Pediatric bronchiectasis: No longer an orphan disease

Bronchiectasis is described classically as a chronic pulmonary disorder characterized by a persistent productive cough and irreversible dilatation of one or more bronchi. However, in children unable to expectorate, cough may instead be wet and intermittent and bronchial dilatation reversible in the early stages. Although still considered an orphan disease, it is being recognized increasingly as causing significant morbidity and mortality in children and adults in both affluent and developing countries. While bronchiectasis has multiple etiologies, the final common pathway involves a complex interplay between the host, respiratory pathogens and environmental factors. These interactions lead to a vicious cycle of repeated infections, airway inflammation and tissue remodelling resulting in impaired airway clearance, destruction of structural elements within the bronchial wall causing them to become dilated and small airway obstruction. In this review, the current knowledge of the epidemiology, pathobiology, clinical features, and management of bronchiectasis in children are summarized. Recent evidence has emerged to improve our understanding of this heterogeneous disease including the role of viruses, and how antibiotics, novel drugs, antiviral agents, and vaccines might be used. Importantly, the management is no longer dependent upon extrapolating from the cystic fibrosis experience. Nevertheless, substantial information gaps remain in determining the underlying disease mechanisms that initiate and sustain the pathophysiological pathways leading to bronchiectasis. National and international collaborations, standardizing definitions of clinical and research end points, and exploring novel primary prevention strategies are needed if further progress is to be made in understanding, treating and even preventing this often life-limiting disease.

The Epidemiology of Chronic Suppurative Lung Disease and Bronchiectasis in Children and Adolescents

In the modern era, the global burden of childhood chronic suppurative lung disease (CSLD) remains poorly captured by the literature. What is clear, however, is that CSLD is essentially a disease of poverty. Disadvantaged children from indigenous and low- and middle-income populations had a substantially higher burden of CSLD, generally infectious in etiology and of a more severe nature, than children in high-income countries. A universal issue was the delay in diagnosis and the inconsistent reporting of clinical features. Importantly, infection-related CSLD is largely preventable. A considerable research and clinical effort is needed to identify modifiable risk factors and socioeconomic determinants of CSLD and provide robust evidence to guide optimal prevention and management strategies. The purpose of this review was to update the international literature on the epidemiology, etiology, and clinical features of pediatric CSLD.

Bronchiectasis in Children: Current Concepts in Immunology and Microbiology

Bronchiectasis is a complex chronic respiratory condition traditionally characterized by chronic infection, airway inflammation, and progressive decline in lung function. Early diagnosis and intensive treatment protocols can stabilize or even improve the clinical prognosis of children with bronchiectasis. However, understanding the host immunologic mechanisms that contribute to recurrent infection and prolonged inflammation has been identified as an important area of research that would contribute substantially to effective prevention strategies for children at risk of bronchiectasis. This review will focus on the current understanding of the role of the host immune response and important pathogens in the pathogenesis of bronchiectasis (not associated with cystic fibrosis) in children.

Detection of biofilm in bronchoalveolar lavage from children with non-cystic fibrosis bronchiectasis

BACKGROUND

The presence of Pseudomonas aeruginosa biofilms in lower airway specimens from cystic fibrosis (CF) patients is well established. To date, biofilm has not been demonstrated in bronchoalveolar lavage (BAL) from people with non-CF bronchiectasis. The aim of this study was to determine (i) if biofilm was present in BAL from children with and without bronchiectasis, and (ii) if biofilm detection differed between sequentially collected BAL.

METHODS

Testing for biofilm in two sequentially collected BAL from children with and without bronchiectasis was done using BacLight™ live-dead staining and lectin staining for extracellular polymeric biofilm matrices. Bacterial culture and cytological measures were performed on the first and second lavages, respectively. Clinically important BAL infection was defined as >10⁴  cfu of respiratory pathogens/ml BAL.

RESULTS

Biofilm was detected in BAL from seven of eight (87.5%) children with bronchiectasis (aged 0.8-6.9 years), but was not detected in any of three controls (aged 1.3-8.6 years). The biofilms contained both live and dead bacteria irrespective of antibiotic use prior to bronchoscopy. Biofilm was detected more frequently in the second lavage than the first. Three of the seven biofilm-positive BAL were culture-positive for respiratory pathogens at clinically important levels.

