Differences in nasopharyngeal bacterial carriage in preschool children from different socio-economic origins

Prevalence of Haemophilus influenzae in the nasopharynx of children from regions with varying incidence of invasive H. influenzae serotype a disease: Canadian Immunization Research Network (CIRN) study

Haemophilus influenzae serotype a (Hia) has recently emerged as an important cause of invasive disease in the North American Arctic and Sub-Arctic regions, mainly affecting young Indigenous children. In this study, we addressed the question of whether the prevalence of Hia and all H. influenzae in the nasopharynx differed between paediatric populations from regions with high versus low incidence of invasive Hia disease. Nasopharyngeal specimens from children with acute respiratory tract infections (ARTI) collected for routine diagnostic detection of respiratory viruses were analysed with molecular-genetic methods to identify and serotype H. influenzae. In Nunavut, a region with a high incidence of invasive Hia disease, all H. influenzae and particularly Hia were found in the nasopharynx of 60.6% and 3.0% children. In Southern Ontario (Hamilton region), where Hia invasive disease is rare, the frequencies of all H. influenzae and Hia detection were 38.5% and 0.6%, respectively. In both cohorts, non-typeable H. influenzae was prevalent (57.0% and 37.9%, respectively). Considering that Hia is an important cause of severe invasive disease in Nunavut children, 3% prevalence of Hia among children with ARTI can reflect continuing circulation of the pathogen in the Northern communities that may result in invasive disease outbreaks.

Exploring the pediatric nasopharyngeal bacterial microbiota with culture-based MALDI-TOF mass spectrometry and targeted metagenomic sequencing

The nasopharynx is an important reservoir of disease-associated and antimicrobial-resistant bacterial species. This proof-of-concept study assessed the utility of a combined culture, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and targeted metagenomic sequencing workflow for the study of the pediatric nasopharyngeal bacterial microbiota. Nasopharyngeal swabs and clinical metadata were collected from Cambodian children during a hospital outpatient visit and then biweekly for 12 weeks. Swabs were cultured on chocolate and blood-gentamicin agar, and all colony morphotypes were identified by MALDI-TOF MS. Metagenomic sequencing was done on a scrape of all colonies from a chocolate agar culture and processed using the mSWEEP pipeline. One hundred one children were enrolled, yielding 620 swabs. MALDI-TOF MS identified 106 bacterial species/40 genera: 20 species accounted for 88.5% (2,190/2,474) of isolates. Colonization by Moraxella catarrhalis (92.1% of children on ≥1 swab), Haemophilus influenzae (87.1%), and Streptococcus pneumoniae (83.2%) was particularly common. In S. pneumoniae-colonized children, a median of two serotypes [inter-quartile range (IQR) 1-2, range 1-4] was detected. For the 21 bacterial species included in the mSWEEP database and identifiable by MALDI-TOF, detection by culture + MALDI-TOF MS and culture + mSWEEP was highly concordant with a median species-level agreement of 96.9% (IQR 86.8%-98.8%). mSWEEP revealed highly dynamic lineage-level colonization patterns for S. pneumoniae which were quite different to those for S. aureus. A combined culture, MALDI-TOF MS, targeted metagenomic sequencing approach for the exploration of the young child nasopharyngeal microbiome was technically feasible, and each component yielded complementary data.

IMPORTANCE

The human upper respiratory tract is an important source of disease-causing and antibiotic-resistant bacteria. However, understanding the interactions and stability of these bacterial populations is technically challenging. We used a combination of approaches to determine colonization patterns over a 3-month period in 101 Cambodian children. The combined approach was feasible to implement, and each component gave complementary data to enable a better understanding of the complex patterns of bacterial colonization.

Impact of vaccines on Staphylococcus aureus colonization: A systematic review and meta-analysis

BACKGROUND

Concerns regarding vaccine effects on microbial ecology have led to interest in the non-targeted effects of vaccinations.

OBJECTIVES

To systematically review the literature related to the impact of vaccines on S. aureus carriage.

METHODS

We conducted a systematic search of MEDLINE, Scopus and clinical trials.gov for studies that assessed vaccine effects on S. aureus carriage in children and adults using predefined inclusion and exclusion criteria. Generic inverse variance meta-analysis was done using random-effects models.

RESULTS

Of 1,686 studies screened, 34 were eligible for inclusion, of which 22 were observational and 12 randomized controlled studies (RCTs). 88.2% (30/34) provided data on pneumococcal conjugate vaccines (PCV), 23.5% on influenza vaccines (8/34), 6% on other vaccines (2/34) and 20.6% on more than one vaccine (7/34). Most studies tested nasopharyngeal specimens (82.3%, 28/34). Among children aged more than 18-24 months, evidence suggested no effect of PCV on S. aureus colonization [2 RCTs, pooled OR 1.09 (95% CI 0.94-1.25), p 0.25; 7 observational studies, pooled OR: 1.02 (95% CI 0.83-1.25), p 0.86]. A transient increase in S. aureus carriage in PCV-vaccinated infants 9-15 months was shown [2 RCTs, pooled OR 1.11 (95% CI 1.00-1.23), p 0.06; 4 observational studies, pooled OR 1.64 (95% CI 1.00-2.68), p 0.05]. A reduction in S. aureus carriage was observed after influenza vaccination [4 observational studies; OR 0.85 (95% CI 0.78-0.94), p 0.0001]. Based on the Grading of Recommendations Assessment, Development and Evaluation, the quality of evidence was considered low for randomized and very low for non-randomized trials.

CONCLUSION

Evidence did not suggest long-term effects of pneumococcal vaccinations on S. aureus nasopharyngeal carriage in children, however transient niche changes may occur in infants. Influenza vaccination was related to decreased rates of S. aureus carriage. Data regarding other vaccines is scarce. Further research and ongoing surveillance are needed to monitor colonization changes.

Epidemiology and burden of Haemophilus influenzae disease in Thai children before implementation of the routine immunisation programme: A National Health Data Analysis

OBJECTIVES

To conduct the first pre-Haemophilus influenzae (Hi) type b (Hib) immunisation programme-based epidemiological study using national health data.

METHODS

We analysed National Health Security Office data, which cover 72% of the Thai population. The study population included children aged <18 years admitted for Hi disease from 2015 to 2019. Hi disease diagnosis and death were based on the International Statistical Classification of Diseases and Related Health Problems (10th revision) hospital discharge summary codes. We estimated the hospital cost per admission using diagnosis-related grouping with a global budget.

RESULTS

A total of 1125 children aged <18 years were admitted for Hi disease. During the 5-year-study, the annual incidence of Hi disease varied from 1.5 to 1.9 per 100,000 children, with an overall case fatality rate (CFR) of 2%. Pneumonia was the most common clinical form, followed by meningitis and sepsis. The incidence, clinical forms and severity of Hi disease were age specific. Infant CFR was higher than that of other age groups. The incidence of Hi disease in children aged <5 years was 4.9 per 100,000 (CFR = 2.0%). Sepsis was the primary cause of infant death, whereas pneumonia was the cause of death in children aged >5 years. The hospital cost ranged from 25,000 to 30,000 THB per admission.

CONCLUSIONS

This analysis provided epidemiological data of Hi in Thai children before the Hib routine immunisation programme. The incidence of Hi disease was lower than that previously speculated. Our results could facilitate an assessment of the impact of Hib immunisation programme in Thailand.

Prevalence of Moraxella Catarrhalis as a Nasal Flora among Healthy Kindergarten Children in Bhaktapur, Nepal

Introduction

Moraxella catarrhalis causes mild to severe disease in all age groups, mainly in children. This study investigates the prevalence of M. catarrhalis, its cocolonization with other common nasal flora, and associated risk factors in kindergarten children in Bhaktapur.

Method

A cross-sectional study was conducted among 136 healthy school-going children from four kindergartens of Bhaktapur Municipality. Nasal swabs were examined for identification and isolation of M. catarrhalis and its antibiotic susceptibility pattern. Additionally, further analysis was performed for cocolonization and associated risk factors.

Results

Out of 136 students, M. catarrhalis was detected in 80 (58.8%) children. Using bivariate and multivariate analysis, the associated risk factors with significantly high carriage rates were age group of 3–4 years, classroom occupancy with 15–30 children, and antibiotic consumption within 6 months, with a p value of ≤0.05 in each of the cases. Multiple logistic regression analysis of bacterial coexistence depicted M. catarrhalis to be positively associated with Streptococcus pneumoniae and Haemophilus influenzae and negatively associated with Staphylococcus aureus. Furthermore, the highest double colonization occurred among M. catarrhalis and S. aureus and the highest triple colonization occurred among M. catarrhalis, S. aureus, and S. pneumoniae. The antibiogram pattern showed the target organisms to be highly resistant to amoxycillin/clavulanate (18.8%) and most sensitive to chloramphenicol (100%).

Conclusion

This study shows a high prevalence of M. catarrhalis in healthy kindergarten children and is positively associated with other nasal isolates like S. pneumoniae and H. influenzae.

