Microsporidia generic

Microsporidia generic

Microsporidia are intracellular protozoan living as a parasite in many animal species.

Their role in human pathology, essentially in chronic diarrhea, keratitis or generalized infections in AIDS patients, is recently known. 6 genders of Microsporidia were identified in human affections: Enterocytozoon, Encephalitozoon,Nosema,Pleistophora and Trachipleistophora, Vitaforma, Brachiola.

Some rare auto-resolutive microsporidioses cases were reported on immunocompetent or immunosuppressed patients non HIV infected. But the majority of the cases concern HIV+ patients at an advanced stadium (< 50 CD4) of the disease, and are essentially caused by the Enterocytozoon and Encephalitozoongenders.

Enterocytozoon bieneusi is the only known specie of Enterocytozoon. This enterocyte parasite would be responsible of 15 to 30 % of chronic diarrhea with a bad absorption syndrome observed on these patients, leading to a progressive thinning down, dehydration and denutrition. E. cuniculi, E. hellem, E. intestinalisbelong to the gender Encephalitozoon. The affinity of these parasites for macrophage explains their dissemination in the organism with diverse clinical manifestations (hepatitis, peritonitis, pneumopathia?). Only E. intestinalis develops in enterocytes and in macrophages, it is responsible for chronic diarrhea and disseminated infections.

The spore is the resistance and dissemination form. The contamination is made by ingesting water or food containing spores, sometimes by inhalation.

There is no molecule able to treat with success every Microsporidia species infecting human. Only E. intestinalis is sensible to a treatment by albendazole, which makes it its first intention treatment. Fumagilline is also very effective in treating infections caused by E. hellem or E. intestinalis, but it would be very effective against intestinal infections caused by E. bieneusi. However, its prescription remains sensible due to a strong toxicity.