Acute viral bronchiolitis and its sequelae in developing countries

Solar radiation, air pollution, and bronchiolitis hospitalizations in Chile: An ecological study

OBJECTIVE

To evaluate trends and geographic distribution of infant bronchiolitis hospitalizations in Chile, a country with large variation in solar radiation (SR) and high rates of urban air pollution.

METHODS

We performed a nationwide ecological study of bronchiolitis hospitalizations from 2001 to 2014. We investigated the associations of regional SR (a proxy of vitamin D status) and regional fine particulate matter (PM2.5) air pollution with bronchiolitis hospitalizations. We also evaluated the role of sociodemographic factors, including regional poverty, education, indigenous population, and rurality rates.

RESULTS

During the study period, 119 479 infants were hospitalized for bronchiolitis in Chile; 59% were boys. The mean bronchiolitis hospitalization rate increased from 29 to 41 per 1000 infants per year (P = .02). There was an inverse correlation between regional SR and incidence of hospital admissions for bronchiolitis (r = -0.52, P = .049), accounting for 27% of these hospitalizations. There was also a significant direct correlation between regional ambient PM2.5 and bronchiolitis hospitalizations (R = 0.68, P = .006), accounting for 42% of the variation in admission rate. High firewood and/or coal residential use for heating, high regional poverty, lower years of education, and high rurality rates were also significantly correlated with bronchiolitis hospitalization rates. None of the environmental or sociodemographic factors evaluated were correlated with regional case fatality rates or length of stay at the hospital.

CONCLUSIONS

This ecological study revealed significant associations between regional SR, air pollution, and sociodemographic factors with infant bronchiolitis hospitalizations in Chile, suggesting that these factors play a major role in the incidence and severity of respiratory infections in early childhood.

Long-Term Lung Function and Exercise Capacity in Postinfectious chILD

Background: Severe postinfectious diffuse pulmonary disease may clinically mimic other entities of children's interstitial lung disease and is clinically challenging comprising various disease severities despite treatment. Long-term lung function trend and physical capacity in children with postinfectious diffuse pulmonary disease are rarely reported. We investigated trends in pulmonary function by long-term follow-up and assessed physical capacity in such patients.

Methods: We performed a descriptive, single-center follow-up study in children with biopsy-verified postinfectious diffuse pulmonary disease. Patients with completed primary treatment course were eligible for follow-up, including pulmonary function and exercise (VO_2peak) testing.

Results: Thirty patients with postinfectious diffuse pulmonary disease were identified and included. Median (range) age at diagnose was 27.5 (2–172) months after a mean lag time of 23 months. H. influenzae and rhinovirus were the most frequent pathogens. Fifteen patients were available for follow-up after mean (range) 7.6 (2–15) years of treatment completion. Lung clearance index (LCI_2.5), forced expiratory volume in 1 second (FEV₁), and bronchodilator responsiveness were abnormal in 80%, 53%, and 44%, respectively. Diffusion capacity for monoxide was abnormal in 7% and total lung capacity in 33%. Only 8% demonstrated low VO_2peak, while 40% reported difficulties during physical exertion. Longitudinal data on spirometry (n = 14) remained unchanged from end of treatment throughout follow-up. A significant association was found between zLCI_2.5 and zFEV₁ (multiple linear regression; r² = 0.61; P = 0.0003).

Conclusion: Postinfectious diffuse pulmonary disease in children carries a varying degree of chronic pulmonary impairment with onset of symptoms in the first months of life and a typical considerable lag time before diagnosis. Follow-up several years after the initial injury demonstrated moderate-to-severe peripheral airway impairment although no further lung function decline was found years after completion of treatment. Despite acceptable VO_2peak, a considerable proportion struggled during heavy exercise.

Postinfectious bronchiolitis obliterans in children: the South American contribution

Postinfectious bronchiolitis obliterans (PIBO) is an infrequent chronic lung that causes irreversible obstruction and, or, obliteration of the smaller airways. This review particularly focuses on more than 30 studies from South America.

CONCLUSION

The initial PIBO event occurs in the early years of life and is strongly associated with adenovirus infection and the need for mechanical ventilator support. Treatment requires a multidisciplinary strategy. Multicentre studies are needed to determine progression, optimal management and long-term follow-up.

