Intradermal Response to Egg Antigen in Humans with Active and Treated (Fuadin) Schistosoma mansoni Infections

Summary 104 Puerto Rican individuals known to be infected with Schistosoma man-soni were skin tested with antigen prepared from lyophilized eggs and cercariae. 35.6% reacted to egg antigen while 95.2% reacted to the cercarial antigen. The discrepancy was found to lie in those who were passing living eggs and had no skin sensitivity to egg antigen while those who had been treated more than a year before approached in percentage the skin reactivity with cercarial antigen.