A note on the transmission of spiroch ætes

Abstract

Leishman and other authors have shown that the anal and coxal excretions voided by ticks (Ornithodoros moubata), capable of transmitting spirochætes (Spirochæta duttoni), are infective and that susceptible animals inoculated with these fluids develop a spirochætal infection. It has been asserted that animals upon which infected ticks have fed will not become infected, unless these fluids are voided while the ticks feed, and it has been suggested that the infection is transmitted by the flowing of the fluids into the wounds made by the mouth-parts of the ticks in feeding. Spirochætes had not been seen in these fluids and it was suggested that they existed there in a coccoid form.

On several occasions, coxal and anal fluids, excreted by infected ticks, coming from Uganda and British Central Africa, have been examined. In every instance the fluid was taken while the ticks fed upon an uninfected animal. The fluid collected was free from blood and, in two instances, coxal fluid was collected apparently free from anal excretion. On six occasions, after the fluid had been centrifugalized, spirochætes were found in it; their morphology is not distinct from that of Spirochœta duttoni. Spirochætes were found in the fluid that apparently contained no anal excretion.