Characteristics and etiology of hospitalized pediatric community-acquired pneumonia in Taiwan

Human monoclonal antibodies protect against viral-mediated pneumococcal superinfection

Introduction

Community-acquired pneumonia (CAP) is a global health concern, with 25% of cases attributed to Streptococcus pneumoniae (Spn). Viral infections like influenza A virus (IAV), respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) increase the risk of Spn, leading to severe complications due to compromised host immunity.

Methods

We evaluated the efficacy of an anti-PhtD monoclonal antibody (mAb) cocktail therapy (PhtD3 + 7) in improving survival rates in three viral/bacterial coinfection models: IAV/Spn, hMPV/Spn, and RSV/Spn.

Results

The PhtD3 + 7 mAb cocktail outperformed antiviral mAbs, resulting in prolonged survival. In the IAV/Spn model, it reduced bacterial titers in blood and lungs by 2-4 logs. In the hMPV/Spn model, PhtD3 + 7 provided greater protection than the hMPV-neutralizing mAb MPV467, significantly reducing bacterial titers. In the RSV/Spn model, PhtD3 + 7 offered slightly better protection than the antiviral mAb D25, uniquely decreasing bacterial titers in blood and lungs.

Discussion

Given the threat of antibiotic resistance, our findings highlight the potential of anti-PhtD mAb therapy as an effective option for treating viral and secondary pneumococcal coinfections.

Epidemiological characteristics of human metapneumovirus among children in Nanjing, China

PURPOSE

The objective of this study was to examine the molecular epidemiology and clinical characteristics of HMPV infection among children with ARIs in Nanjing.

METHODS

The respiratory samples were collected from 2078 children (≤ 14 years) with acute respiratory infections and were tested for HMPV using real-time RT-PCR. Amplification and sequencing of the HMPV G gene were followed by phylogenetic analysis using MEGA 7.0.

RESULT

The detection rate of HMPV among children was 4.7% (97/2078), with a concentration in those under 5 years of age. Notably, the peak season for HMPV prevalence was observed in winter. Among the 97 HMPV-positive samples, 51.5% (50/97) were available for characterization of the HMPV G protein gene. Phylogenetic analysis indicated that the sequenced HMPV strains were classified into three sublineages: A2c111nt - dup (84.0%), B1 (2.0%), and B2 (14.0%).

CONCLUSION

There was an incidence of HMPV among hospitalized children during 2021-2022 in Nanjing with A2c111nt - dup being the dominant strain. This study demonstrated the molecular epidemiological characteristics of HMPV among children with respiratory infections in Nanjing, China.

Childhood Pneumonia in Low- and Middle-Income Countries: A Systematic Review of Prevalence, Risk Factors, and Healthcare-Seeking Behaviors

Childhood pneumonia is a major contributor to illness and death in children under the age of five globally. Despite advancements in medical science, the burden of pediatric community-acquired pneumonia (CAP) remains high, particularly in low- and middle-income countries. This systematic review aims to synthesize existing literature on the prevalence, risk factors, and healthcare-seeking behaviors associated with pediatric CAP to inform the development of targeted community-based interventions. An extensive search of various databases such as Medline, EMBASE, Web of Science, Cochrane, PubMed, PubMed Central, Helinet, SpringerLink, Google Scholar, and Biomed Central was performed, resulting in 65 potentially relevant studies. After a thorough evaluation process, 25 studies were selected for the final analysis. These selected studies offered valuable information on the epidemiology, risk factors, and healthcare-seeking behaviors associated with childhood pneumonia. The review revealed that environmental factors such as indoor air pollution, overcrowding, and exposure to tobacco smoke are significant risk factors for pediatric pneumonia. Additionally, socioeconomic factors, including poverty and a lack of access to clean water and sanitation, contribute to the vulnerability of children to this disease. Poor healthcare-seeking behaviors, driven by limited knowledge and awareness of pneumonia symptoms and treatment, further exacerbate the situation. The review also highlighted the critical role of vaccination, particularly against Haemophilus influenzae type b (Hib) and pneumococcus, in preventing pneumonia. However, gaps in vaccination coverage and challenges in accessing healthcare services remain barriers to effective pneumonia control. In light of these findings, the review recommends the implementation of community-based interventions that address the multifaceted determinants of pediatric pneumonia. These interventions should focus on improving environmental conditions, enhancing access to preventive measures such as vaccination, and promoting better healthcare-seeking behaviors through education and awareness campaigns. It is essential for healthcare providers, policymakers, and community members to collaborate in developing and implementing culturally appropriate and sustainable interventions. This cooperation aims to lessen the impact of pneumonia on children and their families.

