Cause Of Pneumonia In Children Research Articles

MODERN METHODS OF HERNIOPLASTY TREATMENT FOR COMPRESSED ABDOMINAL HERNIAS AFTER SURGERY

Globally, pneumonia is the leading cause of morbidity and mortality in children under 5 years of age. While the majority of pneumonia-related deaths in children are mostly in developing countries, the burden of the disease is large and there are significant health-related costs associated with pneumonia in developed countries. This article discusses the causes of pneumonia in children. Untreated pneumonia is aggravated by the development of pulmonary and extrapulmonary complications.

MONITORING AND MEASURES FOR PNEUMONIA IN CHILDREN

Globally, pneumonia is the leading cause of morbidity and mortality in children under 5 years of age. While the majority of pneumonia-related deaths in children are mostly in developing countries, the burden of the disease is large and there are significant health-related costs associated with pneumonia in developed countries. This article discusses the causes of pneumonia in children. Untreated pneumonia is aggravated by the development of pulmonary and extrapulmonary complications.

Determinant Of Pneumonia In Children Under Five Years Old Related To Environmental And Behavioral Factors

Background: Pneumonia is an acute lower respiratory tract infection that affects the lung tissue (alveoli) and is the single biggest cause of death in children under 5 years old. Several factors cause pneumonia, namely, environmental factors, individual child factors, and behavioral factors . The purpose of this study was to determine the relationship between the physical home environment and behavior with the incidence of pneumonia in children. Methods: This research is an analytic observational study using a Cross Sectional Study design. The population of this study was all mothers who had children aged 0-59 months in 2021 with a total of 1,045 people and 92 samples were obtained from the slovin formula. Results: We found that out of 92 children who had pneumonia, around 34 children( 37 %) had poor lighting, 34 children ( 37 %) had floors that did not meet the requirements, 36 (39.1%) had ventilation that did not meet the requirements, 20 children(21.7%) family members had a habit of smoking inside the house and 37 (30.2%) house windows that were not opened frequently. The results of statistical tests using the Chi-Square Test concluded that lighting, house floors, ventilation, smoking habits and the habit of opening windows were significantly related to the incidence of pneumonia in children with a p-value of 0.00 ; 0.002 ; 0.004; 0.005; 0.015 respectively. Conclusions: Physical environmental factors of the house, lighting conditions, floors and ventilation that do not meet the requirements, and factors of smoking behavior and rarely opening the windows of the house are causes of pneumonia in children.

Bronchop Neumonia Detection Using Novel Multilevel Deep Neural Network Schema

Pneumonia is a dangerous disease that can occur in one or both lungs and is usually caused by a virus, fungus or bacteria. Respiratory syncytial virus (RSV) is the most common cause of pneumonia in children. With the development of pneumonia, it can be divided into four stages: congestion, red liver, gray liver and regression. In our work, we employ the most powerful tools and techniques such as VGG16, an object recognition and classification algorithm that can classify 1000 images in 1000 different groups with 92.7% accuracy. It is one of the popular algorithms designed for image classification and simple to use by means of transfer learning. Transfer learning (TL) is a technique in deep learning that spotlight on pre-learning the neural network and storing the knowledge gained while solving a problem and applying it to new and different information. In our work, the information gained by learning about 1000 different groups on Image Net can be used and strive to identify diseases.

Pneumonia hospitalizations of children aged

ABSTRACT As infection with Streptococcus pneumoniae is an important cause of pneumonia in children, the World Health Organization recommends childhood pneumococcal conjugate vaccines (PCVs). In January 2017, PCV universal mass vaccination (UMV) was introduced in Poland for children aged <2 years. The objective of this study was to estimate and describe the trends in the incidences of various types of pneumonia hospitalizations in Poland before (2013–2016) and after (2017–2018) introduction of the UMV program. The study was conducted at the regional hospitals of Opole and Bialystok and included all hospitalized children aged <2 years with a primary or secondary diagnosis of pneumonia in their electronic medical records. Pneumonia diagnoses were identified based on International Classification of Diseases 10th revision (ICD-10) codes for bacterial, viral, and other/unknown-cause pneumonias. The effect of the implementation of PCV UMV was modeled via an inferential multivariate model. Among 4,168 children included in the study, 64.3% were admitted before PCV UMV. The number of radiograph-confirmed likely bacterial pneumonia cases varied between 55 and 176 cases per 100,000 person-years, and no trend was observed over time. However, inferential modeling showed statistically significant decreasing trends in the incidence rates of bacterial-coded pneumonia (28.48%), viral-coded pneumonia (35.36%), all-cause pneumonia (24.60%), and radiograph-confirmed likely non-bacterial pneumonia (24.98%) among children eligible for UMV. This might be the first indication of the impact of the PCV UMV program in Poland.

