Recent advances in the diagnosis of schistosomiasis

Abstract

The techniques for the immunologic diagnosis of schistosomiasis include serologic methods and the use of the intradermal test. In the serology of schistosomiasis, a number of techniques, such as flocculation methods utilizing cholesterol/lecithin, bentonite, and latex, have been employed. Soluble antigens have been used in complement fixation and hemagglutination tests and in agar gel methods such as gel diffusion, immunoelectrophoresis, and countercurrent electrophoresis. Particulate antigens prepared from life cycle stages of the parasite or cryostat sections of adult worms or soluble antigens covalently bound to agarose beads (DASS) have been used in the immunofluorescent test. Life cycle stages (eggs, miracidia, and cercariae) have been used in a number of different in vitro tests. A new enzyme linked immune sorbent assay (ELISA) for schistosomiasis has been recently used for this and a number of other parasitic diseases. A comparative evaluation is made of the usefulness of the various serologic methods for the detection of infections in children (acute) and in adults (chronic) for epidemiologic purposes, for chemotherapeutic cure, and as an evaluation of the immune status of the individual. The sensitivity and specificity of the intradermal test when performed with homologous and heterologous antigens are reviewed. The usefulness of the immediate skin test, the Arthus reaction, and the delayed skin reaction for diagnosis, epidemiology, and evaluation of the immune status of the infected individual are discussed.