[Biological diagnosis of Schistosoma infestation]

For general practitioners the most important step towards the clinical and laboratory diagnosis of infestation with Schistosoma spp. is to think of it. Although schistosomiasis is the world's most frequent parasitosis after malaria, it is found in France only as imported cases (immigrants, tourists, etc.) with clinical signs that are not always very suggestive at the stage of invasion. The laboratory examinations requested can then make the diagnosis, irrespective of the time elapsed since infestation. In the early invasion stage, only the indirect serological methods (ELISA, IFI, precipitation techniques) are appropriate. The direct methods are not always informative since the parasites are still immature and do not lay eggs. But when the disease is established the diagnosis rests essentially on direct examination of urine and faeces which discloses schistosoma eggs the morphology of which varies from one species to the other.