during the passage to England, just as we were getting into cold weather. It appears, therefore, that after remittent a person continues long liable to intermittent, and further that remittent and intermittent are produced by the same cause in different degrees of intensity. While the system is in this condition of susceptibility, a second attack of remittent will certainly follow exposure to malaria, while a return of intermittent may be induced even in a healthy district by slight indiscretion in diet, or by sudden changes in the condition of the atmosphere. In nearly all the chronic cases of intermittent a marked increase in the duration and severity of the attacks was observed when they came on during the first quarter of the moon’s age.
One man, who was born at Greenhithe in Kent, and who had been, in his youth, subject to ague, was again seized with it in the Niger, but it speedily degenerated into the remittent type. The case of Dr. Stanger is somewhat remarkable: this gentleman was brought up in a fenny district, and had suffered a good deal from ague: he escaped the fever of the Niger entirely; but on his return home to England he had several very severe fits of ague.