Investigators from multiple institutions conducted a prospective cohort study to describe the epidemiology of lower respiratory infections in children with cystic fibrosis (CF). Patients were eligible if they were diagnosed with CF after newborn screening and were participating in the Australian Respiratory Early Surveillance Team for CF program at 2 Australian hospitals between 2000–2018. Participants received a bronchoscopy with bronchoalveolar lavage (BAL) at 3 months, 12 months, and annually until age 6. BAL was collected in the right middle lobe and lingula and sent for culture. Clinical management of participants’ CF followed international guidelines, including routine anti-staphylococcal prophylaxis from diagnosis until age 2 years and attempts to eradicate Pseudomonas aeruginosa when detected on BAL with IV, inhaled, and/or oral antibiotics.
Investigators used descriptive statistics to determine the point prevalence of pathogens cultured from BAL samples. Associations between infections were also assessed. The change in pathogen prevalence over time was determined using generalized estimating equation models.
There were 380 participants included in the study, with 1,759 BALs. The most common cultured pathogens overall were Aspergillus species (11%), Staphylococcus aureus (11%), nontypeable Haemophilus influenzae (9%), and P aeruginosa (8%). The median age at first acquisition of these common pathogens was 2.4 years for P aeruginosa, 2.5 years for S aureus, 3.1 years for H influenzae, and 3.2 years for Aspergillus. There were significantly increased odds of P aeruginosa, Aspergillus, or S aureus infections if the same pathogens were detected in the previous year.
By 6 years of age, 89% of participants had at least one lower respiratory tract infection, with 32% having at least one infection with P aeruginosa and 40% with Aspergillus. There were significant decreases in the prevalence of P aeruginosa, S aureus, and H influenzae over the study period. There was no significant change in the prevalence of Aspergillus over time.
Investigators conclude that P aeruginosa, S aureus, H influenzae, and Aspergillus are all common early pathogens in children with CF, and all but Aspergillus have declined in prevalence over the last 2 decades.
Dr Winer has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
Airway infection remains a major cause of morbidity and mortality in children with CF.1 The current investigators evaluated the longitudinal results of an aggressive treatment approach that included amoxicillin-clavulanate prophylaxis from birth through age 2 years and antipseudomonal eradication. During the study period, there was a significant decrease in the prevalence of S aureus and P aeruginosa. Although Aspergillus was the most prevalent pathogen at the end of the study, its prevalence did not change over time.