Community-acquired pneumonia requiring hospitalization among U.S. children

Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen that causes community-acquired pneumonia in children. The clinical presentation of this pathogen can range from mild self-limiting illness to severe and refractory cases. Complications may occur, such as necrotizing pneumonia and respiratory failure. Extrapulmonary complications, including encephalitis, myocarditis, nephritis, hepatitis, or even multiple organ failure, can also arise. In this editorial, we discuss the clinical implications of the significant findings from the article "Serum inflammatory markers in children with M. pneumoniae pneumonia and their predictive value for mycoplasma severity" published by Wang et al. They reported that measuring lactic dehydrogenase, interleukin-6 levels, and D-dimer effectively predicts refractory M. pneumoniae pneumonia cases.

Working group summary of the 2023 full update of the Finnish national guidelines for paediatric lower respiratory tract infections

AIM

The first evidence-based Finnish guidelines for paediatric lower respiratory tract infections (LRTIs) were published in 2014 and completely updated in 2023. This paper, by the interdisciplinary working group that developed the 2023 guidelines, summarises the main recommendations.

METHODS

The 2023 guidelines were produced after a systematic review. Strong evidence was at least two separate, high-quality studies, moderate evidence was at least one high-quality study and weak evidence was at least one satisfactory study. The authors have now summarised the key points.

RESULTS

There was strong evidence that antitussives and beta-sympathomimetics were not effective for bronchitis-related cough and that laryngitis should be treated with oral corticosteroids, with adrenaline inhalations added in severe cases. Also, that amoxicillin for 5 days provided sufficient treatment for paediatric community-acquired pneumonia and that children with apparent viral pneumonia could be observed without antimicrobial therapy. There was moderate evidence that corticosteroids or inhaled agents were not effective for bronchiolitis and that administering salbutamol with a holding chamber could relieve symptoms of wheezing bronchitis. Also, pertussis should be considered for unvaccinated infants with coughs.

CONCLUSION

The 2023 guidelines aim to improve acute evidence-based treatment of LRTIs, through appropriate antibiotics, inhaled drugs, corticosteroids, radiology and laboratory testing.

Overview of Pediatric Respiratory Syncytial Virus (RSV) infections: has risk perception for RSV changed in children with comorbid conditions?

OBJECTIVE

Respiratory syncytial virus (RSV) is the primary etiology of lower respiratory tract infection in children. The fluctuating incidence of RSV, particularly in light of the COVID-19 pandemic, has shifted the spotlight onto preventive strategies. Our study aims to investigate both the risk factors and clinical symptoms of RSV.

MATERIALS AND METHODS

From February 2015 to February 2023, samples were analyzed during all seasons to identify viral respiratory infections. RSV was identified in a total of 835 individuals.

RESULTS

In 2021, following the easing of limitations after the COVID-19 pandemic, the largest number of identified cases was recorded. January was the most commonly used month. The median age were 5 months (min-max: 1-204 months) and 128 (17.7%) cases had a history of prematurity. Around 24.7% of the patients had a preexisting medical condition. Neurological disease patients were followed up in the intensive care unit more often than others (53.3 vs. 35.8% p = 0.036). While the hospital stay of pediatric patients born under the 29th week of gestation is almost twice as long compared to other groups, the hospital stay is almost twice as long as that of patients between 29 and 32 weeks. (p = 0.046, p = 0.012 respectively).

CONCLUSION

RSV was a powerful companion during the pandemic and a persistent reminder of its severity. Our initial data suggest that RSV prevention is difficult for children with pre-existing diseases, notably neurological abnormalities, who are not advised for preventive treatments. Given this outcome, late-premature newborns and children with medical issues should receive RSV prophylaxis first.

Multiplex Polymerase Chain Reaction Versus Standard Bacterial Culture in Critically Ill Children With Suspected Pneumonia

BACKGROUND

Bacterial lower respiratory tract infection, particularly ventilator-associated pneumonia (VAP), is a significant cause of morbidity and mortality in children who require mechanical ventilation (MV). Microbiologic diagnosis has relied on bacterial culture, but reverse transcriptase polymerase chain reaction (RT-PCR) with bacterial targets is now available for clinical use. We compared the diagnostic performance of tracheal aspirate (TA) multiplex RT-PCR to culture in children requiring MV with suspected lower respiratory tract infection.

