A Characteristic Exanthem in Epizootic Plague and the Experimental Reproduction of This Lesion in the Guinea Pig.

Abstract

Just subsequent to the outbreak of the epidemic of bubonic plague in New Orleans, the occurrence of a concurrent rodent plague was revealed. Every rat trapped, captured or found dead, either from disease or from fumigation, was sent to the Health Department Laboratory for full investigation.

Because of the occurrence of this epizootic, the opportunity for study of approximately 150,000 rats was presented. While engaged in this routine work, we observed that many of the rats presented a peculiar discoloration of the feet. This discoloration occurred in the living trapped rats, as well as those that were dead. The lesion was so striking in appearance that the investigation of its significance seemed justified. A special study of the rats having this discoloration was made and it was noted that, in all instances, these animals were proven to be infected with plague.

Character of Lesion: The color presented is very apparent in the feet of the infected rodent animal and occurs in both extremities; it varies from a pink to a salmon tint. The lesion is clear cut, having a distinct line of demarcation and varies in its extent of distribution. In slight infections, it is confined to the feet alone, covering both the dorsal and plantar aspects, hence the appellation “pink feet” was applied. In more marked infections, the color extends over the entire extremities and, at times, appears upon the abdominal and thoracic walls. The discoloration is not due to petechial hemorrhages such as seen in hog cholera or the hemorrhagic septicemias nor is it analogous to a scarlatina erythema, but rather suggests the tissue discolorations that are seen in carbon monoxide poisoning. It appears that there occurs either some hemolytic change, causing a laked blood aspect or that the hemoglobin is, in some manner, modified and permeates the structure.