Antigenic Property of the Oral Secretion of Fleas

Abstract

THE development of hypersensitivity to bites of blood-sucking insects in man and animals requires an initial sensitization by the insect, or by antigens prepared from the insect. A latent period occurs between the time of the initial exposure and the time when challenge elicits skin reactions characterized by delayed and/or immediate types. Thus B. Hudson et al.1 and Benjamini et al.2 demonstrated that when guinea pigs were exposed to flea bites they developed an allergic state which required a latent period of 5–7 days for the appearance of delayed reactions, and an additional 2–5 days for the onset of immediate reactions. It was further shown by Benjamini et al. that guinea pigs could be sensitized to flea bites by intradermal injection of saline solution containing antigens prepared from fleas, or by the intramuscular injection of such antigens in combination with the complete Freund's adjuvant. When sensitization to flea bites with prepared flea antigens was achieved, the latent period required for the appearance of delayed skin reactions extended from 10 to 14 days, the immediate reaction still appearing within 2–5 days following first appearance of the delayed reaction.