METHODS

This is a secondary analysis of a prospective cohort of children (30 days to 18 years) at a single center requiring MV via an endotracheal tube for >72 hours in whom daily research TAs were collected. TAs were collected within 24 hours of clinically obtained cultures and analyzed by RT-PCR using the Biofire FilmArray Pneumonia Panel and compared with clinical culture results.

RESULTS

We compared the results of culture to RT-PCR for 56 samples at intubation and 74 samples from patients with suspected VAP. RT-PCR demonstrated increased detection of on-panel bacteria compared with culture (intubation 73.2% vs. 55.3% P = 0.048, suspected VAP 68.9% vs. 58.1%, P = 0.17) and had an overall sensitivity of 93.9%, specificity of 43.2% and negative predictive value of 92.1% for detection of pathogenic organisms. Overall, 33.8% of samples were positive by both methods, and 29.2% were negative by both methods. Two samples were positive by both methods but detected different on-panel organisms between culture and RT-PCR.

CONCLUSIONS

RT-PCR demonstrates high sensitivity and negative predictive value for the detection of on-panel pathogens in respiratory samples from critically ill children requiring MV. RT-PCR use may alter antibiotic prescriptions in this population.

Dynamic analysis of the epidemiology and pathogen distribution of bronchoalveolar lavage fluid in children with severe pulmonary infection: a retrospective study

BACKGROUND

Severe pulmonary infection is the primary cause of death in children aged < 5 years. The early identification of pathogenic bacteria and targeted anti-infective therapies can significantly improve the prognosis of children with severe infections. This study aims to provide a reference for the rational use of antibiotics at an early stage in children with severe pulmonary infections.

METHODS

A retrospective, single-center longitudinal study included children with severe pulmonary infections between January 2017 and December 2022 by obtaining their bacterial culture results of bronchoalveolar lavage fluid.

RESULTS

This study included 4080 samples. The age of onset for severe pulmonary infection increased annually. The proportion of severe pulmonary infections across the different age groups and years was statistically significant (p < 0.001). Among children with severe pulmonary infections, bacilli were the most prevalent, followed by cocci and fungi. The predominant bacilli were Acinetobacter baumannii and Klebsiella pneumoniae. The predominant cocci identified in this study were Streptococcus pneumoniae and Staphylococcus aureus. The primary fungi included Candida albicans and Aspergillus fumigatus, which showed significant differences (p < 0.05). The incidence of drug-resistant bacteria has gradually declined, with infection rates of multidrug-resistant bacteria and extended-spectrum beta-lactamases consistently decreasing annually. For carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, the infection rates peaked in 2018, with statistical significance (p < 0.001).

CONCLUSIONS

Severe pulmonary infections in children are significantly associated with age and types of infectious pathogens. Gram-negative bacteria are the primary cause of severe pulmonary infections in children. Clinicians should rationally use antibiotics according to the local distribution and drug resistance of pathogens, thereby enhancing therapeutic outcomes.

Antibiotics for Paediatric Community-Acquired Pneumonia: What is the Optimal Course Duration?

Despite significant global reductions in cases of pneumonia during the last 3 decades, pneumonia remains the leading cause of post-neonatal mortality in children aged <5 years. Beyond the immediate disease burden it imposes, pneumonia contributes to long-term morbidity, including lung function deficits and bronchiectasis. Viruses are the most common cause of childhood pneumonia, but bacteria also play a crucial role. However, the optimal duration of antibiotic therapy for bacterial pneumonia remains uncertain in both low- and middle-income countries and in high-income countries. Knowing the optimal duration of antibiotic therapy for pneumonia is crucial for effective antimicrobial stewardship. This is especially important as concerns mount over rising antibiotic resistance in respiratory bacterial pathogens, which increases the risk of treatment failure. Numerous studies have focused on the duration of oral antibiotics and short-term outcomes, such as clinical cure and mortality. In contrast, only one study has examined both intravenous and oral antibiotics and their impact on long-term respiratory outcomes following pneumonia hospitalisation. However, study findings may be influenced by their inclusion criteria when children unlikely to have bacterial pneumonia are included. Efforts to differentiate between bacterial and non-bacterial pneumonia continue, but a validated, accurate, and simple point-of-care diagnostic test remains elusive. Without certainty that a child has bacterial pneumonia, determining the optimal duration of antibiotic treatment is challenging. This review examines the evidence for the recommended duration of antibiotics for treating uncomplicated pneumonia in otherwise healthy children and concludes that the question of duration is unresolved.