Nasal colonization by potential bacterial pathogens in healthy kindergarten children of Nepal: a prevalence study

INTRODUCTION

In low- and middle-income countries including Nepal, respiratory tract infection (RTI) is considered as one of the most prominent public health problems in children. Multiple carriage of respiratory pathogens is common in children, especially in preschoolers as they are easily transmitted through close contact and poor hygienic condition. Thus, this research is based on the study of prevalence, co-existence, associated factors and antibiogram of nasal isolates among healthy preschoolers.

METHODS

The study was conducted in four randomly selected kindergarten schools (two government run and two private run) of Bhaktapur Municipality. Out of a total 140 students, 136 eligible participants of age group 2-5 years old were involved in the study. Nasal swab was collected for the isolation of five target isolates (Staphylococcus aureus, Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae and Haemophilus parainfluenzae) and their antibiotic resistance determination.

RESULTS

Of 136 participants involved, 128 (94.5%) were positive for carriage of at least one of the target bacteria. The most common isolate was M. catarrhalis 62.5% (80/128) followed by S. aureus 43.0% (55/128). There was a significant difference in bacterial carriage with respect to type of school (p value<0.05, OR=0.50, CI=0.20-0.90). Regarding bacterial co-existence, the most common co-existence was of S. aureus and M. catarrhalis & S. pneumoniae and M. catarrhalis 48.8%. Multiple logistic regression analysis showed that S. aureus was negatively associated with S. pneumoniae, M. catarrhalis and H. influenzae and S. pneumoniae was positively associated with M. catarrhalis and H. influenzae. Multidrug resistance was seen in 63 isolates (29.4%).

CONCLUSIONS

Nepalese kindergarten children are at a high risk of respiratory tract infection by multidrug resistant bacteria.

Nasopharyngeal carriage of Haemophilus influenzae among adults with co-morbidities

After the widespread use of Haemophilus influenzae type b (Hib) vaccine, H. influenzae invasive disease is now commonly due to non-encapsulated (NTHi), affecting mostly the youngest and the elderly. The objective of this study was to investigate H. influenzae nasopharyngeal carriage rate in adults with co-morbidities and possible associated risk factors.

METHODS

Patients aged >50 years with co-morbidities attending medical centres were examined. A nasopharyngeal swab was analysed for H. influenzae presence by cultural and molecular methods (RT-PCR). Univariable and multivariable analysis of risk factors for H. influenzae carriage were performed. Serotype of isolates was determined by PCR capsular genotyping. Minimum inhibitory concentration (MIC) was determined by MIC gradient test and β-lactamase production was detected by the nitrocephin test. Genotyping was performed by Multilocus sequence typing (MLST). Phylogenetic relationships among carriage and invasive NTHi strains were assessed.

RESULTS

Among 248 enrolled patients (median age: 73 years), the carriage rate was 5.6% and 10.5% by cultural method or RT-PCR, respectively. Colonization with H. influenzae was significantly associated with the presence of acute respiratory symptoms (adjusted OR = 12.16, 95% CI: 3.05-48.58, p < 0.001). All colonizing isolates were NTHi. Three isolates (3/14, 21.4%) were resistant to ampicillin and beta-lactamase positive. MLST revealed a high degree of genetic diversity, with 11 different STs from 14 isolates. Eight out of the 11 (72.7%) STs were shared among carriage and invasive isolates.

CONCLUSIONS

Adults ≥50 years old with co-morbidities are occasionally colonized by H. influenzae, even if the presence of co-morbidities is not a risk factor for colonization. The presence of acute respiratory symptoms is the only factor associated with H. influenzae colonization. Colonizing H. influenzae are all NTHi. Colonizing H. influenzae often belong to the same STs of invasive disease isolates.

Outcomes of Cystic Fibrosis Screening-Positive Infants With Inconclusive Diagnosis at School Age

BACKGROUND AND OBJECTIVES

Cystic fibrosis (CF) screen-positive infants with an inconclusive diagnosis (CFSPID) are infants in whom sweat testing and genetic analysis does not resolve a CF diagnosis. Lack of knowledge about the health outcome of these children who require clinical follow-up challenges effective consultation. Early predictive biomarkers to delineate the CF risk would allow a more targeted approach to these children.

METHODS

Prospective, longitudinal, multicenter, Canada-wide cohort study of CF positive-screened newborns with 1 to 2 cystic fibrosis transmembrane conductance regulator gene variants, of which at least 1 is not known to be CF-causing and/or a sweat chloride between 30 and 59 mmol/L. These were monitored for conversion to a CF diagnosis, pulmonary, and nutritional outcomes.

RESULTS

The mean observation period was 7.7 (95% confidence interval 7.1 to 8.4) years. A CF diagnosis was established for 24 of the 115 children with CFSPID (21%) either because of reinterpretation of the cystic fibrosis transmembrane conductance regulator genotype or because of increase in sweat chloride concentration ≥60 mmol/L. An initial sweat chloride of ≥40 mmol/l predicted conversion to CF on the basis of sweat testing. The 91 remaining children with CFSPID were pancreatic sufficient and showed normal growth until school age. Pulmonary function as well as lung clearance index in a subgroup of children with CFSPID were similar to that of healthy controls.

CONCLUSIONS

Children with CFSPID have good nutritional and pulmonary outcomes at school age, but rates of reclassifying the diagnosis are high. The initial sweat chloride test can be used as a biomarker to predict the risk for CF in CFSPID.

The microbiome of the nasopharynx

The nasopharyngeal microbiome is a dynamic microbial interface of the aerodigestive tract, and a diagnostic window in the fight against respiratory infections and antimicrobial resistance. As its constituent bacteria, viruses and mycobacteria become better understood and sampling accuracy improves, diagnostics of the nasopharynx could guide more personalized care of infections of surrounding areas including the lungs, ears and sinuses. This review will summarize the current literature from a clinical perspective and highlight its growing importance in diagnostics and infectious disease management.

A comparative profile of oropharyngeal colonization of Streptococcus pneumoniae and Hemophilus influenzae among HealthCare Workers (HCW) in a tertiary care hospital and non-healthcare individuals

Introduction

Streptococcus pneumoniae and Hemophilus influenzae are two major bacterial human pathogens responsible for causing both acute respiratory tract and life threatening invasive infections. Oropharyngeal carriage of these isolates can lead to its transmission frequently in healthcare settings between patients and HealthCare workers (HCW) and also common among population living in crowded communities resulting in serious invasive infections. Furthermore, awareness about preventive measures including appropriate vaccination against these bacterial infections, oropharyngeal carrier status, prevalent serotypes and the antimicrobial susceptibility pattern these bacterial strains among HCW and Non-HCW in the community in India remains inadequate. Therefore the current study is aimed to understand the prevalence of oropharyngeal carrier status, prevalent serotypes and antimicrobial susceptibility profile of these organisms among HCW and non-HCW.

Methods

A total of 200 oropharyngeal swabs were collected from HealthCare Workers and 200 from Non-Health care individuals of age 18 to 70. Antimicrobial susceptibility profile was studied for Pneumococci and H. influenzae. Specific serotypes for the carrier isolates of Pneumococci were identified using primers appropriate to the prevalent serotypes by multiplex PCR.

Results

About 30% of the HCW were colonized with S.pneumoniae and H. influenzae (P ≤ 0.0001). Out of which 19% of them were S.pneumoniae and 11% were H. influenzae. A total of 23% of the Non-HCW was colonized with S. pneumoniae and H. influenzae. Out of which 16% had pneumococcal carriage and 7% had H. influenzae. Individuals in the age group 56-70 years had significantly a greater prevalence rate when compared to young people (P = 0.0014). Thus in this study 30% of the HCW and 23% of the Non-HCW were colonized with S. pneumoniae and H. influenzae. Both Pneumococci and H. influenzae showed 100% susceptibility to Penicillin and other cephalosporins. However, Pneumococcal isolates from HCW showed better susceptibility towards erythromycin & clindamycin whereas isolates from Non- HCW showed better susceptibility towards ofloxacin and tetracycline. Serotypes detected in our study include 19F, 3, 1 and 5.

Conclusions

The present study gives a greater prevalence rate of S.pneumoniae and H. influenzae among HCW when compared to Non-HCW. This will definitely increase horizontal spread of infections and further accelerate the occupational risk. Increased carrier state prevalence among old age group underscores the importance of vaccination among these individuals.

Risk Factors for Carriage of Antibiotic-resistant Bacteria in Healthy Children in the Community: A Systematic Review

BACKGROUND

In addition to health care settings, antibiotic resistance has also been increasing in the community. Healthy children represent an important potential reservoir of antibiotic-resistant (AR) bacteria. However, strategies to reduce the spread of AR bacteria often fail to specifically address the factors that promote the carriage of AR bacteria in this population.The objective of this review was to Identify risk factors for carriage of AR bacteria by healthy children.

METHODS

We did a systematic search of MEDLINE, Embase and PubMed for studies in developed (OECD) countries that assessed risk factors for carriage of AR bacteria in healthy children in the community. We excluded studies done before 1998 and studies of AR Streptococcus pneumoniae carriage in the absence of pneumococcal conjugate vaccination.