Systematic review and meta-analysis on the etiology of bacterial pneumonia in children in sub-Saharan Africa.

IntroductionBefore the introduction of vaccination to protect children from pneumonia, Streptococcus pneumoniae and Haemophilus influenzae type B (HiB) were the most frequent aetiological agents causing bacterial pneumonia in children under five years old. However, the etiology of childhood pneumonia appears to be changing and nonvaccine- type S. pneumoniae, non-typeable H. influenzae, and Staphylococcus aureus are becoming more relevant.ObjectiveWe conducted a systematic review aimed at identifying the common causes of bacterial pneumonia in children in sub-Saharan Africa.MethodsWe searched PubMed, Web of Science and African Index Medicus and included primary studies conducted since January 2010 that reported on the bacterial causes of pneumonia in children under five from sub-Saharan Africa. We extracted data items (about the study setting, pneumonia diagnosis, sampling, microbiological methods, and etiological agents) as well as study quality indicators.ResultsStreptococcus pneumoniae was the most common bacteria in blood cultures from children with pneumonia (8%, 95% CI: 4-14%), and H. influenzae was second (3%, 95% CI: 1-17%). Children’s nasopharynx commonly contained S. pneumoniae (66%), Moraxella catarrhalis (62%), and H. influenzae (44%).ConclusionS. pneumoniae and H. influenzae cause bacterial pneumonia in sub-Saharan African children. Our review also highlights the prevalence of potentially pathogenic bacteria in the nasopharynx of children under five and calls for more research into how nasopharyngeal colonization causes pneumonia.

Codon-optimization of the respiratory syncytial virus (RSV) G protein expressed in a vesicular stomatitis virus (VSV) vector improves immune responses in a cotton rat model

Respiratory syncytial virus is an important cause of pneumonia in children, the elderly, and immunocompromised individuals. The attachment (G) protein of RSV generates neutralizing antibodies in natural RSV infection which correlate with protection against disease. The immune response to RSV is typically short-lived, which may be related to the heavy glycosylation of RSV-G. In order to improve its immunogenicity, we expressed G protein mutants in a vesicular stomatitis virus (VSV) vector system and tested their ability to protect cotton rats from RSV challenge. We found that the most protective construct was codon-optimized RSV-G, followed by wild-type G and membrane-bound G. Constructs which expressed the G protein with reduced glycosylation or the secreted G protein provided either partial or no protection. Our results demonstrate that modifications to the G protein are not advantageous in a VSV vector system, and that an intact, codon-optimized G is a superior vaccine candidate.

Mycoplasma pneumoniae Compared to Streptococcus pneumoniae Avoids Induction of Proinflammatory Epithelial Cell Responses despite Robustly Inducing TLR2 Signaling.