Impact of COVID-19 pandemic measures on hospitalizations and epidemiological patterns of twelve respiratory pathogens in children with acute respiratory infections in southern China

OBJECTIVES

To investigate the impact of COVID-19 pandemic measures on hospitalizations and the alterations and persistence of the epidemiological patterns of 12 common respiratory pathogens in children during the COVID-19 pandemic and after the cessation of the "zero-COVID-19" policy in southern China.

METHODS

Respiratory specimens were collected from hospitalized children with acute respiratory infections at Shenzhen Children's Hospital from January 2020 to June 2024. Twelve common respiratory pathogens were detected using multiplex PCR. Data on demographic characteristics, pathogen detection rates, epidemiological patterns, co-infections, and ICU admission rates were compared between the 'during COVID-19' period (Phase 1: January 2020 to December 2022) and the 'post COVID-19' period (Phase 2: January 2023 to June 2024).

RESULTS

In Phase 2, there was a significant increase in average annual cases, with a higher median age of affected children, higher pathogen detection rates, and increased co-infection rates compared to Phase 1. The epidemiological patterns of most pathogens were altered by the COVID-19 pandemic. Human Parainfluenza Virus, Human Metapneumovirus, Human Bocavirus (HBOV), and Human Coronavirus remained active during Phase 1, while Mycoplasma pneumoniae (Mp) and Adenovirus (ADV) were low, and Respiratory Syncytial Virus (RSV) lacked a seasonal peak in 2022. In Phase 2, Mp, ADV, and RSV experienced outbreaks, with Mp's high prevalence continuing into 2024. RSV showed out-of-season epidemics for two consecutive years. Influenza A (H1N1), Influenza A (H3N2), and InfB lost their seasonal patterns during Phase 1 but reemerged and regained their seasonal characteristics in 2023-2024. ICU admission rates did not significantly differ between the two phases, except for HBOV, which had higher rates in Phase 2.

CONCLUSION

The epidemiological patterns of various respiratory pathogens were affected by the COVID-19 pandemic to varying degrees. Pathogens suppressed during the pandemic experienced outbreaks or out-of-season epidemics after the lifting of non-pharmaceutical interventions, with Mp and RSV continuing into the second year and HBOV associated ICU admission rates increasing in the post-pandemic era. Continuous monitoring of these patterns is essential to understand the duration of these effects and to inform effective response strategies.

The role of IFN-γ/CXCL10 axis in Mycoplasma pneumonia infection

Mycoplasma pneumoniae caused lower respiratory tract infection in children and can exacerbate these infections through the production of various inflammatory factors, with chemokines playing a key role. However, the pathogenesis of this infection is complicated and thus has not been thoroughly studied. We clarified that cytokine expression levels were analyzed in both peripheral blood and bronchoalveolar lavage fluid (BALF), and in vitro assays were conducted using THP-1 macrophages. We discovered that, compared to control children, M. pneumoniae pneumonia (MPP) patients expressed significantly higher levels of CXCL10 both in the peripheral blood and BALF. Moreover, numbers of macrophages, predominantly with a M1 phenotype, were significantly increased in BALFs of children of MPP. In vitro, coculture with IFN-γ or activated CD4+ Th1 cells significantly promoted CXCL10 expressions in THP-1 derived macrophages, which was largely reversed by siRNA-mediated down regulation of STAT1. In addition, IFN-γ-stimulated macrophages greatly promoted the trans-migration of Th1 cells. our data show that Th1 cells-derived IFN-γ augments CXCL10 production in macrophages via the JAK-STAT1 pathway, which subsequently recruits more immune cells like Th1 cells into the infection sites, thereby constituting a positive feedback loop and aggravating the type I inflammatory responses in MPP patients.

Etiology and Clinical Prediction of Community-Acquired Lower Respiratory Tract Infection in Children

BACKGROUND

Community acquired lower respiratory tract infection (LRTI) is a leading cause for hospitalization in children and important cause for antibiotic prescription. We aimed to describe the aetiology of LRTI in children and analyse factors associated with bacterial or viral infection.

METHODS

Patients aged < 19 years with a diagnosis of LRTI were identified from the Observational Medical Outcomes Partnership Common Data Model Database of Seoul National University Bundang Hospital from January 2005-July 2019, and their clinical characteristics were obtained from the electronic medical records and retrospectively reviewed.