Development and validation of the Liverpool infant bronchiolitis severity score: a research protocol

AIM

To develop and validate a bronchiolitis severity scoring instrument for use by nurses and other healthcare professions.

BACKGROUND

Bronchiolitis is a viral lower respiratory tract infection of infancy. In industrialized countries, admission rates have increased over the last decade with up to 3% of all infants born being admitted to hospital. A small number of these hospitalized infants will require admission to critical care for either invasive or non-invasive ventilation. During the seasonal epidemic, the number of unplanned admissions to critical care with bronchiolitis substantially increases.

DESIGN

We will use a mixed methods study design.

METHODS

We will use scale development and psychometric methods to develop a scoring instrument and to test the instrument for content, construct and criterion validity and reliability in several different clinical locations. This study protocol has been reviewed and approved by the NHS National Research Ethics Service, January 2011.

DISCUSSION

There is an urgent need to develop a valid and reliable severity scoring instrument sensitive to clinical changes in the infant, to facilitate clinical decision-making and help standardize patient care. Furthermore, a valid and reliable scoring instrument could also be used as a proxy patient-reported outcome measure to evaluate the efficacy of clinical interventions in randomized controlled trials.

Post infectious bronchiolitis obliterans in children

Bronchiolitis Obliterans (BO) is an infrequent chronic and obstructive lung disease secondary to an insult to the terminal airway and its surroundings. In children, the most common presentation is the post-infectious variant, closely related to a severe viral infection in the first three years of life. However, the increase in the number of lung and bone-marrow transplants has also been followed by an increase in post-transplant BO. Post-transplant BO is progressive while post-infectious BO does not seem to be, but both forms share some common pathways that result in a characteristic histopathology of bronchiolar obliteration. This review covers up-to-date evidence on epidemiology, diagnosis, treatment and prognosis of post-infectious bronchiolitis obliterans, including areas of controversy that need to be addressed in future studies.

WITHDRAWN: Immunoglobulin treatment for respiratory syncytial virus infection

BACKGROUND

Respiratory syncytial virus (RSV) bronchiolitis and pneumonia hospitalise hundreds of thousands of infants every year. Treatment is largely supportive therapy, (for example, oxygen, fluids and occasionally mechanical ventilation). Ribavirin, an antiviral agent, is licensed for severe RSV infection, although systematic reviews find it of no benefit. Passive protection against RSV can be achieved through monthly intramuscular injections of the humanised monoclonal anti-RSV antibody palivizumab (Synagis), and yields a 55% reduction in RSV hospitalisation in susceptible infants. This review assesses immunoglobulin treatment of RSV infection rather than its role as a prophylactic measure.

OBJECTIVES

To assess the efficacy of adding human or humanised immunoglobulin therapy to supportive therapy in infants hospitalised with laboratory-determined RSV infection.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2006, issue 1) which contains the Acute Respiratory Infections Group's specialized regsiter, MEDLINE (1966 to Week 4, January 2006) and EMBASE (1980 to September 2005). We also ran searches of reference lists of relevant trials and review articles and searches of personal files. We did not impose any language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) that compared immunoglobulin treatment with a placebo control in children hospitalised for RSV infection with bronchiolitis or pneumonia or other lower respiratory tract infection (LRTI) with laboratory-documented RSV infection. The primary outcomes of interest were mortality, length of hospitalisation, length of ventilation and oxygen dependence. Secondary outcome measures were pulmonary function and re-hospitalisations for recurrent breathing difficulties in subsequent years. Any adverse effects of the treatments were also noted, for example, hypersensitivity reactions.

DATA COLLECTION AND ANALYSIS

Data were extracted but cross-comparison was not possible due to the shortage of studies and lack of comparative measurements.

MAIN RESULTS

Four papers fitted the search criteria. None demonstrated statistically significant benefit of intravenous immunoglobulin (IVIG) treatment added to supportive care compared with supportive care alone. The evidence does not support a role for RSVIG in such a setting, with the doses used in the studies.

