Bacterial and viral upper and lower airways infection in people with cystic fibrosis in stable condition

Background: Bacterial and viral airway infections are adverse factors for prognosis in people with cystic fibrosis (CF). The role of viral infections is unclear. Proper microbiological follow-up is essential, and the correlation between upper (UAW) and lower airway (LAW) microbiology may be important for lung disease management. We aim to evaluate airway microbiology in patients in stable clinical condition. Method(s): Between September 2021 and March 2022 in the Florence CF center, 144 nasal lavage-throat swab paired samples were collected from 72 clinically stable people with CF not chronically colonized by Pseudomonas aeruginosa. The study enrolled 59 children (median age 9, range 2-16) and 13 adults (median age 28, range 18-59). LAW specimens (72)were sampled as throat swab and UAWspecimens (72)were randomly collected by nasal lavage with two methods-Mainz (44) or Ryno-set (28). We performed conventional microbiological analyses on all samples. To screen for respiratory viruses, multiplex polymerase chain reaction (BioFire FilmArray RP 2.1 Plus) was performed. Respiratory symptoms and forced expiratory volume in 1 second (FEV1) valueswere evaluated for all patients. Result(s): Twenty-one (29%) patients tested positive for at least one virus in UAW and LAW specimens. The most frequently identified viruses were human rhinovirus or enterovirus (22%) and respiratory syncytial virus (6%). Two (3%) patients tested positive for SARS-CoV-2. Concordance between sampling methods for viral detection in UAW and LAW specimens was observed in 59 paired samples (82%), including 40 patients with no viral infections and 19 virus positive for both samples. Discordance was described in 13 subjects;10 of 13 did not show viral infection in nasal lavage. Twenty-one percent of positive nasal lavage was performed using Ryno-set and 36% using the Mainz approach. The prevalent bacteriumwas Staphylococcu aureus in UAW (53%) and LAW (69%) cultures, followed by Enterobacteriaceae (UAW 8%, LAW 6%), methicillin-resistant S. aureus (UAW 7%, LAW 6%), P. aeruginosa (UAW 4%, LAW 6%), and other clinically relevant gram-negative bacteria such as Achromobacter xylosoxidans, Stenotrophomonas maltophilia, and Ochrobactrum anthropi (UAW 7%, LAW 13%). Nasal lavage performed with Ryno-set tested positive in 72% of patients, and 64% of Mainz lavage were positive. Mainz nasal lavage showed different S. aureus and P. aeruginosa isolations (48% and 5%, respectively) than the samples collected with Ryno-set technique (61% and 4%, respectively). Concordance between sampling methods for bacterial detection in UAW and LAW was the same with the two methods (53%). Bacterial and viral infections were found in UAWand LAWof stable people with CF, but no clinical correlation was observed. Conclusion(s): The two methods of UAW lavage had slight differences in performance. Virus infection appeared to be less prevalent than bacterial infection in UAWand LAW.We did not find correlations between presence of viruses and respiratory symptoms, but further investigation is needed for a better understanding of the clinical role of viral infection in people with CF.Copyright © 2022, European Cystic Fibrosis Society. All rights reserved

Effects of the SARS-CoV-2 pandemic on attendance at the cystic fibrosis centre and the definition of the microbiological status of cystic fibrosis patients in Tuscany

Objectives: The SARS-CoV-2 pandemic and the consequent lockdown periods have profoundly changed the health habits of patients. The fear of the viral infection as well as the reorganisation of staff within the health services due to the pandemic caused a drop in patients’ attendance at CF centres. This resulted in a decrease in cultures performed, on which the definition of microbiological status is based. The ECFS definition of patients’ microbiological status (mainly the definition of chronic P. aeruginosa infection) is based on the modified Leeds criteria (>50% of the samples positive, at least 4 samples collected) or significantly raised anti-Pa antibodies. Following the different lockdown periods imposed in Tuscany in 2020 (March 9th – May 18th) we verified: • the number of outpatient visits to the Centre • the number of cultures performed compared with previous years • compliance with the criteria suggested by disease registries/standards of care for the definition of chronic infection • the utility of anti-Pa serology in the correct definition of chronic Pain the epidemic context Methods: Retrospective study on data regarding outpatient examinations, number of cultures performed and serology tests. Results: Outpatients’ attendance at the Centre (2020) [Table presented] % of patients with at least 4 cultures performed yearly. [Table presented] In 2020 we observed a significant reduction (p <0.05) in the mean number of cultures per patient and in the percentage of patients who performed at least 4 cultures. During 2020, 108 (29.2%) patients with fewer than 4 cultures performed Pa serology, 25 (23.1%) tested positive, completing the definition required by the ECFS. Conclusions: The SARS-CoV-2 infection caused a drop in patients’ attendance at the centre, compromising the correct definition of Pa chronic infection based on the number of cultures. In the pandemic context, serology could be a useful complementary test to correctly fulfill the ECFS definition. Funding: Regione Toscana K38