RESULTS

Among 5,924 cases of LRTI, 74.2% were pneumonia and 25.8% were bronchiolitis/bronchitis. Patients' median age was 1.8 (interquartile range, 3.1) years and 79.9% were < 5 years old. Pathogens were identified in 37.8%; 69.1% were viral and 30.9% were bacterial/Mycoplasma pneumoniae. Respiratory syncytial virus was most common (70.9%) among viruses and M. pneumoniae (94.6%) was most common among bacteria. Viral LRTI was associated with winter, age < 2 years, rhinorrhoea, dyspnoea, lymphocytosis, thrombocytosis, wheezing, stridor, chest retraction, and infiltration on imaging. Bacteria/M. pneumoniae LRTI was associated with summer, age ≥ 2 years, fever, decreased breathing sounds, leucocytosis, neutrophilia, C-reactive protein elevation, and positive imaging findings (consolidation, opacity, haziness, or pleural effusion).

CONCLUSION

In children with LRTI, various factors associated with viral or bacterial/M. pneumoniae infections were identified, which may serve as guidance for antibiotic prescription.

Description of a Current Outbreak of Mycoplasma pneumoniae in the United States

During the COVID-19 pandemic, a significant decline in Mycoplasma pneumoniae was observed; however, M. pneumoniae re-emerged globally in 2023. Here, we describe a current outbreak of M. pneumoniae infections in the United States (US). More than 287 million patient records from all 50 states in the US were reviewed to identify patients with a M. pneumoniae diagnosis between 1 January 2017 and 30 September 2024. A c-chart was created by calculating the mean and standard error (SE) of cases during the pre-COVID-19 pandemic period, with the upper control limit (UCL) set at 3 SE above the mean. The presence of an outbreak was defined as counts above the UCL. Cumulative excess cases were used to estimate the magnitude of the outbreak, and the fold increase was calculated. A US outbreak of M. pneumoniae began at the end of 2023, resulting in 9708 excess cases corresponding to a 9.0-fold increase over the baseline UCL. The outbreak is ongoing, affects both children and adults, and includes patients with M. pneumoniae community-acquired pneumonia requiring hospitalization. This US outbreak of M. pneumoniae has significant implications for the management of patients with respiratory infections during the current pneumonia season.

The application value of targeted next-generation sequencing using bronchoalveolar lavage fluid samples in community-acquired pneumonia in children

BACKGROUND

The precise identification of pathogens responsible for community-acquired pneumonia (CAP) in children is essential for effective treatment. However, the performance of targeted next-generation sequencing (tNGS) in the detection of pathogens associated with CAP in children remains unclear.

METHODS

In this study, 216 children diagnosed with CAP were enrolled, and bronchoalveolar lavage fluid (BALF) samples underwent detection through tNGS, culture, and multiplex quantitative polymerase chain reaction (qPCR).

RESULTS

In 208 children, tNGS identified a total of 389 strains of microorganisms, including 111 Mycoplasma pneumoniae, 123 bacteria, 127 viruses, and 28 fungi. Among the cases, 89 presented as single-pathogen detection, while 119 exhibited multiple pathogens co-detection. The positive detection rates of bacteria and fungi through tNGS were significantly higher than those achieved through the traditional culture method, with rates of 56.9 % vs 8.3 % for bacteria and 13.0 % vs 4.2 % for fungi, respectively. The overall agreement between tNGS and multiplex qPCR ranged from 89.4 % to 99.1 %, with Kappa values ranging from 0.541 to 0.912 (P = 0.000).

CONCLUSIONS

The tNGS technique demonstrates rapid and effective capabilities in identifying a wide array of pathogens with a detection sensitivity that surpasses traditional culture methodologies while exhibiting a high degree of consistency with multiplex qPCR in detecting respiratory viruses. The tNGS detection method can serve as an important complement to traditional diagnostic approaches; however, caution must be exercised when interpreting tNGS findings due to its heightened sensitivity which may lead to identification of pathogens that are not necessarily responsible for causing disease.