CONCLUSIONS

Biofilm is present in BAL from children with non-CF bronchiectasis even when BAL-defined clinically important infection was absent. Studies to characterize lower airway biofilms and determine how biofilm contributes to bronchiectasis disease progression and treatment outcomes are necessary. Pediatr Pulmonol. 2015; 50:284-292. © 2014 Wiley Periodicals, Inc.

Defining lower airway bacterial infection in children with chronic endobronchial disorders

BACKGROUND

Differentiating lower airway bacterial infection from possible upper airway contamination in children with endobronchial disorders undergoing bronchoalveolar lavage (BAL) is important for guiding management. A diagnostic bacterial load threshold based on inflammatory markers has been determined to differentiate infection from upper airway contamination in infants with cystic fibrosis, but not for children with protracted bacterial bronchitis (PBB), chronic suppurative lung disease (CSLD), or bronchiectasis.

METHODS

BAL samples from children undergoing bronchoscopy underwent quantitative bacterial culture, cytologic examination, and respiratory virus testing; a subset also had interleukin-8 examined. Geometric means (GMs) of total cell counts (TCCs) and neutrophil counts were plotted by respiratory pathogen bacterial load. Logistic regression determined associations between age, sex, Indigenous status, antibiotic exposure, virus detection and bacterial load, and elevated TCCs (>400 × 10³ cells/mL) and airway neutrophilia (neutrophils >15% BAL leukocytes).

RESULTS

From 2007 to 2016, 655 children with PBB, CSLD, or bronchiectasis were enrolled. In univariate analyses, Indigenous status and bacterial load ≥10⁵ colony-forming units (CFU)/mL were positively associated with high TCCs. Viruses and bacterial load ≥10⁴ CFU/mL were positively associated with neutrophilia; negative associations were seen for Indigenous status and macrolides. In children who had not received macrolide antibiotics, bacterial load was positively associated in multivariable analyses with high TCCs at ≥10⁴ CFU/mL and with neutrophilia at ≥10⁵ CFU/mL; GMs of TCCs and neutrophil counts were significantly elevated at 10⁴ and 10⁵ CFU/mL compared to negative cultures.

CONCLUSIONS

Our findings support a BAL threshold ≥10⁴ CFU/mL to define lower airway infection in children with chronic endobronchial disorders.

Azithromycin for Indigenous children with bronchiectasis: study protocol for a multi-centre randomized controlled trial

BACKGROUND

The prevalence of chronic suppurative lung disease (CSLD) and bronchiectasis unrelated to cystic fibrosis (CF) among Indigenous children in Australia, New Zealand and Alaska is very high. Antibiotics are a major component of treatment and are used both on a short or long-term basis. One aim of long-term or maintenance antibiotics is to reduce the frequency of acute pulmonary exacerbations and symptoms. However, there are few studies investigating the efficacy of long-term antibiotic use for CSLD and non-CF bronchiectasis among children. This study tests the hypothesis that azithromycin administered once a week as maintenance antibiotic treatment will reduce the rate of pulmonary exacerbations in Indigenous children with bronchiectasis.

METHODS/DESIGN

We are conducting a multicentre, randomised, double-blind, placebo controlled clinical trial in Australia and New Zealand. Inclusion criteria are: Aboriginal, Torres Strait Islander, Maori or Pacific Island children aged 1 to 8 years, diagnosed with bronchiectasis (or probable bronchiectasis) with no underlying disease identified (such as CF or primary immunodeficiency), and having had at least one episode of pulmonary exacerbation in the last 12 months. After informed consent, children are randomised to receive either azithromycin (30 mg/kg once a week) or placebo (once a week) for 12-24 months from study entry. Primary outcomes are the rate of pulmonary exacerbations and time to pulmonary exacerbation determined by review of patient medical records. Secondary outcomes include length and severity of pulmonary exacerbation episodes, changes in growth, school loss, respiratory symptoms, forced expiratory volume in 1-second (FEV(1); for children ≥6 years), and sputum characteristics. Safety endpoints include serious adverse events. Antibiotic resistance in respiratory bacterial pathogens colonising the nasopharynx is monitored. Data derived from medical records and clinical assessments every 3 to 4 months for up to 24 months from study entry are recorded on standardised forms.

DISCUSSION

Should this trial demonstrate that azithromycin is efficacious in reducing the number of pulmonary exacerbations, it will provide a much-needed rationale for the use of long-term antibiotics in the medical management of bronchiectasis in Indigenous children.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12610000383066.

