21 Quoted by Murchison.
The mean age of the male patients treated at the London Fever Hospital was slightly in excess of that of the female, but in the cases analyzed by Jackson the reverse of this was observed.
The statistics of all general hospitals, with very few exceptions, show a greater or less preponderance of males over females among the typhoid fever patients treated in them. According to Murchison, of 5988 cases admitted into the London Fever Hospital during twenty-three years, 3001 were males and 2987 were females. Of 891 cases admitted into the Glasgow Infirmary during twelve years, 527 were males and 364 females. Liebermeister states that 1297 male typhoid patients and 751 female were treated in the hospital at Basle from 1865 to 1870. Occasionally, the difference is even greater than is indicated by these figures. Thus, of 138 cases observed by Louis, all but 32 occurred in males. When, however, we consider that the proportion of men who apply for admission to hospitals when sick is much larger than that of women, we should hesitate before accepting these statistics as proof that the former are more liable to be attacked by typhoid fever than the latter. Indeed, the opinion which Murchison expresses is generally accepted as correct by authors, that neither sex is more likely than the other to contract the disease. Liebermeister asserts that pregnant and puerperal women and those who are nursing infants enjoy a relative immunity. On the other hand, Nathan Smith says that while the sexes are equally liable to it, more women are cut off by it than men, in consequence of its appearance during pregnancy or soon after parturition.
It was long ago pointed out by certain French observers that newcomers are much more liable to be attacked by typhoid fever than persons who have lived for some time in an infected locality. In 129 cases examined with reference to this point by Louis, the patients in 73 had not resided in Paris more than ten months, and in 102 not more than twenty months. Bartlett noticed that during an epidemic in Lowell which he had the opportunity of observing the disease attacked the recent residents in much larger proportion than the old. Liebermeister also calls attention to this peculiarity of the disease. Murchison's experience in reference to this point has been somewhat similar, for he found upon examination of the records of the London Fever Hospital that 21.84 per cent. of the patients admitted there for typhoid fever had been residents of London for less than two years. Almost all of these patients came, he says, from the provinces of England, and were in good health and comfortable circumstances at the date of their arrival in London and for some time after. Moreover, a large proportion of them were first attacked within a few weeks after changing their residence from one part of London to another. He also refers to instances in which successive visitors at the same house at intervals of months, or even years, have been seized shortly after their arrival with typhoid fever or with diarrhoea, from which the ordinary occupants were exempt. These facts indicate with sufficient clearness that habitual exposure to the causes of the disease confers, to a certain extent at least, an immunity from their effects, just as it does in the various forms of disease arising from malaria. It is not unlikely, as has been suggested by Wilson,22 that one of the causes of the frequency of typhoid fever in the early autumn in our American cities among well-to-do people is to be formed in the circumstance that during an absence of two months or more in the mountains or by the sea they have to some extent lost the immunity acquired by habitual exposure to sewer emanations, and return to the atmosphere of the city unprotected.
22 The occurrence of typhoid fever in the early fall among persons who have spent the summer out of town is, however, susceptible of another explanation. In many instances they have returned to houses which have been not only unoccupied, but closed, during several months, and which, in consequence of the more or less complete evaporation of the water in the traps of the drain-pipes, have been thoroughly permeated by sewer gas.
There is no evidence that any particular occupation acts as a predisposing cause of typhoid fever. Among the 621 patients treated at the Pennsylvania Hospital during the last ten years, were representatives of every branch of industry, and the same fact has been observed at every general hospital, not only in this country, but abroad. There is also no reason to believe that the station in life of itself exerts much influence in predisposing to the disease. The rich suffer equally with the poor. It would appear, indeed, that since the recent general introduction of ill-ventilated water-closets and stationary washstands into the houses of the better classes the liability of the former to suffer from the disease is greater than that of the latter.
Persons recovering from an illness or in an infirm condition of health do not appear to be more liable than others to be attacked by typhoid fever. Among the many patients who have fallen under my care only a very few were in ill-health at the time of their seizure. The same fact has been noticed by Murchison and other observers. Indeed, Liebermeister goes so far as to say that typhoid fever attacks by preference strong and healthy persons, while it avoids those suffering with chronic ailments. That this latter class of patients enjoys no immunity from the disease when exposed to its causes is shown by a fact which he himself records. During his service at the hospital at Basle from 1865 to 1871 several of the patients in the medical and surgical wards were attacked by typhoid fever, the cases being especially numerous in two rooms which were situated one directly over the other. Upon investigation it was found that a wooden pipe which extended from the sewer to the roof ran by both of these rooms. The sewer at the point where this pipe ran into it was of faulty construction, and was turned at a right angle, so that the refuse matter collected there. Since this source of infection was made known repeated cleansings, washings, and disinfections have been followed by satisfactory improvement, and Liebermeister believes that if the sewer were entirely altered the infection would disappear.
It would seem only natural that intemperance, by diminishing the powers of resistance in the individual, would increase his liability to contract typhoid fever, but there is no proof that it does so. Few of the patients who have come under my care were intemperate, and still fewer were broken down by this cause. There is also no evidence that grief, fear, or any other depressing emotion is a predisposing cause of the disease, and the same may be said of bodily fatigue and overcrowding. On the other hand, much importance has been attached by writers to idiosyncrasy as a predisposing cause of typhoid fever. What the peculiarities of constitution are which increase the liability to the disease are not definitely known, but there can be no question that it occurs much more frequently, and is much more fatal, in some families than in others.
Typhoid fever occurs with the greatest frequency in this country, as it does with very few exceptions elsewhere, during the latter half of summer and the early part of autumn. Indeed, its greater prevalence at this season than at other times has given to it the name of "autumnal" and "fall fever," by which it is popularly known in many sections of this country as well as of England. On the other hand, the disease is usually at its minimum in May and June. The number of cases, however, does not usually immediately diminish upon the onset of cold weather. On the contrary, R. D. Cleemann,23 from a comparison of the mortality returns of Philadelphia for a period of ten years, observed that after diminishing in November they not infrequently underwent a marked increase in December. Of 621 cases treated at the Pennsylvania Hospital during the last ten years, 89 were admitted during spring, 259 during summer, 182 during autumn, and 91 during winter. Of 5988 cases treated at the London Fever Hospital,24 759 were admitted in the spring, 1490 in summer, 2461 in autumn, and 1278 in winter. Of the whole number, 27.7 per cent. were admitted in the two months of October and November, and in April and May only 7.3 per cent. Hirsch25 has published statistics which do not differ materially from these. He also mentions the interesting fact that in Rio Janeiro the maximum of the disease occurs in the months from March to June, or, in other words, in the season which in that latitude corresponds to our autumn. There are, however, some exceptions to the general rule of the greater prevalence of the disease during the autumn. Bartlett, who was aware of its greater frequency at that time, refers to an extensive and fatal epidemic which occurred in the city of Lowell in Massachusetts during the winter and early spring; and similar visitations have been observed in other places.
23 Transactions of the College of Physicians of Philadelphia, 3d S. vol. iii.