[Familial eosinophilia: contribution of parasitology to its diagnosis].

It has been observed, at the turn of the century, that members of some families showed a peripheral blood hypereosinophilia. Despite all possible investigations at that time, it was not possible to link it up with a known and well established disease. It was named "family acquired eosinophilia" by Di Guglielmo. nowadays, it has been established that some congenital defects such as the Omenn syndrome and the Wiskott-Aldrich syndrome are associated with hypereosinophilia. Eosinophilia is well known as a sign of allergy, but contaminations with helminths are an important cause of familial hypereosinophilia. In a case of familial distomatosis by Fasciola hepatica, several members of the same family were infected after eating wild cress. An epidemiological study was carried out on 22 families whose several members in a same family had an hypereosinophilia, a parasitosis was serologically diagnosed using such methods as immunoelectrophoresis, Elisa or Western blot. Among these 22 families, 10 had contracted fascioliasis and 4 who had eaten contaminated horse meat contracted trichinosis. For some other families, eosinophilia was not well documented, it concerned cysticercosis for 3 couples after eating meat of raw pork, one family with intestinal distomatosis to F. buski after consumption of aquatic plants and lastly toxocarosis, zoonosis whose contamination is acquired by geophagy but also by eating raw vegetables (salad), fruit (strawberries) and by drinking contaminated water, affected 5 families. In one family, anisakiasis with hypereosinophilia had been contracted by eating raw fish. In another one, trichostrongyloidiasis was contracted by eating raw vegetables from the family garden. The diagnosis is often oriented, for the members of a same family, who are asymptomatic or pauci-symptomatic, by the blood cell count that shows an hypereosinophilia. Furthermore, a collective outbreak of strongyloidiasis epidemic among 115 individuals by oral route is reported, showing that such a way of transmission is possible.