RESULTS

Of 1234 studies identified, 30 were eligible for inclusion. These studies assessed the impact of 49 risk factors on AR strains of S. pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli. The majority of these risk factors were assessed in 2 or fewer studies per bacteria. Recent antibiotic consumption was associated with carriage of resistant respiratory bacteria (S. pneumoniae, H. influenzae); however, it was not consistently associated with carriage of AR bacteria in skin or stool (S. aureus and E. coli). For AR S. aureus, transmission within households appeared to have a greater impact than individual antibiotic use.

CONCLUSIONS

The factors that promote carriage of AR bacteria by healthy children differed between bacterial species. To reduce reservoirs of AR bacteria in the community, it is essential for intervention strategies to target the specific risk factors for different bacteria.

The characterization of bacterial communities of oropharynx microbiota in healthy children by combining culture techniques and sequencing of the 16S rRNA gene

The high incidence of bacterial respiratory infections has led to a focus on evaluating the human respiratory microbiome. Studies based on culture-based and molecular methods have shown an increase in the bacterial community that includes the bacterial phyla Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria in the oropharynx of healthy individuals. Therefore, recognizing this microbial compound and subsequently identifying those carriers of specific pathogens can be of great help in predicting future infections and their control. In this prospective study, we sought to characterize the bacterial communities of the respiratory microbiome in healthy children aged between 3 and 6 years old by combining both cultural techniques and sequencing of the 16S rRNA gene. Seventy-seven oropharynx samples using Dacron swabs were collected from 77 healthy children in the kindergartens of Ilam, Iran. Bacterial identification was performed by phenotypic methods and in house developed PCR-based sequencing (the V1-V9 hypervariable region of the bacterial 16S ribosomal RNA gene). In total, 346 bacterial isolates were characterized based on phenotypic and sequencing-based molecular methods. The 3 most predominant phyla were Firmicutes (74%), Proteobacteria (22%), and Actinobacteria (4%). At the level of the genus, Staphylococci (coagulase-positive and coagulase-negative) and Streptococci were dominant. Also, the most commonly identified potentially pathogenic colonisers were S. aureus (75%), Enterobacteriaceae spp. (40.1%), and A. baumannii (15.6%). The present study identified 3 phyla and 9 family of bacteria in the oropharyngeal microbiome. Remarkably, the presence of potential pathogenic bacteria in the nasopharynx of healthy children can predispose them to infectious diseases, and also frequent exposure to human respiratory bacterial pathogens are further risk factors.

The association between pneumococcal vaccination, ethnicity, and the nasopharyngeal microbiota of children in Fiji

BACKGROUND

Streptococcus pneumoniae is a significant global pathogen that colonises the nasopharynx of healthy children. Pneumococcal conjugate vaccines, which reduce nasopharyngeal colonisation of vaccine-type S. pneumoniae, may have broader effects on the nasopharyngeal microbiota; however, data are limited. In Fiji, nasopharyngeal carriage prevalence of S. pneumoniae and other colonising species differ between the two main ethnic groups. Here, we examined the association between the 7-valent pneumococcal conjugate vaccine (PCV7) and the nasopharyngeal microbiota of children in Fiji, including for each of the two main ethnic groups-indigenous Fijians (iTaukei) and Fijians of Indian descent (FID).

METHOD

The nasopharyngeal microbiota of 132 Fijian children was examined using nasopharyngeal swabs collected from 12-month-old iTaukei and FID children who were vaccinated (3 doses PCV7) or unvaccinated in infancy as part of a phase II randomised controlled trial. Microbiota composition was determined by sequencing the V4 region of the 16S rRNA gene. Species-specific carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus was determined using real-time quantitative PCR. Associations between microbiota composition and other host and environmental factors were considered in the analysis.

RESULTS

PCV7 had no overall impact on microbial diversity or composition. However, ethnic differences were observed in both diversity and composition with iTaukei children having higher relative abundance of Moraxella (p = 0.004) and Haemophilus (p = 0.004) and lower relative abundance of Staphylococcus (p = 0.026), Dolosigranulum (p = 0.004) and Corynebacterium (p = 0.003) compared with FID children. Further, when we stratified by ethnicity, associations with PCV7 could be detected: vaccinated iTaukei children had a lower relative abundance of Streptococcus and Haemophilus compared with unvaccinated iTaukei children (p = 0.022 and p = 0.043, respectively); and vaccinated FID children had a higher relative abundance of Dolosigranulum compared with unvaccinated FID children (p = 0.037). Children with symptoms of an upper respiratory tract infection (URTI) had a significantly different microbiota composition to children without symptoms. The microbiota composition of iTaukei children without URTI symptoms was most similar to the microbiota composition of FID children with URTI symptoms.

CONCLUSIONS

Associations between PCV7 and nasopharyngeal microbiota differed within each ethnic group. This study highlights the influence that ethnicity and URTIs have on nasopharyngeal microbiota.

Comparing the yield of oropharyngeal swabs and sputum for detection of 11 common pathogens in hospitalized children with lower respiratory tract infection

Background

Advances in molecular laboratory techniques are changing the prospects for the diagnosis of viral infectious diseases. Multiplex polymerase chain reaction assay (multiplex-PCR) can detect dozens of pathogens simultaneously, greatly reducing turnaround time (TAT) and improving detection sensitivity. But as a double-edged sword, due to the high sensitivity of PCR, the type of respiratory specimens is critical to diagnosis. In this work, we performed a head-to-head comparison to evaluate the multiplex-PCR yields between two samples, sputum and flocked oropharyngeal swabs (OPS).

Methods

Eleven common respiratory pathogens were tested in hospitalized children< 13 years of age who met the criteria for lower respiratory tract infection by GeXP-based multiplex-PCR of paired OPS and sputum.

Results

From January to June 2018, 440 children with paired OPS and sputum were tested. The positive rate was 84% (369/440) for OPS and 88% (386/440) for sputum (p = .007). The frequency of detection of HRV, RSV, Influenza A virus, HMPV, parainfluenza virus, adenovirus, M. pneumoniae, coronavirus, bocavirus and C. pneumoniae in sputa was higher than that of OPSs (all p < .001). Both types of specimens had similarly very good kappa values for most of pathogens, except for Mycoplasma pneumonia (κ = 0.61) and Chlamydia pneumoniae (κ = 0.24). Additionally, 79.3% (349/440) of cases showed consistent results between the two types of samples, and they were significantly younger than patients with inconsistent results (p = .002).

Conclusions

Flocked oropharyngeal swabs and sputum performed similarly for the detection of common respiratory pathogens in hospitalized children by multiplex-PCR, except for Mycoplasma pneumoniae and Chlamydia pneumoniae. Young patients are likely to have consistent results between the two specimens.

Electronic supplementary material

The online version of this article (10.1186/s12985-019-1177-x) contains supplementary material, which is available to authorized users.

The pharyngeal carriage of Haemophilus influenzae among healthy population in China: a systematic review and meta-analysis

BACKGROUND

A nationwide investigation on the carriage proportion of H. influenzae among healthy populations is lacking in China. The purpose of the study was to review the prevalence of pharyngeal carriage of H. influenzae among healthy populations in China, and explore its influencing factors. The serotypes distribution of H. influenzae was also analyzed.

METHODS

A systematic search was conducted with key words "Haemophilus influenzae", "Carriage", and "China" or "Chinese" from inception to March 2018. After careful screening, the data of included articles were extracted with a pre-designed excel form. Then, the pooled carriage proportion of H. influenzae was calculated using the random effect model.

RESULTS

A total of 42 studies with 17,388 participants were included. The overall pooled carriage proportion of H. influenzae was 0.17 (95% CI: 0.13-0.21), and the carriage proportion largely varied by province. Subgroup analysis indicated that the pooled carriage proportion was 0.17 (0.13-0.21) for children, and 0.14 (0.7-0.23) for adults. There were no statistically significant heterogeneity between subgroups by age (p = 0.65), sex (p = 0.88), and season (p = 0.10). The pooled carriage proportion of Hib was 0.01 (0-0.02), while the carriage proportion of NTHi was 0.22 (0.13-0.31).

CONCLUSION

In China, the carriage proportion of H. influenzae among healthy population was low, but it largely varied by provinces.

Colonization rate of Streptococcus pneumoniae, its associated factors and antimicrobial susceptibility pattern among children attending kindergarten school in Hawassa, southern Ethiopia

OBJECTIVE

The aim of this study was to determine the colonization rate of Streptococcus pneumoniae, antimicrobial susceptibility pattern and associated risk factors among children attending kindergarten school in Hawassa, Ethiopia.

RESULTS

Out of 317 study participants, 68 (21.5%) were colonized with S. pneumoniae. Colonization rate was significantly associated with factors such as age (3 to 4 years old) (P = 0.01), having a sibling whose age was less than 5 years (P = 0.011), sharing a bed with parents (P = 0.005), cooking within bedroom (P = 0.002), and previous hospitalization (P = 0.004). Forty-four (64.6%), 33 (48.5%), and 2942.6%) of S. pneumoniae isolated were resistant to cotrimoxazole, penicillin, and tetracycline respectively.