Mycoplasma pneumoniae and Streptococcus pneumoniae are the most common bacterial causes of pneumonia in children. The clinical characteristics of pneumonia differ significantly between the two bacteria. We aimed to elucidate the differences in pathogenesis between M. pneumoniae and S. pneumoniae by characterizing the respiratory epithelial cell immune response to both pathogens. Using primary human bronchial epithelial cells in air-liquid interface cultures, we observed lower production of the proinflammatory cytokines interleukin-6 (IL-6) and IL-8 in response to M. pneumoniae than to S. pneumoniae. In contrast to the differences in proinflammatory cytokine production, Toll-like receptor 2 (TLR2)-mediated signaling in response to M. pneumoniae was stronger than to S. pneumoniae. This difference largely depended on TLR1 and not TLR6. We found that M. pneumoniae, but not S. pneumoniae, also induced signaling of TLR10, a coreceptor of TLR2 that has inhibitory properties. M. pneumoniae-induced TLR10 signaling on airway epithelial cells was partially responsible for low IL-8 production, as blocking TLR10 by specific antibodies increased cytokine production. M. pneumoniae maintained Th2-associated cytokine production by epithelial cells, which concurs with the known association of M. pneumoniae infection with asthma. M. pneumoniae left IL-33 levels unchanged, whereas S. pneumoniae downregulated IL-33 production both under homeostatic and Th2-promoting conditions. By directly comparing M. pneumoniae and S. pneumoniae, we demonstrate that M. pneumoniae avoids induction of proinflammatory cytokine response despite its ability to induce robust TLR2 signaling. Our new findings suggest that this apparent paradox may be partially explained by M. pneumoniae-induced signaling of TLR2/TLR10.

Mycoplasma pneumoniae Infections and Primary Immune Deficiencies.

Mycoplasma pneumoniae (M. pneumoniae) is one of the leading causes of community-acquired pneumonia in children and is also implicated in a variety of reactive extrapulmonary diseases. Recurrent and/or severe respiratory infections are one of the most frequent manifestations of several types of primary immunodeficiency. Here, we reviewed the medical literature to assess the potential relevance of M. pneumoniae in the infections observed in children affected with combined, humoral, and innate primary immune deficiencies. M. pneumoniae does not result to be epidemiologically prevalent as a cause of pneumonia in children affected by primary immunodeficiencies, but this infection can have a persistent or severe course in this category of patients. Indeed, the active search of M. pneumoniae could be useful and appropriate especially in children with humoral immune deficiencies. Indeed, most cases of M. pneumoniae infection in primary immunodeficiencies are described in patients affected by a/hypo-gammaglobulinemia.

Intestinal bacteria flora changes in patients with Mycoplasma pneumoniae pneumonia with or without wheezing

Mycoplasma pneumoniae (MP) infection is a common cause of community-acquired pneumonia in children. Furthermore, many children with Mycoplasma pneumoniae pneumonia (MPP) have recurrent wheezing and reduced small airway function after their clinical symptoms have resolved, eventually leading to asthma. MPP can trigger immune disorders and systemic inflammatory responses. Hence, the intestine is the largest immune organ of the body. Therefore, we sought to investigate whether the alteration of intestinal flora is correlated with the development of wheezing in children with MPP. We collected 30 healthy children as group A, 50 children with nonwheezing MPP as group B, and 50 children with wheezing MPP as group C. We found that the percentage of eosinophil cells (EC) was significantly higher in group C than that in group B for routine blood tests and serum inflammatory factors. The serum cytokines, including IL-4, IL-17, TNF-α, and TGF-β, were significantly higher in group C than in group B. In addition, the level of IL-10 was significantly lower in group C than in group B. The distribution characteristics of intestinal flora strains in children with MPP were detected by sequencing of 16S rRNA gene amplicon sequencing. There were differences in the abundance of intestinal flora between children with MPP and healthy children, with lower abundance of Ruminococcus flavefaciens, Clostridium butyricum, Lactobacillus, and Bifidobacterium in the intestine of children with MPP compared to healthy children. The abundance of Ruminococcus flavefaciens and Clostridium butyricum was significantly lower in the intestine of children with wheezing MPP compared to children without wheezing MPP. In the correlation analysis between children with MPP and inflammatory factors, Ruminococcus flavefaciens was found to be negatively correlated with IL-17. Clostridium butyricum was negatively correlated with L-4, IL-17, TNF-α, and TGF-β; however, it positively correlated with IL-10. Thus, it was concluded that alterations in intestinal flora play a crucial role in the immune response to MPP, where a significant decline in intestinal Ruminococcus flavefaciens and Clostridium butyricum leads to an exacerbation of the inflammatory responses, which may promote the development of children with wheezing MPP.

M ycoplasma pneumoniae carriage evades induction of protective mucosal antibodies.

