Photo Credit: Kateryna Kon

The following is a summary of “Clinical epidemiology and impact of Haemophilus influenzae airway infections in adults with cystic fibrosis,” published in the October 2024 issue of Infectious Disease by Weyant et al. 

Haemophilus influenzae is prevalent in the airways of persons with cystic fibrosis (pwCF), and its association with pulmonary exacerbations (PEx), yields a decline in lung function.  

Researchers conducted a retrospective study to examine the prevalence, natural history, and clinical impact of H. influenzae in adults pwCF.  

They reviewed all adults pwCF who had positive sputum cultures for H influenzae between 2002 and 2016. Persistently individuals infected (≥2 samples with the same pulsotype and > 50% sputum culture-positive for H. influenzae each year) were matched 1:2 with controls without H. influenzae. Demographic and clinical data, baseline and during PEx, were collected at each H. influenzae-positive visit. Pulsed-field gel electrophoresis (PFGE) was used annually on biobank isolates to assess genetic relatedness.  

The results showed that over the study period, 30% (n = 70/240) of adults pwCF were culture-positive for H. influenzae, with 54% (n = 38) testing positive multiple times and 17% (n = 12) having a persistent infection, PFGE on 137 isolates revealed 94 unique pulsotypes; 1.5% (n = 2) were serotype f, while the remaining 98.5% were non-typeable. H. Influenzae isolation increased the risk of PEx (RR = 1.61 [1.14–2.27], P = 0.006), though this association disappeared for those who only produced sputum during PEx and annual lung function decline showed no difference.  

Investigators concluded that H. influenzae infection was common but transient among adult pwCF and was not associated with acute PEx decline. 

Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-10050-7