High-density Bacterial Nasal Carriage in Children Is Transient and Associated With Respiratory Viral Infections-Implications for Transmission Dynamics

BACKGROUND

This longitudinal study describes the associations between respiratory viral infections, rhinitis and the prevalence and density of the common nasopharyngeal bacterial colonizers, Streptococcus pneumoniae (Sp), Moraxella catarrhalis (Mc), Haemophilus influenzae (Hi) and Staphylococcus aureus.

METHODS

In an observational cohort study, 161 children attending day care centers in Bristol, United Kingdom, were recruited. Monthly nasopharyngeal swabs were taken and stored frozen in Skim-milk, tryptone, glucose and glycerin broth (STGG) broth. Quantitative polymerase chain reaction was used for detection of respiratory viruses and 4 bacterial species. t tests and logistic regression models were used for analysis.

RESULTS

The frequent colonisers, Sp, Mc and Hi were more frequently found at high density in contrast to Staphylococcus aureus although temporally, high-density carriage was short lived. Respiratory viral infections and symptoms of rhinitis were both independently and consistently associated with higher bacterial density with an observed 2-fold increase in density for Sp, Mc and Hi (P = 0.004-0.017).

CONCLUSIONS

For Sp and Hi, the association between young age and higher bacterial DNA density was explained by more frequent viral infection and increased nasal discharge, while the associations between some viral specie's and some bacterial species' density appear to be stronger than others. Increased colonization density and rhinitis may promote transmission of these commonly carried organisms.

Risk factors associated with nasopharyngeal carriage and density of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus in young children living in Indonesia

Background

Potentially pathogenic bacteria Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus are commonly carried in the nasopharynx of young children. Host and environmental factors have been linked with pathogen carriage, and in many studies rural children have higher carriage rates than their urban counterparts. There are few published data on what factors contribute to increased pathogen density. The objectives of this study were to identify risk factors for nasopharyngeal carriage and density of S. pneumoniae, H. influenzae, M. catarrhalis, and S. aureus in young children in Indonesia.

Methods

Risk factor analysis was done using data on bacterial carriage and participant characteristics from a cross-sectional study that enrolled 302 children aged 12–24 months living in urban or semi-rural areas of Indonesia. Associations between host factors and odds of pathogen carriage were explored using logistic regression. Characteristics identified to be independent predictors of carriage by univariable analysis, as well as those that differed between urban and semi-rural participants, were included in multivariable models. Risk factors for increased pathogen density were identified using linear regression analysis.

Results

No differences in carriage prevalence between urban and semi-rural children were observed. Multiple children under the age of 5 years in the household (< 5y) and upper respiratory tract infection (URTI) symptoms were associated with S. pneumoniae carriage, with adjusted odds ratios (aOR) of 2.17 (95% CI 1.13, 4.12) and 2.28 (95% CI 1.15, 4.50), respectively. There was some evidence that URTI symptoms (aOR 1.94 [95% CI 1.00, 3.75]) were associated with carriage of M. catarrhalis. Children with URTI symptoms (p = 0.002), and low parental income (p = 0.011) had higher S. pneumoniae density, whereas older age was associated with lower S. pneumoniae density (p = 0.009). URTI symptoms were also associated with higher M. catarrahlis density (p = 0.035). Low maternal education (p = 0.039) and multiple children < 5y (p = 0.021) were positively associated with H. influenzae density, and semi-rural residence was associated with higher S. aureus density (p < 0.001).

Conclusions

This study provides a detailed assessment of risk factors associated with carriage of clinically-relevant bacteria in Indonesian children, and new data on host factors associated with pathogen density.

Electronic supplementary material

The online version of this article (10.1186/s41479-018-0058-1) contains supplementary material, which is available to authorized users.

Asymptomatic carriage of antibiotic-resistant Gram-positive cocci among different background populations in East Timor, Southeast Asia

Dissemination of pathogenic multiresistant bacteria is of public health concern. Reliable data can be difficult to obtain, especially in developing countries. This work aimed to characterize the skin and oropharyngeal microbiota, as well as their antimicrobial resistance profiles, of East-Timor populations to identify potentially pathogenic Gram-positive cocci. In order to assess the prevalence of pathogenic bacteria in East-Timor, the oropharyngeal and skin microbiota of 74 individuals was characterized. Gram-positive cocci were evaluated and their antimicrobial resistance profiles were determined. A total of 228 oropharyngeal and 278 skin samples were obtained. The population consisted of 36.5% of asymptomatic carriers of Gram-positive cocci. Kocuria rosea (n = 7, 19.4%), Staphylococcus spp. (n = 6, 16.7%), and Micrococcus luteus (n = 6, 16.7%) were isolated, among others. Antimicrobial resistance levels ranged between 0% and 36.1%, and a multiresistance profile was observed in one third of the isolates. Gram-positive cocci colonization was associated with age group. Prevalence of multiresistant isolates was higher in males who were sampled at the refugee camp. Results show that the prevalence of antimicrobial resistance on East Timor may be underestimated. This study represents the first step toward the full characterization of potential pathogenic Gram-positive cocci present in the populations from East Timor.

Investigating the impact of poverty on colonization and infection with drug-resistant organisms in humans: a systematic review

BACKGROUND

Poverty increases the risk of contracting infectious diseases and therefore exposure to antibiotics. Yet there is lacking evidence on the relationship between income and non-income dimensions of poverty and antimicrobial resistance. Investigating such relationship would strengthen antimicrobial stewardship interventions.

METHODS

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Ovid, MEDLINE, EMBASE, Scopus, CINAHL, PsychINFO, EBSCO, HMIC, and Web of Science databases were searched in October 2016. Prospective and retrospective studies reporting on income or non-income dimensions of poverty and their influence on colonisation or infection with antimicrobial-resistant organisms were retrieved. Study quality was assessed with the Integrated quality criteria for review of multiple study designs (ICROMS) tool.

RESULTS

Nineteen articles were reviewed. Crowding and homelessness were associated with antimicrobial resistance in community and hospital patients. In high-income countries, low income was associated with Streptococcus pneumoniae and Acinetobacter baumannii resistance and a seven-fold higher infection rate. In low-income countries the findings on this relation were contradictory. Lack of education was linked to resistant S. pneumoniae and Escherichia coli. Two papers explored the relation between water and sanitation and antimicrobial resistance in low-income settings.

CONCLUSIONS

Despite methodological limitations, the results suggest that addressing social determinants of poverty worldwide remains a crucial yet neglected step towards preventing antimicrobial resistance.

Risk factors for carriage of Streptococcus pneumoniae in children

Background

During the past decades Streptococcus pneumoniae has developed significant resistance to many classes of antimicrobial drugs. Potential risk factors for colonization of the nasopharynx by Streptococcus pneumoniae in children and for carriage of drug resistant strains were examined.

Methods

Between 2007 and 2008 nasopharyngeal swabs were collected from 402 children 6 months to 5 years old visiting the public sector immunization centers and outpatient departments as well as offices of paediatricians from private practice in Nicosia district in Cyprus. Information on demographic characteristics and potential risk factors of participating children were collected using a standardized questionnaire distributed to parents.

Results

In multivariable analyses we found that attendance at day care center, having siblings in the family and having both parents originating from Cyprus, statistically increased the risk of pneumococcal colonization. Full immunization with PCV7 appears to be a protective factor against colonization by pneumococcus. Previous administration of antimicrobials during the last month prior to specimen collection appeared to be the most consistent risk factor for carrying a non susceptible strain of Streptococcus pneumoniae to either penicillin or erythromycin. Factors such as age, nationality, previous or current breastfeeding, passive exposure to cigarette smoke and attendance in a day care center do not appear as independent risk factors for colonization by non susceptible strains.

Conclusions

Prudent use of antibiotics especially for upper respiratory tract infections in children as well as increased vaccination coverage by the pneumococcal conjugate vaccines could prove effective in reducing levels of colonization by drug resistant pneumococcal strains.

Limited Utility of Polymerase Chain Reaction in Induced Sputum Specimens for Determining the Causes of Childhood Pneumonia in Resource-Poor Settings: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study

Background.

Sputum examination can be useful in diagnosing the cause of pneumonia in adults but is less well established in children. We sought to assess the diagnostic utility of polymerase chain reaction (PCR) for detection of respiratory viruses and bacteria in induced sputum (IS) specimens from children hospitalized with severe or very severe pneumonia.

Methods.

Among children aged 1–59 months, we compared organism detection by multiplex PCR in IS and nasopharyngeal/oropharyngeal (NP/OP) specimens. To assess whether organism presence or density in IS specimens was associated with chest radiographic evidence of pneumonia (radiographic pneumonia), we compared prevalence and density in IS specimens from children with radiographic pneumonia and children with suspected pneumonia but without chest radiographic changes or clinical or laboratory findings suggestive of pneumonia (nonpneumonia group).