BackgroundMycoplasma pneumoniae is the most common bacterial cause of pneumonia in children hospitalised for community-acquired pneumonia (CAP). Prevention of infection by vaccines may be an important strategy in the presence of emerging macrolide-resistant M. pneumoniae. However, knowledge of immune responses to M. pneumoniae is limited, complicating vaccine design.MethodsWe studied the antibody response during M. pneumoniae respiratory tract infection and asymptomatic carriage in two different cohorts.ResultsIn a nested case–control study (n=80) of M. pneumoniae carriers and matched controls we observed that carriage by M. pneumoniae does not lead to a rise in either mucosal or systemic M. pneumoniae-specific antibodies, even after months of persistent carriage. We replicated this finding in a second cohort (n=69) and also found that during M. pneumoniae CAP, mucosal levels of M. pneumoniae-specific IgA and IgG did increase significantly. In vitro adhesion assays revealed that high levels of M. pneumoniae-specific antibodies in nasal secretions of paediatric patients prevented the adhesion of M. pneumoniae to respiratory epithelial cells.ConclusionsOur study demonstrates that M. pneumoniae-specific mucosal antibodies protect against bacterial adhesion to respiratory epithelial cells, and are induced only during M. pneumoniae infection and not during asymptomatic carriage. This is strikingly different from carriage with bacteria such as Streptococcus pneumoniae where mucosal antibodies are induced by bacterial carriage.

Quantitative proteomics analysis of Mycoplasma pneumoniae identifies potential macrolide resistance determinants

Mycoplasma pneumoniae is one of the leading causes of community-acquired pneumonia in children and adolescents. Because of the wide application of macrolides in clinical treatment, macrolide-resistant M. pneumoniae strains have become increasingly common worldwide. However, the molecular mechanisms underlying drug resistance in M. pneumoniae are poorly understood. In the present work, we analyzed the whole proteomes of macrolide-sensitive and macrolide-resistant strains of M. pneumoniae using a tandem mass tag-labeling quantitative proteomic technique, Data are available via ProteomeXchange with identifier PXD022220. In total, 165 differentially expressed proteins were identified, of which 80 were upregulated and 85 were downregulated in the drug-resistant strain compared with the sensitive strain. Functional analysis revealed that these proteins were predominantly involved in protein and peptide biosynthesis processes, the ribosome, and transmembrane transporter activity, which implicates them in the mechanism(s) of resistance of M. pneumoniae to macrolides. Our results provide new insights into drug resistance in M. pneumoniae and identify potential targets for further studies on resistance mechanisms in this bacterium.

43. The Capsule and Beyond: Genetic Determinants of Pediatric streptococcus Pneumoniae empyema

Background Streptococcus pneumoniae is the most common cause of pneumonia in children, including empyema, a severe complication with increasing incidence in the post-pneumococcal vaccine era. Only a subset of > 90 serotypes cause empyema. Virulence determinants of empyema remain largely unknown.MethodsWe performed Illumina sequencing of invasive Pneumococcal isolates from pediatric patients at Primary Children’s Hospital (Salt Lake City, UT) isolated between 1996–2018, de novo genome assembly (SPADES), annotation (PROKKA), serotyping (Quelling and SeroBA), and pan-genome assembly (ROARY). SCOARY and pyseer were used for microbial GWAS. Maximum likelihood phylogeny was calculated using RAxML/Gubbins.Results366 pneumococcal isolates were analyzed from 39 serotypes and multiple phenotypes including pneumonia (n=76), empyema (n=63), CNS infection (n=54), and isolated bacteremia (n=79). Serotypes and empyema phenotype clustered roughly by phylogeny. Most analyzed empyema isolates after 2010 were serotype 3 (19/25); prior to PCV-13 introduction serotypes 1 (8/38), 7F (7/38), and 19A (11/38) were more highly represented. Genes implicated in capsule synthesis, transposases, and metabolism were statistically correlated with the empyema phenotype.ConclusionSpecific capsular or metabolic genes may confer optimal fitness for pleural disease. Further characterization of these genetic associations is needed and will inform future treatment and prevention.Disclosures Carrie L. Byington, MD, BioFire (Other Financial or Material Support, Royalties for Intellectual Property)IDbyDNA (Advisor or Review Panel member) Krow Ampofo, MBChB, Merck (Grant/Research Support)

