Outcomes in children treated for persistent bacterial bronchitis

Pro-Con Debate: Protracted Bacterial Bronchitis as a Cause of Chronic Cough in Children

Pro: Children with chronic cough present a diagnostic challenge. Protracted bacterial bronchitis (PBB) is a chronic, persistent bacterial infection of conducting airways defined by the presence of cough for longer than 4 weeks that resolves with antimicrobial therapy and without an alternative diagnosis. The diagnosis is made by the findings of increased bronchial secretions and edema of the lower airways on flexible bronchoscopy and positive cultures on bronchoalveolar lavage. It is speculated that an initial respiratory insult such as viral infection disrupts normal surface morphology and ciliary function, which leads to chronic self-perpetuating inflammation with the formation of bacterial biofilms, leading to PBB. PBB is often misdiagnosed as asthma, leading to inappropriate and excessive use of steroids. The importance of timely diagnosis should be emphasized due to the potential that PBB may be a precursor to chronic suppurative lung disease or bronchiectasis if left untreated; however, every patient should be adequately assessed to exclude other causes of chronic cough. Con: Clinical criteria for the diagnosis of PBB are nonspecific and may not distinguish it from other known causes of chronic cough, including viral infections. Benefits from antibiotic therapy (particularly prolonged therapy) have not been demonstrated. Respiratory conditions are the most common reason for antibiotic prescriptions during ambulatory visits in the United States, and many of these prescriptions are inappropriate and/or unnecessary. The proposed diagnostic criteria and recommendations for the treatment of PBB will lead to unnecessary overuse of antibiotics.

Mediators of neutrophil function in children with protracted bacterial bronchitis

BACKGROUND

Protracted bacterial bronchitis (PBB) is a common and treatable cause of chronic wet cough in children in which the mechanisms are not understood. This study investigates the IL-1 pathway and a neutrophil gene expression signature in PBB.

METHODS

BAL was collected from children in an experimental cohort (n = 21, PBB; n = 33, control subjects), and a second validation cohort (n = 36, PBB; n = 11, control subjects). IL-1β, IL-1 receptor antagonist (IL-1RA), and α-defensins 1-3 were assayed by enzyme-linked immunosorbent assay, western blot, and quantitative real-time polymerase chain reaction, together with selected IL-1 pathway members and neutrophil-related molecules.

RESULTS

In the experimental cohort, children with symptomatic PBB had significantly higher levels of IL-1β and α-defensin gene and protein expression. Expression of the neutrophil chemokine receptor C-X-C motif receptor 2 was also higher in PBB. IL-1RA protein was higher, however, the IL-1RA:IL-1β ratio was lower in children with PBB than control subjects. In the validation cohort, protein and gene expression of IL-1β and α-defensins 1-3 were confirmed higher, as was gene expression of IL-1 pathway members and C-X-C motif receptor 2. IL-1β and α-defensin 1-3 levels lowered when PBB was treated and resolved. In children with recurrent PBB, gene expression of the IL-1β signaling molecules pellino-1 and IL-1 receptor-associated kinase 2 was significantly higher. IL-1β protein levels correlated with BAL neutrophilia and the duration and severity of cough symptoms. IL-1β and α-defensin 1-3 levels were highly correlated.

CONCLUSIONS

PBB is characterized by increased IL-1β pathway activation. IL-1β and related mediators were associated with BAL neutrophils, cough symptoms, and disease recurrence, providing insight into PBB pathogenesis.

Prospective characterization of protracted bacterial bronchitis in children

BACKGROUND

Prior studies on protracted bacterial bronchitis (PBB) in children have been retrospective or based on small cohorts. As PBB shares common features with other pediatric conditions, further characterization is needed to improve diagnostic accuracy among clinicians. In this study, we aim to further delineate the clinical and laboratory features of PBB in a larger cohort, with a specific focus on concurrent viral detection.

METHODS

Children with and without PBB (control subjects) undergoing flexible bronchoscopy were prospectively recruited. Basic immune function testing and lymphocyte subset analyses were performed. BAL specimens were processed for cellularity and microbiology. Viruses were identified using polymerase chain reaction (PCR) and bacteria were identified via culture.

RESULTS

The median age of the 104 children (69% male) with PBB was 19 months (interquartile range [IQR], 12-30 mo). Compared with control subjects, children with PBB were more likely to have attended childcare (OR, 8.43; 95% CI, 2.34-30.46). High rates of wheeze were present in both groups, and tracheobronchomalacia was common. Children with PBB had significantly elevated percentages of neutrophils in the lower airways compared with control subjects, and adenovirus was more likely to be detected in BAL specimens in those with PBB (OR, 6.69; 95% CI, 1.50-29.80). Median CD56 and CD16 natural killer (NK) cell levels in blood were elevated for age in children with PBB (0.7 × 109/L; IQR, 0.5-0.9 cells/L).

CONCLUSIONS

Children with PBB are, typically, very young boys with prolonged wet cough and parent-reported wheeze who have attended childcare. Coupled with elevated NK-cell levels, the association between adenovirus and PBB suggests a likely role of viruses in PBB pathogenesis.

Bacterial distribution in the lungs of children with protracted bacterial bronchitis

OBJECTIVES

Flexible bronchoscopy with bronchoalveolar lavage (FB-BAL) is increasingly used for the microbiological confirmation of protracted bacterial bronchitis (PBB) in children with a chronic wet cough. At our centre, when performing FB-BAL for microbiological diagnosis we sample 6 lobes (including lingula) as this is known to increase the rate of culture positive procedures in children with cystic fibrosis. We investigated if this is also the case in children with PBB.

METHODS

We undertook a retrospective case note review of 50 children investigated for suspected PBB between May 2011 and November 2013.

