Isolation of Blastomyces dermatitidis from pigeon manure.

We recently diagnosed and treated a 45-year-old white male horticulturist with acute progressive blastomycosis. Epidemiologic studies revealed that the patient used a load of pigeon manure as fertilizer approximately 6 weeks before becoming ill. He used the pigeon manure only once, resealed the remainder, and stored it in his hothouse. Samples of the pigeon guano were digested with 10 per cent KOH, and the characteristic yeast forms of Blastomyces dermatitidis were seen in large numbers. The fungus was cultured from another sample of the same material. This is the first time that the pathogenic fungus B. dermatitidis has been isolated from the environment in association with a human case.