Community-acquired pneumonia in children: updated perspectives on its etiology, diagnosis, and treatment

Pneumonia is a common pediatric infectious disease that is familiar to pediatricians and a major cause of hospitalization worldwide. Recent well-designed epidemiologic studies in developed countries indicated that respiratory viruses are detected in 30%-70%, atypical bacteria in 7%-17%, and pyogenic bacteria in 2%-8% of children hospitalized with community-acquired pneumonia (CAP). The etiological distribution of CAP varies widely by child age and the epidemiological season of the respiratory pathogen. Moreover, diagnostic tests, particularly for the detection of Streptococcus pneumoniae and Mycoplasma pneumoniae, the 2 major bacterial pathogens involved in pediatric CAP, have several limitations. Therefore, management and empirical antimicrobial therapy for children with CAP should be applied in a stepwise manner based on recent epidemiological, etiological, and microbiological evidence.

Assessing the utilization of antimicrobial agents in pediatric pneumonia during the era of the 13-valent pneumococcal conjugate vaccine: A retrospective, single-center study

BACKGROUND AND PURPOSE

Pneumonia and bronchopneumonia are the most common infectious diseases in children. This study aimed to analyze changes in causative pathogens and antibiotic use for bronchopneumonia or pneumonia after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in children.

METHODS

This retrospective study was conducted from 2009 to 2019. Hospitalized children aged 6 months-3 years with a discharge diagnosis of bronchopneumonia or pneumonia were included to analyze changes in the potential mismatch between the diagnosed pathogen and antibiotic use.

RESULTS

The cohort comprised 1100 patients, including 648 (59%) and 452 (41%) with a discharge diagnosis of bronchopneumonia and pneumonia, respectively. The trend of viral pneumonia increased every year (rs = 0.101, p < 0.05) Antibiotics were administered in 97% patients, with an increasing annual trend in macrolide use (rs = 0.031, p = 0.009). Regarding antibiotic utilization, no significant variations were observed in the days of therapy (DOT) (rs = 0.076, p = 0.208) or length of therapy (LOT) (rs = -0.027, p = 0.534) per patient-year throughout the study duration. Interestingly, the LOT for combined therapy with macrolides and first-line beta-lactams was high (rs = 0.333, p = 0.028). In viral pneumonia treatment, neither the DOT nor LOT exhibited significant variations (rs = -0.006, p = 0.787 and rs = -0.156, p = 0.398).

CONCLUSION

After the introduction of PCV13 in Taiwan, no decrease in antibiotic use has been observed among children aged 6 months-3 years with a discharge diagnosis of bronchopneumonia and pneumonia.

Clinical features and risk factors of plastic bronchitis caused by Mycoplasma pneumoniae pneumonia in children

BACKGROUND

We analyzed the clinical characteristics of children with plastic bronchitis (PB) caused by Mycoplasma pneumoniae (MP) and explored its risk factors.

METHODS

We prospectively analyzed clinical data of children with MP pneumonia (MPP) treated with fiberoptic bronchoscopy (FB). Patients were classified into a PB and non-PB group. General information, clinical manifestations, laboratory tests, results of computed tomography scan, and FB findings were compared between groups. We conducted statistical analysis of risk factors for developing PB.

RESULTS

Of 1169 children who had MPP and were treated with FB, 133 and 1036 were in the PB and non-PB groups, respectively. There were no significant differences in sex, age, and incident season between groups (P > 0.05). The number of children in the PB group decreased during the COVID-19 pandemic. Compared with children in the non-PB group, those in the PB group had longer duration of hospitalization, increased levels of neutrophil (N), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate transaminase (AST); lower levels of lymphocyte (L) and platelet (PLT); and higher incidence of lack of appetite, decreased breath sounds, single lobar infiltrate, pleural effusion, pericardial effusion, mucosal erosion and/or necrosis, and bronchial embolization. L levels and pleural effusion were identified as risk factors in multivariate logistic regression.

CONCLUSIONS

Children with PB caused by MPP had a strong and local inflammatory response. L levels and pleural effusion were independent risk factors of PB with MPP in children. Our findings will help clinicians identify potential PB in pediatric patients for early and effective intervention.

