Relationship of Cryptococcus Neoformans to Pigeons in Milwaukee, Wisconsin

In a longitudinal study in an around the city of Milwaukee, pigeon excreta and soil containing pigeon droppings were assayed for the presence of animal or human pathogenic fungi. Cryptococcus neoformans was isolated by intravenous and intraperitoneal mouse inoculation and by direct culture on laboratory media. The yeast was found to exist in almost all old nesting places of all sizes examined. Over a 3-year period, C. neoformans was isolated regularly from dried pigeon droppings dislodged by birds from roosting places on a large building and collected as sidewalk sweepings. This was considered indicative of active dispersal of the fungus into the air.