Prevention of chronic infection with Pseudomonas aeruginosa infection in cystic fibrosis

Abstract

Purpose of review: This review provides an update on definitions of chronicity of infection, approaches to airway sampling to detect infection, strategies for Pseudomonas aeruginosa eradication, impact of cystic fibrosis transmembrane regulator protein (CFTR) modulators and future challenges for clinical trials.

Recent findings: Rates of P. aeruginosa have decreased over the past two decades with establishment of effective eradication protocols. Definitions of chronic P. aeruginosa infection have required adaptation for healthier populations. Although molecular (PCR) approaches to early P. aeruginosa detection are sensitive, to date, earlier diagnosis has not impacted on clinical outcomes. Despite eradication regimens, some people with early P. aeruginosa fail to clear their infection. Most people also experience a recurrence and eventual transition to chronic infection. Several recent studies sought to address this gap. CFTR modulators (predominantly ivacaftor) demonstrated reduced P. aeruginosa density, although infection may persist or recur demonstrating the need for continued antiinfective therapies in the modulator era.

Summary: Future studies of approaches to P. aeruginosa eradication will be complex due to expanded availability and ongoing competitive clinical trials of CFTR modulators. Studies to address optimal eradication therapy, particularly in adults, will be required, though adequate recruitment to power these studies may prove challenging.

FIGURE 1.

Median FEV₁% predicted for people with cystic fibrosis in the United States by age (1998–2018). Source of data: Cystic fibrosis patients under care at CF Foundation accredited care centre in the United States, who consented to have their data entered. Reproduced with permission from [7^■].

FIGURE 2.

P. aeruginosa infection status based on Leeds criteria of people with cystic fibrosis in the United States by age (2017). Source of data: Cystic fibrosis patients under care at CF Foundation accredited care centre in the United States, who consented to have their data entered. Reproduced with permission from [7^■].