Cause of Death Analysis in a 9½-Year-Old with COVID-19 and Dravet Syndrome

Background: Cause of death analysis is fundamental to forensic pathology. We present the case of a 9½-year-old girl with a genetically confirmed diagnosis of Dravet syndrome who died in her sleep with no evidence of motor seizure. She also had a lifelong history of recurrent pneumonias and, along with her family, had tested positive for COVID-19 10 days before death. Methods: Long-term clinical history of Dravet Syndrome and respiratory infections were obtained from patient's medical charts and radiology reports. A Rapid-Antigen Test was used to confirm SARS-CoV2 infection days prior to death. At autopsy, brain, heart and lung tissues were obtained. Paraffin-embedded tissues were double-stained with H&E, and immunohistochemically stained using various antibodies. Results: Autopsy revealed evidence of previous seizure activity in the brain and cellular interstitial thickening in the lung. The brain showed edema and fibrillary gliosis without neuronal loss in neocortex and hippocampus. The lung showed inflammatory interstitial thickening with histiocytes, megakaryocytes, B-lymphocytes, and T-lymphocytes, including helper/suppressor cells and cytotoxic T-lymphocytes. Diffuse alveolar damage was observed as alveolar flooding with proteinaceous fluid. Conclusions: The cause of death may be attributed to Sudden Unexpected Death in Epilepsy (SUDEP) in Dravet syndrome, sudden death in viral pneumonia, or some combination of the two. When two independent risk factors for sudden unexpected death are identified due to co-pathology, it may not be possible to determine a single cause of death beyond a reasonable doubt.

Impact of co-infections and immune responses on clinical severity of human adenovirus 3 and 7 infections in hospitalized children with lower respiratory tract infections: a comparative study

Background

The pathogenic distribution of co-infections and immunological status of patients infected with human adenovirus serotypes 3 or 7 (HAdV-3 or HAdV-7) were poorly understood.

Methods

This study involved a retrospective analysis of respiratory specimens collected from enrolled children with lower respiratory tract infections (LRTIs), positive for HAdV-3 or HAdV-7 from January 2017 to December 2019. Demographic data, clinical features, laboratory and radiographic findings were compared to delineate the impact of co-infections, and immune responses on clinical severity of HAdV-3 or HAdV-7 infections.

Results

Among 1311cases enrolled, there were 66 infected with HAdV-3 and 58 with HAdV-7. HAdV-7-infected patients exhibited more prolonged fever (100% vs 89.4%, p=0.014), pneumonia (100% vs 89.4%, p=0.014), hypoxia (34.5% vs 12.1%, p=0.003), higher propensity for aspartate aminotransferase exceeding 80U/L (21.1% vs 4.7%, p=0.006), D-Dimer exceeding 1.65mg/L (64.9% vs 12.5%, p<0.001), consolidation (50.0% vs 27.4%, p=0.011), and pleural effusion (32.8% vs 6.5%, p<0.001), co-infections with Mycoplasma pneumoniae (77.1% vs 32.6%, p<0.001), and multiple infections (56.8% vs 41.3%, p=0.007), compared to those with HAdV-3 infections. Immune cell analysis indicated that HAdV-7 infections led to a more pronounced decrease in CD3+ T cells (1596.8 vs 2444.8 cells/𝛍l, p=0.042), CD8+ cytotoxic T cells (668.6 vs 774.0 cells/µl, p=0.045), and increased NK cell percentages (11.5% vs 9.0%, p=0.044) compared to HAdV-3 infections.

Conclusions

Hospitalized children with HAdV-7-associated LRTIs exhibit greater severity, multiple infections, and significant potential for greater cellular immune dysregulation compared to those with HAdV-3 infection, indicating a more severe clinical course and distinct pathogenic profiles.

Variants in the β-globin locus are associated with pneumonia in African American children

In African American adults, the strongest genetic predictor of pneumonia appears to be the A allele of rs334, a variant in the β-globin gene, which in homozygous form causes sickle cell disease (SCD). No comparable studies have been done in African American children. We performed genome-wide association analyses of 482 African American children with documented pneumonia and 2,048 African American control individuals using genotypes imputed from two reference panels: 1000 Genomes (1KG) (which contains rs334) and TOPMed (does not contain rs334). Using 1KG imputed genotypes, the most significant variant was rs334 (A allele; odds ratio [OR] = 2.76; 95% CI, 2.21-3.74; p = 5.9 × 10-19); using TOPMed imputed genotypes the most significant variant was rs2226952, found in the β-globin locus control region (G allele; OR = 2.14; 95% CI, 1.78-2.57; p = 5.1 × 10-16). After conditioning on rs334, the most strongly associated variant in the β-globin locus, rs33930165 (T allele, 1KG: OR = 4.09; 95% CI, 2.29-7.29; p = 1.7 × 10-6; TOPMed: OR = 3.58; 95% CI, 2.18-5.90; p = 4.7 × 10-7), which as a compound heterozygote with rs334 A allele, can cause SCD. To compare the power of different sample sets we developed a way to estimate the power of sample sets with different sample sizes, genotype arrays, and imputation platforms. Our results suggest that, in African American children, the strongest genetic determinants of pneumonia are those that increase the risk of SCD.

