Airborne fungal organisms are ubiquitous in the environment and are a significant cause of morbidity and mortality in avian as well as other zoological species.1,2,3 Prevention is an important strategy in controlling aspergillosis, and requires a clear understanding of environmental risk factors.4 The purpose of the study was to identify environmental variables that can influence positive detection of airborne Aspergillus spp. in a zoological park. Twenty-one predetermined locations around SeaWorld of California were sampled using the portable Super Air Systems (SAS) Super 180 Microbial Air Sampler (Bioscience International, Rockville, MD) every two weeks for twenty-four continuous months. At each sampling twenty-two environmental variables were documented. The frequencies of environmental factors associated with positive detection of airborne Aspergillus spp. were compared by the use of logistic regression. The lowest monthly prevalence of airborne Aspergillus spp. was during the warmest months of June through August. The odds of detecting aerosolized Aspergillus spp. were 3.03 times lower in indoor spaces with high-efficiency particulate air (HEPA) filtration systems, daily cleaning protocols used to routinely remove organic material, and the maintenance of cool ambient temperatures. In contrast, the odds of airborne Aspergillus spp. detection were 1.63 times higher in samples collected indoors without the protective features listed above. Locations with organic material present, with the exclusion of wood, were 1.77 times more likely to have Aspergillus spp. detected. Previously established environmental risk factors such as moisture and environmental disruption, were not found to be associated with aerosolized Aspergillus spp. in the present study.5,6,7 Our findings suggests that aerosolized fungus may not be seasonally influenced in mild climates, such as in San Diego, CA. The results further confirm that protective features, such as HEPA filters, removing organic debris and cool ambient temperatures, can be successful in minimizing the aerosolized fungal loads, and should be utilized when appropriate for zoological species. Thus environmental air sampling in zoological facilities may shed light on environmental variables unique to each facility. Aerosolized fungal surveillance is an effective way for zoological facilities to identify environmental risk factors for Aspergillus spp. and direct prevention of aspergillosis in susceptible animals.
The authors wish to thank our colleagues at SeaWorld of California. We are especially grateful to Justin Brackett, Lara Jones, Stephanie Costelow, Lauren Dubois, Pamela Thomas, and the SeaWorld Clinical Laboratory Scientists for their efforts and support of the project.
* Presenting author
+ Student presenter
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