AUTHORS' CONCLUSIONS

The evidence on the role of respiratory syncytial virus immunoglobulin (RSVIG) in treating RSV severe infections is limited. Future research might consider using stronger titres of neutralising antibodies; and further analyse severely ill children (who might respond differentially compared to those less ill, but yet hospitalised).

Post-infectious bronchiolitis obliterans: can CT scan findings at early age anticipate lung function?

BACKGROUND

The image findings of post-infectious bronchiolitis obliterans (PIBO) have been described, however, we do not know if such findings can predict lung function (LF) deterioration with increasing patient age.

AIM

To assess whether computed tomography (CT) abnormalities detected at an early stage of the disease can anticipate abnormal LF a decade later in children with PIBO.

METHODS

We compared CT scans of 21 children with PIBO, done within their first 3 years of life, and their actual LF. To evaluate CT scans we used a modified Bhalla score and, for LF, FEV1 as percentage of predicted values. We calculated prevalence ratios (PRs) by comparing the proportion of patients with worst CT score and worst LF, with the proportion of those with best CT score and worst LF.

RESULTS

PR was 1.17 (CI 1.02; 1.34, P = 0.02).

CONCLUSIONS

The CT finding early in the life of children with PIBO, when assessed by the Bhalla, score seem to anticipate future LF status.

Fatores de risco para internação por doença respiratória aguda em crianças até um ano de idade

OBJETIVO: Avaliar fatores de risco para hospitalização por doença respiratória aguda em crianças até um ano de idade. MÉTODOS: Estudo de casos e controles na cidade de Pelotas, RS. Os casos foram crianças de até um ano de idade, que se hospitalizaram por doença respiratória aguda, de agosto de 1997 a julho de 1998. Os controles foram crianças da comunidade, da mesma idade, sem hospitalização prévia por essa doença. Um questionário investigando exposição a fatores de risco foi aplicado às mães de casos e controles. Os dados foram submetidos à análise univariada, bivariada e multivariada por meio de regressão logística para avaliação dos fatores de risco sobre o desfecho de interesse. RESULTADOS: Foram analisadas 777 crianças, sendo 625 casos e 152 controles. Na análise bruta, os fatores de risco associados ao desfecho foram: sexo masculino, faixa etária menor de seis meses, aglomeração familiar, escolaridade materna, renda familiar, condições habitacionais inadequadas, desmame precoce, tabagismo materno, uso de bico, história de hospitalização e antecedentes de sintomas respiratórios. O trabalho materno foi fator de proteção para internação por doença respiratória aguda. Na análise multivariada, permaneceram associadas: ausência de ou baixa escolaridade materna (OR=12,5), história pregressa de sibilância (OR=7,7), desmame precoce (OR=2,3), uso de bico (OR=1,9), mãe fumante (OR=1,7), idade abaixo de seis meses (OR=1,7) e sexo masculino (OR=1,5). CONCLUSÕES: Os resultados mostraram a importância dos aspectos sociais e comportamentais da família, assim como morbidade respiratória anterior da criança como fatores de risco para hospitalização por doença respiratória aguda.

Non-cystic-fibrosis bronchiectasis: a perspective from South America

Nowadays, bronchiectasis tends to be considered a rare disease. This is really the case in developed countries, where good standards of living have been prevalent for many decades. But it might not be the case in the developing world, where better sanitary conditions are still needed. This article reviews non-cystic fibrosis bronchiectasis, emphasising differences between developed and developing countries. Diagnostic methods and therapeutic issues are discussed as is the Latin American experience of postviral bronchiectasis.

Immunoglobulin treatment for respiratory syncytial virus infection

BACKGROUND

Respiratory syncytial virus (RSV) bronchiolitis and pneumonia hospitalize hundreds of thousands of infants every year. Treatment is largely supportive therapy, (for example, oxygen, fluids and occasionally mechanical ventilation). Ribavirin, an antiviral agent, is licensed for severe RSV infection, although systematic reviews find it of no benefit. Passive protection against RSV can be achieved through monthly intramuscular injection of the humanized monoclonal anti-RSV antibody palivizumab (Synagis), and yields a 55% reduction in RSV hospitalisation in susceptible infants. This review assesses immunoglobulin treatment of RSV infection rather than its role as a prophylactic measure.

