Diagnostic des microsporidioses intestinales

Microsporidia are spore forming obligate intracellular parasites, recently reclassified from protozoa to fungi. Human microsporidiosis have emerged with the HIV/AIDS pandemic. Enterocytozoon bieneusi and Encephalitozoon intestinalis, which causes gastrointestinal diseases, are the most prevalent agents. Currently, they are increasingly diagnosed in otherwise immunocompromised patients, including organ transplant recipients, but also in children, travelers and the ederly. Chronic or self-limiting diarrhoea is the most common symptoms in immunodeficient or immunocompetent individuals. Direct examination of the stools stained by chemofluorescent agents stains (UVITEX 2B, calcofluor white M2R) and/or Weber's modified trichrome stain is a sensitive, noninvasive test which can be successfully implemented in a clinical laboratory. Species identification, which is absolutely necessary to start the relevant treatment, can be achieved by PCR targeting the small subunit rRNA or indirect immunofluorescence using monoclonal antibodies directed against spore wall. The newly described PCR methods, quantitative for assessing spore shedding intensity and treatment efficiency, multiplex for the simultaneous detection of the 2 species, are very powerful tools. Infections caused by E. intestinalis were treated with albendazole, while only fumagillin has been shown effective for eradicating E. bieneusi.