Results.

Among 4232 cases with World Health Organization–defined severe or very severe pneumonia, we identified 1935 (45.7%) with radiographic pneumonia and 573 (13.5%) with nonpneumonia. The organism detection yield was marginally improved with IS specimens (96.2% vs 92.4% for NP/OP specimens for all viruses combined [P = .41]; 96.9% vs 93.3% for all bacteria combined [P = .01]). After accounting for presence in NP/OP specimens, no organism was detected more frequently in the IS specimens from the radiographic pneumonia compared with the nonpneumonia cases. Among high-quality IS specimens, there were no statistically significant differences in organism density, except with cytomegalovirus, for which there was a higher quantity in the IS specimens from cases with radiographic pneumonia compared with the nonpneumonia cases (median cycle threshold value, 27.9 vs 28.5, respectively; P = .01).

Conclusions.

Using advanced molecular methods with IS specimens provided little additional diagnostic information beyond that obtained with NP/OP swab specimens.

Nasal colonization and antimicrobial susceptibility pattern of Staphylococcus aureus among pre-school children in Ethiopia

Background

Staphylococcus aureus is one of the bacterium that can asymptomatically colonize the human upper respiratory tract (i.e. nose and throat). Carriage of S. aureus, including methicillin resistant S. aureus, is common to children. The aim at this study was to determine the nasal colonization, associated factors and antimicrobial susceptibility patterns of S. aureus isolates among pre-school children in Debre Markos town.

Methods

Institutional-based cross sectional study was conducted. A total of 400 nasal swabs were collected from pre-school children from April to June, 2015 following standard microbiological methods. MRSA was detected using both Cefoxitin (30 μg) and Oxacillin (6 μg) (Oxoid Ltd. England) discs in combination and associated factors were assessed using self-administered pretested questionnaires, which were delivered to the children’s parents/guardians. Statistical analysis of the data (logistic regression) was done using SPSS V-22.

Results

A total of 52 S. aureus isolate was recovered from 400 nasal swap samples. The prevalence of S. aureus among pre-School children was 13% (52/400). The susceptibility patterns of the isolates to commonly used antibiotics were: 84.62% to Chloramphenicol, 69.2% to Doxycycline and Tetracycline, 92.3% to Kanamycin, 7.7% to Ampicillin and Penicillin, 86.6% to Ceftriaxone, and 76.9% to Augmentin. All the isolates were sensitive to Oxacillin and Cefoxitin, mean there was no methicillin resistant S. aureus isolate, and also sensitive to Gentamycin, Erythromycin and Clindamycin. The main associated factors of nasal colonization of S. aureus in the study area was, having recurrent acute otitis media (AOM) [AOR = 2.37 (1.11, 5.06)], Children admission in hospital [AOR = 1.96 (1.03, 3.73)] and cough [AOR = 2.09 (1.08, 4.09)].

Conclusions

The prevalence of S. aureus nasal colonization among pre-school children was relatively low in absence of MRSA. Factors like; recurrent AOM, hospital admission and cough were significantly associated with S. aureus nasal colonization. Most of the isolates were resistant to β-lactam drugs and sensitive to drugs like Gentamycin, Erythromycin, Clindamycin, Chloramphenicol, Doxycycline, Tetracycline, Kanamycin and Augmentin.

Viral and bacterial upper respiratory tract infection in hospital health care workers over time and association with symptoms

Background

Bacterial colonisation of the respiratory tract is commonly described and usually thought to be of no clinical significance. The aim of this study was to examine the presence and significance of bacteria and viruses in the upper respiratory tract of healthcare workers (HCWs), and association with respiratory symptoms.

Methods

A prospective cohort study was conducted in China and 223 HCWs were recruited from fever clinics and respiratory, paediatric, emergency/Intensive medication wards. Participants were followed over 4 weeks (7th May 2015 to 4th June 2015) for development of clinical respiratory illness (CRI). Nasopharyngeal swabs were obtained at baseline and at the end of the study. The primary endpoints were laboratory-confirmed bacterial colonisation and viral respiratory infection. Rates of the following infections in symptomatic and asymptomatic participants were compared at the start or end of the study; 1) all bacterial/viral infections, 2) bacterial infection and bacterial-viral co-infections, excluding virus only infections, and 3) only bacterial infections.

Results

Bacterial colonisation was identified in 88% (196/223) of participants at the start or end of the study. Among these participants, 66% (148/223) had only bacterial colonisation while 22% (48/223) had co-infection with a virus. Bacteria were isolated from 170 (76.2%) participants at baseline and 127 (57%) participants at the end of the study. Laboratory confirmed viral infections were identified in 53 (23.8%) participants - 35 (15.7%) at the baseline and 20 (9.0%) at the end of the study.

CRI symptoms were recorded in 12 participants (4.5%) and all had a positive bacterium isolation at baseline (n = 11) or end of the study (n = 1). Among asymptomatic participants, 187 (87%) had bacterial colonisation or bacterial/viral co-infection at baseline or end of the study. Viruses were also isolated from 5 (2.4%) asymptomatic cases. Rates of all infection outcomes were higher in symptomatic participants, however differences were not statistically significant.

Conclusion

We isolated high rates of bacteria and viruses in the upper respiratory tract of hospital HCWs, which may reflect greater exposure to respiratory infections in the hospital. Although respiratory infections are mostly symptomatic, the association between bacterial colonization and symptomatic illness is not clear. In the healthcare setting, HCWs may acquire and transmit infection to patients and other HCWs around them. Larger studies are required to explore ongoing occupational risk of respiratory infection in hospitals HCWs.

Nasopharyngeal Carriage and Antimicrobial Susceptibility Patterns of Streptococcus pneumoniae among Children under Five in Southwest Ethiopia

Nasopharyngeal carriage of Streptococcus pneumoniae is found to play an important role in the development and transmission of pneumococcal diseases. In this study, we assessed the nasopharyngeal carriage, antimicrobial susceptibility patterns and associated risk factors of S. pneumoniae among children under five. A total of 361 children under five attending the outpatient department of Shanan Gibe Hospital in Jimma, Southwest Ethiopia were enrolled from June to September 2014. Nasopharyngeal specimens were collected using sterile plastic applicator rayon tipped swab and inoculated on tryptone soy agar supplemented with 5% sheep blood and 5 µg/mL gentamycin. Antimicrobial susceptibility testing was performed using the modified disk diffusion method. The overall prevalence of S. pneumoniae carriage was 43.8% (158/361) among children under five. Resistance to tetracycline, cotrimoxazole, penicillin, chloramphenicol and erythromycin was observed in 53.2% (84/158), 43.7% (69/158), 36.1% (57/158), 13.3% (21/158) and 8.9% (14/158) of isolates respectively. Multidrug resistance was seen in 17.7% (28/158) of isolates. In multivariate logistic regression analysis, children living with sibling(s) < 5 years old (adjusted odds ratio (AOR) = 1.798; 95% confidence interval (CI), 1.169–2.766) and malnutrition (AOR = 2.065; 95% CI, 1.239–3.443) were significantly associated with S. pneumoniae carriage. A high nasopharyngeal carriage of S. pneumoniae was observed among children under five in Southwest Ethiopia. There should be a strategy to prevent S. pneumoniae nasopharyngeal colonization and identify the appropriate antibiotic to the individual child.

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

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

Upper airway viruses and bacteria and clinical outcomes in children with cough

BACKGROUND

Cough is symptomatic of a broad range of acute and chronic pediatric respiratory illnesses. No studies in children have tested for an extended panel of upper airway respiratory viruses and bacteria to identify whether they predict cough outcomes, irrespective of clinical diagnosis at the time of acute respiratory illness (ARI). We therefore determined whether upper airway microbes independently predicted hospitalization and persistent cough 28-days later in children presenting with an ARI, including cough as a symptom.

METHODS

A cohort study of children aged <15-years were followed for 28-days after presenting to a pediatric emergency department with an ARI where cough was also a symptom. Socio-demographic factors, presenting clinical features and a bilateral anterior nasal swab were collected at enrolment. Polymerase chain reaction assays tested for seven respiratory bacteria and 17 viruses. Predictors of hospitalization and persistent cough at day-28 were evaluated in logistic regression models.

RESULTS

Eight hundred and seventeen children were included in the analysis; median age 27.7-months. 116 (14.2%, 95%CI 11.8, 16.6) children were hospitalized and 163 (20.0%, 95%CI 17.2, 22.7) had persistent cough at day-28. Hospitalized children were more likely to have RSV A or B detected on nasal swab than those not admitted (adjusted relative risk (aRR) 1.8, 95%CI 1.0, 3.3). M. catarrhalis was the only microbial difference between children with and without cough persistence (aRR for those with cough at day 28: 2.1, 95%CI 1.3, 3.1).

DISCUSSION

An etiologic role for M. catarrhalis in the pathogenesis of persistent cough post-ARI is worth exploring, especially given the burden of chronic cough in children and its relationship with chronic lung disease. Pediatr Pulmonol. 2017;52:373-381. © 2016 Wiley Periodicals, Inc.

