since the epidemic heretofore referred to, which occurred in the city of Philadelphia in the years 1869– 70. Should cases of the disease again be brought to our shores, prompt isolation of the sick and the disinfection of excreta would probably suffice to prevent its extension

CHAPTER VI

TYPHUS FEVER

TYPHUS YPHUS fever, also known as "spotted fever," "ship-fever," etc., is an infectious disease which has doubtless prevailed in Europe for many centuries, although no definite account of a disease which can be identified with typhus is known of an earlier date than the eleventh century. It was not, however, until the sixteenth century that the disease was described in a tolerably satisfactory manner by the Italian physicians (1505 to 1530). Epidemics of typhus have frequently been associated with the devastations of war and the scarcity of food resulting from such devastations; or from failure of crops, which is one of the principal predisposing causes of the disease.

During the eighteenth century the disease prevailed extensively in the various countries of Europe and especially in England, in which country three severe epidemics occurred. In two of these (1718-21 and 1728-31) the disease was widely prevalent in England

and Scotland. During the ten years following 1734, and again in 1757 to 1775, the disease prevailed in the track of contending armies over a large part of eastern and central Europe. The last mentioned period includes the time of the Seven Years' War, and of the war between England and Spain. At the end of the eighteenth and the beginning of the nineteenth centuries typhus was again very prevalent in Europe. Hirsch, in his Handbook of Geographical and Historical Pathology, says with reference to this period :

"The fourth and by far the severest period of typhus in the eighteenth century occupies the last ten years of it; it begins with the revolutionary wars on French soil, and ends, in the second decade of the present century, with the final retreat of the French army across the Rhine, the overthrow of the empire of Napoleon, and the restoration of peace."

Widespread epidemics of typhus in Europe ceased with the ravages attending the wars of Napoleon, with the exception of the years 1846-47 when the disease was somewhat widely diffused. In Ireland and in certain other parts of Europe the disease is apparently endemic, and any unusual period of distress is apt to be followed by an epidemic. In America the disease has prevailed in Mexico from an early date and is said to be endemic in the city of Mexico and other localities in the interior. It has also been

of frequent occurrence in Chili and in Peru. The disease has frequently been introduced into the United States by immigrants from Europe, and local epidemics have resulted from such importation, especially in New York (1818, 1827, 1837, 1847) and in Philadelphia (1827, 1835, 1847). Fortunately the disease is unknown in other portions of the United States, probably because our history does not include any famine periods, such as have apparently constituted an essential factor in the epidemic prevalence of the disease in European countries. Africa and Asia have been to a great extent exempt from this scourge, although it has prevailed in northern Africa, in Persia, and in Syria. Typhus is essentially a disease of temperate and cold countries. In the populous countries and islands of the tropics it is practically unknown. Epidemics occur more frequently during the winter and spring months than in summer. This is probably due to the fact that it is personally contagious. Like other diseases which are communicated from person to person, it is more likely to extend when cold weather leads to an indoor life and more intimate and continued association of individuals. Again, the fact that scarcity of food is more likely to occur in winter and in the early spring is probably a factor of some importance in determining the seasonal prevalence of the disease.

The influence of insanitary conditions in favouring the epidemic extension of typhus is generally admitted. This is so well stated by Hirsch that I cannot refrain from again quoting from this trustworthy author:

"It is always and everywhere the wretched conditions of living, which spring from poverty and are fostered by ignorance, laziness, helplessness, in which typhus takes root and finds nourishment; and it is above all in want of cleanliness, and in the overcrowding of dwellings, that are ventilated badly or not at all, and are tainted with corrupt effluvia of every kind. The prototype of these conditions is found in Ireland, which is the greatest sufferer from this disease."

The same conditions as to overcrowding, want of ventilation, and insanitary surroundings have been the determining factors in the development of epidemics in prisons, on shipboard ("ship-fever"), and among colonies of workmen brought together to prosecute great engineering enterprises (canals, railways, etc.), and not provided with proper quarters. When poorly housed and left to their own resources, labourers or soldiers will inevitably develop insanitary conditions in and around the barracks, huts, or tents occupied by them, and some pestilential malady will just as inevitably obtain a foothold among them, with more or less disastrous consequences.

The germ of typhus fever has not been discovered, but it is an eruptive fever in which, as in smallpox, the infectious agent is probably given off from the