OBJECTIVES

To assess the efficacy of adding human or humanized immunoglobulin therapy to supportive therapy in infants hospitalized with laboratory-determined RSV infection.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2006), MEDLINE (1966 to Week 4, January 2006) and EMBASE (1980 to September 2005). We also ran searches of reference lists of relevant trials and review articles and searches of personal files. We did not impose any language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) that compared immunoglobulin treatment with a placebo control in children hospitalized for RSV infection with bronchiolitis or pneumonia or other lower respiratory tract infection (LRTI) with laboratory-documented RSV infection. The primary outcomes of interest were mortality, length of hospitalisation, length of ventilation and oxygen dependence. Secondary outcome measures were pulmonary function and re-hospitalisations for recurrent breathing difficulties in subsequent years. Any adverse effects of the treatments were also noted, for example, hypersensitivity reactions.

DATA COLLECTION AND ANALYSIS

Data were extracted but cross-comparison was not possible due to the shortage of studies and lack comparative measurements.

MAIN RESULTS

Four papers fitted the search criteria. None demonstrated statistically significant benefit of intravenous immunoglobulin (IVIG) treatment added to supportive care compared with supportive care alone. The evidence does not support a role for RSVIG in such a setting, with the doses used in the studies.

AUTHORS' CONCLUSIONS

The evidence on the role of respiratory syncytial virus immunoglobulin (RSVIG) in treating RSV severe infections is limited. Future research might consider using stronger titres of neutralising antibodies; and further analyse severely ill children (who might respond differentially compared to those less ill, but yet hospitalised).

Levels of Th1 and Th2 cytokines in children with post-infectious bronchiolitis obliterans

BACKGROUND

Post-infectious bronchiolitis obliterans (BO) is a chronic obstructive airway disease associated with inflammation and fibrosis of the small airways; it is more common in children who have had acute viral bronchiolitis. No previous studies have reported the immune response of BO. Unbalanced Th1/Th2 immune response might be one of the risk factors for developing this illness.

AIM

To compare the production of interferon (IFN)-gamma, interleukin (IL)-4 and IL-10 in peripheral blood mononuclear cell cultures in children with BO and in healthy children.

METHODS

From March 2003 to October 2003, children with BO and healthy children were selected from the paediatric outpatient clinics in our centre. Peripheral blood was collected and mononuclear cells were separated and cultured (96 hours) with 1% phytohaemagglutinin stimulation. The supernatant was stored and cytokine levels were measured through ELISA.

RESULTS

IFN-gamma, IL-4 and IL-10 levels were not significantly different between the groups studied. Family history of atopy was significantly associated with subjects with BO (p=0.02).

CONCLUSIONS

Our results suggest that unbalanced peripheral blood Th1/Th2 immune response of children with post-infectious BO might not be associated with its pathophysiology. Further studies are required to better understand the role of risk factors, including viral genotype, viral load or tissue repair abnormalities in the development of post-infectious BO.

Nitric Acid-Induced Bronchiolitis in Rats Mimics Childhood Bronchiolitis obliterans

BACKGROUND

Childhood bronchiolitis obliterans (CBO) is an infrequent but severe disease, characterized by persistent obstructive respiratory symptoms after an acute episode of bronchiolitis. Its etiology is mostly postviral, especially in developing countries. Pathologically, CBO is characterized as constrictive-type BO. The pathogenesis of this disease is poorly understood and there is no specific treatment. Animal models could help to better understand the sequence of events culminating in bronchiolar obliteration and serve as basis for experimental therapeutic research.

OBJECTIVES

In this study, we adapted the nitric acid (NA) technique to develop a suitable model to study CBO in rats.

METHODS

We have intratracheally instilled 0.5% NA or saline and studied the histological lesions on days 2, 7, 14 and 30. NA-instilled animals developed a sequence of bronchiolar lesions that included necrotizing bronchiolitis, proliferative (PROL) bronchiolar lesions and constrictive (CONS) bronchiolar lesions with bronchiectasis, mucostasis and macrophagic accumulation.