The pathogens profile in children with otitis media with effusion and adenoid hypertrophy

Objectives

To evaluate the presence of viruses and bacteria in middle ear and adenoids of patients with and without otitis media with effusion (OME).

Methods

Adenoid samples and middle ear washes (MEW) were obtained from children with OME associated with adenoid hypertrophy undergoing adenoidectomy and tympanostomy, and compared to those obtained from patients undergoing cochlear implant surgery, as a control group. Specific DNA or RNA of 9 respiratory viruses (rhinovirus, influenza virus, picornavirus, syncytial respiratory virus, metapneumovirus, coronavirus, enterovirus, adenovirus and bocavirus) and 5 bacteria (S. pneumoniae, H. influenzae, M. catarrhalis, P. aeruginosa and S. aureus) were extracted and quantified by real-time PCR.

Results

37 OME and 14 cochlear implant children were included in the study. At the adenoid, virus and bacteria were similarly detected in both OME and control patients. At the middle ear washes, however, a higher prevalence of bacteria was observed in patients with OME (p = 0.01). S. pneumoniae (p = 0.01) and M. catarrhalis (p = 0.022) were the bacteria responsible for this difference. Although total virus detection was not statistically different from controls at the middle ear washes (p = 0.065), adenovirus was detected in higher proportions in adenoid samples of OME patients than controls (p = 0.019).

Conclusions

Despite both OME and control patients presented similar rates of viruses and bacteria at the adenoid, children with OME presented higher prevalence of S. pneumonia, M. catarrhalis in middle ear and adenovirus in adenoids when compared to controls. These findings could suggest that these pathogens could contribute to the fluid persistence in the middle ear.

Population density profiles of nasopharyngeal carriage of 5 bacterial species in pre-school children measured using quantitative PCR offer potential insights into the dynamics of transmission

Bacterial vaccines can reduce carriage rates. Colonization is usually a binary endpoint. Real time quantitative PCR (qPCR) can quantify bacterial DNA in mucosal samples over a wide range. Using culture and single-gene species-specific qPCRs for Streptococcus pneumoniae (lytA), Streptococcus pyogenes (ntpC), Moraxella catarrhalis (ompJ), Haemophilus influenzae (hdp) and Staphylococcus aureus (nuc) and standard curves against log-phase reference strain broth cultures we described frequency and peak density distributions of carriage in nasopharyngeal swabs from 161 healthy 2-4 y old children collected into STGG broth. In general, detection by qPCR and culture was consistent. Discordance mostly occurred at lower detection thresholds of both methods, although PCR assays for S. pyogenes and S. aureus were less sensitive. Density varied across 5-7 orders of magnitude for the 5 species with the abundant species skewed toward high values (modes: S. pneumoniae log3-4, M. catarrhalis & H. influenzae log4-5 CFU/ml broth). Wide ranges of bacterial DNA concentrations in healthy children carrying these bacteria could mean that different individuals at different times vary greatly in infectiousness. Understanding the host, microbial and environmental determinants of colonization density will permit more accurate prediction of vaccine effectiveness.

Nasal carriage of common bacterial pathogens among healthy kindergarten children in Chaoshan region, southern China: a cross-sectional study

BACKGROUND

Nasal colonization with bacterial pathogens is associated with risk of invasive respiratory tract infections, but the related information for Chinese healthy children is scarce.

METHODS

This cross-sectional study was conducted with healthy children from 6 kindergartens in the Chaoshan region, southern China during 2011-2012. Nasal swabs were examined for five common bacterial pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, and Staphylococcus aureus.

RESULTS

Among 1,088 children enrolled, 79.6 % (866) were target-bacterial carriers, of which 34.4 % (298/866) were positive for ≥2 bacteria species. The most common pathogen in the bacterial carriers was M. catarrhalis (76.6 %), followed by S. pneumoniae (26.6 %), S. aureus (21.8 %), H. parainfluenzae (12.7 %), and H. influenzae (2.3 %). Multiple logistic regression analyses showed negative associations between age and the overall or multiple bacterial carriage, and between the father's education level and multiple bacterial carriage (all p < 0.05). Age was negatively associated with the carriage of M. catarrhalis and S. pneumoniae, and positively associated with the S. aureus carriage (all p < 0.0001).

CONCLUSIONS

This study shows high nasal carriage of common pathogenic bacteria and coexistence of multiple pathogens in healthy Chaoshan kindergarten children, with M. catarrhalis as the commonest colonizer. Increasing age of children and higher paternal education are associated with lower risk of bacterial carriage. Longitudinal follow-up studies would be helpful for better understanding the infection risk in bacterial pathogen carriers.

Reassuringly low carriage of enteropathogens among healthy Swedish children in day care centres

OBJECTIVES

Infectious gastroenteritis is one of the most common diseases among children and has a considerable impact on health and socio-economy. Day care centres are high-risk environments for infections. The aim of this study was to investigate if asymptomatic preschool children constitute a reservoir for potential enteropathogens.

STUDY DESIGN

In total, 438 individual diapers were collected from day care centres in Uppsala, Sweden, during spring and autumn, and molecular techniques were used to estimate the prevalence of asymptomatic carriage of multiple enteropathogens.

METHODS

Faecal samples were analysed with multiplex polymerase chain reaction (PCR) (xTAG^® Gastrointestinal Pathogen Panel; Luminex Corporation, Toronto, Canada) targeting 21 different pathogens. Samples with a median fluorescence intensity above threshold were re-analysed with a second PCR assay.

RESULTS

Sixteen of the 438 samples were positive for enteropathogens, 1.6% for enteric adenovirus, 0.7% for Campylobacter spp., and 0.7% for norovirus.

CONCLUSIONS

Preschool children in Uppsala constitute a limited reservoir for potential enteropathogens.

Crowdsourced Data Indicate Widespread Multidrug Resistance in Skin Flora of Healthy Young Adults

In a laboratory exercise for undergraduate biology majors, students plated bacteria from swabs of their facial skin under conditions that selected for coagulase-negative Staphylococcus; added disks containing the antibiotics penicillin, oxacillin, tetracycline, and erythromycin; and measured zones of inhibition. Students also recorded demographic and lifestyle variables and merged this information with similar data collected from 9,000 other students who had contributed to the database from 2003 to 2011. Minimum inhibitory concentration (MIC) testing performed at the Harborview Medical Center Microbiology Laboratory (Seattle, WA) indicated a high degree of accuracy for student-generated data; species identification with a matrix-assisted laser desorption ionization (MALDI) Biotyper revealed that over 88% of the cells analyzed by students were S. epidermidis or S. capitus. The overall frequency of resistant cells was high, ranging from 13.2% of sampled bacteria resistant to oxacillin to 61.7% resistant to penicillin. Stepwise logistic regressions suggested that recent antibiotic use was strongly associated with resistance to three of the four antibiotics tested (p = 0.0003 for penicillin, p << 0.0001 for erythromycin and tetracycline), and that age, gender, use of acne medication, use of antibacterial soaps, or makeup use were associated with resistance to at least one of the four antibiotics. Furthermore, drug resistance to one antibiotic was closely linked to resistance to the other three antibiotics in every case (all p values << 0.0001), suggesting the involvement of multidrug-resistant strains. The data reported here suggest that citizen science could not only provide an important educational experience for undergraduates, but potentially play a role in efforts to expand antibiotic resistance (ABR) surveillance.

The role of respiratory viruses in the etiology of bacterial pneumonia: An ecological perspective

Pneumonia is the leading cause of death among children less than 5 years old worldwide. A wide range of viral, bacterial and fungal agents can cause pneumonia: although viruses are the most common etiologic agent, the severity of clinical symptoms associated with bacterial pneumonia and increasing antibiotic resistance makes bacterial pneumonia a major public health concern. Bacterial pneumonia can follow upper respiratory viral infection and complicate lower respiratory viral infection. Secondary bacterial pneumonia is a major cause of influenza-related deaths. In this review, we evaluate the following hypotheses: (i) respiratory viruses influence the etiology of pneumonia by altering bacterial community structure in the upper respiratory tract (URT) and (ii) respiratory viruses promote or inhibit colonization of the lower respiratory tract (LRT) by certain bacterial species residing in the URT. We conducted a systematic review of the literature to examine temporal associations between respiratory viruses and bacteria and a targeted review to identify potential mechanisms of interactions. We conclude that viruses both alter the bacterial community in the URT and promote bacterial colonization of the LRT. However, it is uncertain whether changes in the URT bacterial community play a substantial role in pneumonia etiology. The exception is Streptococcus pneumoniae where a strong link between viral co-infection, increased carriage and pneumococcal pneumonia has been established.