Does a 10-valent pneumococcal-Haemophilus influenzae protein D conjugate vaccine prevent respiratory exacerbations in children with recurrent protracted bacterial bronchitis, chronic suppurative lung disease and bronchiectasis: protocol for a randomised controlled trial

BACKGROUND

Recurrent protracted bacterial bronchitis (PBB), chronic suppurative lung disease (CSLD) and bronchiectasis are characterised by a chronic wet cough and are important causes of childhood respiratory morbidity globally. Haemophilus influenzae and Streptococcus pneumoniae are the most commonly associated pathogens. As respiratory exacerbations impair quality of life and may be associated with disease progression, we will determine if the novel 10-valent pneumococcal-Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) reduces exacerbations in these children.

METHODS

A multi-centre, parallel group, double-blind, randomised controlled trial in tertiary paediatric centres from three Australian cities is planned. Two hundred six children aged 18 months to 14 years with recurrent PBB, CSLD or bronchiectasis will be randomised to receive either two doses of PHiD-CV or control meningococcal (ACYW₁₃₅) conjugate vaccine 2 months apart and followed for 12 months after the second vaccine dose. Randomisation will be stratified by site, age (<6 years and ≥6 years) and aetiology (recurrent PBB or CSLD/bronchiectasis). Clinical histories, respiratory status (including spirometry in children aged ≥6 years), nasopharyngeal and saliva swabs, and serum will be collected at baseline and at 2, 3, 8 and 14 months post-enrolment. Local and systemic reactions will be recorded on daily diaries for 7 and 30 days, respectively, following each vaccine dose and serious adverse events monitored throughout the trial. Fortnightly, parental contact will help record respiratory exacerbations. The primary outcome is the incidence of respiratory exacerbations in the 12 months following the second vaccine dose. Secondary outcomes include: nasopharyngeal carriage of H. influenzae and S. pneumoniae vaccine and vaccine- related serotypes; systemic and mucosal immune responses to H. influenzae proteins and S. pneumoniae vaccine and vaccine-related serotypes; impact upon lung function in children aged ≥6 years; and vaccine safety.

DISCUSSION

As H. influenzae is the most common bacterial pathogen associated with these chronic respiratory diseases in children, a novel pneumococcal conjugate vaccine that also impacts upon H. influenzae and helps prevent respiratory exacerbations would assist clinical management with potential short- and long-term health benefits. Our study will be the first to assess vaccine efficacy targeting H. influenzae in children with recurrent PBB, CSLD and bronchiectasis.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Registry (ANZCTR) number: ACTRN12612000034831.

A decade on: Follow-up findings of indigenous children with bronchiectasis

OBJECTIVE

The sole prospective longitudinal study of children with either chronic suppurative lung disease (CSLD) or bronchiectasis published in the current era was limited to a single center. We sought to extend this study by evaluating the longer-term clinical and lung function outcomes and their associated risk factors in Indigenous children of adolescents from Australia, Alaska, and New Zealand who participated in our previous CSLD or bronchiectasis studies during 2004-2010.

METHODS

Between 2015 and 2018, we evaluated 131 out of 180 (72.8%) children of adolescents from the original studies at a single follow-up visit. We administered standardized questionnaires, reviewed medical records, undertook clinical examinations, performed spirometry, and scored available chest computed tomography scans.

RESULTS

Participants were seen at a mean age of 12.3 years (standard deviation: 2.6) and a median of 9.0 years (range: 5.0-13.0) after their original recruitment. With increasing age, rates of acute lower respiratory infections (ALRI) declined, while lung function was mostly within population norms (median forced expiry volume in one-second = 90% predicted, interquartile range [IQR]: 81-105; forced vital capacity [FVC] = 98% predicted, IQR: 85-114). However, 43 out of 111 (38.7%) reported chronic cough episodes. Their overall global rating judged by symptoms, including ALRI frequency, examination findings, and spirometry was well (20.3%), stable (43.9%), or improved (35.8%). Multivariable regression identified household tobacco exposure and age at first ALRI-episode as independent risk factors associated with lower FVC% predicted values.

CONCLUSION

Under our clinical care, the respiratory outcomes in late childhood or early adolescence are encouraging for these patient populations at high-risk of premature mortality. Prospective studies to further inform management throughout the life course into adulthood are now needed.

Do combined upper airway cultures identify lower airway infections in children with chronic cough?