RESULTS

The median (IQR) age at bronchoscopy was 2.9 (1.7-4.4) years and the median (IQR) duration of cough was 11 (8.0-14) months. Positive cultures were obtained from 41/50 (82%) and 16 (39%) of these patients isolated ≥2 organisms. The commonest organisms isolated were Haemophilus influenzae (25 patients), Moraxella catarrhalis (14 patients), Staphylococcus aureus (11 patients) and Streptococcus pneumoniae (8 patients). If only one lobe had been sampled (as per the European Respiratory Society guidance) 17 different organisms would have been missed in 15 patients, 8 of whom would have had no organism cultured at all. The FB-BAL culture results led to an antibiotic other than co-amoxiclav being prescribed in 17/41 (41%) patients.

CONCLUSIONS

Bacterial distribution in the lungs of children with PBB is heterogeneous and organisms may therefore be missed if only one lobe is sampled at FB-BAL. Positive FB-BAL results are useful in children with PBB and can influence treatment.

Non-typeable Haemophilus influenzae, an under-recognised pathogen

Non-typeable Haemophilus influenzae (NTHi) is a major cause of mucosal infections such as otitis media, sinusitis, conjunctivitis, and exacerbations of chronic obstructive pulmonary disease. In some regions, a strong causal relation links this pathogen with infections of the lower respiratory tract. In the past 20 years, a steady but constant increase has occurred in invasive NTHi worldwide, with perinatal infants, young children, and elderly people most at risk. Individuals with underlying comorbidities are most susceptible and infection is associated with high mortality. β-lactamase production is the predominant mechanism of resistance. However, the emergence and spread of β-lactamase-negative ampicillin-resistant strains in many regions of the world is of substantial concern, potentially necessitating changes to antibiotic treatment guidelines for community-acquired infections of the upper and lower respiratory tract and potentially increasing morbidity associated with invasive NTHi infections. Standardised surveillance protocols and typing methodologies to monitor this emerging pathogen should be implemented. International scientific organisations need to raise the profile of NTHi and to document the pathobiology of this microbe.

Wet cough in children: infective and inflammatory characteristics in broncho-alveolar lavage fluid

Wet cough is a common feature of many disease processes affecting children. Our aim was to examine the relationships between cough nature, lower airway infection (bacterial, viral, and viral-bacterial) and severity of neutrophilic airway inflammation. We hypothesized that viral-bacterial co-infection of the lower airway would be associated with wet cough and heightened neutrophilic airway inflammation. We prospectively recruited 232 children undergoing elective flexible bronchoscopy. Participants were grouped using a cough nature symptom-based approach, into wet, dry or no cough groups. Broncho-alveolar lavage (BAL) and clinical data, including presence, nature, and duration of cough and key demographic factors, were collected. Children with wet cough (n = 143) were more likely to have lower airway bacterial infection (OR 2.6, P = 0.001), viral infection (OR 2.04, P = 0.045) and viral-bacterial co-infection (OR 2.65, P = 0.042) compared to those without wet cough. Wet cough was associated with heightened airway neutrophilia (median 19%) as compared to dry or no cough. Viral-bacterial co-infection was associated with the highest median %neutrophils (33.5%) compared to bacteria only, virus/es only and no infection (20%, 18%, and 6%, respectively, P < 0.0001). Children with wet cough had higher rates of lower airway infection with bacteria and viruses. Maximal neutrophilic airway inflammation was seen in those with viral-bacterial co-infection. Cough nature may be a useful indicator of infection and inflammation of the lower airways in children.

Recurrent wheeze and cough in young children: is it asthma?

A clinical diagnosis of asthma is often considered when a child presents with recurrent cough, wheeze and breathlessness. However, there are many other causes of wheeze in a young child. These range from recurrent viral infections to chronic suppurative lung disease, gastro-oesophageal reflux disease and rare structural abnormalities. Arriving at a diagnosis includes taking into consideration the symptomatology, triggers, atopic features, family history, absence of red flags and therapeutic trial, where indicated.

Are airways structural abnormalities more frequent in children with recurrent lower respiratory tract infections?

We report bronchoscopic changes observed in children with recurrent lower airways infections (RLAI) and findings in control children undergoing bronchoscopy for causes other than RLAI.

PATIENTS AND METHODS

Retrospective case-control cohorts study. The clinical records of children who had fiberoptic bronchoscopy (FB) for a history of RLAI without any known underlying disorder between 2007 and 2013 and of control children who required FB for other causes were reviewed. Clinical features, bronchospic findings and bronchoalveolar lavage (BAL) results were assessed.

RESULTS

Cases were 62 (32 female) children aged 5 years (1-12) and controls 29 children aged 4.5 years (0.5-14). Airway malacia was observed in 32 (52%) vs. 4 (13%) (p = 0.001), profuse respiratory secretions in 34(55%) vs. 6 (20%) (p = 0.007). Endobronchial obstruction: 4 (6.4%) and tracheobronchomegaly were observed only in cases. In cases with profuse respiratory secretions there was a higher prevalence of airways malacia: 64.7% vs. 35.7% (p = 0.04) and of positive BAL cultures: 45.5% vs. 13.3% (p = 0.04). Isolated organisms in cases were non-typable Haemophilus influenzae and Streptococcus pneumoniae most frequently. Pneumocystiis jirovecii, Staphylococcus aureus, and Streptococcus mitis were isolated in controls.

CONCLUSIONS

Half of the children with RLAI had tracheo and/or bronchomalacia, their frequency being in keeping with previous reports and far higher than that observed in controls. It was associated with profuse respiratory secretions and with a higher frequency of positive BAL cultures mostly for non typable H. influenzae and S. pneumoniae which were not isolated in controls.

Cough in children

Cough during childhood is very common, and is one of the most frequent reasons for consultation in daily pediatric practice. The causes differ from those in adults, and specific pediatric guidelines should be followed for correct diagnosis and treatment. The most common cause of cough in children is viral infection producing "normal cough", but all children with persistent cough, i.e. a cough lasting more than 4-8weeks or "chronic cough", must be carefully evaluated in other to rule out specific causes that may include the entire pediatric pulmonology spectrum. The treatment of cough should be based on the etiology. Around 80% of cases can be diagnosed using an optimal approach, and treatment will be effective in 90% of them. In some cases of "nonspecific chronic cough", in which no underlying condition can be found, empirical treatment based on the cough characteristics may be useful. There is no scientific evidence to justify the use of over-the-counter cough remedies (anti-tussives, mucolytics and/or antihistamines), as they could have potentially serious side effects, and thus should not be prescribed in children.

