[Molecular probes in the study and diagnosis of parasitic diseases]

Molecular biology techniques have contributed, in the last ten years, to a better understanding of parasitic diseases. DNA probes, for example, have been successfully used not only for taxonomic purposes, but also for the diagnosis, the epidemiology and the pathogenicity of these infections. Due to their high sensitivity and specificity, the DNA probes allow, from a diagnostic point of view, the detection of very few of parasites in a given sample. This detection is also valid for any parasitic stage considered. It can be specially used to detect the infective stage in the vector, which, in epidemiological studies, is very important. The identification of parasitic species or sub-species indicates the human infectivity of species considered in the past as zoophilic. Finally, by allowing the specific identification of strains, isolates or even particular clones, the DNA probes also show differences which can be related to pathogenicity, to particular biological characteristics, or even to drug sensitivity. In this review, I relate the main results obtained in malaria and toxoplasmosis in our laboratory in Grenoble. I will also consider some recent data on amoebiasis, leishmaniasis, trypanosomiasis, filariasis, schistosomiasis and echinococcosis.