Atypical bacterial pathogen infection in children with acute bronchiolitis in northeast Thailand

Association between surfactant protein B gene locus and acute bronchiolitis in infants

Purpose: The aim of this study was to investigate whether there is a relationship between surfactant protein B (SFTPB) C1580T polymorphism and acute bronchiolitis. Materials and Methods: The study analyzed the allele frequency and genotype distribution for the SFTPB C1580T polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique in 103 acute bronchiolitis infants and 102 healthy infants. Results: The results showed no association between SFTPB C1580T polymorphism and clinical characteristics of acute bronchiolitis. The distribution of the CT genotype was higher in acute bronchiolitis infants (43%) than in healthy subjects (39%) and distribution of the TT genotype was found lower in acute bronchiolitis infants (38%) than in healthy subjects (41%). No significant differences in genotype distribution and allele frequency for the SFTPB C1580T polymorphism were found between case group and control group Conclusion: SFTPB C1580T gene polymorphism plays no important role in susceptibility to acute bronchiolitis. Further work on the relevance of SFTPB C1580T polymorphism in larger cohorts will require validating our results.

Etiology, clinical characteristics and coinfection status of bronchiolitis in Suzhou

Background

Bronchiolitis is a clinical syndrome commonly encountered in practice, particularly among infants and young children. To investigate the prevalence of pathogens in hospitalized children with bronchiolitis and study the clinical characteristics of bronchiolitis with or without coinfections.

Methods

We investigated the respiratory specimens and clinical data of 1012 children with bronchiolitis who were treated at the Children’s Hospital of Soochow University between November 2011 and December 2018. The nasopharyngeal aspirates were examined to detect viruses by direct immunofluorescence assay or polymerase chain reaction (PCR). Mycoplasma pneumoniae (MP) was tested by PCR and enzyme-linked immunosorbent assay.

Results

Of the 1134 children less than 2 years with bronchiolitis, 122 were excluded by exclusion criteria. Causative pathogen was detected in 83.2% (842 of 1012). The majority of these (614 [72.9%] of 842) were single virus infection. The most common pathogens detected were respiratory syncytial virus (RSV) (44.4%), MP (15.6%), and human rhinovirus (HRV) (14.4%). Coinfection was identified in 13.5% (137 of 1012) of the patients. Coinfection included mixed virus infection and virus infection with MP infection. Children with single virus infection had a higher rate of oxygen therapy compared with single MP infection.

Conclusions

The most common pathogen detected in children with bronchiolitis is RSV, followed by MP and HRV. Coinfection leads to a longer period of illness, increased severity of the symptoms and increased risk of hypoxemia.

Human coronavirus OC43 and other respiratory viruses from acute respiratory infections of Egyptian children

Respiratory infections have a significant impact on health worldwide. Viruses are major causes of acute respiratory infections among children. Limited information regarding its prevalence in Egypt is available. This study investigated prevalence of 10 respiratory viruses; Adenovirus, influenza A, B, respiratory syncytial virus (RSV), Parainfluenza virus (PIV)type 1-4, enterovirus, and human coronavirus OC43 (HCoV-OC43) among children in Alexandria, Egypt presenting with acute lower respiratory tract infections.The study was conducted on children <14 years of age selected from ElShatby Pediatric Hospital, Alexandria University, Egypt. One hundred children presenting during winter season with influenza-like illness were eligible for the study. Oropharyngeal swabs were collected and subjected to viral RNA and DNA extraction followed by polymerase chain reaction.Viral infections were detected in 44% of cases. Adenovirus was the most common, it was found in 19% of the patients. Prevalence of PIV (3 and 4) and enterovirus was 7% each. Prevalence of RSV and HCoV-OC43 was 5% and 3% respectively. Two percentage were Influenza A positive and 1% positive for influenza B. Mixed viral infection was observed in 7%.To the best of our knowledge, this is the first report of the isolation of HCoV-OC43 from respiratory infections in Alexandria, Egypt.

The clinical features and therapy of community-acquired gram negative bacteremia in children less than three years old

BACKGROUND

Community-acquired Gram-Negative (GN) bacteremia caused more morbidity and mortality recently in children. The increasing drug resistance was also an important issue. However, published reference was few about children.

METHODS

We conducted a retrospective study to collect febrile patients with blood culture from a pediatric emergency department during 2007∼2013, and exclude cases ever admitted to hospital within 14 days. These blood cultures all showed single GN organism. The demographic characteristics of enrolled patients and the antibiogram of pathogens were recorded, and then were compared statistically to find out the immediate and appropriate antibiotics.

