Parasitological examinations and immunodiagnostic advances in fluke infections.
A reliable diagnosis of fluke infections should be based on the demonstration of parasite eggs in either faeces, duodenal liquid or sputum, depending on the type of infection. Such an examination permits the identification of the species, and counting eggs establishes the intensity of infection. Unfortunately this examination is useful only when intensity is rather high. The diagnosis of slight infections is uncertain and can vary considerably from one sample to another. In this area of parasitological diagnosis no significant progress has been made in the last few years. On the other hand, in serodiagnosis many recent studies have been published. It should be noted that there are cross reactions between various human fluke species and Schistosoma mansoni. The common antigen varies accordingly. There are 4 groups of parasites that are antigenically close: F. hepatica and F. gigantica; Clonorchis sinensis and Opisthorchis viverrini; P. westermani; P. africanus, P. uterobilateralis, P. ecuadoriensis. The cross reactions between these groups are not very intense and forbid the use of heterologous antigens. On the other hand, among the Paragonimus spp., P. westermani is antigenically quite distinct from the others. Antigens extracted from these various species can be purified. The main progress in this area has been made with Fasciola hepatica. Certain authors have suggested the use of excreted-secreted antigens that seem to improve the specificity. For early serodiagnosis, IFI (indirect immunofluorescence) and the ELISA test (enzyme linked immunosorbent assay) are probably the best (positive two weeks after experimental infection of mice with F. hepatica).(ABSTRACT TRUNCATED AT 250 WORDS)
D000947:Antigens, Helminth / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D010270:Parasite Egg Count; D014201:Trematode Infections / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology
D000947:Antigens, Helminth; D007074:Immunoglobulin G