BACKGROUND

Obtaining lower airway specimens is important for guiding therapy in chronic lung infection but is difficult in young children unable to expectorate. While culture-based studies have assessed the diagnostic accuracy of nasopharyngeal or oropharyngeal specimens for identifying lower airway infection, none have used both together. We compared respiratory bacterial pathogens cultured from nasopharyngeal and oropharyngeal swabs with bronchoalveolar lavage (BAL) cultures as the "gold standard" to better inform the diagnosis of lower airway infection in children with chronic wet cough.

METHODS

Nasopharyngeal and oropharyngeal swabs and BAL fluid specimens were collected concurrently from consecutive children undergoing flexible bronchoscopy for chronic cough and cultured for bacterial pathogens.

RESULTS

In cultures from 309 children (median age, 2.3 years) with chronic endobronchial suppuration, all main pathogens detected (Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis) were more prevalent in nasopharyngeal than oropharyngeal swabs (37%, 34%, and 23% vs 21%, 6.2%, and 3.2%, respectively). Positive and negative predictive values for lower airway infection by any of these three pathogens were 63% (95% confidence interval [95% CI] 55, 70) and 85% (95% CI, 78, 91) for nasopharyngeal swabs, 65% (95% CI, 54, 75), and 66% (95% CI, 59, 72) for oropharyngeal swabs, and 61% (95% CI, 54,68), and 88% (95% CI, 81, 93) for both swabs, respectively.

CONCLUSIONS

Neither nasopharyngeal nor oropharyngeal swabs, alone or in combination, reliably predicted lower airway infection in children with chronic wet cough. Although upper airway specimens may be useful for bacterial carriage studies and monitoring antimicrobial resistance, their clinical utility in pediatric chronic lung disorders of endobronchial suppuration is limited.

Comparison of Profiles of First Nations and Non-First Nations Children With Bronchiectasis Over Two 5-Year Periods in the Northern Territory, Australia

BACKGROUND

Although the burden of bronchiectasis is recognized globally, pediatric data are limited, particularly on trends over the years. Also, no published data exists regarding whether vitamin D deficiency or insufficiency and human T-cell lymphotropic virus type 1 (HTLV-1) infection, both found to be related to severe bronchiectasis in First Nations adults, also are important in children with bronchiectasis.

RESEARCH QUESTION

Among children with bronchiectasis, (1) have the clinical and BAL profiles changed between two 5-year periods (period 1, 2007-2011; period 2, 2012-2016) and (b) are vitamin D deficiency or insufficiency, HTLV-1 infection, or both associated with radiologic severity of bronchiectasis?

STUDY DESIGN AND METHODS

We analyzed the data from children with bronchiectasis prospectively enrolled at Royal Darwin Hospital, Australia, at the first diagnosis; that is, no child was included in both periods. Data collected include demographics, BAL, routine investigation bloods, and high-resolution CT scan of the chest evaluated using the Bhalla and modified Bhalla scores.

RESULTS

The median age of the 299 children was 2.2 years (interquartile range, 1.5-3.7 years). One hundred sixty-eight (56%) were male and most were First Nations (92%). Overall, bronchiectasis was high over time, particularly among First Nations children. In the later period, numbers of non-First Nations children more than tripled, but did not reach statistical significance. In period 2 compared with period 1, fewer First Nations children demonstrated chronic cough (period 1, 61%; period 2, 47%; P = .03), and were younger, First Nations children were less likely to have received azithromycin (period 1, 42%; period 2, 21%; P < .001), and the BAL fluid of First Nations children showed lower Haemophilus influenzae and Moraxella catarrhalis infection. HTLV-1 infection was not detected, and vitamin D deficiency or insufficiency did not correlate with severity of bronchiectasis.

INTERPRETATION

Bronchiectasis remains high particularly among First Nations children. Important changes in their profiles that arguably reflect improvements were present, but overall, the profiles remained similar. Although vitamin D deficiency was uncommon, its role in children with bronchiectasis requires further evaluation. HTLV-1 infection was nonexistent and is unlikely to play any role in First Nations children with bronchiectasis.

Clinical course of chronic suppurative lung disease and bronchiectasis in Alaska Native children

INTRODUCTION

Alaska Native (AN) children from the Yukon Kuskokwim (YK) Delta region have high rates of chronic suppurative lung disease (CSLD), including bronchiectasis. We characterized the clinical progress of an AN adolescent cohort with CSLD/bronchiectasis, and estimated bronchiectasis prevalence trends in this region.