RESULTS

Total 143 sets of blood culture were GN bacilli and the median age of cases was 2 (IQR, 1-5) years old. Male gender was predominant. Non-fermenting Gram-negative bacilli group (NFGNB spp.), Salmonella spp. and Escherichia coli were first three common pathogens respectively. However, total 37 cases of NFGNB spp. other than Pseudomonas aeruginosa were the possible pathogens. By multiple logistic regression analysis, lower hemoglobin and higher alanine aminotransferase were significant difference between common pathogens and possible ones. Besides, the prevalent age regarding resistant strains of Escherichia coli and Pseudomonas aeruginosa were both focused on less than 1 year old. However, Salmonella spp. were prevalent in the age from 1 to 3 years old.

CONCLUSIONS

For different age groups, Salmonella spp. and Escherchia coli were the most common pathogens of community-acquired GN bacteremia. For infants, Pseudomonas aeruginosa sepsis and resistant strain of Escherchia coli should be alert, and broader antibiotics should be considered.

The Association Between Mycoplasma pneumoniae and Chlamydia pneumoniae, a Life-Threatening Condition in Small Children-A Case Report and a Review of the Literature

Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) are two atypical pathogens that may result in mild, moderate or severe acute respiratory infections. We report the case of a 2 years and 9-month-old male child admitted with prolonged fever, dry cough, and shortness of breath for which he underwent symptomatic treatment. The laboratory tests showed leukocytosis with neutrophilia, anemia, and elevated inflammatory biomarkers and the thoracic radiography revealed pleural effusion raising the suspicion of inferior right pneumonia. Although we the initial evolution was favorable being treated with 3rd class cephalosporin and Oxacillin, on the 8th day of admission the fever and the acute phase reactants levels increased as well as the quantity of the pleural effusion, requiring surgical drainage. We ruled out lung tuberculosis, but we identified positive IgM for both MP and CP. Based on these findings we changed the antibiotic therapy on Levofloxacin for 10 days with favorable evolution. MP and CP are two atypical pathogen that are difficult to be diagnosed due to their slow-growing pattern. Despite their self-limiting feature, the association between them might carry a vital risk in small children, especially in the lack of a proper and timely diagnosis.

Impact and clinical profiles of Mycoplasma pneumoniae co-detection in childhood community-acquired pneumonia

BACKGROUND

Increasing number of hospitalized children with community acquired pneumonia (CAP) is co-detected with Mycoplasma pneumoniae (Mp). The clinical characteristics and impact of Mp co-detected with other bacterial and/or viral pathogens remain poorly understood. The purpose of this study was to evaluate the demographic and clinical features of CAP children with Mp mono-detection and Mp co-detection.

METHODS

A total of 4148 hospitalized children with CAP were recruited from January to December 2017 at the Children's Hospital of Hebei Province, affiliated to Hebei Medical University. A variety of respiratory viruses, bacteria and Mp were detected using multiple modalities. The demographic and clinical features of CAP children with Mp mono-detection and Mp co-detection were recorded and analyzed.

RESULTS

Among the 110 CAP children with Mp positive, 42 (38.18%) of them were co-detected with at least one other pathogen. Co-detection was more common among children aged ≤3 years. No significant differences were found in most clinical symptoms, complications, underlying conditions and disease severity parameters among various etiological groups, with the following exceptions. First, prolonged duration of fever, lack of appetite and runny nose were more prevalent among CAP children with Mp-virus co-detection. Second, Mp-virus (excluding HRV) co-detected patients were more likely to present with prolonged duration of fever. Third, patients co-detected with Mp-bacteria were more likely to have abnormal blood gases. Additionally, CAP children with Mp-HRV co-detection were significantly more likely to report severe runny nose compared to those with Mp mono-detection.

CONCLUSION

Mp co-detection with viral and/or bacterial pathogens is common in clinical practice. However, there are no apparent differences between Mp mono-detection and Mp co-detections in terms of clinical features and disease severity.

Viral etiology of acute respiratory infections in children in Southern Iran

INTRODUCTION

Prevalence of influenza A virus (Flu-A), respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) was assessed in children with acute respiratory infections (ARIs).

METHODS

Nasopharyngeal aspirates and throat swabs were subjected to real-time polymerase chain reaction (PCR) to detect RSV and Flu-A and to conventional PCR to detect hMPV.

