Elimination of a Potential Cryptococcus Neoformans Health Hazard in a Historic Building about to be Renovated

The accumulation of pigeon excrement in buildings presents a potential human health hazard from infection with Cryptococcus neoformans. This pathogenic yeast was found in specimens from an abandoned railroad terminal in Nashville, Tennessee, during the planning stage for the building's renovation. The Division of Mycotic Diseases of the Centers for Disease Control (CDC) was requested to evaluate the potential health hazard posed by the infested excrement. We recommended that the C. neoformans-positive areas be decontaminated with formalin and repairs made to the building to prevent its further use by pigeons. Workers first attempted to decontaminate the building by applying 1 quart of 5% formalin per 6 square feet of contaminated area, contrary to the amount that CDC recommended. This attempt failed to eliminate the pathogen. A second application was made seven months later using the recommended dosage of 1 gallon of formalin per 6 square feet of area. Wire and wooden panels were placed over the openings to the building to prevent further entry by pigeons. Samples of the excrement collected after the second application of the formalin were negative for C. neoformans. After the successful decontamination, renovation of the building proceeded.