Frequent Occurrence of Human-Associated Microsporidia in Fecal Droppings of Urban Pigeons in Amsterdam, The Netherlands

ABSTRACT Human-associated microsporidia were frequently observed in fecal samples of 331 feral pigeons in Amsterdam, The Netherlands, obtained during high- and low-breeding periods. Thirty-six of 331 samples (11%) contained the human pathogens Enterocytozoon bieneusi ( n = 18), Encephalitozoon hellem ( n = 11), Encephalitozoon cuniculi ( n = 6), and Encephalitozoon intestinalis ( n = 1); 5 samples contained other microsporidia. Pigeon feces can be an important source of human microsporidian infection.