RESULTS

Of the 156 children assessed, 93 (59.6%) carried at least one virus, with 35.9% positive for RSV, 14.1% for hMPV, and 9.6% for Flu-A. The prevalence of co-infections was 2.6%.

CONCLUSIONS

The high detection rate may reflect increased sensitivity of real-time PCR compared to traditional PCR and viral culture.

"Epidemiology and aetiology of influenza-like illness among households in metropolitan Vientiane, Lao PDR": A prospective, community-based cohort study

Respiratory diseases are a major contributor to morbidity and mortality in many tropical countries, including Lao PDR. However, little has been published regarding viral or bacterial pathogens that can contribute to influenza-like illness (ILI) in a community setting. We report on the results of a community-based surveillance that prospectively monitored the incidence of ILI and its causative pathogens in Vientiane capital in Lao PDR. A cohort of 995 households, including 4885 study participants, were followed-up between May 2015 and May 2016. Nasopharyngeal swabs, throat swabs, and sputum specimens were collected from ILI cases identified through active case-finding. Real-Time PCR was used to test nasopharyngeal swabs for 21 respiratory pathogens, while throat and sputum samples were subjected to bacterial culture. Generalized linear mixed models were used to assess potential risk factors for associations with ILI. In total, 548 episodes of ILI were reported among 476 (9.7%) of the study participants and 330 (33.2%) of the study households. The adjusted estimated incidence of ILI within the study area was 10.7 (95%CI: 9.4-11.9) episodes per 100 person-years. ILI was significantly associated with age group (p<0.001), sex (p<0.001), and number of bedrooms (p = 0.04) in multivariate analysis. In 548 nasopharyngeal swabs, the most commonly detected potential pathogens were Streptococcus pneumoniae (17.0%), Staphylococcus aureus (11.3%), influenza A (11.1%; mostly subtype H3N2), rhinovirus (7.5%), and influenza B (8.0%). Streptococci were isolated from 42 (8.6%) of 536 throat swabs, most (27) of which were Lancefield Group G. Co-infections were observed in 132 (24.1%) of the 548 ILI episodes. Our study generated valuable data on respiratory disease burden and patterns of etiologies associated with community-acquired acute respiratory illness Laos. Establishment of a surveillance strategy in Laos to monitor trends in the epidemiology and burden of acute respiratory infections is required to minimize their impact on human health.

Chlamydia trachomatis infection influences the clinical course of acute bronchiolitis

The frequency of Chlamydia trachomatis infection among young infants admitted with acute bronchiolitis was analysed to determine whether the former affects the clinical course of the latter. A total of 92 infants aged <6 months admitted with acute bronchiolitis were tested for C. trachomatis by a cell culture technique, obtaining nasal smears from each infant's nostrils. A second nasal sampling was taken for respiratory viruses from the study group and tested with real-time polymerase chain reaction. Clinical characteristics of C. trachomatis-positive and -negative cases were compared. C. trachomatis was detected in 22.8% of the infants, mostly as coinfection with respiratory viral agents. Infection with C. trachomatis affected the clinical outcome in acute bronchiolitis and such infants tended to have severe bronchiolitis.

Epidemiology of Respiratory Pathogens in Children with Lower Respiratory Tract Infections in Shanghai, China, from 2013 to 2015

This study aimed to explore the epidemiology of pathogens in children who were hospitalized with lower respiratory tract infections (LRTIs) at the Children's Hospital of Fudan University, Shanghai, China. Children aged less than 18 years who were hospitalized with LRTIs were enrolled from January 2013 to December 2015. Respiratory specimens were collected for the detection of common respiratory viruses, atypical bacteria, and other bacteria using current laboratory diagnostic tests. The epidemiological characteristics of the respiratory pathogens were analyzed. Of the 10,123 specimens obtained from the patients, 5,966 (58.7%) were positive for at least 1 pathogen. Mycoplasma pneumoniae (M.pneumoniae) was the most commonly detected pathogen (15.7%), followed by respiratory syncytial virus (RSV) (13.9%). Co-infections were found in 11.4% of patients. Of these co-infections, viral-bacterial co-infections were the most common. The detection rates for the respiratory pathogens varied considerably by age. RSV was the most common pathogen in children aged less than 24 months. Clear seasonal peaks were observed for RSV, M. pneumoniae, parainfluenza virus, human metapneumovirus, Moraxella catarrhalis, and Haemophilus influenza infections. Our findings demonstrate specific epidemiological patterns in children with LRTIs in Shanghai, China.

