Infections à microsporidies, Isospora et Sarcocystis

Abstract

Microsporidia and Isospora and Sarcocystis coccidia are unicellular parasites responsible for enteric infections in humans. The development of these parasites is intracellular. Microsporidia and Isospora infect predominantly immunocompromised patients. Severe clinical manifestations result from the dissemination of the infection in the absence of cellular immune response. Intestinal microsporidiosis, an infection unknown before AIDS pandemia, was the prevalent cause of diarrhoea in HIV infected patients from industrial countries, before the introduction of highly active antiretroviral therapies. Apparently HIV infection did not increase the incidence of Sarcocystosis. Microsporidiosis and isosporosis are still reported in countries where AIDS pandemia remains uncontrolled. Recent epidemiological data indicate the occurrence of a wide reservoir of animal hosts for microsporidia causing intestinal infections in humans. Man is the unique reservoir for Isospora belli, the species responsible for human isosporosis. One animal host (pig or bovine) is reported for the two Sarcocystis species which complete their development in the human. Different methods are available for the detection of these pathogens in patients, human and animal hosts and the environment.