Lower Airway Diseases in the Paediatric Population: A Two-Year, Single-Centre, Retrospective Study

Background: Lower airway diseases in children are one of the major causes of hospitalisation. This study aimed to evaluate the characteristics of children admitted to a tertiary pediatric hospital diagnosed with lower airway disease and to identify differences between age groups and the two years of the study. Methods: In this single-centre retrospective observational study, demographic and clinical information about children hospitalised in the emergency pediatric ward and diagnosed with lower respiratory disease from 1 June 2021 to 30 June 2023 were retrospectively reviewed. Results: A total of 410 episodes of hospitalisation for lower airway diseases were registered. In 83.9% of cases, the patient needed hospitalisation for respiratory failure, and children <1 year of age were at higher risk. Rhinovirus and respiratory syncytial virus (RSV) were the leading causes of lower respiratory tract infections. No death has been recorded. In 8.8% of cases, the patient was admitted to the Pediatric Intensive Care Unit. In 2021-2022, we recorded more hospitalisations for bronchiolitis with RSV as the primary pathogen detected and more patients were admitted to the hospital for respiratory failure. In 2022-2023, we registered more admissions for bacterial pneumonia and the need for intravenous therapy. Conclusions: Lower respiratory tract diseases are frequent in the pediatric population, and the risk of respiratory failure is higher. Analysing the differences between the two years of study, we underline how the COVID-19 pandemic has changed the epidemiology of acute respiratory infections in children.

Epidemiology of respiratory viruses according to age group, 2023-24 winter season, Kyoto, Japan

The seasonality and epidemiology of viral acute respiratory infections (ARIs) have changed since the coronavirus disease 2019 pandemic. However, molecular-based ARI surveillance has not been conducted in Japan. We developed a regional surveillance program to define the local epidemiology of ARIs. Between December 2023 and March 2024, 2,992 upper respiratory samples collected from patients suspected of having ARIs at five facilities in Kyoto City, Japan, were tested for SARS-CoV-2, influenza virus, and respiratory syncytial virus (RSV) using RT‒PCR. Samples negative for these viruses were randomly selected for testing with the FilmArray Respiratory Panel, and the detection rates of other viruses were estimated. SARS-CoV-2, influenza virus, and RSV were detected in 598 (20.3%), 165 (5.6%), and 40 (1.4%) of the 2,949 samples with valid RT‒PCR results, respectively. The most prevalent viruses in the < 6, 6-17, 18-64, and ≥ 65 year age groups were rhinovirus/enterovirus, RSV, and SARS-CoV-2; influenza virus, seasonal coronavirus, and rhinovirus/enterovirus; SARS-CoV-2, seasonal coronavirus, and influenza virus; and SARS-CoV-2, seasonal coronavirus, and influenza virus, respectively. Significant differences in the detection rates of these viruses were detected between the age groups. This study highlights the importance of age-stratified molecular-based surveillance for a comprehensive understanding of the epidemiology of ARIs.

Characterization of diffuse lung function in children with Mycoplasma pneumoniae pneumonia

Background

Mycoplasma pneumoniae infection accounts for a high proportion of community-acquired pneumonia and the incidence rate of severe M. pneumoniae pneumonia (MPP) has increased year by year. This study investigated the changes in lung diffusion function after M. pneumoniae infection, compared the lung diffusion and ventilation function of children with mild (MMPP) or severe M. pneumoniae pneumonia (SMPP) infections, and explored their clinical significance.

Objective

To study the changes in pulmonary ventilation and pulmonary diffusion function in children with MPP, and explore their clinical significance.

Methods

Data from 97 children with M. pneumoniae pneumonia hospitalized in Chengdu Women and Children's Central Hospital from June 2023 to December 2023 were collected and the participants were divided into an MMPP group (n = 44) and an SMPP group (n = 53). The changes in pulmonary ventilation function and diffusion function were compared between the two groups.