Etiology, Seasonality, and Clinical Features of Viral Respiratory Tract Infections in Children Hospitalized With Acute Bronchiolitis: A Single-Center Study

The purpose of this study was to evaluate the viral frequency, seasonality, and clinical and demographic features of patients hospitalized with acute bronchiolitis. A cross-sectional, descriptive study was performed in 316 infants younger than 2 years of age who were hospitalized for acute viral bronchiolitis. Respiratory tract infection agents were investigated with polymerase chain reaction (PCR). A total of 316 infants were included in this study. Of the 316 infants, at least one respiratory tract pathogen was detected in 75% (237/316). Respiratory syncytial virus (RSV) was the most common virus identified in 127 infants (40.1%) followed by rhinovirus (n = 78, 24.6%). In this study, where viral agents were determined via PCR in patients who were followed-up due to the diagnosis of acute bronchiolitis, RSV was detected as the most common agent, as in other studies. In almost half of the RSV-positive patients, RSV was accompanied by a second or third agent.

Etiology and clinical features of viral bronchiolitis in infancy

BACKGROUND

Bronchiolitis is a common lower respiratory tract infection in infancy. The aim of this review is to present the clinical profile of viral bronchiolitis, the different culprit viruses and the disease severity in relation to the viral etiology.

DATA SOURCES

Databases including PubMed and Google Scholar were searched for articles about the clinical features of bronchiolitis and its viral etiology. The most relevant articles to the scope of this review were analyzed.

RESULTS

Currently there are two main definitions for bronchiolitis which are not identical, the European definition and the American one. The most common viral pathogen that causes bronchiolitis is respiratory syncytial virus which was identified in 1955; now many other viruses have been implicated in the etiology of bronchiolitis such as rhinovirus, adenovirus, metapneumovirus, and bocavirus. Several studies have attempted to investigate the correlation of bronchiolitis severity with the type of detected virus or viruses. However, the results were not consitent.

CONCLUSIONS

For the time being, the diagnosis of bronchiolitis remains clinical. The isolation of the responsible respiratory pathogens does not seem to confer to the prognosis of the disease severity.

Chlamydia trachomatis Infection in Pregnancy: The Global Challenge of Preventing Adverse Pregnancy and Infant Outcomes in Sub-Saharan Africa and Asia

Screening and treatment of sexually transmitted infections (STIs) in pregnancy represents an overlooked opportunity to improve the health outcomes of women and infants worldwide. Although Chlamydia trachomatis is the most common treatable bacterial STI, few countries have routine pregnancy screening and treatment programs. We reviewed the current literature surrounding Chlamydia trachomatis in pregnancy, particularly focusing on countries in sub-Saharan Africa and Asia. We discuss possible chlamydial adverse pregnancy and infant health outcomes (miscarriage, stillbirth, ectopic pregnancy, preterm birth, neonatal conjunctivitis, neonatal pneumonia, and other potential effects including HIV perinatal transmission) and review studies of chlamydial screening and treatment in pregnancy, while simultaneously highlighting research from resource-limited countries in sub-Saharan Africa and Asia.

Viral and atypical bacterial aetiologies of infection in hospitalised patients admitted with clinical suspicion of influenza in Thailand, Vietnam and Indonesia

Background

Influenza constitutes a leading cause of morbidity and mortality worldwide. There is limited information about the aetiology of infection presenting clinically as influenza in hospitalised adults and children in South-East Asia. Such data are important for future management of respiratory infections.

Objectives

To describe the aetiology of infection presenting clinically as influenza in those hospitalised in South-East Asia.

Methods

Respiratory specimens archived from July 2008 to June 2009 from patients hospitalised with suspected influenza from Indonesia, Thailand and Vietnam were tested for respiratory viruses and atypical bacteria by polymerase chain reaction.

Results

A total of 1222 patients’ samples were tested. Of 1222, 776 patients (63·5%) were under the age of 5. Viruses detected included rhinoviruses in 229 of 1222 patients (18·7%), bocaviruses in 200 (16·4%), respiratory syncytial viruses in 144 (11·8%), parainfluenza viruses in 140 (11·5%; PIV1: 32; PIV2: 12; PIV3: 71; PIV4: 25), adenovirus in 102 (8·4%), influenza viruses in 93 (7·6%; influenza A: 77; influenza B: 16) and coronaviruses in 23 (1·8%; OC43: 14; E229: 9). Bacterial pathogens were Mycoplasma pneumoniae (n = 33, 2·7%), Chlamydophila psittaci (n = 2), C. pneumoniae (n = 1), Bordetella pertussis (n = 1) and Legionella pneumophila (n = 2). Overall, in-hospital case fatality rate was 29 of 1222 (2·4%).

