Page:Transactions of the Royal Society of Tropical Medicine and Hygiene, volume 9 (7).djvu/7

Rh "The base of the brain was covered by yellow puriform mntter, with no obvious change in the underlying cerebral tissue. The exudation covered the optic chiasma. and extended backwards towards the cerebellum, reaching for the space of an inch down the vertebral canal."

The subsequent history of the disease is well described in and 's monograph published this year.

Read in the light of our present knowledge, the part played by the carrier in the spread of the disease affords a clear explanation of the records of these long past epidemics.

Assuming the presence of a few permanent carriers, it only requires outside conditions which facilitate the spread of the organisms to create a large number of temporary carriers, in other words, "the number of the carriers constitutes the epidemic."

The persons who fall sick of the disease are thus but the concrete evidence of the wide diffusion of temporary carriers.

The disease spread to Canada in 1807, to Virginia, Kentucky and Ohio in 1808, appearing in "the State of New York" and in Pennsylvania in 1809.

This American epidemic was remarkable in the giving of it the name of "spotted fever," by which name it is described in a book entitled, Treatise on a Malignant Epidemic called Spotted Fever, written by North in 1811.

During this period the disease was rife in Europe also.

In 1806-7 it broke out in the Prussian Army, amongst the Spanish prisoners at Brianca, at Brest in 1813, and at Paris in 1814. These epidemics coincided with several outbreaks of typhus fever, with which the cases of cerebro-spinal fever were often confounded.

Between 1837-1850 a very wide-spread epidemic appeared in France, the disease being carried from place to place by the transfer of troops.

The years 1851-61 included a large epidemic in Norway and Sweden; in the years during which the disease raged it caused no less than 1,138 deaths in Sweden, where only two provinces out of twentv-four, and those the most northerly, escaped.

Coming down to recent years (1905-15), there has been a revival of the disease in an epidemic form over a very large area. This revival of cases appeared to have started by the large outbreak which occurred in the United States in 1904.