Results

The Z-scores of forced vital capacity and forced expiratory volume in the first second in the SMPP and MMPP groups were -1.684 ± 0.902 and -1.986 ± 0.818, and 0.164 ± 1.795 and -0.6104 ± 1.276, respectively. In the SMPP group, the two aforementioned indicators were lower than the normal value and significantly lower than those in the MMPP group (P < 0.001). The carbon monoxide diffusion capacity in the SMPP group (-5.931 ± 0.827) was significantly lower than that in the MMPP group (-5.0775 ± 1.1134) (P < 0.001). The forced expiratory flow at 75% vital capacity and the maximum mid expiratory flow in the SMPP group were -2.006 ± 1.2582 and -1.878 ± 1.008, respectively, which were lower than the normal value.

Conclusion

SMPP results in more severe ventilation dysfunction and diffuse dysfunction than MMPP.

Potential Impact of Rapid Molecular Microbiologic Diagnosis for Mechanically Ventilated Children in Intensive Care With Suspected Pneumonia

BACKGROUND

Lower respiratory tract infections (LRTIs) remain a leading cause of community-acquired and nosocomial infection in children and a common indication for antimicrobial use and intensive care admission. Determining the causative pathogen for LRTIs is difficult and traditional culture-based methods are labor- and time-intensive. Emerging molecular diagnostic tools may identify pathogens and detect antimicrobial resistance more quickly, to enable earlier targeted antimicrobial therapy.

METHODS

This is a single-center, prospective observational laboratory study evaluating the use of the Biofire FilmArray pneumonia panel (FA-PP) (BioFire Diagnostics, Salt Lake City, UT) for bronchoalveolar lavage specimens from mechanically ventilated children admitted with suspected or presumed pneumonia. We aimed to determine its feasibility and utility for identifying pathogens, antimicrobial resistance and its potential influence on antibiotic prescribing.

RESULTS

We analyzed 50 samples taken from 41 children with a median age of 6 months. Positive agreement between culture and FA-PP was 83% and negative agreement was 76%. Agreement between FA-PP ( mecA/C or MREJ ) and culture was high for methicillin-resistant Staphylococcus aureus . In 3 cases, extended-spectrum beta-lactamase-producing Gram-negative organisms were detected by culture and not FA-PP. Hypothetically, FA-PP results would have affected antimicrobial prescribing in approximately half the cases (24, 48%).

CONCLUSIONS

FA-PP is a useful adjunct to traditional culture methods in mechanically ventilated children with LRTIs and may influence clinical decision-making regarding antibiotic escalation or stewardship.

Adenoviral Pneumonia Outbreak in Immunocompetent Adults-A Missed Antimicrobial Stewardship Opportunity?

Background/Objectives: While the concept of viral community-acquired pneumonia (CAP) changed with COVID-19, the role of non-influenza viruses as a cause of CAP is less clear. The aim of this study was to describe the clinical course, risk factors, inflammatory profiles, antibiotic use, outcomes and complications of adenoviral (AdV) CAP. Methods: A prospective, non-interventional, observational cohort study included consecutively hospitalized immunocompetent adult patients with AdV CAP during an 18-month period. Clinical and laboratory data, including lymphocyte subpopulations and serum cytokine profiles were collected and correlated to clinical outcomes. Results: Fifty-eight patients with AdV CAP were included; 81% were males, with a median age of 33 (IQR 28-41) years and 62% without any comorbidities. All patients initially had high-grade fever for a median duration of 6 (5-7) days and respiratory symptoms. Increased CRP and procalcitonin, lymphopenia, mild thrombocytopenia and liver injury were frequent. Radiographic findings mimicked bacterial pneumonia (83% had unilateral involvement). Twenty-two patients (38%) had criteria for severe CAP, and these patients had higher procalcitonin, NLR, AST, ALT, LDH and CK, and lower T-lymphocyte CD4+ count. In comparison to influenza and bacterial CAP, patients with AdV had higher serum IL-2, IL-1β, IL-8, IL-10, CXCL10 and MCP-1, and lower TGF-β1 concentration. Thirteen patients required low-flow oxygen therapy, and 13 advanced respiratory support. Complications occurred in 29%, with one fatal outcome. While all patients received empirical antibiotic therapy, after AdV detection it was stopped in 21%, although only one patient had detected a possible bacterial coinfection. Conclusions: Since AdV CAP in immunocompetent patients is clinically and radiologically indistinguishable from bacterial CAP, it is associated with prolonged clinical course and lack of clinical response to antibiotics. This emphasizes the importance of AdV testing which could lead to more rational antimicrobial treatment.