Etiology and Clinical Characteristics of Community-Acquired Pneumonia in Korean Children During the Pre-COVID-19 Period, 2015-2020

BACKGROUND

There have been many epidemiologic studies on community-acquired pneumonia (CAP) among children, most of which had substantial limitations. This study investigated the etiologic distribution and clinical characteristics of CAP in Korean children for 5 years before the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

A retrospective analysis of children hospitalized for CAP at 4 referral hospitals during 2015-2020 was performed. Cases in which bronchiolitis was suspected or pulmonary infiltration was not evident on chest radiography (CXR) were excluded. Viruses and atypical bacteria were defined as detected when positive in the polymerase chain reaction test performed for respiratory specimens. Serologic testing result for Mycoplasma pneumoniae was incorporated with strict interpretation. Pyogenic bacteria were included only when cultured in blood, pleural fluid, or bronchoalveolar lavage, but those cultured in endotracheal aspirate or sputum when the case was clinically evident bacterial pneumonia were also included.

RESULTS

A total of 2,864 cases of suspected pneumonia were selected by diagnosis code and CXR findings. Medical chart and CXR review excluded nosocomial pneumonia and cases without evident infiltration, resulting in 517 (18.1%) CAP cases among 489 children. Regarding clinical symptoms, high fever was present in 59.4% and dyspnea in 19.9% of cases. Respiratory support was required for 29.2% of patients, including mechanical ventilation for 3.9%. Pathogens were detected in 49.9% of cases, with viruses in 32.3%, atypical bacteria in 17.8%, and pyogenic bacteria in 2.3% of cases. As single pathogens, M. pneumoniae (16.8%) and respiratory syncytial virus (RSV, 13.7%) were the most common. Parenteral β-lactam and macrolide antibiotics were administered in 81.6% and 50.7% of cases, respectively. A total of 12 (2.3%) cases resulted in poor outcomes, including 3 deaths.

CONCLUSION

M. pneumoniae and RSV were the most commonly detected pathogens of pediatric CAP, which was selected by strict clinical and radiologic criteria. It is necessary to carefully decide whether to use parenteral antibiotics based on the epidemiology and clinical features of CAP in children.

Clinical characteristics of hospitalized children with community-acquired pneumonia and respiratory infections: Using machine learning approaches to support pathogen prediction at admission

BACKGROUND

Acute respiratory infections (ARIs) are common in children. We developed machine learning models to predict pediatric ARI pathogens at admission.

METHODS

We included hospitalized children with respiratory infections between 2010 and 2018. Clinical features were collected within 24 h of admission to construct models. The outcome of interest was the prediction of 6 common respiratory pathogens, including adenovirus, influenza virus types A and B, parainfluenza virus (PIV), respiratory syncytial virus (RSV), and Mycoplasma pneumoniae (MP). Model performance was estimated using area under the receiver operating characteristic curve (AUROC). Feature importance was measured using Shapley Additive exPlanation (SHAP) values.

RESULTS

A total of 12,694 admissions were included. Models trained with 9 features (age, event pattern, fever, C-reactive protein, white blood cell count, platelet count, lymphocyte ratio, peak temperature, peak heart rate) achieved the best performance (AUROC: MP 0.87, 95% CI 0.83-0.90; RSV 0.84, 95% CI 0.82-0.86; adenovirus 0.81, 95% CI 0.77-0.84; influenza A 0.77, 95% CI 0.73-0.80; influenza B 0.70, 95% CI 0.65-0.75; PIV 0.73, 95% CI 0.69-0.77). Age was the most important feature to predict MP, RSV and PIV infections. Event patterns were useful for influenza virus prediction, and C-reactive protein had the highest SHAP value for adenovirus infections.

CONCLUSION

We demonstrate how artificial intelligence can assist clinicians identify potential pathogens associated with pediatric ARIs upon admission. Our models provide explainable results that could help optimize the use of diagnostic testing. Integrating our models into clinical workflows may lead to improved patient outcomes and reduce unnecessary medical costs.

Clinical characteristics of community-acquired pneumonia in children caused by mycoplasma pneumoniae with or without myocardial damage: A single-center retrospective study

BACKGROUND

Mycoplasma pneumoniae (MP) is a prevalent pathogen that causes respiratory infections in children and adolescents.

AIM

To assess the differences in the clinical features of MP-associated community-acquired pneumonia (CAP) in children who presented with mild or severe mycoplasma pneumoniae pneumonia (MPP); to identify the incidence of myocardial damage between the two groups.

METHODS

This work is a retrospective study. We identified children between 2 mo and 16 years of age with clinical and radiological findings consistent with CAP. We admitted patients to the inpatient department of the Second Hospital of Jilin University, Changchun, China, from January 2019 to December 2019.