Chronic cough in preschool children

Cough may be the first overt sign of disease of the airways or lungs when it represents more than a defense mechanism, and may by its persistence become a helpful pointer of potential disease for both patient and physician. On the other hand, impairment or absence of the coughing mechanism can be harmful and even fatal; this is why cough suppression is rarely indicated in childhood. Pediatricians are concerned more with the etiology of the cough and making the right diagnosis. Whereas chronic cough in adults has been universally defined as a cough that lasts more than 8 weeks, in childhood, different timing has been reported. Many reasons support defining a cough that lasts more than 4 weeks in preschool children as chronic, however; and this is particularly true when the cough is wet. During childhood, the respiratory tract and nervous system undergo a series of anatomical and physiological maturation processes that influence the cough reflex. In addition, immunological response undergoes developmental and memorial processes that make infection and congenital abnormalities the overwhelming causes of cough in preschool children. Cough in children should be treated on the basis of etiology, and there is no evidence in support of the use of medication for symptomatic cough relief or adopting empirical approaches. Most cases of chronic cough in preschool age are caused by protracted bacterial bronchitis, tracheobronchomalacia, foreign body aspiration, post-infectious cough or some combination of these. Other causes of chronic cough, such as bronchiectasis, asthma, gastroesophageal reflux, and upper respiratory syndrome appear to be less frequent in this age group. The prevalence of each depends on the population in consideration, the epidemiology of infectious diseases, socioeconomic aspects, and the local health system.

Contemporary topics in pediatric pulmonology for the primary care clinician

Disorders of the respiratory system are commonly encountered in the primary care setting. The presentations are myriad and this review will discuss some of the more intriguing or vexing disorders that the clinician must evaluate and treat. Among these are dyspnea, chronic cough, chest pain, wheezing, and asthma. Dyspnea and chest pain have a spectrum ranging from benign to serious, and the ability to effectively form a differential diagnosis is critical for reassurance and treatment, along with decisions on when to refer for specialist evaluation. Chronic cough is one of the more common reasons for primary care office visits, and once again, a proper differential diagnosis is necessary to assist the clinician in formulating an appropriate treatment plan. Infant wheezing creates much anxiety for parents and accounts for a large number of office visits and hospital admissions. Common diagnoses and evaluation strategies of early childhood wheezing are reviewed. Asthma is one of the most common chronic diseases of children and adults. The epidemiology, diagnosis, evaluation, treatment, and the patient/parent education process will be reviewed. A relatively new topic for primary care clinicians is cystic fibrosis newborn screening. The rationale, methods, outcomes, and implications will be reviewed. This screening program may present some challenges for clinicians caring for newborns, and an understanding of the screening process will help the clinician communicate effectively with parents of the patient.

Chronic cough in children

Chronic cough has been variably defined as a cough lasting longer than 3, 4 or 8 weeks. Many post viral or pertussis like illnesses are associated with prolonged coughing that resolves over time. Management involves first trying to make a diagnosis and identify the presence of any underlying condition. Targeted treatments can then be employed. Trials of treatments are often used to make a diagnosis. Because natural resolution of cough is so common any trial of treatment to confirm a diagnosis should be time limited and the treatment only restarted if the coughing returns. Only a small proportion of children with an isolated non-specific dry cough have asthma and care is needed not to over diagnose asthma. Children with chronic wet cough may have protracted bacterial bronchitis (PBB) that responds to a full course of antibiotics. Children with PBB failing to respond to treatment or with specific pointers should be investigated for specific causes of suppurative lung disease.

Bacterial bronchitis caused by Streptococcus pneumoniae and nontypable Haemophilus influenzae in children: the impact of vaccination

BACKGROUND

Protracted bacterial bronchitis is a major cause of persistent cough in childhood. The organisms most commonly isolated are nontypable Haemophilus influenzae and Streptococcus pneumoniae . There are no studies addressing typing of these organisms when recovered from the lower airways.

METHODS

Isolates of these two organisms (identified in BAL samples from children undergoing routine investigation of a chronic cough thought to be attributable to a protracted bacterial bronchitis) were subject to typing. Samples were collected in Sheffield, England, and Athens, Greece. The majority of the children from Sheffield had received pneumococcal-conjugate vaccines 7 or 13 (PCV-7 or PCV-13) conjugate vaccine but only a minority of Greek children had received PCV-7.

RESULTS

All 18 S pneumoniae isolates from Greek BAL samples are serotypes contained in PCV-13 while 10 are contained in PCV-7. In contrast, 28 of the 39 samples from Sheffield contained serotypes that are not included in PCV-13. All 26 of the nontypable H influenzae samples obtained in Sheffield produced distinct multilocus variable-number tandem repeat analysis profiles. There was a significant difference between children from Athens and Sheffield in the distribution of serotypes contained or not contained in the pneumococcal vaccine ( P = .04). More specifically, immunization with pneumococcal vaccine was related with isolation of S pneumoniae serotypes not included in the vaccine (OR, 0.021; CI, 0.003-0.115; P < .001).

CONCLUSIONS

The data suggest that both vaccine and nonvaccine S pneumoniae serotypes may play a role in protracted bacterial bronchitis and provide some hints that serotype replacement may occur in response to the introduction of conjugate vaccines.

Causes of recurrent pneumonia in children in a general hospital

AIM

Because the few previous studies on underlying causes of recurrent pneumonia in children have come from tertiary care referral centres where selection bias may be important, the aim of this study was to examine underlying causes of recurrent pneumonia in children in a general hospital.

METHODS

We performed a retrospective chart review in a general hospital of 62 children with recurrent pneumonia over a 7.5 years period.

