Isolation of blastomyces dermatitidis from avian excrete in association with a human case of blastomycosis

The authors recently diagnosed and treated a 45 year old while male professional horticulturist with acute progressive blastomycosis. Epidemiologic studies revealed that the patient used a load of pigeon manure as fertilizer approximately 6 weeks prior to becoming ill. Because of a great deal of dust and unpleasant smell of the material, he used the guano only once, resealing the remainder and storing it in his hot house. Samples of the pigeon guano were digested with 10% KOH and the characteristic yeast forms of B. dermatitidis were seen in large numbers. Samples of the same material were directly cultured on various media and yielded the fungus. This is the first time that the pathogenic fungus B. dermatitidis has been isolated from nature in association with a human case.