RESULTS

A total of 409 hospitalized patients were diagnosed with MPP. Among them were 214 (52.3%) males and 195 (47.7%) females. The duration of fever and cough was the longest in severe MPP cases. Similarly, plasma levels of highly sensitive C-reactive protein (t = -2.834, P < 0.05), alanine transaminase (t = -2.511, P < 0.05), aspartate aminotransferase (t = -2.939, P < 0.05), and lactate dehydrogenase (LDH) (t = -2.939, P < 0.05) were all elevated in severe MPP cases compared with mild MPP cases, and these elevations were statistically significant (P < 0.05). Conversely, the neutrophil percentage was significantly lower in severe MPP cases than in mild MPP cases. The incidence of myocardial damage was significantly higher in severe MPP cases than in mild MPP cases (χ² = 157.078, P < 0.05).

CONCLUSION

Mycoplasma pneumoniae is the main cause of CAP. The incidence of myocardial damage was higher and statistically significant in severe MPP cases than in mild MPP cases.

Pathogenic Role and Antibiotic Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) Strains Causing Severe Community-Acquired Pneumonia in Vietnamese Children

In recent years, the pathogenic role and antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) strains causing severe community-acquired pneumonia (CAP) have received increasing attention in clinical practice. The aim of this study was to determine the rate of isolates of MRSA strains causing severe CAP in children and to assess their level of antibiotic resistance. The study design was cross-sectional. Children with severe CAP were sampled by nasopharyngeal aspiration for the culture, isolation, and identification of MRSA. Antimicrobial susceptibility testing was performed using the gradient diffusion method to determine the minimum inhibitory concentration (MIC) of antibiotics. Results: MRSA was identified as the second leading cause of severe CAP in Vietnamese children. The rate of isolates of S. aureus was 41/239 (17.5%), of which most were MRSA, at 32/41 (78.0%). MRSA strains were completely non-susceptible to penicillin (100%), more resistant to clindamycin and erythromycin, less sensitive to ciprofloxacin and levofloxacin, and fully susceptible to vancomycin and linezolid, with a 32-fold decreased MIC90 for vancomycin (0.5 mg/L) and a 2-fold decreased MIC90 for linezolid (4 mg/L). Therefore, vancomycin and linezolid may be appropriate options for severe CAP identified by MRSA.

Respiratory Syncytial Virus Outbreak in Infants and Young Children during COVID-19 Pandemic in Taiwan

Respiratory syncytial virus (RSV) is a major burden of disease in babies and young children, including hospitalizations and deaths. RSV is a seasonal disease that peaks when temperatures decrease in temperate zones and humidity increases in tropical regions. Existing research reveals that RSV hospitalization activity is year-round in Taiwan, which is a subtropical region with small peaks in spring and fall. The monthly distribution and COVID-19 pandemic impact were unclear. The aim of this study was to investigate Taiwan’s RSV hospitalization seasonality and the COVID-19 pandemic effects. The National Health Insurance Database and Death Registration Files from the Center for Health and Welfare Data Science Center were connected to birth data for this study. RSV hospitalization (RSVH) in infants aged 0–1 years ranged from 0.9518% (2009) to 1.7113% (2020), substantially higher than in children aged 1–5. Most years had 2 or 3 RSV epidemic seasons in 0–5-year-olds over the 13-year follow-up. RSVH incidence was low until the autumn of 2020, when a major rise occurred after September and lasted until December 2020. We detected RSVH peaks in February–May and July–August. The 2020 RSV outbreak was found at the end of 2020.

Trend in the admissions of patients with non-COVID-19 respiratory symptoms during COVID-19 pandemic and its impact on hospital finances in surabaya, Indonesia

Background

COVID-19 cases surge, it has a crucial impact on healthcare systems, with rapidly increasing demand for healthcare resources in hospitals and intensive care units (ICUs) in Indonesia and worldwide. It is necessary to quantify the extent to which the effects of the COVID-19 pandemic on the hospital admissions, and clinical and financial outcomes of patients with non-COVID-19 respiratory symptoms.

Objective

To determine whether the COVID-19 pandemic changed the hospitalisation of child and adult patients with non-COVID-19 respiratory conditions and whether these changes affected the patient's disease condition, clinical outcomes, and hospital finances.

Methods

A retrospective cohort study was conducted from May 1, 2018 (before the COVID-19 pandemic) until December 31, 2021. Total sampling was done to compare hospital admission of patients with non-COVID-19 respiratory symptoms before versus during the COVID-19 pandemic. The results were analyzed using SPSS 26.0 and SmartPLS.v.3.2.9.

