A study entitled “Prevalence and impact of Streptococcus pneumoniae in adult cystic fibrosis patients: a retrospective chart review and capsular serotyping study” was published in the BMC Pulmonary Medicine by Christina S. Thornton, first author, and Michael D. Parkins, senior author, from the University of Calgary along with colleagues. In this study, the research team determined the incidence, prevalence, serotype and clinical impact of Streptococcus pneumonia in adults with Cystic Fibrosis.
Cystic fibrosis (CF) is a genetic disease that affects various organs, characterized by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein and by complex polymicrobial communities within the lower respiratory tract. The disease can lead to regular infective pulmonary exacerbations with opportunistic pathogens.
Streptococcus pneumonia (S. pneumonia) is a relevant pathogen implicated in various respiratory diseases including otitis media, pneumonia and sinusitis. While S. pneumonia is a common pathogen affecting the general population, it has not been identified in CF. The prevalence of pneumococcal nasal-pharyngeal asymptomatic colonization in the healthy adult population has been estimated to be around 20 to 50%. Additionally, prevalence studies on Pneumococcus in patients with cystic fibrosis have been mainly focused on the pediatric groups and outcome data is absent. In various studies it was found in CF patients increased biofilm formation of S. pneumoniae and antibiotic resistance.
The research team analyzed the incidence, prevalence, serotype and clinical impact of S. pneumoniae in adults with CF by performing a review on a clinical and microbiologic database from a single adult CF center in Canada between 1978 and 2013. During the review, the authors found 15 out of 318 adult CF patients (5%) with transient Pneumococcus colonization, with none developing persistent infection. They performed capsular serotyping that revealed a wide distribution of various serotypes within these isolates. The lung function was evaluated during the isolation of incident Pneumococcus and compared with values before and after isolation. They did not observe considerable reduction in spirometry values, nor an augmentation in antibacterial therapy prescription.
Overall, the research team concluded that incident S. pneumonia infection is neither frequently correlated with an increase in clinical aggravation nor indicative of chronic infection in this group of patients.