RESULTS

In 19 patients (30.6%), no cause was identified, commonly because favourable natural history obviated the need for a full and invasive diagnostic work-up. Other underlying causes included recurrent aspiration in 16 patients (25.7%), lung disease (airway stenosis, bronchiectasis, middle lobe syndrome or tracheooesophageal fistula) in 10 patients (16.1%) and immune deficiency in 10 patients (16.1%). In contrast to previous studies, asthma was never diagnosed as an underlying cause, but diagnostic confusion between asthma (or recurrent upper respiratory tract infections) and recurrent pneumonia was common.

CONCLUSION

The cause of recurrent pneumonia in children remains elusive in almost a third of patients, partly because the favourable natural history consistent with immune system maturation eliminates the need for further diagnostic procedures. Asthma is more likely a differential diagnostic consideration than an underlying cause of recurrent pneumonia in children. A standardised diagnostic guideline is needed to improve knowledge on causes of recurrent pneumonia in children.

Bronchiectasis exacerbation study on azithromycin and amoxycillin-clavulanate for respiratory exacerbations in children (BEST-2): study protocol for a randomized controlled trial

BACKGROUND

Bronchiectasis unrelated to cystic fibrosis (CF) is being increasingly recognized in children and adults globally, both in resource-poor and in affluent countries. However, high-quality evidence to inform management is scarce. Oral amoxycillin-clavulanate is often the first antibiotic chosen for non-severe respiratory exacerbations, because of the antibiotic-susceptibility patterns detected in the respiratory pathogens commonly associated with bronchiectasis. Azithromycin has a prolonged half-life, and with its unique anti-bacterial, immunomodulatory, and anti-inflammatory properties, presents an attractive alternative. Our proposed study will test the hypothesis that oral azithromycin is non-inferior (within a 20% margin) to amoxycillin-clavulanate at achieving resolution of non-severe respiratory exacerbations by day 21 of treatment in children with non-CF bronchiectasis.

METHODS

This will be a multicenter, randomized, double-blind, double-dummy, placebo-controlled, parallel group trial involving six Australian and New Zealand centers. In total, 170 eligible children will be stratified by site and bronchiectasis etiology, and randomized (allocation concealed) to receive: 1) azithromycin (5 mg/kg daily) with placebo amoxycillin-clavulanate or 2) amoxycillin-clavulanate (22.5 mg/kg twice daily) with placebo azithromycin for 21 days as treatment for non-severe respiratory exacerbations. Clinical data and a parent-proxy cough-specific quality of life (PC-QOL) score will be obtained at baseline, at the start and resolution of exacerbations, and on day 21. In most children, blood and deep-nasal swabs will also be collected at the same time points. The primary outcome is the proportion of children whose exacerbations have resolved at day 21. The main secondary outcome is the PC-QOL score. Other outcomes are: time to next exacerbation; requirement for hospitalization; duration of exacerbation, and spirometry data. Descriptive viral and bacteriological data from nasal samples and blood inflammatory markers will be reported where available.

DISCUSSION

Currently, there are no published randomized controlled trials (RCT) to underpin effective, evidence-based management of acute respiratory exacerbations in children with non-CF bronchiectasis. To help address this information gap, we are conducting two RCTs. The first (bronchiectasis exacerbation study; BEST-1) evaluates the efficacy of azithromycin and amoxycillin-clavulanate compared with placebo, and the second RCT (BEST-2), described here, is designed to determine if azithromycin is non-inferior to amoxycillin-clavulanate in achieving symptom resolution by day 21 of treatment in children with acute respiratory exacerbations.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Register (ANZCTR) number http://ACTRN12612000010897. http://www.anzctr.org.au/trial_view.aspx?id=347879.

Pulmonary innate immunity in children with protracted bacterial bronchitis

OBJECTIVE

To determine bronchoalveolar lavage (BAL) levels of 3 innate immunity components (human β-defensin-2 [hBD2], mannose-binding lectin [MBL], and surfactant protein-A [SP-A]), the relationship with airway neutrophilia and infection, and cytokine production of stimulated BAL cells in children with current protracted bacterial bronchitis (PBB), children with resolved PBB (PBB well), and controls.

STUDY DESIGN

BAL of 102 children (mean age 2.8 years) fulfilling predefined criteria of current PBB (n = 61), PBB well (n = 20), and controls (n = 21) was cultured (quantitative bacteriology) and viruses examined by polymerase chain reaction. hBD2, MBL, and SP-A were measured, and cytokine production by lipopolysaccharide-stimulated BAL cells was determined.

RESULTS

Median hBD2 and MBL levels were significantly higher in the current PBB group (hBD2 = 164.4, IQR 0-435.5 pg/mL; MBL = 1.7, 0.4-4 ng/mL) than in the PBB well group (hBD2 = 0, IQR 0-85.2; MBL = 0.6, IQR 0.03-2.9) and controls (hBD2 = 3.6, IQR 0-126; MBL = 0.4, IQR 0.02-79). hBD2 was significantly higher in children with airway infection (n = 54; median 76.9, IQR 0-397.3) compared with those without (n = 48; 0, IQR 0-236.3), P= .04. SP-A levels and cytokine production of stimulated BAL cells were similar between groups.

CONCLUSION

In children's airways, hBD2, but not MBL and SP-A, relates to inflammation and infection. In children with PBB, mechanisms involving airway hBD2 and MBL are augmented. These pulmonary innate immunity components and the ability of BAL cells to respond to stimuli are unlikely to be deficient.

'Recurrent lower respiratory tract infections' - going around in circles, respiratory medicine style

Recurrent lower respiratory tract infections are very common in childhood, particularly the pre-school years. The term lower respiratory tract infection [LTRI] is, as with many terms used in respiratory medicine, used very loosely and carries little more information than the often decried term 'chest infections'. LRTIs should more accurately be characterised by the type of infection [viral or bacterial], the site of infection [conducting airways, or respiratory compartment or both - bronchitis/pneumonia/bronchopneumonia], the nature of the episode [acute or acute on chronic (exacerbation)], the interaction with co-morbidities such as asthma. The limited nature of the responses of the lower airways to any insult whether it is infective or irritation due to inhaled or aspirated chemicals means that almost any aetiology can lead to cough, shortness of breath and noisy breathing. We lack good non-invasive techniques to study the nature of the inflammation in the lower airways and hence the cause of chronic and recurrent symptoms in patients is frequently mis-diagnosed.

