The prevalence of lower airway infections with Pseudomonas aeruginosa, Staphylococcus aureus and Haemophilus influenzae among young children with cystic fibrosis has decreased significantly during the past 2 decades, according to a study published in the American Journal of Respiratory and Critical Care Medicine.
To analyze the prevalence of early lower airway infections among children with cystic fibrosis, researchers evaluated data for all after newborn screening who were participating in the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (ARREST CF) cohort study. Infants underwent bronchoalveolar lavage at 3 to 6 months, 1 year and annually up to age 6 years.
The study included 380 infants who underwent 1,759 bronchoalveolar lavages at two Australian hospitals from 2000 to 2018.
Among all bronchoalveolar lavage samples taken, the most common pathogens cultured included Aspergillus species (11%), S. aureus (11%), nontypeable H. influenzae (9%) and P. aeruginosa (8%). The median ages of first acquisition were 3.2 years for Aspergillus species, 2.4 years for P. aeruginosa, 2.5 years for S. aureus and 3.1 years for H. influenzae. The median age of first infection did not differ significantly for P. aeruginosa and S. aureus, but both were lower than the median age of first infection with Aspergillus species and H. influenzae (P < .05).
During the study, results showed decreases in the prevalence of lower airway infections with P. aeruginosa (P < .001), S. aureus (P < .001) and H. influenzae (P =.023). These decreases, the researchers noted, are likely why Aspergillus species — the prevalence of which did not significantly change during the study period — has recently become the most commonly isolated lower airway pathogen.
Alongside these changes in the prevalence of infections, there were significant increases in the use of chronic therapies for routine treatment of cystic fibrosis lung disease, including azithromycin, hypertonic saline and dornase alfa (Pulmozyme, Genentech) and antipseudomonal oral and inhaled antibiotics, such as ciprofloxacin and inhaled tobramycin. Use of IV antibiotics, however, which included treatment for newly acquired P. aeruginosa infections, did not change, suggesting a more aggressive approach to treatment, according to the researchers.
In an accompanying editorial, Jordana E. Hoppe, MD, MSCS, and Scott D. Sagel, MD, PhD, both from the department of pediatrics at Children’s Hospital Colorado and the University of Colorado School of Medicine, noted that the study’s findings may not be generalizable as treatment strategies at the two hospitals in the study may differ from those at other centers. The study also raises questions about the clinical significance of the increased prevalence of Aspergillus species as well as how samples should be collected.
“The findings from this study support the need for targeted research focused on the acquisition and evolution of airway pathogens early in life, and their relationship with clinical outcomes and treatment,” Hoppe and Sagel wrote. “It is vital to have a better understanding of airway infection to optimize treatment and alter the cycle of infection and inflammation and subsequent lung function decline and disease progression in patients with cystic fibrosis.” – by Melissa Foster
Disclosures: The authors report no relevant financial disclosures. Sagel reports he has received grants from the Cystic Fibrosis Foundation and NIH.