Differentiating Viral and Bacterial Pneumonia by Clinical Manifestations among Children in Chiang Mai, Thailand

Background: Viral pneumonia is a common complication of influenza like illness including COVID-19. Virus is the most common cause of pneumonia in children. While there are important cues in history, the laboratory examination that can help differentiate viral and bacterial causes. There are limited clinical manifestations to differentiate viral and co-infection bacterial and viral pneumonia. Objective: To determine basic clinical manifestations and laboratory performed at bedside as predictors to differentiate viral and co-infection bacterial and viral pneumonia. Materials and Methods: A retrospective study was conducted in pediatric patients with radiographic evidence of severe pneumonia and admitted in Nakornping Hospital, Chiang Mai, Thailand between October 2017 and April 2020. Multiplex real time polymerase chain reactions (PCRs) (RP-24-26) were used to identify the cause of the pneumonia. Demographic data and basic clinical predictors such as age, comorbidity, symptoms, and physical findings, and basic laboratory such as complete blood count were collected. Patients were divided into three groups, no infection detected, viral infection, and bacterial and viral co-infection. Polytomous logistic regression was performed to investigate predictors for type of infection. Area under the receiver operating characteristic curve (AuROC) and 95% confidence interval (CI) were further determined for a final model to differentiate type of infection. Results: Two hundred eight cases participated in this study and included 122 males (58.7%). The etiology of pneumonia identified by RP-24-26, pathogen was detected among 166 cases (79.8%). A virus was detected in 141 cases (67.8%), co-infection was detected in 25 cases (12%), and no infection was detected in 42 cases (20.2%). The statistically significant predictor for viral pneumonia was cough, with an adjusted relative risk ratio (RRR) of 4.42 (1.41 to 13.82). The statistically significant predictors for co-infection were age 13 to 24 months and lymphocytes at 40.0% or greater with adj. RRR 14.28 (1.47 to 138.52), and 4.60 (1.24 to 17.04), respectively. Pneumonia patients with cough were 4.42 times more to have viral cause. Those with lymphocytes of 40.0% or greater were 4.60 times more to be co-infected with both virus and bacteria, especially in the age group 13 to 24 months compared with 1 to 12 months. The age group13 to 24 months, cough, and lymphocytes at 40.0% or greater were 74% (95% CI 0.66 to 0.82) correctly predicted to viral pneumonia. Conclusion: Coughing is a predominant symptom for childhood pneumonia caused by virus. In addition, pneumonia patients age 13 to 24 months who have lymphocyte of more than 40% should start and continue antibiotics until complete course. Keywords: Childhood pneumonia, Respiratory panel 24, Respiratory panel 26, Co-infection bacterial pneumonia, Predictor

Epidemiological and Clinical Features of Patients Suffering from Severe Pneumonia Caused by RSV in the Respiratory Center of the Viet Nam National Children's Hospital

Background/Purpose: Pneumonia is a common respiratory and life-threatening disease in pediatrics. Virus is an important cause of pneumonia in children, of which Respiratory syncytial virus (RSV) is the most common cause. The aim of this research is to access the clinical, epidemiological features and risk factors of patients suffering from RSV severe pneumonia.&#x0D; Methods: We studied 250 patients suffering from severe pneumonia caused by RSV from June 2019 to December 2019 in the Respiratory Center of the Vietnam National Children’s Hospital.&#x0D; Results: In Respiratory Center of our hospital, 3472 hospitalizations caused by pneumonia occurred in the last 6 months in 2019; 7.2% of these caused by RSV severe pneumonia. Pneumonia caused by RSV occurred most in male (66,7%), the rate of male/female = 2/1. The mean age was 4,94 ± 6,04 months. The prevalence of RSV in age groups is, respectively, as follows: less than 3 months (21,3%), from 3 months to 6 months (23,4%), from 6 months to 12 months (27%), from 12 months to 24 months (19%), over 2 years (9,3%). The most common symptoms which were accounted for over 80% were rhinorrhea, cough, wheeze, tachypnea and chest recession. The rate of admission increased sharply in December with 25.1% of cases. All hospitalized patients had respiratory distress symptoms with the frequent changes in blood gas, accounting for 59.2% of hypercapnia. The mean of hospitalization was 6,2 ± 7,4 days.&#x0D; Conclusion: the rate of RSV infection increased in the last 6 months in 2019. Most of patients who less than 1 year of age were admitted to hospital because of severe clinical symptoms and respiratory distress. Risk factors were related to the severity of RSV severe pneumonia were: premature, mal-nutrition, bronchopulmonary dysplasia.