Evaluating the child with recurrent lower respiratory tract infections

We review the limited available evidence on underlying causes of recurrent pneumonia in children, supplemented by our own clinical experience. Diagnosing recurrent pneumonia in children is difficult. Diagnostic confusion is possible with recurrent upper respiratory tract infections and asthma. In our series of children with recurrent pneumonia, we never identified asthma as an underlying cause. Because the frequency or severity of recurrent pneumonia does not always justify additional invasive investigations, the diagnostic work-up may be incomplete in a number of cases. This may help to explain why an underlying cause for recurrent pneumonia cannot be found in approximately 30% of cases. Finally, the paradigm that recurrent pneumonia in the same lung lobe has a differential diagnosis different from those recurring in multiple lobes was not borne out in our case series. A stepwise and pragmatic approach to evaluating children with recurrent lower respiratory tract infections is recommended.

The immunological investigation of a child with chronic wet cough

Immunological investigations need to be considered in any child presenting with chronic wet cough. Not infrequently, such children are subjected to a detailed, expensive battery of immune function tests, without consideration as to whether such extensive testing is necessary or indeed helpful. The main aim of this review is to discuss which immune function tests are and are not particularly helpful when investigating a child with persistent wet cough.

Antibiotics for bronchiectasis exacerbations in children: rationale and study protocol for a randomised placebo-controlled trial

BACKGROUND

Despite bronchiectasis being increasingly recognised as an important cause of chronic respiratory morbidity in both indigenous and non-indigenous settings globally, high quality evidence to inform management is scarce. It is assumed that antibiotics are efficacious for all bronchiectasis exacerbations, but not all practitioners agree. Inadequately treated exacerbations may risk lung function deterioration. Our study tests the hypothesis that both oral azithromycin and amoxicillin-clavulanic acid are superior to placebo at improving resolution rates of respiratory exacerbations by day 14 in children with bronchiectasis unrelated to cystic fibrosis.

METHODS

We are conducting a bronchiectasis exacerbation study (BEST), which is a multicentre, randomised, double-blind, double-dummy, placebo-controlled, parallel group trial, in five centres (Brisbane, Perth, Darwin, Melbourne, Auckland). In the component of BEST presented here, 189 children fulfilling inclusion criteria are randomised (allocation-concealed) to receive amoxicillin-clavulanic acid (22.5 mg/kg twice daily) with placebo-azithromycin; azithromycin (5 mg/kg daily) with placebo-amoxicillin-clavulanic acid; or placebo-azithromycin with placebo-amoxicillin-clavulanic acid for 14 days. Clinical data and a paediatric cough-specific quality of life score are obtained at baseline, at the start and resolution of exacerbations, and at day 14. In most children, blood and deep nasal swabs are also collected at the same time points. The primary outcome is the proportion of children whose exacerbations have resolved at day 14. The main secondary outcome is the paediatric cough-specific quality of life score. Other outcomes are time to next exacerbation; requirement for hospitalisation; duration of exacerbation; and spirometry data. Descriptive viral and bacteriological data from nasal samples and blood markers will also be reported.

DISCUSSION

Effective, evidence-based management of exacerbations in people with bronchiectasis is clinically important. Yet, there are few randomised controlled trials (RCTs) in the neglected area of non-cystic fibrosis bronchiectasis. Indeed, no published RCTs addressing the treatment of bronchiectasis exacerbations in children exist. Our multicentre, double-blind RCT is designed to determine if azithromycin and amoxicillin-clavulanic acid, compared with placebo, improve symptom resolution on day 14 in children with acute respiratory exacerbations. Our planned assessment of the predictors of antibiotic response, the role of antibiotic-resistant respiratory pathogens, and whether early treatment with antibiotics affects duration and time to the next exacerbation, are also all novel.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Register (ANZCTR) number ACTRN12612000011886.

In young children, persistent wheezing is associated with bronchial bacterial infection: a retrospective analysis

Background

Young children with persistent wheezing pose a diagnostic and therapeutical challenge to the pediatrician.

We aimed to evaluate bacterial bronchial infection as a possible reason for non response to conventional asthma therapy, and to identify and characterise the predominant pathogens involved.

Methods

We retrospectively analysed microbiological and cytological findings in a selected population of young wheezers with symptoms unresponsive to inhaled corticosteroid (ICS) therapy, who underwent flexible bronchoscopy with bronchoalveolar lavage (BAL). Procedural measures were taken to limit contamination risk and quantitative bacterial culture of BAL fluid (significance cut-off ≥ 10⁴ colony-forming units/ml) was used. Modern microbiological methods were used for detection of a wide panel of pathogens and for characterisation of the bacterial isolates.

Results

33 children aged between 4 and 38 months, without structural anomalies of the conductive airways were evaluated. Significant bacterial BAL cultures were found in 48,5 % of patients. Haemophilus influenzae was isolated in 30,3 %, Streptococcus pneumoniae in 12,1 % and Moraxella catarrhalis in 12,1 %. All H. influenzae isolates were non-encapsulated strains and definitely distinguished from non-haemolytic H. haemolyticus. Respiratory viruses were detected in 21,9 % of cases with mixed bacterial-viral infection in 12,1 %. Cytology revealed a marked neutrophilic inflammation.

Conclusions

Bacterial infection of the bronchial tree is common in persistent preschool wheezers and provides a possible explanation for non response to ICS therapy. Non-typeable H. influenzae seems to be the predominant pathogen involved, followed by S. pneumoniae and M. catarrhalis.