METHODS

The original cohort comprised 41 AN children (originally aged 0.5-8 years) with CSLD/bronchiectasis, recruited between 2005 and 2008, with follow-up in 2015-2016. Clinical assessments, lung function, radiography, medical chart review, and spirometry were obtained. We also conducted data queries of bronchiectasis diagnoses in YK individuals born between 1990 and 2010 to estimate prevalence.

RESULTS

Thirty-four (83%) of the original cohort aged 7.3-17.6 years were reviewed, of whom 14 (41%) had high-resolution computed tomography (HRCT)-confirmed bronchiectasis, eight (24%) had no evidence of bronchiectasis on HRCT scans, while 12 (35%) had not undergone HRCT scans. Annual lower respiratory tract infection (LRTI) frequency decreased with age, although 27 (79%) still had respiratory symptoms, including all with HRCT-confirmed bronchiectasis, who were also more likely than those without confirmed bronchiectasis to have recent wheeze (80 vs 25%, P = 0.005), auscultatory crackles (60 vs 0%, P < 0.001), and lower mean forced expiratory volume in 1-second/forced vital capacity ratio (73 vs 79%, P = 0.03). The bronchiectasis prevalence for YK AN people born during 2000-2009 was 7 per 1000 births, which was lower than previously reported.

CONCLUSION

Despite reduced LRTI frequency, most AN children with CSLD/bronchiectasis had symptoms/signs of underlying lung disease as they entered adolescence. Close clinical follow-up remains essential for managing these patients as they transition to adulthood.

The clinical, immunological and microbiological impact of the 10-valent pneumococcal-Protein D conjugate vaccine in children with recurrent protracted bacterial bronchitis, chronic suppurative lung disease and bronchiectasis: A multi-centre, double-blind, randomised controlled trial

We aimed to determine the efficacy of the 10-valent pneumococcal-Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in children aged 18-months to <18-years with recurrent protracted bacterial bronchitis (rPBB), chronic suppurative lung disease (CSLD) or bronchiectasis. In a multi-centre, double-blind randomised controlled trial, children received two doses, 2-months apart of the 10vPHiD-CV or quadrivalent meningococcal-ACYW₁₃₅ conjugate vaccine. Active surveillance for acute exacerbations, respiratory symptoms and antibiotic use was undertaken through to 12-months after the second vaccine dose (clinical cohort only). Serum, saliva and nasopharyngeal swabs were collected to measure immunological and microbiological effects (immunology cohort). Between December 2012 and August 2015, 62 children were enrolled onto the clinical protocol (1 excluded from clinical analyses due to unblinding), while 74 contributed to the immunology cohort (overall mean age = 6.8-years (standard deviation = 3.7), 42 (56.8%) male). The absolute risk difference comparing the 10vPHiD-CV group (n = 31 children) to the MenACYW₁₃₅ group (n = 30 children) for acute exacerbations was -0.5 exacerbations/100-weeks at risk (95% confidence interval (CI) -2.0, 0.9). Compared to the MenACYW₁₃₅ group, children who received the 10vPHiD-CV were less likely to have respiratory symptoms in each fortnight of surveillance (incidence density ratio (IDR) 0.82, 95%CI 0.61, 1.10) and required fewer short-course (<14-days duration) antibiotics (IDR 0.81, 95% CI 0.61, 1.09). The vaccine was immunogenic and no serious adverse events related to the vaccine were reported. In conclusion, 10vPHiD-CV might have a future role in managing children with rPBB, CSLD and bronchiectasis, but larger multicentre trials are needed to confirm or refute findings from this preliminary study.

Azithromycin Prescribing by Respiratory Pediatricians in Australia and New Zealand for Chronic Wet Cough: A Questionnaire-Based Survey