Investigation of the Chest Radiograph Findings in Children with Pneumonia Hospitalized in a Children's Hospital, Tabriz, Iran

Introduction: Pneumonia has been regarded as the leading cause of death among the elderly, very young children, and those who suffer from chronic diseases. Among the underlying causes, viral infections have been addressed as the most frequent cause of pneumonia in children. Materials and Methods: This study investigated a total of 300 subjects with pneumonia hospitalized in Tabriz Children's Hospital, Tabriz, Iran. Moreover, a comparison was made between the type of pneumonia and associated radiologic features. Age, gender, performed laboratory tests, symptoms, and final interpretations of the chest x-ray (CXR) images were included in the checklist. Results: The mean age of the patients was 6.09 2.45 years. Moreover, the mean erythrocyte sedimentation rate was estimated at 27.86±22.73 mm/h. In this study, 174 (58%), 57 (19%), 50 (16.7%), and 19 (6.3%) patients were C-reactive protein (CRP) negative, CRP (+), CRP (++), and CRP (+++), respectively. Furthermore, in 238 (79.3%) patients, white blood cell (WBC) count in serum was within the normal range, whereas high WBC count was reported in 62 individuals (20.7%). In addition, four positive blood cultures as well as 27 (9%) cases with pleural effusion were identified in this study. Reticulonodular involvement was recognized in up to 246 (82%) subjects. It should be noted that 63 (21%) and 237 (79%) patients showed unilateral and bilateral involvement in chest radiography, respectively. Regarding the frequency of radiographic evidence, the most common patterns of involvement in descending frequencies were reticulonodular and lobar alveolar. Conclusion: The most common pattern of involvement in children's CXRs with pneumonia is a reticulonodular pattern associated with bilateral peribronchial cuffing.

Causes of severe pneumonia in children.

The Pneumonia Etiology Research for Child Health (PERCH) study reports the results of a case–control study to characterize the causes of pneumonia in children without HIV infection from Africa and Asia.

716. Molecular Epidemiology of Respiratory Syncytial Virus in Children and Adults in Seattle, WA

BackgroundRespiratory syncytial virus (RSV) is the most important cause of pneumonia in children <5 years worldwide and may cause severe disease in elderly and high-risk adults. Multiple RSV strains co-circulate and evolve over seasons. We seek to describe the evolution of RSV over five seasons in Seattle, WA, USA with two seasons reported here.MethodsFrom 2014 to 2016, subjects 6 months and older seeking outpatient care for acute respiratory illness at Kaiser Permanente Washington were enrolled in the Influenza Vaccine Efficacy Network (Flu VE Network) and a respiratory swab was collected. Real-time polymerase chain reaction (RT-PCR) was performed to test and quantify RSV and subtype positive samples. A subset of RSV samples with cycle threshold (CT) value <30 will be sequenced using a metagenomic next-generation sequencing (NGS) approach. Specific RSV genotypes will be associated with severe disease, defined as requiring emergency department care or hospitalization, or chest radiographic findings.ResultsA total of 8,730 patients were enrolled in the Flu VE Network and PCR testing of seasons 2014/2015 and 2015/2016 resulted in 562 of 4,137 (13.6%) RSV-positive specimens. Of patients with RSV-positive specimens, 204 (36.5%) were adults 18–64 years and 112 (20.0%) were 65+ years. RSV-B predominated in the 2014/2015 season (n = 298; 83.7%), whereas RSV-A was more common in the 2015/2016 season (n = 154; 79.8%) (Figure 1). The median (IQR) CT value for RSV-A specimens was 26.7 (23.3–29.9) compared with 27.9 (25.2–31.3) for RSV-B.ConclusionOne RSV subtype predominated within each season. Similar RSV subtype distributions were seen across age categories. With multiple RSV vaccine candidates in development, understanding the genetic diversity and circulation of RSV various viruses within a population is important for analyzing the effects of a vaccine on the evolution of RSV. Figure 1, Total counts (A) and proportions (B) of RSV-A and RSV-B specimens collected from study patients in Seattle, WA during 2014/2015 and 2015/2016 seasons, by age category.Disclosures M. L. Jackson, sanofi pasteur: Grant Investigator, Research support. H. Chu, Sanofi-Pasteur: Grant Investigator, Grant recipient.

