Coccidioides posadasii infection in bats, Brazil

Abstract

Studies have demonstrated that bats (order Chiroptera) are reservoirs for many infectious agents, including protozoa, bacteria, viruses, and fungi (1). Several studies confi rm that bats have a great effect on human health because they can transmit numerous infectious agents and provide a reservoir for emerging pathogens (1,2). The interaction between these animals and pathogenic fungi is well illustrated by the occurrence of histoplasmosis outbreaks in humans who are exposed to bat droppings in the environment (3,4). In Brazil, histoplasmosis is an endemic disease that occurs mainly in patients with AIDS (5), but Histoplasma capsulatum var. capsulatum has also been isolated from bats captured in urban areas (4). To analyze the eco-epidemiologic aspects of H. capsulatum in northeast Brazil, we captured bats from urban and rural areas of Ceará State. However, the research revealed the existence of a bat that was naturally infected with Coccidioides posadasii and 2 other chiropterans with coccidioidal immunologic responses. This fungal pathogen can cause coccidioidomycosis, a serious infection in humans and animals. The mycosis is presently considered to be endemic to Northeast Brazil, as evidenced by human autochthonous cases (6–8), positive coccidioidin skin-test results (7), and isolation of the fungus from soil (7,9). We describe the isolation of C. posadasii in bats and discuss the epidemiologic effects of this finding.