Aims: To determine how respiratory pediatricians across Australia and New Zealand prescribe azithromycin for children with chronic wet cough, including recurrent protracted bacterial bronchitis, chronic suppurative lung disease (CSLD) and bronchiectasis. Methods: A prospective web-based questionnaire was emailed to members of the Pediatric Special Interest Group of the Thoracic Society of Australia and New Zealand (TSANZ) between April and May 2018. It comprised eight demographic and 15 clinically focused questions. Results: Of the 73 respiratory pediatricians listed across Australia and New Zealand, 29 (40%) responded and all prescribed azithromycin for chronic wet cough. Twelve (41%) indicated that they would consider prescribing a short-course (2-4 weeks) of azithromycin for children with a chronic wet cough. Although most respondents reported prescribing long-term (>4-weeks) azithromycin for either CSLD (n = 23, 79%) or bronchiectasis (n = 24, 83%), only nine (31%) respondents would commence treatment if in the previous 12-months these children experienced three non-hospitalized exacerbations and just 12 (41%) would do so if there had been two hospitalisations for severe exacerbations during the same period in accordance with the TSANZ national guidelines. A lower threshold for prescribing azithromycin was described for Indigenous children or if co-morbidities were present. None prescribed azithromycin for >24-months. Macrolide-resistance was reported in Streptococcus pneumoniae and Staphylococcus aureus. Conclusion: Although Australian and New Zealand respiratory pediatricians in this survey prescribed azithromycin for chronic wet cough most often in children with either CSLD or bronchiectasis, many did so outside the current national guidelines. Reasons for this need exploring.

Contemporary management of bronchiectasis in children

Introduction: Bronchiectasis is increasingly recognized as a major cause of morbidity and mortality worldwide. It affects children of all ethnicities and socioeconomic backgrounds and represents a far greater burden than cystic fibrosis (CF). Bronchiectasis often begins in childhood and the radiological changes can be reversed, when mild, with optimal management. As there are limited pediatric studies in this field, current treatment approaches in children are based largely upon adult and/or CF studies. The recent establishment of bronchiectasis registries will improve understanding of pediatric bronchiectasis and increase capacity for large-scale research studies in the future. Areas covered: This review summarizes the current management of bronchiectasis in children and highlights important knowledge gaps and areas for future research. Current treatment approaches are based largely on consensus guidelines from international experts in the field. Studies were identified through searching Medline via the Ovid interface and Pubmed using the search terms 'bronchiectasis' and 'children' or 'pediatric' and 'management' or 'treatments'. Expert opinion: Bronchiectasis is heterogeneous in nature and a one-size-fits-all approach has limitations. Future research should focus on advancing our understanding of the aetiopathogenesis of bronchiectasis. This approach will facilitate development of targetted therapeutic interventions to slow, halt or even reverse bronchiectasis in childhood.

The Likelihood of Preventing Respiratory Exacerbations in Children and Adolescents with either Chronic Suppurative Lung Disease or Bronchiectasis

Chronic suppurative lung disease (CSLD) and bronchiectasis in children and adolescents are important causes of respiratory morbidity and reduced quality of life (QoL), also leading to subsequent premature death during adulthood. Acute respiratory exacerbations in pediatric CSLD and bronchiectasis are important markers of disease control clinically, given that they impact upon QoL and increase health-care-associated costs and can adversely affect future lung functioning. Preventing exacerbations in this population is, therefore, likely to have significant individual, familial, societal, and health-sector benefits. In this review, we focus on therapeutic interventions, such as drugs (antibiotics, mucolytics, hyperosmolar agents, bronchodilators, corticosteroids, non-steroidal anti-inflammatory agents), vaccines and physiotherapy, and care-planning, such as post-hospitalization management and health promotion strategies, including exercise, diet, and reducing exposure to environmental toxicants. The review identified a conspicuous lack of moderate or high-quality evidence for preventing respiratory exacerbations in children and adolescents with CSLD or bronchiectasis. Given the short- and long-term impact of exacerbations upon individuals, their families, and society as a whole, large studies addressing interventions at the primary and tertiary prevention phases are required. This research must include children and adolescents in both developing and developed countries and address long-term health outcomes.

Predictors of time to cough resolution in children with chronic wet cough treated with antibiotics after bronchoscopy

BACKGROUND

Chronic wet cough is common in pediatric pulmonology practice and is clinically important. Guidelines recommend treatment with antibiotics as their effectiveness has been proven. However, factors associated with duration of cough in response to antibiotics in children with chronic wet cough have not been prospectively examined.

OBJECTIVE

To determine if demographic, clinical and/or bronchoalveolar lavage (BAL) factors are associated with "time to cough resolution" in children with chronic wet cough treated with antibiotics after bronchoscopy.

METHODS

Data from children with chronic wet cough treated with antibiotics after bronchoscopy were extracted from a prospective cohort study database. Cough dairies were used to determine when the cough resolved. Associations between various factors with "time to cough resolution" were examined using regression.