Conclusion

Respiratory viruses were the most commonly detected pathogens in patients hospitalised with a clinical suspicion of influenza. Rhinovirus was the most frequently detected virus, and M. pneumoniae, the most common atypical bacterium. The low number of detected influenza viruses demonstrates a low benefit for empirical oseltamivir therapy, unless during an influenza outbreak.

Inflammation and infections in asthma

INTRODUCTION

Asthma is driven by an inflammatory response against normally harmless environmental inorganic and organic compounds in the respiratory tract. Immune responses to airborne pathogens such as viruses and bacteria may reduce the allergic responses but are also known to trigger asthma attacks and eventually lead to severe disease condition.

OBJECTIVE

To investigate the role of respiratory pathogens concerning the induction or protection against acute or chronic asthma manifestations.

METHODS

We included 131 articles for the final review according to their relevance with the subject.

RESULTS

There is apparently contradictory interaction of respiratory germs in the airways of asthmatics which may be protective on one angle but deleterious on the other.

CONCLUSION

The relationship between inflammation and remodeling and the pathogenic role of viral and bacterial infection in the airways of asthmatic patients is still highly debatable and incompletely understood.

Bronchiolitis associated with Mycoplasma pneumoniae in infants in Suzhou China between 2010 and 2012

Viruses cause most cases of bronchiolitis in infants; consequently the importance of other agents such as Mycoplasma pneumoniae (MP) in the etiology of bronchiolitis may not be fully recognized. We investigated the prevalence and seasonal distribution of bronchiolitis caused by MP in 674 children admitted to the Children's Hospital affiliated with Soochow University from January 2010 to December 2012. The presence of MP was confirmed by real-time PCR. During the 3 years, we identified MP in 17.2% of the children with bronchiolitis. The annual MP detection rates were 16.6% in 2010, 17.8% in 2011, and 17.2% in 2012. MP was detected throughout the year, with a peak from July to September. The median age of MP-positive children was 10 months. Common clinical manifestations included cough, wheezing, and high fever. Moist and/or wheezing rales were frequent, and pulmonary interstitial infiltration was seen in 66.4% of chest X-rays. Patients with MP infection were older, were more likely to have pulmonary interstitial infiltration, and had shorter hospital stays than those with respiratory syncytial virus infection. Our study revealed MP as an important cause of bronchiolitis, with peaks of occurrence during the summer and early autumn. Pulmonary interstitial infiltrations were a common event.

Pediatricians' attitudes and costs of bronchiolitis in the emergency department: a prospective multicentre study

BACKGROUND

How pediatricians manage bronchiolitis and the derived total costs (direct and indirect) in the emergency department (ED) have not been fully characterized. The aim of the present study is to calculate those costs in a European country.

METHODS

A prospective and observational study, including 10 EDs of tertiary hospitals throughout Spain and during the bronchiolitis season 2010-2011, was performed. Every ED recruited children on random days of the week (3 days per week; always including one non-working day per every week). Recruitment aimed at a total sample size of 600 children. Direct (diagnostic procedures, time spent in the ED and medication) and indirect costs (work hours lost by parents, babysitting, travels, and meals) were collected. Comparisons between bronchiolitis caused by respiratory syncytial virus (RSV) and non-RSV bronchiolitis, as well as costs across severity categories were performed with the Kruskal-Wallis test. A multiple regression model was built to assess the influence of several of the studied factors on the total costs, including a RSV positive test and episode severity as independent variables; and gender, age, attending nursery school, preterm birth, low birth weight, smoker mother during pregnancy, and current smoker father as covariates.

RESULTS

From the 664 recruited children, direct mean costs were €213.2 ± 91.8 and indirect ones were €35.9 ± 55.3; the total costs being €249.2 ± 122.9. Costs were significantly higher in children positive to RSV and rose with increased severity. Those associations were maintained in the multiple regression analysis.

CONCLUSIONS

Although relatively low at the individual level (€249.2, mean total cost) the costs for just the ED expenses of bronchiolitis in Spain would add up to about €20 million per year.