Bronchoscopic findings in children with chronic wet cough

OBJECTIVES

Protracted bacterial bronchitis is defined as the presence of more than 4 weeks of chronic wet cough that resolves with appropriate antibiotic therapy, in the absence of alternative diagnoses. The diagnosis of protracted bacterial bronchitis is not readily accepted within the pediatric community, however, and data on the incidence of bacterial bronchitis in children are deficient. The objective of this study was to determine the frequency of bacterial bronchitis in children with chronic wet cough and to analyze their bronchoscopic findings.

METHODS

We performed a retrospective review of charts of children who presented with chronic wet cough, unresponsive to therapy, before referral to the pediatric pulmonary clinic.

RESULTS

A total of 197 charts and bronchoscopy reports were analyzed. Of 109 children who were 0 to 3 years of age, 33 (30.3%) had laryngomalacia and/or tracheomalacia. The bronchoscopy showed purulent bronchitis in 56% (110) cases and nonpurulent bronchitis in 44% (87). The bronchoalveolar lavage bacterial cultures were positive in 46% (91) of the children and showed nontypable Haemophilus influenzae (49%), Streptococcus pneumoniae (20%), Moraxella catarrhalis (17%), Staphylococcus aureus (12%), and Klebsiella pneumoniae in 1 patient. The χ(2) analysis demonstrated that positive bacterial cultures occurred more frequently in children with purulent bronchitis (74, 69.8%) than in children with nonpurulent bronchitis (19, 19.8%) (P < .001).

CONCLUSIONS

Children who present with chronic wet cough are often found to have evidence of purulent bronchitis on bronchoscopy. This finding is often indicative of a bacterial lower airway infection in these children.

Protracted bacterial bronchitis in young children: association with airway malacia

OBJECTIVE

To examine associated findings and clinical outcome in young children with prolonged cough, wheeze, and/or noisy breathing in whom high colony counts of potentially pathogenic bacteria were cultured from bronchoalveolar lavage (BAL) during diagnostic flexible fiberoptic bronchoscopy.

STUDY DESIGN

This was a retrospective review of all medical records of children from infancy to 60 months of age seen in our specialty clinic from 1999 to 2009 with protracted cough, wheeze, and/or noisy breathing in whom BAL found ≥ 10(4) colony forming units per milliliter of potentially pathogenic bacteria. Children with other major diagnoses were excluded.

RESULTS

With quantitative culture from BAL, ≥ 10(4) colony forming units per milliliter of Streptococcus pneumoniae, Haemophilus influenza, or Moraxella catarrhalis, separately or in combination, were found in 70 children. Neutrophilia was present in 87% of BALs. Tracheomalacia, bronchomalacia, or both was present in 52 children (74%). Symptoms were eliminated with antibiotics in all 61 children with follow-up data. Relapse and subsequent successful re-treatment occurred in 43 children.

CONCLUSIONS

High colony counts of potentially pathogenic bacteria associated with neutrophilia in the BAL identifies protracted bacterial bronchitis. The predominance of airway malacia in these patients suggests an etiologic role for those airway anomalies. The potential for chronic airway damage from protracted bacterial bronchitis warrants further investigation.

Therapy for cough: where does it fall short?

Studies on cough have come a long way but many shortfalls still exist. These shortfalls can be attributed to: the lack of randomized controlled studies with a focus on cough; studies not using robust cough outcome measures, poor definition of target groups in studies and guidelines, the lack of safe and efficacious treatments; difficulty in defining etiological factors, and the lack of data on the predictors of response to therapies for cough dominant etiologies. Addressing shortfalls in cough therapy that focuses on improving the lives of people with cough requires a systematic approach that includes better medications, high quality studies, improved multidisciplinary guidelines and education (of both health professionals and patients). To achieve new cough therapeutics requires an improved understanding of cough in humans (i.e., not just in animals). Development of new medications without substantial adverse events is long awaited for cough.

Wheeze in preschool age is associated with pulmonary bacterial infection and resolves after antibiotic therapy

Background

Neonates with airways colonized by Haemophilus influenzae, Streptococcus pneumoniae or Moraxella catarrhalis are at increased risk for recurrent wheeze which may resemble asthma early in life. It is not clear whether chronic colonization by these pathogens is causative for severe persistent wheeze in some preschool children and whether these children might benefit from antibiotic treatment. We assessed the relevance of bacterial colonization and chronic airway infection in preschool children with severe persistent wheezing and evaluated the outcome of long-time antibiotic treatment on the clinical course in such children.

Methodology/Principal Findings

Preschool children (n = 42) with severe persistent wheeze but no symptoms of acute pulmonary infection were investigated by bronchoscopy and bronchoalveolar lavage (BAL). Differential cell counts and microbiological and virological analyses were performed on BAL samples. Patients diagnosed with bacterial infection were treated with antibiotics for 2–16 weeks (n = 29). A modified ISAAC questionnaire was used for follow-up assessment of children at least 6 months after bronchoscopy. Of the 42 children with severe wheezing, 34 (81%) showed a neutrophilic inflammation and 20 (59%) of this subgroup had elevated bacterial counts (≥10⁴ colony forming units per milliliter) suggesting infection. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis were the most frequently isolated species. After treatment with appropriate antibiotics 92% of patients showed a marked improvement of symptoms upon follow-up examination.

Conclusions/Significance

Chronic bacterial infections are relevant in a subgroup of preschool children with persistent wheezing and such children benefit significantly from antibiotic therapy.

Diagnosing and preventing chronic suppurative lung disease (CSLD) and bronchiectasis

Current diagnostic labelling of childhood bronchiectasis by radiology has substantial limitations. These include the requirement for two high resolution computerised tomography [HRCT] scans (with associated adversity of radiation) if criteria is adhered to, adoption of radiological criteria for children from adult data, relatively high occurrence of false negative, and to a smaller extent false positive, in conventional HRCT scans when compared to multi-detector CT scans, determination of irreversible airway dilatation, and absence of normative data on broncho-arterial ratio in children. A paradigm presenting a spectrum related to airway bacteria, with associated degradation and inflammation products causing airway damage if untreated, entails protracted bacterial bronchitis (at the mild end) to irreversible airway dilatation with cystic formation as determined by HRCT (at the severe end of the spectrum). Increasing evidence suggests that progression of airway damage can be limited by intensive treatment, even in those predestined to have bronchiectasis (eg immune deficiency). Treatment is aimed at achieving a cure in those at the milder end of the spectrum to limiting further deterioration in those with severe 'irreversible' radiological bronchiectasis.

