Patrick Manson

“ Perhaps the most common error is to regard the hectic of liver abscess as attributable to malaria. The regularity with which the daily fever recurs, the daily chilliness or even rigor coming on about the same hour, the profuse sweating, and other circumstances so compatible with a diagnosis of malaria, all contribute to this mistake. So common is the error that Osier says he hardly ever meets with a case of liver abscess which has not been drenched with quinine. My experience is the same. I have seen medical men make this mistake not only in their patients but in their own persons. ”

“ It is true the ovum may be infected by a germ, as in syphilis; but infection is not heredity. That the ovum can be infected at some stage of its existence by the lepra bacillus is proved if it be true that children have been born with the lesions of leprosy on them. But the fact that leprosy is common in the descendants and blood collaterals of lepers is no proof of ovum infection in every, or perhaps in any case; for family liability is quite as explicable by an hypothesis of contagion, or outside infection, as by an hypothesis of inherited infection. ”

“ EXTRACORPOREAL OR MOSQUITO CYCLE
As it is unreasonable to suppose that an organism which propagates so actively in the human body has no opportunity, either by passing from one host to another or in other ways, of continuing its species, we are forced to conclude that some provision must exist in the economy of the parasite that enables it to leave and enter successive hosts. The problems suggested by this consideration are first, how does the malaria parasite leave the human body; second, what is its life when temporarily outside the human body ”

“ They are not so, however; experience has taught the old resident that neglect of them means an attack of fever and a week off work. The new-comer takes a cold bath; the old resident takes a warm one. The new-comer sits up late, eats and drinks and smokes as in Europe; the old resident goes to bed betimes, and eats and drinks and smokes in moderation. By and by, sharp lessons teach the new-comer to respect the sun and the rain and the wind, to clothe with a view to avoiding chill, and to live temperately. ”

“ If the cholera vibrio be the germ of cholera, then such healthy, vibrio-bearing individuals may well suffice to start an epidemic. It is impossible, short of absolute and complete isolation, for any practicable system of quarantine to deal efficiently with such cases.
So far from ordinary quarantine proving a defence against cholera, it may actually increase the risk of an epidemic. This it does by fostering a false sense of security, and so leading to neglect of those well-proved guarantors of the public health— domestic, municipal, and personal cleanliness, and a pure water and food supply. ”

“ It is impossible to secure the absolute honesty and efficiency of every individual in a large body of men charged with the details of any system entailing great personal inconvenience and loss to travellers and merchants. Therefore, if the strength of the quarantine chain is to be measured by that of its weakest link, the chain must be weak indeed, as a very slight knowledge of human nature will lead us to suspect, and a very slight acquaintance with the working of quarantine as ordinarily practised will attest. ”

“ It has already been pointed out that the malaria germ may remain dormant for months or even years in the body, and then, on the occurrence of severe physiological strain— such as a chill, shock, excessive fatigue, and so forth— wake up again, and once more multiply and flourish in the blood and give rise to the phenomena of malarial fever. It is a recognized clinical fact, one familiar to our predecessors and much insisted on by them, that any disease process occurring in a person who has once had malarial fever is prone to take on an intermittent or periodic character ”

“ Altogether, the blind, lame, and unhappy wretch— still retaining his intellect, but devoid of every sense except that of hearing, breathing with difficulty through a stenosed larynx, and racked by neuralgic pains and irregular outbursts of fever— comes to present, before the inevitable death from exhaustion occurs, a sadder, more loathsome, and more repulsive picture than anything imagination could conceive. ”

“ It would appear that typhoid is not only a common disease among Europeans in the tropics, but that it is also a very virulent one, with a death-rate twice as heavy as the death - rate of typhoid in England. According to my experience in China, not only is the tropical form grave from the outset, but it is extremely liable to relapse. In England the death-rate is put down at about 1 in 8 attacked; but in India the elaborate and carefully prepared statistics show a death-rate of rather over 1 in 3. Typhoid in India, indeed, kills more European soldiers than does cholera. ”

“ The latency of a germ for twenty, thirty, forty, or even seventy years is an extremely improbable thing and without parallel in pathology. Atavism, or rather, the appearance of atavism, frequently met with in leprosy, is also against such a supposition; for, although we can understand infection of an ovum by a leper parent, we cannot understand the transmission of a germ from a grandparent to a grandchild through a parent who is not, never was, and may never become a leper. Such a thing would imply proliferation of the bacillus in the parent without pathological evidence of its presence. ”