Results

There was a reduction in hospitalisations for respiratory disorders unrelated to COVID-19 during the pandemic by 55.3% in children and 47.8% in adult patients. During the pandemic, the average hospital revenue per patient of child and adult patients increased significantly, but the profit per patient decreased. Pathway analysis showed that in children, the COVID-19 Pandemic changed disease severity and complexity (β = 0.132, P < 0.001), as well as clinical outcomes (β = 0.029, P < 0.05). In adults, the COVID-19 pandemic improves disease severity and complexity (β = -0.020, P < 0.001), as well as clinical outcomes (β = -0.013, P < 0.001). COVID-19 pandemic increases care charges (in children with β = 0.135, P < 0.001; and in the adult patients with β = 0.110, P < 0.001), worsens hospital financial outcomes relating to child (β = -0.093, P < 0.001) and adult patient (β = -0.073, P < 0.001). In adult patients, seasonal variations moderate the impact of the COVID-19 pandemic on improving disease conditions (β = -0.032, P=<0.001). The child structural model effectively predicted clinical outcomes (Q² = 0.215) and financial outcomes (Q² = 0.462). The adult structural model effectively predicted clinical outcomes (Q² = 0.06) and financial outcomes (Q² = 0.472).

Conclusion

The conclusions are that the number of non-COVID respiratory patients decreased during the COVID-19 pandemic (47.8% in adult patients, 55.3% in child patients). Disease severity and complexity increased in child patients but decreased in adult patient. Costs of care and insurance payments increased. Since the insurance payments did not increase as much as the cost of care, hospital profit decreased.

Epidemiology and surveillance implications of community-acquired pneumonia in children

Community-acquired pneumonia (CAP) is the single largest infectious cause of hospitalization and death in children worldwide. With improved immunizations, the incidence of bacterial pneumonia and the number of colonized bacteria have decreased. However, respiratory viruses are still an important cause of CAP, especially as new infectious agents such severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge. The SARS-CoV-2 virus emerged in 2019 and caused the current coronavirus disease 2019 pandemic. Therefore, it is necessary to elucidate the epidemiology and causative pathogens of CAP. Recently, the Pneumonia and Respiratory Disease Study Group, affiliated with the Korean Academy of Pediatric Allergy and Respiratory Disease, investigated the causative pathogens of respiratory infections in children hospitalized with CAP, the serotype of Streptococcus pneumoniae, and the prevalence of Mycoplasma pneumoniae with gene mutations. Antibiotic resistance and serotype test results can determine the use of empirical antibiotics. Moreover, it is possible to help develop future vaccines by comparing bacterial culture results with vaccine serotype and identifying the changes and prevalence of each serotype. Therefore, we will perform continuous national surveillance and monitor the epidemiology of respiratory pathogens in Korea and worldwide. The surveillance of these respiratory infections can play a role in monitoring the emergence of new infectious diseases such as SARS-CoV-2.

Impact of pneumococcal conjugate vaccination on hospitalized childhood pneumonia in Taiwan

BACKGROUND

A national 13-valent pneumococcal conjugate vaccine (PCV13) catch-up program among children aged 2-5 years in 2013, before routine infant immunization in 2015, successfully reduced serotype 19A-related invasive pneumococcal diseases in Taiwan. We aimed to investigate its impact on hospitalized childhood pneumonia.

METHODS

We analyzed the National Health Insurance Research Database, 2001-2017, for hospitalized children aged <18 years with the diagnoses of all-cause pneumonia, lobar/pneumococcal pneumonia, and pneumococcal parapneumonic diseases. The study period was divided into 2001-2005 (pre-PCV), 2006-2012 (private sectors), and 2013-2017 (universal PCV13 vaccination).

RESULTS

On pneumococcal parapneumonic diseases, the national PCV13 vaccination program was associated with an immediate decline in 2-4-year-old children and significant decreasing trends in all ages. The incidence rate ratios of 2016-2017/2011-2012 were 0.16 (95% confidence interval [CI], 0.06-0.40) and 0.18 (95% CI, 0.13-0.23) in children aged < 2 and 2-4 years, respectively. We observed an increase of lobar/pneumococcal pneumonia cases after an early decline. The intensive/invasive medical needs and the fatality of all-cause pneumonia decreased significantly in children of all ages.

CONCLUSIONS

Pneumococcal parapneumonic diseases and the disease burden of lobar/pneumococcal pneumonia and lower respiratory tract infections declined after the national PCV13 vaccination program.

IMPACT

The impact study of the PCV13 immunization program on childhood pneumonia in Asian countries remained limited. The unique PCV13 immunization program in Taiwan, catch-up before primary infantile series, reduced severe childhood pneumococcal pneumonia at 5 years post PCV13. The intensive and invasive medical needs and fatality of all-cause pneumonia decreased significantly in children of all ages. We observed an increase in lobar/pneumococcal pneumonia after an early decline.