Bronchoscopic and high-resolution CT scan findings in children with chronic wet cough

BACKGROUND

Chronic wet cough strongly suggests endobronchial infection, which, if left untreated, may progress to established bronchiectasis. Our aim was to compare the effectiveness of chest high-resolution CT (HRCT) scanning and flexible bronchoscopy (FB) in detecting airway abnormalities in children with chronic wet cough and to explore the association between radiologic and bronchoscopic/BAL findings.

METHODS

We retrospectively evaluated a selected population of 93 children (0.6-16.4 years) with wet cough for > 6 weeks who were referred to a specialized center and deemed unlikely to have asthma. All patients were submitted to hematologic investigations, chest radiographs (CXRs), HRCT scanning, and FB/BAL. HRCT scans were scored with the Bhalla method, and bronchoscopic findings of bronchitis were grouped into five grades of severity.

RESULTS

Positive HRCT scan findings were present in 70 (75.2%) patients (P = .76). A positive correlation was found between Bhalla score and duration of cough (ρ = 0.23, P = .028). FB/BAL was superior to HRCT scan in detecting abnormalities (P < .001). The Bhalla score correlated positively with type III (OR, 5.44; 95% CI, 1.92-15.40; P = .001) and type IV (OR, 8.91; 95% CI, 2.53-15.42; P = .001) bronchoscopic lesions; it also correlated positively with the percentage of neutrophils in the BAL (ρ = 0.23, P = .036).

CONCLUSIONS

HRCT scanning detected airway wall thickening and bronchiectasis, and the severity of the findings correlated positively with the length of clinical symptoms and the intensity of neutrophilic inflammation in the airways. However, HRCT scanning was less sensitive than FB/BAL in detecting airway abnormalities. The two modalities should be considered complementary in the evaluation of prolonged wet cough.

Do sex and atopy influence cough outcome measurements in children?

BACKGROUND

Despite the commonality of cough and its burden, there are no published data on the relationship between atopy or sex on objectively measured cough frequency or subjective cough scores in children. In 202 children with and without cough, we determined the effect of sex and atopy on validated cough outcome measurements (cough receptor sensitivity [CRS], objective cough counts, and cough scores). We hypothesized that in contrast to adult data, sex does not influence cough outcome measures, and atopy is not a determinant of these cough measurements.

METHODS

We combined data from four previous studies. Atopy (skin prick test), the concentration of capsaicin causing two and five or more coughs (C2 and C5, respectively), objectively measured cough frequency, and cough scores were determined and their relationship explored. The children's (93 girls, 109 boys) mean age was 10.6 years (SD 2.9), and 56% had atopy.

RESULTS

In multivariate analysis, CRS was influenced by age (C2 coefficient, 5.9; P = .034; C5 coefficient, 29.1; P = .0001). Atopy and sex did not significantly influence any of the cough outcomes (cough counts, C2, C5, cough score) in control subjects and children with cough.

CONCLUSIONS

Atopy does not influence important cough outcome measures in children with and without chronic cough. However, age, but not sex, influences CRS in children. Unlike adult data, sex does not affect objective counts or cough score in children with and without chronic cough. Studies on cough in children should be age matched, but matching for atopic status and sex is less important.

Bacterial infections and pediatric asthma

Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis seem to have no role in asthma in children. Mycoplasma pneumoniae and Chlamydophila pneumoniae can induce wheezing and cause asthma exacerbations in children, and chronic Chlamydophila infections may even participate in asthma pathogenesis. However, studies have failed to show any benefits from antibiotics for incipient or stable pediatric asthma, as well as for asthma exacerbations in children. Exposure to antibiotics in infancy has been an independent risk factor of later asthma in many studies. A recent study applying molecular biology methods to lower airway samples provided preliminary evidence that lower airways are not sterile but have their own protective microbiota, which can be disturbed in lung diseases like asthma.

Can a management pathway for chronic cough in children improve clinical outcomes: protocol for a multicentre evaluation

BACKGROUND

Chronic cough is common and is associated with significant economic and human costs. While cough can be a problematic symptom without serious consequences, it could also reflect a serious underlying illness. Evidence shows that the management of chronic cough in children needs to be improved. Our study tests the hypothesis that the management of chronic cough in children with an evidence-based management pathway is feasible and reliable, and improves clinical outcomes.

METHODS/DESIGN

We are conducting a multicentre randomised controlled trial based in respiratory clinics in 5 major Australian cities. Children (n = 250) fulfilling inclusion criteria (new patients with chronic cough) are randomised (allocation concealed) to the standardised clinical management pathway (specialist starts clinical pathway within 2 weeks) or usual care (existing care until review by specialist at 6 weeks). Cough diary, cough-specific quality of life (QOL) and generic QOL are collected at baseline and at 6, 10, 14, 26, and 52 weeks. Children are followed-up for 6 months after diagnosis and cough resolution (with at least monthly contact from study nurses). A random sample from each site will be independently examined to determine adherence to the pathway. Primary outcomes are group differences in QOL and proportion of children that are cough free at week 6.

DISCUSSION

The clinical management pathway is based on data from Cochrane Reviews combined with collective clinical experience (250 doctor years). This study will provide additional evidence on the optimal management of chronic cough in children.

TRIAL REGISTRATION

ACTRN12607000526471.

