Yellow fever was until recently one of the most dreaded of epidemic diseases. It is an acute, specific and infectious disease, non-contagious in character but occurring in epidemics, or endemics, within a peculiarly limited geographical area. It is highly fatal, but those who recover are generally immune from subsequent attacks.
It is generally regarded as an American disease, having been found by Cortez, in Mexico, and being confined principally to the American continents and islands. It also occurs in Africa and attempts have been made to show that it was originally an African disease but there is not sufficient evidence to establish this view.
There have been many noted outbreaks in the United States. Boston suffered from it in 1691 and again in 1693; New York in 1668 and as late as 1856; Baltimore in 1819. In 1793 occurred the great epidemic in Philadelphia, with a death rate of one in ten of the population. In the past century it was present almost every year in some locality of our Southern States, New Orleans being the greatest sufferer. In the latter city there were 7848 deaths from the disease in 1853, 4854 in 1858, and 4046 in 1878. The last notable outbreak was in 1905. Reed and Carroll (1901) estimated that during the period from 1793 to 1900 there had not been less than 500,000 cases in the United States.
As in the case of the plague, the most stringent methods of control proved ineffective and helplessness, almost hopelessness marked the great epidemics. A vivid picture of conditions is that given by Mathew Cary, 1793 (quoted by Kelly, 1906) in "A Short Account of the Malignant Fever Lately Prevalent in Philadelphia."
"The consternation of the people of Philadelphia at this period was carried beyond all bounds. Dismay and affright were visible in the countenance of almost every person. Of those who remained, many shut themselves in their houses and were afraid to walk the streets. * * * The corpses of the most respectable citizens, even those who did not die of the epidemic, were carried to the grave on the shafts of a chair (chaise), the horse driven by a negro, unattended by friends or relative, and without any sort of ceremony. People hastily shifted their course at the sight of a hearse coming toward them. Many never walked on the footpath, but went into the middle of the streets to avoid being infected by passing by houses wherein people had died. Acquaintances and friends avoided each other in the streets and only signified their regard by a cold nod. The old custom of shaking hands fell into such disuse that many shrunk back with affright at even the offer of the hand. A person with a crape, or any appearance of mourning was shunned like a viper. And many valued themselves highly on the skill and address with which they got to the windward of every person they met. Indeed, it is not probable that London, at the last stage of the plague, exhibited stronger marks of terror than were to be seen in Philadelphia from the 24th or 25th of August until pretty late in September."