The Etiology of Community-Acquired Pneumonia Correlates with Serum Inflammatory Markers in Children

Community-acquired pneumonia (CAP) severely affects pediatric hospitalizations. This study assessed the contribution of CAP to hospitalizations, its etiology in relationship with age, and the inflammatory markers. Between 2013 and 2018, 1064 CAP patients were hospitalized and diagnosed with bacterial/possibly bacterial pneumonia (BP), viral/possibly viral pneumonia (VP) and atypical pneumonia (AP). The etiology was confirmed using blood/pleural fluid culture/polymerase chain reaction (PCR), rapid antigen test/PCR in nasopharyngeal swabs, or serological studies. CAP accounted for 9.9% of hospitalizations and 14.8% of patient days. BP was diagnosed in 825 (77.5%), VP in 190 (17.9%), and AP in 49 (4.6%) cases; the confirmed etiology (n = 209; 20%) included mostly influenza (39%; n = 82), respiratory syncytial virus (RSV, 35%; n = 72), and Mycoplasma pneumoniae (19%; n = 39). VP frequency decreased with age (41% in < 3 mo to 9% in ≥ 60 mo), in contrast to AP (13% in ≥ 60 mo). Among the analyzed parameters, the best differentiating potential was shown by: C-reactive protein (CRP, AUCBP-VP = 0.675; 95% CI: 0.634−0.715), procalcitonin (AUCBP-AP = 0.73; 95% CI: 0.67−0.794), and CRP/procalcitonin (AUCAP-VP = 0.752; 95% CI: 0.67−0.83); a good positive predictive value (88.8%, 98.3%, and 91.6%, respectively) but a low negative predictive value (29.5%, 13.1%, and 40.7%, respectively) was observed. CAP influences hospital patient days more than the crude number of patients would suggest. On a clinical basis, BP is mainly recognized, although viral pneumonia is confirmed most often. RSV and influenza are responsible for a huge percentage of hospitalized cases, as well as M. pneumoniae in children aged ≥ 5 years. Serum inflammatory markers may help differentiate etiological factors.

Analysis of national surveillance of respiratory pathogens for community-acquired pneumonia in children and adolescents

Background

Respiratory infections among children, particularly community-acquired pneumonia (CAP), is a major disease with a high frequency among outpatient and inpatient visits. The causes of CAP vary depending on individual susceptibility, the epidemiological characteristics of the community, and the season. We performed this study to establish a nationwide surveillance network system and identify the causative agents for CAP and antibiotic resistance in Korean children with CAP.

Methods

The monitoring network was composed of 28 secondary and tertiary medical institutions. Upper and lower respiratory samples were assayed using a culture or polymerase chain reaction (PCR) from August 2018 to May 2020.

Results

A total of 1023 cases were registered in patients with CAP, and PCR of atypical pneumonia pathogens revealed 422 cases of M. pneumoniae (41.3%). Respiratory viruses showed a positivity rate of 65.7% by multiplex PCR test, and human rhinovirus was the most common virus, with 312 cases (30.5%). Two hundred sixty four cases (25.8%) were isolated by culture, including 131 cases of S. aureus (12.8%), 92 cases of S. pneumoniae (9%), and 20 cases of H. influenzae (2%). The cultured, isolated bacteria may be colonized pathogen. The proportion of co-detection was 49.2%. The rate of antibiotic resistance showed similar results as previous reports.

Conclusions

This study will identify the pathogens that cause respiratory infections and analyze the current status of antibiotic resistance to provide scientific evidence for management policies of domestic respiratory infections. Additionally, in preparation for new epidemics, including COVID-19, monitoring respiratory infections in children and adolescents has become more important, and research on this topic should be continuously conducted in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07263-z.

Study on the co-infection of children with severe community-acquired pneumonia

BACKGROUD

Pneumonia is one of the leading causes of death in children under 5 years old. Viruses have historically been the most common cause of community-acquired pneumonia in children. Co-infections in severe pneumonia are more concern by clinicians.

METHOD

It was a perspective and descriptive study. Real-time polymerase chain reaction (RT-PCR) is a modern test that was used to detect many new pathogens, including microbiological co-infections. RT-PCR technique was used in this study to investigate the causes of severe pneumonia.

RESULTS

Through the analysis of nasopharyngeal aspiration samples from 95 children with severe community-acquired pneumonia, the positive RT-PCR rate was 90.5%. Viral-bacterial co-infection accounted for the highest proportion (43.1%), followed by bacterial co-infection (33.7%), viral infection (7.4%), bacterial infection (6.3%) and the remaining 9.5% was unknown. In the co-infections groups, the five main bacteria species detected by PCR were Streptococcus pneumoniae, Haemophilus influenzae, MRSA, Moraxella catarrhalis and Mycoplasma pneumoniae.