Chronic suppurative lung disease and bronchiectasis in children and adults in Australia and New Zealand

Consensus recommendations for managing chronic suppurative lung disease (CSLD) and bronchiectasis, based on systematic reviews, were developed for Australian and New Zealand children and adults during a multidisciplinary workshop. The diagnosis of bronchiectasis requires a high-resolution computed tomography scan of the chest. People with symptoms of bronchiectasis, but non-diagnostic scans, have CSLD, which may progress to radiological bronchiectasis. CSLD/bronchiectasis is suspected when chronic wet cough persists beyond 8 weeks. Initial assessment requires specialist expertise. Specialist referral is also required for children who have either two or more episodes of chronic (> 4 weeks) wet cough per year that respond to antibiotics, or chest radiographic abnormalities persisting for at least 6 weeks after appropriate therapy. Intensive treatment seeks to improve symptom control, reduce frequency of acute pulmonary exacerbations, preserve lung function, and maintain a good quality of life. Antibiotic selection for acute infective episodes is based on results of lower airway culture, local antibiotic susceptibility patterns, clinical severity and patient tolerance. Patients whose condition does not respond promptly or adequately to oral antibiotics are hospitalised for more intensive treatments, including intravenous antibiotics. Ongoing treatment requires regular and coordinated primary health care and specialist review, including monitoring for complications and comorbidities. Chest physiotherapy and regular exercise should be encouraged, nutrition optimised, environmental pollutants (including tobacco smoke) avoided, and vaccines administered according to national immunisation schedules. Individualised long-term use of oral or nebulised antibiotics, corticosteroids, bronchodilators and mucoactive agents may provide a benefit, but are not recommended routinely.

Evaluation of infants and children with refractory lower respiratory tract symptoms

OBJECTIVE

To define the diagnostic possibilities for young children who present with recurrent wheeze.

DATA SOURCES

Review of medical literature and 30 years of practice experience.

STUDY SELECTION

Relevant medical literature.

RESULTS

When evaluating an infant or child presenting with recurrent respiratory symptoms, several diagnoses must be considered. The workup should include assessment of the risk factors for asthma and careful investigation into the specific symptoms. Recurrent or persistent wheezing and/or coughing often result in a diagnosis of asthma with therapeutic trials of asthma treatment. When the therapy is ineffective, other diagnoses should be considered, including gastroesophageal reflux, protracted bacterial bronchitis, tracheobronchomalacia, and cystic fibrosis. Appropriate testing should be performed in these pediatric patients.

CONCLUSION

In young children with recurrent lower airway symptoms who have a negative modified Asthma Predictive Index result, the described diagnostic possibilities should be considered.

Longitudinal growth and lung function in pediatric non-cystic fibrosis bronchiectasis: what influences lung function stability?

BACKGROUND

Longitudinal FEV(1) data in children with non-cystic fibrosis (non-CF) bronchiectasis (BE) are contradictory, and there are no multifactor data on the evolution of lung function and growth in this group. We longitudinally reviewed lung function and growth in children with non-CF BE and explored biologically plausible factors associated with changes in these parameters over time.

METHODS

Fifty-two children with > or = 3 years of lung function data were retrospectively reviewed. Changes in annual anthropometry and spirometry at year 3 and year 5 from baseline were analyzed. The impact of sex, age, cause, baseline FEV(1), exacerbation frequency, radiologic extent, socioeconomic status, environmental tobacco smoke exposure, and period of diagnosis was evaluated.

RESULTS

Over 3 years, the group mean forced expiratory flow midexpiratory phase percent predicted and BMI z-score improved by 3.01 (P = .04; 95% CI, 0.14-5.86) and 0.089 (P = .01; 95% CI, 0.02-0.15) per annum, respectively. FEV(1)% predicted, FVC% predicted, and height z-score all showed nonsignificant improvement. Over 5 years, there was improvement in FVC% predicted (slope 1.74; P = .001) annually, but only minor improvement in other parameters. Children with immunodeficiency and those with low baseline FEV(1) had significantly lower BMI at diagnosis. Frequency of hospitalized exacerbation and low baseline FEV(1) were the only significant predictors of change in FEV(1) over 3 years. Decline in FEV(1)% predicted was large (but nonsignificant) for each additional year in age of diagnosis.

CONCLUSIONS

Spirometric and anthropometric parameters in children with non-CF BE remain stable over a 3- to 5-year follow-up period once appropriate therapy is instituted. Severe exacerbations result in accelerated lung function decline. Increased medical cognizance of children with chronic moist cough is needed for early diagnosis, better management, and improving overall outcome in BE.

Disordered microbial communities in asthmatic airways

Background

A rich microbial environment in infancy protects against asthma [1], [2] and infections precipitate asthma exacerbations [3]. We compared the airway microbiota at three levels in adult patients with asthma, the related condition of COPD, and controls. We also studied bronchial lavage from asthmatic children and controls.

Principal Findings

We identified 5,054 16S rRNA bacterial sequences from 43 subjects, detecting >70% of species present. The bronchial tree was not sterile, and contained a mean of 2,000 bacterial genomes per cm² surface sampled. Pathogenic Proteobacteria, particularly Haemophilus spp., were much more frequent in bronchi of adult asthmatics or patients with COPD than controls. We found similar highly significant increases in Proteobacteria in asthmatic children. Conversely, Bacteroidetes, particularly Prevotella spp., were more frequent in controls than adult or child asthmatics or COPD patients.

Significance

The results show the bronchial tree to contain a characteristic microbiota, and suggest that this microbiota is disturbed in asthmatic airways.

Chronic respiratory symptoms and diseases among indigenous children

Children from Indigenous populations experience more frequent, severe, and recurrent lower respiratory infections as infants and toddlers. The consequences of these infections are chronic lung disorders manifested by recurrent wheezing and chronic productive cough. These symptoms are aggravated more frequently by active and passive tobacco smoke exposure among Indigenous groups. Therapies for these symptoms, although not specific to children of Indigenous origins, are described as is the evidence for their use.

Recurrent respiratory infections

The child who has recurrent infections poses one of the most difficult diagnostic challenges in pediatrics. The clinician faces a two-fold challenge in determining first whether the child is normal or has a serious disease, and then, in the latter case, how to confirm or exclude the diagnosis with the minimum number of the least invasive tests. It is hoped that, in the absence of good-quality evidence for most clinical scenarios, the experience-based approach described in this article may prove a useful guide to the clinician.