Interest of Nitazoxanide Treatment of Enterocytozoon Bieneusi Intestinal Microsporidiosis

Microsporidia are pathogenic fungi mainly responsible for profuse watery diarrhea, requiring management in immunocompromised patients. The main immunocompromised population affected by these infections consists of solid organ transplant recipients (SOT), mainly kidney (~70% of cases in immunocompromised patients). In this population, the infection is severe, and becomes chronic in the absence of appropriate care, the species Enterocytozoon bieneusi being found in more than 95% of these cases. Reducing immunosuppression (adjustment of immunosuppressive therapy) can sometimes be enough to eliminate the pathogen. However, in some cases, specific treatment is necessary. The only molecule whose efficacy has been proven to date to treat infections caused by E. bieneusi is fumagillin (FLISINT®), however its production has been stopped for almost 2 years. Due to the therapeutic impasse, the use of nitazoxanide (ALINIA®) to treat E. bieneusi microsporidiosis is becoming common, despite the lack of proof of its efficacy. It seems important and urgent to evaluate the relevance of the use of nitazoxanide, particularly in SOT, for the treatment of intestinal microsporidiosis due to E. bieneusi.