CONCLUSION

Antibiotic treatment should focus on detected microbes in cases of severe pneumonia for having a good result.

Pediatric Non-COVID-19 Community-Acquired Pneumonia in COVID-19 Pandemic

Introduction

The COVID-19 lockdown strategies were associated with a significant decrease in infectious diseases disseminated through airborne or fecal–oral transmissions. Social distancing and other lockdown strategies effectively slowed down the spread of common respiratory viral diseases and decreased the need for hospitalization among children. Thus, a decline in the incidence of respiratory viral diseases had been reported following the COVID-19 outbreak. However, the trend of non-COVID-19 pneumonia in children remains uncertain. This study aimed to assess the impact of the COVID-19 pandemic on the incidence of non-COVID-19 community-acquired pneumonia in children.

Materials and Methods

We conducted a retrospective analysis of all patients (age ≤18 years) presenting with pulmonary infection from January 2019 to December 2020 in a tertiary-level teaching hospital. We compared the number of pediatric patients admitted to our hospital with community-acquired pneumonia from January to December 2020 to those from the same period in 2019.

Results

A total of 65 patients were diagnosed with community-acquired pneumonia in 2019 and 18 in 2020. The number of patients with community-acquired pneumonia in 2020 was lower than that in 2019 by 47 cases in 2020. The most age distribution of pediatric patients with community-acquired pneumonia was 2–5 years in 2019, indicating the decreasing number of community-acquired pneumonia patients from 36 patients in 2019 to 3 in 2020.

Conclusion

The number of pediatric with community-acquired pneumonia was lower than in the same period in 2019, which markedly decreased (−72.3%) in 2020. These interventions applied to control the COVID-19 pandemic were effective not only in substantial changes in the seasonal influenza activity but also in decreasing cases of pediatric community-acquired pneumonia.

Mycoplasma pneumoniae Seroprevalence and Total IgE Levels in Patients with Juvenile Idiopathic Arthritis

Background

Mycoplasma pneumoniae (M. pneumoniae) is implicated in several immune-mediated extrapulmonary manifestations, including reactive arthritis. Recently, increased total serum IgE were reported in children developing M. pneumoniae-related extrapulmonary diseases (MpEPDs). Here, we aimed at analyzing these aspects in children affected with rheumatic disorders and, in detail, Juvenile Idiopathic Arthritis (JIA).

Methods

M. pneumoniae serology (IgG and IgM) and total serum IgE were concomitantly analyzed in 139 pediatric patients diagnosed with: JIA (Group 1, n = 85), or any rheumatic disease other than JIA (Group 2, n = 27), or non-inflammatory endocrinological disorders (Group 3, n = 27).

Results

Overall, 19.4% M. pneumoniae seroprevalence was observed in this hospitalized pediatric population, without signicant differences among the three groups. No significant differences in total serum IgE levels were noted among these groups; however, a second analysis excluding children with very high (and clearly abnormal) IgE levels suggested that JIA patients and, in detail, those with oligopolyarticular forms may have higher serum IgE concentrations. This relative difference among groups in serum IgE level seems to be more pronounced in M. pneumoniae seropositive children.

Conclusions

M. pneumoniae infection should be actively sought in children developing immune-mediated diseases, including patients affected with JIA and, especially, in oligopolyarticular forms. There is some evidence that total serum IgE levels may tend to be increased in patients with oligopolyarticular JIA subtype and especially in those resulting as M. pneumoniae seropositive. However, further and focused research is needed to confirm these preliminary results and to clarify the relation between M. pneumoniae infection, atopic status, and immune-mediated arthritis.

A potent antibody-secreting B cell response to Mycoplasma pneumoniae in children with pneumonia

BACKGROUND

Mycoplasma pneumoniae is a major pathogen for community-acquired pneumonia and frequently causes outbreaks in children. M. pneumoniae-specific antibody response is detected upon acute infection and the serology is widely used in the clinical setting. Nevertheless, the cellular basis for antigen-specific antibody response to acute M. pneumoniae infection is largely undetermined in children.

METHODS

Hospitalized children with community-acquired pneumonia were enrolled and the infection with M. pneumoniae was confirmed with positive PCR result and negative findings for other pathogens. The M. pneumoniae P1-specific antibody-secreting B cell (ASC) response was examined with the ex vivo enzyme-linked immunosorbent spot assay and the relationships between the ASC frequency and serological level and clinical parameters within M. pneumoniae patients were studied.

