Page:Tropical Diseases.djvu/715



Definition.— A specific disease attended with a high mortality and characterized by fever, profound anæmia, and the development of yaws-like, fungating, prone-to-bleed, granulomatous growths on the skin and mucous membranes.

Geographical distribution. Between the 9th and 16th parallels of S. latitude, and at an elevation of from 3,000 to 10,000 feet, in certain narrow valleys of the western slopes of the Andes, an aggravated form of a peculiar disease, locally known as " verruga," is endemic.

The topical as well as the geographical range of verruga is singularly limited; it is confined to certain hot, narrow valleys or ravines, the inhabitants of neighbouring places being exempt. It is said that the disease may be acquired in merely journeying through the endemic districts, more especially if the traveller passes the night there. Etiology.— Although out-of-door workers are most liable, all ages, classes, and both sexes, including infants, are liable to attack. In the endemic centres nearly everyone sooner or later gets the disease, and thus acquires a considerable though not absolute immunity.

The fatal experiment of Carrion, who inoculated himself with the virus from one of the characteristic sores, proved that the disease is communicable. Formerly it was believed that it attacked various domestic animals; this has been disproved. Recently monkeys have been successfully inoculated. During the initial fever certain rod-like bodies are to be found in a large proportion of the red blood-corpuscles. They disappear when the eruption comes out, and are probably associated with or are an