Experimental infection of humans with Ancylostoma ceylanicum: clinical, parasitological, haematological and immunological findings.

Experimental infection of two human volunteers with Ancylostoma ceylanicum produced patent infection. Following percutaneous infection with 1200 infective larvae, there was no evidence of skin eruption, however, severe abdominal discomfort was experienced by both subjects coincidently at various intervals. Eggs appeared in the faeces five weeks after infection; low level excretion continued until termination of the infection 30 weeks after inoculation. Infection had no significant effect on haemoglobin concentrations, total white cell counts, platelet levels or spontaneous and phytohaemagglutinin-induced lymphocyte transformations in either of the infected volunteers. Persistent eosinophilia began four weeks after infection in both infected persons; lymphocytes from one subject responded transiently to stimulation with larval antigen while lymphocytes from both infected subjects responded to stimulation with adult worm antigen. Specific IgM and IgG antibodies appeared two and six weeks after infection, respectively, and persisted for the duration of the experiment.