Transplacental transfer of maternal respiratory syncytial virus (RSV) antibody and protection against RSV disease in infants in rural Nepal

BackgroundRespiratory syncytial virus (RSV) is the most important viral cause of pneumonia in children. RSV-specific antibody (ab) protects infants from disease, and may be increased by a potential strategy of maternal RSV vaccination. ObjectivesTo describe the effect of RSV antibody on RSV infection risk in infants in a resource-limited setting. Study designIn a prospective study in Nepal, women were enrolled during pregnancy and maternal and infant cord blood were collected at birth. Weekly surveillance for respiratory illness was performed from birth to 180days. Nasal swabs were tested for RSV by PCR and serum was tested using an RSV antibody microneutralization assay. Antibody concentrations at time of RSV infection were estimated based on a decay rate of 0.026 log2/day. ResultsCord:maternal RSV antibody transfer ratio was 1.03 (0.88–1.19), with RSV antibody concentration of log2 11.3 and log2 11.7 in 310 paired maternal and infant samples, respectively. Cord blood RSV antibody was log2 12.1 versus 11.6 in those with or without RSV infection (P=0.86). Among infants with RSV infection, estimated RSV antibody concentration at time of infection did not differ in infants with upper (n=8; log2 10.7) versus lower respiratory tract infection (n=21; log2 9.8; P=0.37). Cord blood RSV antibody concentrations did not correlate with age at primary RSV infection (R=0.11; P=0.57). ConclusionsTransplacental transfer of RSV antibody from mother to the fetus was highly efficient in mother-infant pairs in rural Nepal, though higher antibody concentrations were not protective against earlier or more severe RSV infection in infants.

Epidemiological characteristics and immune status of children with Respiratory Syncytial Virus.

Respiratory Syncytial Virus (RSV) infections are the dominant cause of pneumonia in children. In order to determine the epidemiological characteristics and immune status of children with Respiratory Syncytial Virus, a prospective study was performed among patients with RSV infection. Comparisons between RSV pneumonia group and normal control group, RSV pneumonia group had lower IL-2 (median levels, pg/ml: 3.8 vs. 5.1, P < 0.01), and higher IL-4 (median levels, pg/ml: 3.2 vs. 2.4, P < 0.01), IL-10 (median levels, pg/ml: 12.2 vs. 2.3, P < 0.01), and IFN-γ (median levels, pg/ml: 13.4 vs. 4.6, P < 0.01). The level of IgE among pneumonia patients caused by RSV increased sharply (median levels, mg/L: 48.1 vs. 8.8, P < 0.01). Another amazing finding is that after birth, the degree of IgE of the children infected by RSV increases gradually with age. This effect is at its peak in 0.6 years old. The IgE and eosinophil levels were higher when patients suffered from RSV pneumonia with wheeze (IgE median levels, IU/ml: with wheeze: 72.74 vs. without wheeze: 11.5, P < 0.05; eosinophil median levels, ×10(9) /l: with wheeze: 0.21 vs. without wheeze: 0.05, P < 0.05). The main morbidity crowd is the children under the age of 1 year old. The downregulation of IL2 and the upregulation of IL-4, IL-10, IFN-γ, and IgE happen after RSV infection.