RESULTS

The frequency of PROL lesions decreased and that of the CONS lesions increased, with a statistically significant difference at the sacrifice days, except for day 7 (PROL vs. CONS lesions day 2: p = 0.001; PROL vs. CONS lesions day 7: p = 0.38; PROL vs. CONS lesions day 14: p < 0.001; PROL vs. CONS lesions day 30: p < 0.001).

CONCLUSIONS

We conclude that this model presents histological similarities with the histological picture of CBO, being suitable for further developmental and therapeutic experimental research in this field.

Massive lung collapse with partial resolution after several years: a case report

BACKGROUND

Bronchitis obliterans is a severe and extremely rare complication of respiratory tract infections in children and is characterized by massive atelectasis and collapse of the affected lung. Of the rare cases reported in the literature all surviving children underwent surgical resection of the collapsed lung.

CASE PRESENTATION

We report an infant with bronchitis obliterans that was treated conservatively. 5 years after the initial event, partial lung re-expansion was documented.

CONCLUSION

This case therefore supports a conservative treatment whenever possible with pneumonectomy only as a last treatment option.

Lymphocytic inflammation in childhood bronchiolitis obliterans

Childhood bronchiolitis obliterans (CBO) is an infrequent, severe disorder characterized by persistent obstructive respiratory symptoms after an acute episode of bronchiolitis. The viral etiology is most common, and adenovirus is the most frequently identified causative agent. Pathologically, the disease is characterized as constrictive type BO, with variable degrees of chronic inflammation and fibrosis in the bronchioles. The nature of the cellular infiltrate is largely unknown, and its characterization may provide better understanding of the disease and offer clues for therapy. Therefore, the aim of the present study was to characterize the inflammatory infiltrate in the bronchioles of 23 open lung biopsies of children with CBO and to compare this to the infiltrate in histologically normal airways. Our results show that CD3+ T cells were the most frequent cell type observed in CBO, with a predominance of the CD8+ T-cell subtype. When compared to the control group, there was a larger number of CD8+, CD4+, CD20+, granzyme B+, and perforin+ lymphocytes in the CBO group. Further studies are needed to address the role of different cell types in the development of CBO.

Bronquiolite obliterante pós-infecciosa: aspectos clínicos e exames complementares de 48 crianças

INTRODUÇÃO: A evolução clínica da bronquiolite obliterante pós infecciosa é variável. OBJETIVO: Verificar as características clínicas, a evolução e os exames complementares de 48 pacientes com bronquiolite obliterante (BO) pós-infecciosa. MÉTODO: Estudo observacional e retrospecitvo. O diagnóstico de bronquiolite obliterante foi baseado em critérios clínicos, tomográficos e pela exclusão de outras doenças. Avaliou-se a história prévia ao diagnóstico e exames complementares. A saturação arterial foi avaliada pela primeira e última medidas. RESULTADOS: A média da idade dos pacientes (32 do sexo masculino e 16 do feminino) no quadro agudo da doença infecciosa foi de 9,6 meses e na primeira consulta de 30,5 meses, com um tempo médio de acompanhamento de 3,3 anos. Todos foram internados no quadro agudo, sendo que 14 (29%) em UTI.Quatro pacientes faleceram dois anos após o quadro de bronquiolite aguda. Na evolução, todos necessitaram de consultas de emergência por exacerbação do quadro pulmonar e 24 (50%) de hospitalização, dos quais 2 em UTI. A maioria persistiu com tosse, sibilos e estertores, porém em menor intensidade. A média da saturação arterial inicial foi de 89% e a final de 92%. Na cultura de escarro, os agentes infecciosos mais comuns foram: H. influenzae, S. pneumoniae e M. catarrhalis. As imunoglobulinas séricas M e G encontravam-se elevadas em 9 e 7 pacientes, respectivamente. Os achados mais freqüentes na tomografia axial computadorizada de tórax foram: perfusão em mosaico, bronquiectasias, aprisionamento de ar, atelectasia e espessamento brônquico. CONCLUSÃO: A BO pós-infecciosa é uma doença crônica e grave, com sintomas contínuos, que geralmente compromete lactentes. A microbiologia de escarro e as imunoglubulinas séricas aumentadas refletem um processo infeccioso e inflamatório crônico persitente.