Nuevos conceptos acerca de la epidemiología del tifus

Abstract

The classic conception of the man-louse-man cycle of typhus fever was expanded in the early 1930's to separate the flea-borne (murine) form; it was later demonstrated that the epidemic form could recrudesce, often years after an initial attack and in the absence of lice

In the past decade, published and unpublished information in Ethiopia and Egypt has provided overwhelming and surprising evidence that the epidemic form, and probably the murine form also, are involving domestic animals. There is as yet no explanation of how this is occurring, but potentialities in the reservoir mechanism must be considered. The finding by several authors of significant antibody titers to one or both forms in various livestock has been reinforced by isolation of Rickettsia prowazekii from the blood of goats and sheep in Ethiopia by Reiss-Gutfreund and of donkeys in Egypt by Imam and colleagues (unpublished) under circumstances that cannot be impugned. Isolations of R. typhi (murine typhus) from animals have yet to be accomplished, but the proportion of animals which are specifically seropositive in Egypt leaves little room for doubt about the involvement of this agent

Attempts to infect a few young livestock with R. prowazekii in three laboratories have so far revealed high sero-conversion without marked clinical signs or demonstrable rickettsemias, although Reiss-Gutfreund reported infecting ticks ...(AU)