ABSTRACT
OBJECTIVE: Microorganisms present a global public health problem and are the leading cause of hospital-acquired infections. Therefore, it is essential to study the prevalence of microorganisms in hospital environments. The conclusion from such a study can contribute to identify the areas most likely to be contaminated in a hospital and appropriate measures that can decrease the exposure risk. MATERIALS AND METHODS: The prevalence of microorganisms in hospital air was examined in different departments by obtaining air samples with an impactor before and during the SARS-CoV-2 pandemic. A total of 2145 microorganisms were identified, and the corresponding data were jointly analyzed by area, sampling period, and concentration. RESULTS: The most frequently detected microorganisms in hospital air were Staphylococcus, Micrococcus, Neisseria, and fungi, and the more polluted departments were the hemodialysis department, respiratory department, treatment room, and toilet. Significant differences were found between the concentration of bacteria and fungi before and during the pandemic, which could be related to multiple environmental conditions. Furthermore, SARS-CoV-2 was negative in all the air samples. CONCLUSIONS: Overall, this study confirmed the existence and dynamic characteristics of airborne microorganisms in a hospital. The results contribute to the adaptation of specific measures which can decrease the exposure risk of patients, visitors, and staff.