Improved Clinical Outcome After Treatment of Mycobacterium abscessus Complex Pulmonary Disease in Children With Cystic Fibrosis

Epidemiology and management of nontuberculous mycobacterial disease in people with cystic fibrosis, the Netherlands

BACKGROUND

Nontuberculous mycobacteria (NTM) are opportunistic, difficult to treat pathogens. With increasing prevalence of NTM infections in people with cystic fibrosis (pwCF) and the improved life expectancy, the burden is expected to grow.

METHODS

We assessed the epidemiology and management of NTM isolation and disease in pwCF in the Netherlands using a survey and retrospective, case-controlled data from the Dutch CF Registry. We determined the isolation prevalence, treatment and outcomes from 2013-2019.

RESULTS

NTM isolation prevalence increased from 1.0% to 3.6% (2013-2019). This was a single NTM isolation in 53.7% of the adults and 60.0% of the children. M. abscessus and M. avium complex (MAC) were most frequent (47.1 and 30.9%). Of the treated pwCF, 48.5% attained culture conversion of M. abscessus; 54.5% for MAC. Children with an NTM isolation showed more infections with S. maltophilia and/or A. fumigatus (p < 0.001) compared to controls. In the year prior to NTM isolation, children in the NTM group had a lower mean FEV1% predicted (81.5 ± 16.7 vs. 88.6 ± 15.3, p = 0.024), while adults in the NTM group had more IV antibiotic days compared to controls (60 vs. 17, p = 0.047). In the following years, FEV1% predicted declined faster in pwCF with NTM than the control group (children: -3.8% vs. -1.6%, p = 0.023; adults: -0.7% and 0.4%, ns).

CONCLUSIONS

The isolation prevalence of 3.6%, poor treatment outcomes and associated lung function decline emphasize that NTM pulmonary disease (NTM-PD) is a significant health issue among pwCF in the Netherlands. Its prevention and treatment require increased attention.

Hierarchy of customer goals: conceptual framework and new insights

Purpose

The purpose of this paper is to: (1) better understand the structure (hierarchy) of customer goals providing conceptual clarity; and (2) propose a hierarchy of customer goals conceptual framework that explicates how healthcare customer goals are linked to drivers and outcomes, thus building theory and informing practice.

Design/methodology/approach

The research draws on 21 in-depth interviews of patients with a chronic disease. Drawing principally on construal-level theory and using manual thematic analysis and Leximancer, this article provides new insights into customer goals.

Findings

In a first, the authors identify a two-dimensional structure for each of the three main goal types, which previously had been viewed as unidimensional. The authors develop a conceptual framework linking drivers of goal setting (promotion/prevention focus world view and perceived role) with goal type (life goals, focal goals and action plan goals and their respective subgoals) and outcomes (four forms of subjective well-being). Visual concept maps illustrate the relative importance of certain health-related goals over others.

Research limitations/implications

The usefulness of the authors’ conceptual framework is demonstrated through the application of their framework to goal setting among healthcare customers, showing links between the structure of goals (life goals, focal goals and action plan goals) to drivers (promotion/prevention focus world view and perceived role) and outcomes (subjective well-being) and the framework's potential application to other service settings.

Originality/value

This study contributes to healthcare marketing and service management literature by providing new insights into goal setting and proposing a novel hierarchy of customer goals conceptual framework linking drivers, goal types and outcomes.

Biofilms of Mycobacterium abscessus Complex Can Be Sensitized to Antibiotics by Disaggregation and Oxygenation

Pulmonary infection with the multidrug-resistant Mycobacterium abscessus complex (MABSC) is difficult to treat in individuals with cystic fibrosis (CF). MABSC grows as biofilm aggregates in CF patient lungs, which are known to have anaerobic niches. How aggregation and anoxic conditions affect antibiotic tolerance is not well understood. We sought to determine whether disaggregation and oxygen availability sensitize MABSC isolates to recommended antibiotics. We tested the susceptibilities of 33 isolates from 22 CF patients with MABSC infection and a reference strain to the following antibiotics: amikacin, azithromycin, cefoxitin, ciprofloxacin, clarithromycin, imipenem, kanamycin, linezolid, moxifloxacin, rifampin, tigecycline, and sulfamethoxazole-trimethoprim. Isolates were grown in Mueller-Hinton broth with and without the disaggregating detergent Tween 80 (5%). Time-kill curves at days 1 and 3 were generated for oxic and anoxic amikacin treatment in 4-fold dilutions ranging from 2 to 512 mg liter^-1 Scanning electron microscopy was used to visualize the aggregation patterns, while confocal laser scanning microscopy and microrespirometry were used to visualize biofilm growth patterns. Disruption of MABSC aggregates increased susceptibility to amikacin, tigecycline, kanamycin, azithromycin, imipenem, cefoxitin, and clarithromycin (P < 0.05, n = 29 to 31). Oxygenation enhanced the killing of disaggregated MABSC isolates by amikacin (P < 0.05) by 1 to 6 log units when 2 to 512 mg liter^-1 of amikacin was used. This study explains why current drug susceptibility testing results correlate poorly with treatment outcomes. The conditions achieved by oxic culturing of planktonic isolates in vitro do not resemble the hypoxic conditions in CF patient lungs. Biofilm disruption and increased O₂ availability during antibiotic therapy may be new therapeutic strategies for chronic MABSC infection.