Update on Pediatric Cough

Despite the high prevalence of cough in children, the topic has been poorly researched. Although pediatricians recognize that chronic cough in children is different from that in adults, this difference seems less recognizable to other health professionals. During childhood, the respiratory tract and nervous system undergo a series of anatomical and physiological maturation processes that influence the cough reflex. Additionally, immunological responses undergo developmental and memorial processes that make infection and congenital abnormalities the overwhelming cause of cough in children. The lack of comprehensive clinical data regarding chronic cough in children has initially required pediatricians to adopt an adult approach to the problem. In the last 10 years, however, research has led to the reconsideration of the etiology of chronic cough in children. Currently, attention has focused on protracted bacterial bronchitis as a major cause of chronic cough in preschool-aged children and as a possible precursor of bronchiectasis. New research horizons are emerging for both the treatment and prevention of particular causes of chronic cough in children.

The Gene Polymorphism of IL-17 G-152A is Associated with Increased Colonization of Streptococcus pneumoniae in Young Finnish Children

BACKGROUND

Streptococcus pneumoniae is a common respiratory pathogen, and up to 50% of children acquire S. pneumoniae in their nasopharynx during the first 12 months of life. The cytokine interleukin-17A (IL-17A) plays an important role in host defense against extracellular bacterial pathogens. We investigated the effect of IL-17 G-152A polymorphism on pneumococcal colonization in children.

METHODS

Nasopharyngeal swabs and blood samples were collected from healthy Finnish children at 2.6 (N = 405), 13 (N = 198) and 24 (N = 176) months of age. Of them, 160 had both nasopharyngeal swabs and blood samples at each time point. The semiquantitative culture method was used for bacterial culture, Sequenom iPlex Gold System for IL-17A genotyping and Luminex 200 for serum IL-17A determination.

RESULTS

The frequency of IL-17 G-152A genotypes G/G, G/A and A/A was 36%, 45% and 19% in 405 studied subjects, respectively. The colonization rates of S. pneumoniae increased from 10% at 2.6 months to 33% at 24 months of age. Significantly higher pneumococcal colonization was found in subjects with A/A genotype at 13 and 24 months of age compared with those of G/G (RR, 2.30; P = 0.02; RR, 1.91, P = 0.03). This genotype was associated with lower levels of serum IL-17A, and only 6% of subjects with A/A had detectable serum IL-17A compared with 75% and 33% of subjects with G/G and G/A (P < 0.001 and P < 0.01), respectively.

CONCLUSIONS

Our results indicate that IL-17 G-152A is associated with increased colonization rate of S. pneumoniae in young children, suggesting that IL-17A plays an important role in protection against pneumococcal colonization.

Long-term impact of pneumococcal polysaccharide vaccination on nasopharyngeal carriage in children previously vaccinated with various pneumococcal conjugate vaccine regimes

Previously, the Fiji Pneumococcal Project (FiPP) evaluated reduced dose immunization schedules that incorporated pneumococcal protein conjugate and/or polysaccharide vaccine (PCV7 and 23vPPV, respectively). Immune hyporesponsiveness was observed in children vaccinated with 23vPPV at 12 months of age compared with children who did not receive 23vPPV. Here we assess the long-term impact of 23vPPV vaccination on nasopharyngeal carriage rates and densities of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus and Moraxella catarrhalis. Nasopharyngeal swabs (n=194) were obtained from healthy children who participated in FiPP (now aged 5-7 years). S. pneumoniae were isolated and identified by standard culture-based methods, and serotyped using latex agglutination and the Quellung reaction. Carriage rates and densities of S. pneumoniae, H. influenzae, S. aureus and M. catarrhalis were determined using real-time quantitative PCR. There were no differences in the rate or density of S. pneumoniae, H. influenzae or M. catarrhalis carriage by PCV7 dose or 23vPPV vaccination in the vaccinated participants overall. However, differences were observed between the two main ethnic groups: Fijian children of Indian descent (Indo-Fijian) were less likely to carry S. pneumoniae, H. influenzae and M. catarrhalis, and there was evidence of a higher carriage rate of S. aureus compared with indigenous Fijian (iTaukei) children. Polysaccharide vaccination appeared to have effects that varied between ethnic groups, with 23vPPV vaccination associated with a higher carriage rate of S. aureus in iTaukei children, while there was a lower carriage rate of S. pneumoniae associated with 23vPPV vaccination in Indo-Fijian children. Overall, polysaccharide vaccination had no long-term impact on pneumococcal carriage, but may have impacted on S. aureus carriage and have varying effects in ethnic groups, suggesting current WHO vaccine schedule recommendations against the use of 23vPPV in children under two years of age are appropriate.

Nasopharyngeal carriage and antimicrobial susceptibility of Haemophilus influenzae among children younger than 5 years of age in Beijing, China

Background

Haemophilus influenzae is one of the main pathogens that cause community-acquired respiratory infections in children. Our previous study showed that H. influenzae is the second most common pathogen causing pneumonia and accounts for 30–50% of bacterial meningitis among Chinese children. H. influenzae carriage in children and its resistance to commonly used antimicrobials varies widely both geographically and over time.

Results

Surveys of the nasopharyngeal carriage of H. influenzae in children younger than 5 years of age with acute respiratory tract infection (ARI) were conducted in Beijing Children’s Hospital, China in 2000, 2002, 2010, and 2012. The overall annual carriage rates of H. influenzae among children younger than 5 years of age with ARI were 35.5%, 20.6%, 14.4%, and 18.7%, and the percentages of H. influenzae isolates producing β-lactamase were 4%, 13%, 27.1%, and 31%, respectively. The percentages of susceptibility to ampicillin progressively decreased from 96% (2000) to 87% (2002) to 63% (2010) to 61% (2012). All of the ampicillin-resistant isolates were found to be beta-lactamase producers. The susceptibility to tetracycline increased from 54% (2000) to 60% (2002) to 91.5% (2010) to 94.5% (2012). No statistically significant differences were observed in the susceptibility to cefaclor, cefuroxime, sulfamethoxazole, and chloramphenicol. Amoxicillin/clavulanic acid and ceftriaxone were the most effective antimicrobials for the isolates of H. influenzae across the 10-year period.

Conclusions

This report on the H. influenzae carriage rates in children and the susceptibility of these bacteria to commonly used antibiotics showed that H. influenzae carriage decreased from 2000 to 2012. Additionally, the percentage of β-lactamase-producing isolates increased while their susceptibility to ampicillin progressively decreased during this time. These results indicate that the appropriate empirical antimicrobial therapy should be changed for pediatric patients in China.

The bacterial interactions in the nasopharynx of children receiving adenoidectomy

Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae are the common pathogens that colonize in the nasopharynx of children. Polymicrobial interactions are thought to play an important role in different sites throughout the human body. However, there are currently very few studies that investigate the interactions between S. aureus, S. pneumoniae, and H. influenzae in the nasopharynx. We retrospectively analyzed the adenoid tissue culture from 269 children who received adenoidectomy. S. aureus, S. pneumoniae, and H. influenzae constituted the major microorganisms which were cultured from these adenoidectomies, at 23.4%, 21.6%, and 18.2%, respectively. S. pneumoniae and H. influenzae were the most prevalent in the preschool-aged children (3 < age ≤ 6), whereas S. aureus was more prevalent in infants and toddlers (age ≤ 3) and school-aged children (age > 6). Bacterial interference was found between S. aureus and S. pneumoniae and between S. aureus and H. influenzae, whereas there was an association found between S. pneumoniae and H. influenzae. The synergism and antagonism among these three species are investigated in the following paper, with the possible mechanisms involved in these interactions also discussed.

Nasopharyngeal vs. adenoid cultures in children undergoing adenoidectomy: prevalence of bacterial pathogens, their interactions and risk factors

Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus colonization of the adenoids and nasopharynx in 103 preschool children who underwent adenoidectomy for recurrent upper respiratory tract infections was examined. Bacterial interactions and risk factors for bacterial colonization of the nasopharynx and adenoids, separately, were analysed statistically. The prevalence of simultaneous isolation from both anatomical sites was 45·6% for S. pneumoniae, 29·1% for H. influenzae, 15·5% for M. catarrhalis and 18·4% for S. aureus. Three pathogens were significantly more frequent together from adenoid samples; nasopharyngeal swabs more often yielded a single organism, but without statistical significance. M. catarrhalis and S. aureus significantly more frequently co-existed with S. pneumoniae and H. influenzae than with each other and a positive association of S. pneumoniae and H. influenzae in adenoid samples was evident. Several differences between risk factors for nasopharyngeal and adenoid colonization by the individual pathogens were observed. We conclude that the adenoids and nasopharynx appear to differ substantially in colonization by pathogenic microbes but occurrence of H. influenzae and S. pneumoniae in the nasopharynx could be predictive of upper respiratory tract infections.