RESULTS

The median age of the 133 children was 2.4 years (interquartile range, 1.4-4.9). Duration of prior cough at bronchoscopy was significantly positively related with "time to cough resolution" (β = .010; 95% confidence interval, 0.004-0.017; P = .002). This translated to; for each month of prior cough, it took an extra 1.02 days to achieve cough resolution while on antibiotic treatment. Gender, age, diagnosis, tobacco smoke exposure, pneumonia history, blood cellularity, and BAL cellular and microbiology profiles were not significantly associated with time to cough resolution.

CONCLUSION

In children with chronic wet cough, duration of cough before antibiotic treatment is a small but significant determinant of "time to cough resolution." Research using standardized antibiotic regimes is required to provide clinical and/or biomarkers that can further identify factors associated with the response of chronic cough to antibiotic treatment.

Diagnostic value of sputum cultures in children under 2 years of age with chronic suppurative lung diseases

BACKGROUND

Acquiring sputum cultures from infants is considered challenging. We describe their yield in infants with cystic fibrosis (CF) and other chronic suppurative lung diseases (CSLDs).

METHODS

Retrospective medical record review over a 4-year period, for infants aged 0-2 years with ≥2 airway bacterial cultures acquired by deep suction or induced sputum ≥4 weeks apart. Data included demographics, culture results, and clinical status.

RESULTS

A total of 98 infants (16 CF) were evaluated and 534 sputum cultures acquired, 201 in CF and 333 in CSLD. There were 12 (2-23), median (range) cultures/CF infant, and 3 (2-21)/CSLD infant. Age at first culture was 3.8 (1-19.5) months for CF and 10.4 (0.5-22) months for CSLD; p = .016. In total, 360 cultures (67%) were positive for any bacteria, with 170/234 (73%) positive during exacerbations, compared with 190/300 (63%) during routine visits; p = .05. More infants with CF than CSLD had cultures positive for Staphylococcus aureus (SA; 75% vs. 34%; p = .004) throughout the period. Pseudomonas aeruginosa (PA) was common in both CF and CSLD (56% and 44%, respectively; p = .42) and increased over time for CF but was high throughout for CSLD. The number of hospital days before PA acquisition was 6 (10.2) for CF and 28.8 (38.7) for CSLD (p = .003). No CF but 6/82 (7%) CSLD infants had chronic PA (p = .56).

CONCLUSIONS

Sputum cultures showed that infection, in particular PA, is common in CF and CSLD whereas SA is more common in CF. Prospective studies are warranted to elucidate the role of active surveillance in guiding antibiotic therapy.

Bronchiectasis in children in a high HIV and tuberculosis prevalence setting

Background

Bronchiectasis, a chronic suppurative lung condition, is a largely neglected disease, especially in low- to middle-income countries (LMICs), from which there is a paucity of data. Post-infectious causes are more common in LMICs, while in high-income countries, inborn errors of immunity (IEIs), recurrent aspiration, primary ciliary dyskinesia (PCD) and cystic fibrosis are more common. Children living with HIV (CLWH), especially those who are untreated, are at increased risk of bronchiectasis. Data on risk factors, diagnosis and follow-up of children with bronchiectasis are required to inform clinical practice and policy.

Objectives

To describe the demographics, medical history, aetiology, clinical characteristics and results of special investigations in children with bronchiectasis.

Methods

We undertook a retrospective descriptive study of children aged <16 years with chest computed tomography (CT) scan-confirmed bronchiectasis in Johannesburg, South Africa, over a 10-year period. Demographics, medical history, aetiology, clinical characteristics and results of special investigations were described and compared according to HIV status.

Results

A total of 91 participants (51% male, 98% black African) with a median (interquartile range) age of 7 (3 - 12) years were included in the study. Compared with HIV-uninfected children, CLWH were older at presentation (median 10 (6 - 13) years v. 4 (3 - 9) years; p<0.01), and more likely to be stunted (p<.01), to have clubbing (p<0.01) and hepatosplenomegaly (p=0.03), and to have multilobar involvement on the chest CT scan (p<0.01). All children had a cause identified, and the majority (86%) of these were presumed to be post-infectious, based on a previous history of a severe lower respiratory tract infection. This group included all 38 CLWH. Only a small proportion of the participants had IEIs, secondary immune deficiencies or PCD.

Conclusion

A post-infectious cause for bronchiectasis was the most common aetiology described in children from an LMIC in Africa, especially CLWH. With improved access to diagnostic techniques, the aetiology of bronchiectasis in LMICs is likely to change.

