Asymptomatic Enterocytozoon bieneusi microsporidiosis in captive mammals.

Human microsporidiosis, a serious disease of immunocompetent and immunosuppressed people, can be due to zoonotic transmission of microsporidian spores. A survey utilizing chromotrope 2R stain and fluorescent in situ hybridization techniques for testing feces from 193 captive mammals demonstrated that 3 animals (1.6%) shed Encephalitozoon bieneusi spores. These include two critically endangered species (i.e., black lemurs, Eulemur macaco flavifrons; and Visayan warty pig, Sus cebifrons negrinus) and a threatened species (mongoose lemur, Eulemur mongoz). The concentration of spores varied from 2.7 x 10(5) to 5.7 x 10(5)/g of feces, and all infections were asymptomatic. The study demonstrates that E. bieneusi spores can originate from captive animals, which is of particular epidemiologic importance because the close containment of zoological gardens can facilitate pathogen spread to other animals and also to people such as zoo personnel and visitors.