Impact of experimental human pneumococcal carriage on nasopharyngeal bacterial densities in healthy adults

Colonization of the nasopharynx by Streptococcus pneumoniae is a necessary precursor to pneumococcal diseases that result in morbidity and mortality worldwide. The nasopharynx is also host to other bacterial species, including the common pathogens Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis. To better understand how these bacteria change in relation to pneumococcal colonization, we used species-specific quantitative PCR to examine bacterial densities in 52 subjects 7 days before, and 2, 7, and 14 days after controlled inoculation of healthy human adults with S. pneumoniae serotype 6B. Overall, 33 (63%) of subjects carried S. pneumoniae post-inoculation. The baseline presence and density of S. aureus, H. influenzae, and M. catarrhalis were not statistically associated with likelihood of successful pneumococcal colonization at this study’s sample size, although a lower rate of pneumococcal colonization in the presence of S. aureus (7/14) was seen compared to that in the presence of H. influenzae (12/16). Among subjects colonized with pneumococci, the number also carrying either H. influenzae or S. aureus fell during the study and at 14 days post-inoculation, the proportion carrying S. aureus was significantly lower among those who were colonized with S. pneumoniae (p = 0.008) compared to non-colonized subjects. These data on bacterial associations are the first to be reported surrounding experimental human pneumococcal colonization and show that co-colonizing effects are likely subtle rather than absolute.

Staphylococcus aureus Colonization: Modulation of Host Immune Response and Impact on Human Vaccine Design

In apparent contrast to its invasive potential Staphylococcus aureus colonizes the anterior nares of 20–80% of the human population. The relationship between host and microbe appears particularly individualized and colonization status seems somehow predetermined. After decolonization, persistent carriers often become re-colonized with their prior S. aureus strain, whereas non-carriers resist experimental colonization. Efforts to identify factors facilitating colonization have thus far largely focused on the microorganism rather than on the human host. The host responds to S. aureus nasal colonization via local expression of anti-microbial peptides, lipids, and cytokines. Interplay with the co-existing microbiota also influences colonization and immune regulation. Transient or persistent S. aureus colonization induces specific systemic immune responses. Humoral responses are the most studied of these and little is known of cellular responses induced by colonization. Intriguingly, colonized patients who develop bacteremia may have a lower S. aureus-attributable mortality than their non-colonized counterparts. This could imply a staphylococcal-specific immune “priming” or immunomodulation occurring as a consequence of colonization and impacting on the outcome of infection. This has yet to be fully explored. An effective vaccine remains elusive. Anti-S. aureus vaccine strategies may need to drive both humoral and cellular immune responses to confer efficient protection. Understanding the influence of colonization on adaptive response is essential to intelligent vaccine design, and may determine the efficacy of vaccine-mediated immunity. Clinical trials should consider colonization status and the resulting impact of this on individual patient responses. We urgently need an increased appreciation of colonization and its modulation of host immunity.

Nontypeable Haemophilus influenzae inhibits autolysis and fratricide of Streptococcus pneumoniae in vitro

Streptococcus pneumoniae (SP) and nontypeable Haemophilus influenzae (NTHi) are common commensals of the human airway and major bacterial pathogens of otitis media (OM) and other upper airway infections. The interaction between them may play an important role in the pathogenesis of polymicrobial infections. Although previous studies suggested NTHi could promote pneumococcal survival and biofilm formation, how NTHi affects pneumococcal activities has not been defined. Our data in the present studies indicated that the outcome of the interaction between SP and NTHi was in a cell-density-dependent manner and the enhancement of pneumococcal survival happened at the later stages of culturing. Using quantitative PCR, we found that the expression of pneumococcal genes regulating autolysis and fratricide, lytA and cbpD, were significantly down-regulated in co-culture with NTHi. We further observed that influence of NTHi was not on direct cell-to-cell contact, but that this contact may contribute to the interaction between these two microorganisms. These results suggest that pneumococcal survival and biofilm formation can be enhanced by down-regulating pneumococcal cell wall hydrolase production thereby inhibiting pneumococcal autolysis and fratricide in the presence of NTHi.

Risk of repeated Moraxella catarrhalis colonization is increased in children with Toll-like receptor 4 Asp299Gly polymorphism

BACKGROUND

Moraxella catarrhalis is a common causative agent of acute otitis media and other respiratory infections in children. Toll-like receptor (TLR) 4 is an important protein of human innate immunity. One polymorphic site Asp299Gly of TLR4 is proven to result in an impaired response to lipopolysaccharide from Gram-negative bacteria. We investigated whether Finnish children who carry Asp299Gly had increased risk of M. catarrhalis colonization during their first 2 years of life.

METHODS

This was a prospective cohort study carried out in Turku, Finland. We studied M. catarrhalis colonization in 161 Finnish children, whose nasopharyngeal specimens were taken at 2, 12 and 24 months of age. The semiquantitative culture method was used for identification of different bacterial species and the pyrosequencing-based method for detection of TLR4 Asp299Gly.

RESULTS

Of 161 subjects, 126 (78%) were TLR4 A/A wild type and 35 (22%) were A/G heterozygote variants. The prevalence of M. catarrhalis increased from 24% at 2 months to 48% at 12 months and to 58% at 24 months of age. Of the 35 subjects with TLR4 variant, 15 (43%) were M. catarrhalis positive at all 3 time points, whereas only 11 (9%) subjects with TLR4 wild type were positive at these time points (relative risk 4.91, 95% confidence interval: 2.482-9.711, P=0.0001). Moreover, subjects with TLR4 variant had significantly higher bacterial load of M. catarrhalis in their nasopharynx than those with TLR4 wild type (P=0.0032).

CONCLUSIONS

Our results indicate that children with TLR4 Asp299Gly polymorphism have an increased risk of repeated M. catarrhalis colonization.

Nasopharyngeal carriage and antimicrobial susceptibility pattern of Streptococcus pneumoniae among pediatric outpatients at Gondar University Hospital, North West Ethiopia

BACKGROUND

Pneumonia caused by Streptococcus pneumoniae is the leading cause of death among children in Ethiopia. S. pneumoniae nasopharyngeal carriage can result in endogenous infections and bacterial spread in the community. S. pneumoniae drug resistance is rapidly increasing worldwide. The aim of the study was to assess the nasopharyngeal carriage and antimicrobial susceptibility pattern of S. pneumoniae among pediatric outpatients.

METHODS

A cross-sectional study was conducted on children aged ≤10 years from February to May of 2012. Data on potential risk factors were gathered using an interview-based questionnaire. Nasopharyngeal specimens were collected with a sterile plastic cotton tip swab. Bacteria were characterized by colony appearance, Gram staining, and optochin susceptibility and bile solubility tests. An antimicrobial susceptibility test was performed using the disk diffusion method. A logistic regression analysis was used to examine the possible risk factors. All tests with p value less than 0.05 were considered statistically significant.

RESULTS

Of the 234 children screened, 41.03% carried S. pneumoniae. Age-related downward trend for S. pneumoniae carriages (50.9% in <3-year-olds, 40.7% in 3- to 5-year-olds, 40.0% in 5- to <8-year-olds, and 33.3% in 8- to 10-year-olds) were observed. Children living with siblings < 5 years old (p = 0.003) and in a house having one room (p = 0.004) were associated with higher S. pneumoniae carriage. S. pneumoniae showed 33.2% resistance to erythromycin and tetracycline, 29.2% to cotrimoxazole, 14.6% to chloramphenicol and ciprofloxacin, and 10.4% to penicillin.

CONCLUSION

The S. pneumoniae carriage rate was higher among younger children. High antimicrobial resistance of S. pneumoniae against erythromycin, tetracycline, and cotrimoxazole was observed. Being in the young age group and living with younger children are risk factors for pneumococcal carriage.

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.

Evaluation of a WHO-validated serotype-specific serological assay for the diagnosis of pneumococcal etiology in children with community-acquired pneumonia

BACKGROUND

The etiologic diagnosis of community-acquired pneumonia (CAP) remains challenging in children because blood cultures have low sensitivity. Novel approaches are needed to confirm the role of Streptococcus pneumoniae.

METHODS

In this study, pneumococcal etiology was determined by serology using a subset of blood samples collected during a prospective multicentre observational study of children <15 years of age hospitalized in Belgium with radiogram-confirmed CAP. Blood samples were collected at admission and 3-4 weeks later. Pneumococcal (P)-CAP was defined in the presence of a positive blood or pleural fluid culture. Serotyping of S. pneumoniae isolates was done with the Quellung reaction. Serological diagnosis was assessed for 9 serotypes using World Health Organization-validated IgG and IgA serotype-specific enzyme-linked immunosorbent assays (ELISAs).

RESULTS

Paired admission/convalescent sera from 163 children were evaluated by ELISA (35 with proven P-CAP and 128 with nonproven P-CAP). ELISA detected pneumococci in 82.8% of patients with proven P-CAP. The serotypes identified were the same as with the Quellung reaction in 82% and 59% of cases by IgG ELISA and IgA ELISA, respectively. Overall, ELISA identified a pneumococcal etiology in 55% of patients with nonproven P-CAP. Serotypes 1 (51.6%), 7F (19%) and 5 (15.7%) were the most frequent according to IgG ELISA.

CONCLUSIONS

In conclusion, the serological assay allows recognition of pneumococcal origin in 55% of CAP patients with negative culture. This assay should improve the diagnosis of P-CAP in children and could be a useful tool for future epidemiological studies on childhood CAP etiology.