“ Etiology.—Doubtless depending on the proliferation in the affected tissues of some specific micro-organism, not yet satisfactorily separated, the germ of sloughing phagedæna attacks the healthy as well as the debilitated, young or old, male or female. It finds its special opportunity in the bodies of men who, from overwork, underfeeding, exposure, malaria, dysentery, scorbutus, and the like, are physically depressed. Thus it is apt to attack the half-starved, malaria-stricken pioneers in jungle lands, overdriven slave gangs, and soldiers campaigning in the tropics. ”

“ In many forms of malarial disease, if life is to be saved, action must be prompt, decisive, energetic, and based on accurate diagnosis. The diagnosis of ordinary agues may be postponed for a day or two without much danger, and be made correctly enough without the microscope; but every now and again a pernicious attack is sprung upon the practitioner, the nature of which he must be able to recognize at once, and recognize with confidence. When the parasite is seen in the blood, it is surely known that there is a malarial element in the case and that quinine is indicated. ”

“ In most places in the tropics dysentery of one form or another is always to be found; in some places and seasons more than in others. On the whole, it may be advanced that wherever the general hygienic conditions are bad, wherever the soil is much fouled by excreta, and especially where the water supply is polluted, wherever many people are crowded together in one building or camp, where the food is coarse, monotonous, or unsound, there, especially in tropical and sub-tropical climates, dysentery is or becomes endemic, and may become epidemic. ”

“ In the event of an outbreak in a town, it must be borne in mind— first, that there is an intimate connection between rat plague and human plague; second, that rat plague is conveyed to human beings, and, once established in human beings, is communicable to others and to rats by means of the expectoration, by the discharges from the bowels and by the urine, and by discharges from the buboes or glandular swellings; and third, that a plague in rats usually precedes plague in human beings. ”

“ It is very questionable if in practice any system of rigid quarantine, no matter how carefully devised and theoretically perfect, is ever absolutely protective. Its working is necessarily at the mercy of a large number of individuals, any one of whom, either from incompetence or from dishonesty, may permit its regulations to be broken through. Even if the introduction of plague by man could be prevented in this way, it is difficult to see how its introduction by rats or mice could be effectually guarded against. ”

“ A very few individuals are absolutely immune and can live in intensely malarial places with impunity. It is a well-established fact that the negro in Africa, although he does get fever, does not get it so frequently nor so severely as the European; even although the latter, from his hygienic ways of living, is of the two much the less exposed to infection. The Chinese, the Malays, and some other dark-skinned races also appear to enjoy a comparative immunity—— an immunity considerably less pronounced, however, than that enjoyed by the African and West Indian negro. ”

“ THE subject of liver disease is everywhere a difficult and complicated one. It is especially difficult in tropical countries; for not only is the resident there liable to all the forms found in temperate climates, but he is exposed, in addition, to various potent predisposing and exciting causes of liver disease not present, or only present in a very mild degree, in more temperate latitudes. These additional causes of liver disease, inseparable from the tropics, are heat, malaria, and, especially, amoebic dysentery. ”

“ The only country in northern Europe in which at the present day it may be said to linger to any extent is Norway, where, in places, it is still by no means uncommon (in 1890 there were 1,100, in 1906 under 500 known lepers) ; but even here, under a system of segregation and comparative isolation— more humane perhaps in its application than that practised by our ancestors, although identical with it in principle— the disease is rapidly dying out.
Apart from Egypt, we know nothing of the early history of leprosy in Africa. We are equally ignorant as regards aboriginal America. ”

“ Biological peculiarities explained.— The little we now know of the life-history of the guinea-worm explains many things that were formerly mysterious. We now understand why the parasite, on attaining maturity, makes for the legs and feet; these are the parts of the human body most likely, in tropical countries, to come in contact with puddles of water, the medium in which cyclops— the intermediary host —lives. We can understand, also, why it is that the contact of water with the skin of the host causes the guinea-worm to expel her young ”

“ Whatever favours the presence and increase of the malaria bearing species of mosquito tends to the increase of malaria, and vice versa; whatever favours the access of these insects, and the parasites which have passed into them, to the human body favours the acquisition of malaria.
It must not be forgotten that the malaria parasite, after giving rise to fever within a few days of its original invasion of the human body, tends to pass into a latent condition from which it wakes up into clinical activity again only after longer or shorter intervals ”