Estimating the prevalence of coinfection with influenza virus and the atypical bacteria Bordetella pertussis, Chlamydophila pneumoniae, and Mycoplasma pneumoniae

Coinfections with common bacterial respiratory pathogens and influenza viruses are well-known causes of disease, often via synergistic interactions between the influenza virus, the bacteria, and the human host. However, relatively little is known about interactions between atypical bacteria and influenza viruses. A recent report by Reinton et al. explored this issue by analyzing data from 3,661 patients seeking medical assistance for the presence of Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Bordetella pertussis, as well as influenza A or B virus in nasal swab specimens. The report, however, did not accurately assess the epidemiologic interactions of these pathogens. We aimed to describe the interactions between these bacterial species and influenza infections. Strong and highly statistically significant antagonistic interspecies interactions were detected between C. pneumoniae and influenza virus [odds ratio (OR): 0.09; p < 0.0001) and M. pneumoniae and influenza virus infections (OR: 0.29; p = 0.003). No association was detected between B. pertussis and influenza infection (p = 0.34), contrary to the initial report, and coinfection was not detected at a higher-than-by-chance frequency within the population. Further support of these results is supplied by the analysis of two earlier investigations reporting data on influenza virus and these atypical bacteria. Our results supplement the large body of literature regarding interactions between influenza virus and typical respiratory pathogens, providing a fuller picture of the spectrum of interactions between influenza viruses and respiratory bacteria. Further, we demonstrate the importance of choosing the most appropriate reference populations for the analysis being performed and describe the pitfalls that may occur when care is not taken in this regard.

Etiology of acute bronchiolitis and the relationship with meteorological conditions in hospitalized infants in China

Background/Purpose

To investigate the prevalence of common viruses and Mycoplasma pneumoniae (MP) in hospitalized infants with acute bronchiolitis and study the relationship between bronchiolitis and meteorological conditions.

Methods

A 2-year prospective study was conducted on infants with a first episode of bronchiolitis admitted to Respiratory Department of Suzhou Children's Hospital. Demographic and clinical characteristics and meteorological conditions were obtained and analyzed.

Results

Pathogens were identified in 59.6% of 998 cases analyzed. The most frequent pathogen identified was respiratory syncytial virus (28.7%), followed by human bocavirus (11.6%), MP (9.0%), human parainfluenza virus-3 (7.8%), human metapneumovirus (6.6%), influenza A (3.5%), adenovirus (1.0%), and human parainfluenza virus-1 (0.3%). The clinical scores in children with MP or human metapneumovirus single infections, based on the assessment of severity of acute bronchiolitis, were significantly lower than in children with respiratory syncytial virus single infections. Respiratory syncytial virus had the strongest inverse correlation with mean temperature, followed by influenza A and human metapneumovirus. In addition, MP and human parainfluenza virus-3 showed positive correlations with mean temperature.

Conclusion

Although respiratory syncytial virus was the most frequent pathogen in patients in whom bronchiolitis was diagnosed, other pathogens, including newly identified viruses and MP, also play important roles in infants with bronchiolitis. Different respiratory pathogens have different traits in response to certain meteorological conditions.

Azithromycin therapy in hospitalized infants with acute bronchiolitis is not associated with better clinical outcomes: a randomized, double-blinded, and placebo-controlled clinical trial

OBJECTIVE

To test the hypothesis that azithromycin reduces the length of hospitalization and oxygen requirement in infants with acute viral bronchiolitis (AB).

STUDY DESIGN

We performed a randomized, double-blinded, placebo-controlled trial in southern Brazil, from 2009 to 2011. Infants (<12 months of age) hospitalized with AB were recruited in 2 hospitals. Patients were randomized to receive either azithromycin or placebo, administered orally, for 7 days. At enrollment, clinical data were recorded and nasopharyngeal samples were collected for viral identification through immunofluorescence. Main outcomes were duration of oxygen requirement and length of hospitalization.

RESULTS

One hundred eighty-four patients were included in the study (azithromycin 88 subjects, placebo 96 subjects). Baseline clinical characteristics and viral identification were not different between the groups studied. A virus was detected in 112 (63%) patients, and of those, 92% were positive for respiratory syncytial virus. The use of azithromycin did not reduce the median number of days of either hospitalization (P = .28) or oxygen requirement (P = .47).

CONCLUSIONS

Azithromycin did not improve major clinical outcomes in a large sample of hospitalized infants with AB, even when restricting the findings to those with positive respiratory syncytial virus samples. Azithromycin therapy should not be given for AB because it provides no benefit and overuse increases overall antibiotic resistance.