RESULTS

A robust M. pneumoniae P1-specific ASC response was detected in the peripheral blood among M. pneumoniae-positive patients. By contrast, no M. pneumoniae-specific ASCs were detected among M. pneumoniae-negative patients. The IgM-secreting B cells are the predominant class and account for over 60% of total circulating M. pneumoniae-specific ASCs in the acute phase of illness. The M. pneumoniae P1-specific ASC frequency significantly correlated with the fever duration, and the IgG ASC frequency significantly correlated with serological titer among patients.

CONCLUSION

A rapid and potent elicitation of peripheral M. pneumoniae-specific ASC response to acute infection provides the cellular basis of antigen-specific humoral response and indicates the potential of cell-based diagnostic tool for acute M. pneumoniae infection. Our findings warrant further investigations into functional and molecular aspects of antibody immunity to M. pneumoniae.

RSV pneumonia with or without bacterial co-infection among healthy children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of childhood pneumonia, but there is limited understanding of whether bacterial co-infections affect clinical severity.

METHODS

We conducted a retrospective cohort study at National Taiwan University Hospital from 2010 to 2019 to compare clinical characteristics and outcomes between RSV with and without bacterial co-infection in children without underlying diseases, including length of hospital stay, intensive care unit (ICU) admission, ventilator use, and death.

RESULTS

Among 620 inpatients with RSV pneumonia, the median age was 1.33 months (interquartile range, 0.67-2 years); 239 (38.6%) under 1 year old; 366 (59.0%) males; 201 (32.4%) co-infected with bacteria. The three most common bacteria are Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae. The annually seasonal analysis showed that spring and autumn were peak seasons, and September was the peak month. Compared with single RSV infection, children with bacterial co-infection were younger (p = 0.021), had longer hospital stay (p < 0.001), needed more ICU care (p = 0.02), had higher levels of C-reactive protein (p = 0.009) and more frequent hyponatremia (p = 0.013). Overall, younger age, bacterial co-infection (especially S. aureus), thrombocytosis, and lower hemoglobin level were associated with the risk of requiring ICU care.

CONCLUSION

RSV related bacterial co-infections were not uncommon and assoicated with ICU admission, especially for young children, and more attention should be given. For empirical antibacterial treatment, high-dose amoxicillin-clavulanic acid or ampicillin-sulbactam was recommended for non-severe cases; vancomycin and third-generation cephalosporins were suggested for critically ill patients requiring ICU care.

Analysis of mycoplasma pneumoniae infection among children with respiratory tract infections in hospital in Chengdu from 2014 to 2020

BACKGROUND

Respiratory tract infection (RTIs) is one of common diseases among the children. In recent years, the incidence of mycoplasma pneumoniae (M. pneumoniae) infection rate has been increasing, which cause respiratory tract infection. This study sought to analyze the epidemiological characteristics of M. pneumoniae hospitalized children with RTIs to provide a theoretical basis for clinical diagnosis and treatments in Chengdu, China.

METHODS

The data of 22,882 cases of children who had been hospitalized for RTIs were collected. M. pneumoniae immunoglobulin M (IgM) antibody was detected using the indirect immunofluorescence method and passive agglutination method. The demographic features of patients, clinical diagnoses and laboratory data were also analyzed.

RESULTS

A total of 4,213 children tested positive for M. pneumoniae. The total positive rate was 18.41% (18.30% for males and 22.72% for females). Female children had statistically significant higher positive rates than male children (χ²=198.078, P<0.01). The positive rates of M. pneumoniae differed significantly among children of different ages (F=162.7532, P<0.01). The incidence rate of M. pneumoniae in 2017 and 2019 was significantly higher than the average (F=538.95, P<0.01). There were higher M. pneumoniae positive rates from April to May, and September to October (P<0.05) in 2016, 2017, 2018, and 2019. There was no correlation between M. pneumoniae infection and temperature and humidity (P>0.05). There was negative correlation with PM_2.5 (particulate matter in the air <2.5 µm) (R=-0.293, P<0.01) and PM₁₀ (particulate matter in the air <10 µm). (R=-0.285, P<0.01). There were significant differences in the constituent ratios of cases of M. pneumoniae infection between in 2020 and other years (F=159.35, P<0.01). Bronchopneumonia accounted for the highest proportion of cases, followed by acute bronchitis and the exacerbation of asthma in 2020.

CONCLUSIONS

The epidemiological distribution of M. pneumoniae in children with RTIs in Chengdu was found to be related to gender, age, year and month; however, no relationship was found to temperature and humidity. There was a higher M. pneumoniae positive rate in children with bronchial pneumonia and asthma in cases. The prevention measures used to control Coronavirus Disease 2019 (COVID-19) also effectively controlled the M. pneumoniae infection rate.