Approches diagnostiques des filarioses en France métropolitaine

Abstract

Filariasis is a parasite infection that is rare in Europe. It is mostly imported from Africa, but also from Asia or Central and South America. Therefore in light of suggestive clinical signs and blood eosinophilia, its diagnosis should be primarily considered in migrant subjects or expatriates who have stayed in an endemic area. Depending on the species of filaria that is initially suspected, the direct search of microfilariae larvae has to be carried out in blood (by fresh mounting, thick and thin smear, or buffy coat concentration) or in derma (by snip test or scarification). Different sampling precautions must be associated to optimize the diagnostic performance. Even nowadays in the 21st century, microscopic expertise still plays a key-role in determining species and in counting the number of larva (microfilaria). Indirect methods, such as serology, may be good alternatives to the shortcomings of direct laboratory techniques, but they suffer from lack of specificity. Eventually, one should remember that the guidelines for therapeutic management are closely linked to the accuracy of the laboratory diagnosis.