Introduction. In an earlier communication in this series of studies (1) it has been indicated that positive confirmation of presumptive clinical diagnosis of schistosomiasis japonica depends on demonstration of the egg of the etiologic agent, Schistosoma japonicum. In the average individual in a heavily endemic area direct fecal film examination usually reveals one or more eggs of the parasite for each coverglass preparation. On the other hand, lightly infected persons, or those who have submitted to one or more courses of antimony treatment but are not cured, frequently have so few eggs in their stools that repeated examination of the feces without concentration technics fails to provide confirmatory evidence. For this reason methods for the concentration of eggs from larger amounts of feces are required. Faust and Meleney (2) utilized sedimentation and also a hatching technic, the advantages of which were later demonstrated by Andrews (3).For the related species, S. mansoni, Faust and Hoffman (4) found one-half per cent glycerin in tapwater superior to plain tapwater for sedimentation.
Department of Tropical Medicine, Tulane University of Louisiana, New Orleans, Louisiana; Director, Commission on Schistosomiasis, Commission on Tropical Diseases, Army Epidemiological Board, Preventive Medicine Service, Office of the Surgeon General, Washington, D. C.