April, '13] TOWNSEND: VERRUGA AND TICKS 213 



of the disease, Dr. Odriozola dwells on the fact that verruga localities 

 are invariably situated either in or adjacent to deep narrow canj'ons 

 with exuberant vegetation and great summer heat combined with 

 little ventilation. Infected communities not actually situated within 

 such canyons are so close to them that their inhabitants have to pass 

 through them to a greater or less extent. 



In July. 1912, Dr. Odriozola summed up briefly, in an address on 

 verruga, certain results that have come to light since the publication 

 of his monograph, from which the following points may be given: 

 A few new verruga localities have been found since, and it is most 

 probable that others still unknown exist, being off the roads of ordinary 

 travel. All the known districts are in or next to deep ravines, where 

 malaria is co-existent with verruga. All ages and races of men are 

 susceptible, and it is also reported that verruga attacks domestic 

 animals. One of the forms of the eruption derives its name mular from 

 the fact that mules often exhibit a similar eruption supposed to be the 

 same. The disease graduates all the way from acute to chronic. It 

 thus presents many forms showing various degrees of virulence. The 

 acute form is the Oroya fever or Carrion's grave fever, which is the 

 most serious form of the disease. Three fundamental clinical char- 

 acters distinguish it — fever, anemia, prostration. The anemia is 

 always rapid and profound, and its intensity at times is almost incredi- 

 ble, in some cases the erythrocytes being reduced to 800,000 and even 

 as low as 500,000 per cubic millimeter. At the same time the white 

 corpuscles increase inversely. Patient becomes absolutely indifferent 

 and immovable, in extreme cases even a slight movement of the head 

 on the pillow being sufficient to produce vertigo. Diarrhoea is fre- 

 quent but not always present; usually present in intense cases, at 

 time becoming dysenteric and of inexorable tenacity. The high 

 fever may last from fifteen to thirty days if death does not ensue; after 

 that it begins to lower and the eruptive phase begins. The eruption 

 is of the miliar type, appearing as minute elevations of the skin, pallid 

 or roseate but sometimes intensely red. If the eruption is abundant 

 and generalized, showing vigorously, then the patient is certain to 

 recover. 



The chronic form comprises the great mass of the cases, in which 

 there is fever but not of the acute type above described. The fever 

 here may be intermittent or remittent, pains in the joints are dominant 

 especially in the hands and feet, the joints may swell- and inflame, and 

 anemia is present . The eruption is the culminating phase in both forms 

 and takes various types, the miliar already described, the nodular" of 

 small to large knots or nodules, the mular as an enlarged type of nodu- 

 lar origin, and the pseudomular as an enlarged type of miliar origin. 