Study synopsis

What the study adds. In this retrospective descriptive study of children aged <16 years with chest computed tomography scan-confirmed bronchiectasis in Johannesburg, South Africa (SA), over a 10-year period, we report that a post-infectious cause for bronchiectasis was the most commonly described, and that HIV was an important contributor. A large proportion of children with bronchiectasis in low- and middle-income countries such as SA do not benefit from an extensive work-up for the non-infectious causes of bronchiectasis.Implications of the findings. With improved access to diagnostic techniques, including improvements in early diagnosis and access to treatment for children living with HIV, the aetiology of bronchiectasis is likely to change in the coming years.

Phage Therapy Administration Route, Regimen, and Need for Supplementary Antibiotics in Patients with Chronic Suppurative Lung Disease

Antimicrobial resistance is leading to increased mortality, posing risk to those with chronic suppurative lung disease (CSLD). One therapeutic option may be to target treatment-resistant bacteria using viruses (bacteriophages [phages]). Currently, patients receiving phage therapy on compassionate grounds may not be receiving optimal treatment as there is no defined approach for phage use. This review aims to explore administration route, regimen, and need for supplementary antibiotics in phage therapy to treat bacterial infection in CSLD. Twelve articles totaling 18 participants included details of numerous phage administration routes with varying regimens. All articles reported an initial reduction of bacterial load or an improvement in patient symptoms, highlighting the potential of phage therapy in CSLD. Fifteen out of 18 used supplementary antibiotics. Standardized protocols informed by high-quality research are necessary to ensure safe and effective phage therapy. In the interim, systematic recording of information within case reports may be useful.

The Respiratory Microbiome in Paediatric Chronic Wet Cough: What Is Known and Future Directions

Chronic wet cough for longer than 4 weeks is a hallmark of chronic suppurative lung diseases (CSLD), including protracted bacterial bronchitis (PBB), and bronchiectasis in children. Severe lower respiratory infection early in life is a major risk factor of PBB and paediatric bronchiectasis. In these conditions, failure to clear an underlying endobronchial infection is hypothesised to drive ongoing inflammation and progressive tissue damage that culminates in irreversible bronchiectasis. Historically, the microbiology of paediatric chronic wet cough has been defined by culture-based studies focused on the detection and eradication of specific bacterial pathogens. Various 'omics technologies now allow for a more nuanced investigation of respiratory pathobiology and are enabling development of endotype-based models of care. Recent years have seen substantial advances in defining respiratory endotypes among adults with CSLD; however, less is understood about diseases affecting children. In this review, we explore the current understanding of the airway microbiome among children with chronic wet cough related to the PBB-bronchiectasis diagnostic continuum. We explore concepts emerging from the gut-lung axis and multi-omic studies that are expected to influence PBB and bronchiectasis endotyping efforts. We also consider how our evolving understanding of the airway microbiome is translating to new approaches in chronic wet cough diagnostics and treatments.

Clinical Course of Children with Chronic Suppurative Lung Disease or Bronchiectasis Infected with Pseudomonas aeruginosa

Children with chronic wet cough and without cystic fibrosis (non-CF) may suffer from chronic suppurative lung disease (CSLD) or bronchiectasis. Pseudomonas aeruginosa (Pa) can be one of the offending microbes in these children. The present study aimed to describe the clinical course of children with the above two conditions who were infected with Pa. Data of 54 children with CSLD/bronchiectasis who were diagnosed and attended in our department were retrospectively analysed through a Cox proportional hazard model, with age, presence of bronchiectasis, use of inhaled colistin, azithromycin, inhaled hypertonic saline as the covariates. In 42 of the 54 patients, there was no identifiable cause or underlying chronic disorder. Microbiological clearance was defined as the absence of daily wet cough for four months along with four negative cultures taken during the last four consecutive follow-up visits. Multivariate analysis was performed with a Cox proportional hazard model with time to microbiological clearance as the outcome. Results are described as Hazard Ratios (HR) with 95% Confidence Intervals (95%CI). Nebulised antibiotics and the presence of bronchiectasis were statistically significant predictors of remission (HR: 3.99; 95%CI: 1.12-14.14; p = 0.032, and HR: 0.24; 95%CI: 0.08-0.71; p = 0.010). In conclusion, the rate of microbiological clearance increases with the use of inhaled colistin and decreases when there is established bronchiectasis.