SECTION VII
TROPICAL DISEASES OF DISPUTED NATURE OR MINOR IMPORTANCE
CHAPTER XXXV
VERRUGA PERUVIANA AND OROYA FEVER
It is thought that Oroya fever was the disease which proved so fatal to Pizarro’s army in the 16th century. In 1870, great interest was aroused in these diseases on account of their prevalence in the workmen constructing the railroad from Lima to Oroya, a town in the Andes. At this time there was much conflict of opinion as to whether the two diseases were identical. In 1885, Carrion, a medical student of Lima, inoculated himself with the blood from a verruga lesion and died from Oroya fever about one month later. As the result of this it seemed to be established that infection with verruga material would produce the serious first-stage fever and many call the fever Carrion’s disease. Consequently these two diseases have, until recently, been considered as two stages of the same disease, the usual idea being that Oroya fever is the first stage, following which, provided the patient does not die from this very fatal fever, there sets in an eruption which is the second or verruga stage. In order to reconcile the observations of the development of the eruptive stage without a severe, febrile, preliminary one of three or four weeks, it was considered that the first stage might be exceedingly mild.
Strong and his colleagues, however, inoculated a volunteer with material from verruga lesions and sixteen days later the eruption appeared without the preliminary fever and anaemia that are so characteristic of Oroya fever, and it is now recognized that they are two distinct entities.
OROYA FEVER
General Considerations
Oroya fever is an acute, infectious disease, often terminating fatally, caused by the Bartonella bacilliformis, and characterized by an insidious onset, irregular fever, pains in the bones and a rapidly developing anaemia of the pernicious anaemia type.
The disease is chiefly found in towns situated in narrow, wind-protected valleys of the west side of the Andes, at elevations of from 3000 to 9000 feet. Townsend has suggested that a species of Phlebotomus, P. verrucarum, which is very prevalent, may be the transmitting agent. This investigator believes that verruga and Oroya fever are the same disease. It may be stated that malaria and enteric fevers, as well as verruga, are common in the localities where Oroya fever prevails and much of the confusion in the literature of Oroya fever is due to failure to differentiate the better known conditions. Strong noted that Oroya fever was common from January to April, particularly towards the close of the warm, rainy season. Cases were rare in April and May and did not occur in the months of June, July and August. He notes that verruga was not uncommon at the time when Oroya fever was not occurring. Concomitant infection with Oroya fever and verruga may occur but this is also true of malaria or malaria and verruga may exist at the same time.
Barton isolated a paratyphoid bacillus from the blood of a patient, besides which other bacteria have also been isolated. In 1909, Barton noted certain rod-like organisms in the red cells of Oroya fever patients which he considered protozoal in nature.