Evaluation of bacterial bioaerosol diversity and density in the indoor air of elderly care facilities

Background: Exposure to bacteria due to the presence of pathogenic agents in public centers is a significant health issue. This study aimed to identify and quantify different bacterial species present in the respiratory air of ۱۰ elderly care centers in Tehran. Methods: This cross-sectional study was conducted in public halls and bedrooms across ۱۰ different elderly care centers in Tehran, with three repetitions per location. A total of ۶۰ air samples were collected using three types of media: nutrient agar, MacConkey agar, and mannitol salt agar. Air samples were collected according to the NIOSH ۰۸۰۰ method. The samples were then analyzed using standard microbial diagnostic tests. Results: The average bacterial bioaerosol concentration in elderly care centers was ۱۸۰ ± ۱۱۷.۹ CFU/m³. The highest colony count was observed in the public hall of Elderly Care Center #۴, with a concentration of ۵۴۳ ± ۲۲۰ CFU/m³, accommodating ۳۲ elderly residents. A quarter of the sampling points had Staphylococcus aureus contamination, with Staphylococcus aureus (gram-positive) and Acinetobacter lwoffii (gram-negative) as the most common bacteria found. Conclusion: This study revealed significant variations in bioaerosol concentrations across elderly care centers. The bioaerosol concentrations were higher on average in the bedrooms compared to the common areas. These findings highlight the need for more targeted infection control measures in elderly care facilities. Improved ventilation systems, tailored to the specific conditions of these centers, can help reduce bioaerosol levels. The results also emphasize the necessity of establishing standardized bioaerosol control programs and optimizing building design and environmental conditions to mitigate health risks.

کلیدواژه ها:

Care facilities ، Gram-negative bacteria ، Gram-positive bacteria ، Indoor air quality ، Iran