Declining trend in chronic Staphylococcus aureus and Pseudomonas aeruginosa infections in CF patients: A 4-year retrospective analysis

<bold>Background:</bold> Airway infection with specific pathogenic bacteria is a feature of cystic fibrosis (CF). Staphylococcus aureus both methicillin-sensitive and resistant (MSSA/MRSA), is one of the first pathogens detected in the airways of CF patients. Chronic infection with Pseudomonas aeruginosa (PA) carries significant morbidity and potential mortality in CF, so prevention and/or delay of chronic PA is one of the priorities in patient treatment. <bold>Objective:</bold> We aimed to evaluate the changing rates of chronic infections with SA and PA over 4 years, by undertaking improved patient isolation measures and eradication therapy for each new SA and PA infection. <bold>Methods:</bold> We analyzed the microbiological data from the ECFSPR annual reports, for the period from 2019 to 2022. A total of 127 patients both children and adults were included in the study. <bold>Results:</bold> We identified 32 patients (24.8%) with chronic MSSA infection, 19 children and 13 adults in 2019; 28 patients (23.3%), 20 children and 8 adults in 2020; 23 (17.9%), 12 children and 11 adults in 2021; and 16 patients (13%), 9 children and 7 adults in 2022, respectively. Chronic PA infection was detected in 51 patients (39.5%), 24 children and 27 adults in 2019; 46 individuals (38.3%), 18 children and 28 adults in 2020; 44 patients (34.3%), 14 children and 30 adults in 2021; and 38 patients (30.8%), 9 children and 29 adults in 2022, correspondingly. MRSA colonization rate increased from 18.6% to 32.5% in the same period. <bold>Conclusion:</bold> There has been a decreasing tendency of chronic infections with MSSA and PA, especially in children. MRSA infection is still a significant problem in our CF population.