Impact of respiratory pathogens detection by a rapid multiplex polymerase chain reaction assay on the management of community-acquired pneumonia for children at the paediatric emergency department. A randomized controlled trial, the Optimization of Pneumonia Acute Care (OPTIPAC) study

OBJECTIVES

The pathogen of community-acquired pneumonia (CAP) in children is typically uncertain during initial treatment, leading to systematic empiric antibiotic use. This study investigates if having rapid multiplex PCR results in the emergency department (ED) improves empiric treatment.

METHODS

OPTIPAC, a French multicentre study (2016-2018), enrolled patients consulting for CAP at the paediatric ED in 11 centres. Patients were randomized to either receive a multiplex PCR test plus usual care or usual care alone and followed for 15 days. The primary outcome was the appropriateness of initial antimicrobial management, determined by a blinded committee.

RESULTS

Of the 499 randomized patients, 248 were tested with the multiplex PCR. Appropriateness of the antibiotic treatment was higher in the PCR group (168/245, 68.6% vs. 120/249, 48.2%; Relative risk 1.42 [1.22-1.66]; p < 0.0001), chiefly by reducing unnecessary antibiotics in viral pneumonia (RR 3.29 [2.20-4.90]). No adverse events were identified.

DISCUSSION

The multiplex PCR assay result at the ED improves paediatric CAP's antimicrobial stewardship, by both reducing antibiotic prescriptions and enhancing treatment appropriateness.

Impact of Viral Lower Respiratory Tract Infection (LRTI) in Early Childhood (0-2 Years) on Lung Growth and Development and Lifelong Trajectories of Pulmonary Health: A National Institutes of Health (NIH) Workshop Summary

Viral lower respiratory tract infections (LRTI) are ubiquitous in early life. They are disproportionately severe in infants and toddlers (0-2 years), leading to more than 100,000 hospitalizations in the United States per year. The recent relative resilience to severe Coronavirus disease (COVID-19) observed in young children is surprising. These observations, taken together, underscore current knowledge gaps in the pathogenesis of viral lower respiratory tract diseases in young children and respiratory developmental immunology. Further, early-life respiratory viral infections could have a lasting impact on lung development with potential life-long pulmonary sequelae. Modern molecular methods, including high-resolution spatial and single-cell technologies, in concert with longitudinal observational studies beginning in the prenatal period and continuing into early childhood, promise to elucidate developmental pulmonary and immunophenotypes following early-life viral infections and their impact on trajectories of future respiratory health. In November 2019, under the auspices of a multi-disciplinary Workshop convened by the National Heart Lung Blood Institute and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, experts came together to highlight the challenges of respiratory viral infections, particularly in early childhood, and emphasize the knowledge gaps in immune, virological, developmental, and clinical factors that contribute to disease severity and long-term pulmonary morbidity from viral LRTI in children. We hope that the scientific community will view these challenges in clinical care on pulmonary health trajectories and disease burden not as a window of susceptibility but as a window of opportunity.

Haemophilus influenzae and pneumococci: Co-colonization, interactions, cooperation and competition

Nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae (pneumococcus) are pathobionts that share common environmental niches within the upper respiratory tract. They can form part of the resident upper airway microbiota, but under certain environmental circumstances become pathogenic and induce disease. In children, both organisms have a considerable impact on the healthcare system, commonly causing acute otitis media and pneumonia. They are also associated with chronic biofilm-mediated respiratory infections, such as persistent middle ear effusions and chronic suppurative otitis media, and in the lower airways with protracted bacterial bronchitis and bronchiectasis. Consequently, both organisms are responsible for large numbers of antibiotic prescriptions and substantial healthcare costs. The complex relationship between NTHi and pneumococcal co-interaction during colonization, infection and biofilm formation is poorly understood and a greater understanding is needed to facilitate development of future therapies, and novel interventions and prevention strategies. Co-infections with both bacteria can result in more severe disease, with disease severity likely mediated by their ability to cooperate in some in vivo niches. However, this relationship is not always straightforward, as under certain conditions, these two bacteria compete rather than cooperate. Current opinion supports developing a vaccine targeting NTHi strains, as well as a combined vaccine targeting both NTHi and pneumococci to decrease the respiratory disease burden in young children. This review summarizes our current knowledge of the interactions between NTHi and pneumococci and speculates on the future directions of research to understand how these bacteria co-exist and how to better prevent and treat NTHi and pneumococcal infection.

Epidemiological characteristics of community-acquired Mycoplasma pneumoniae in hospitalized children around COVID-19 from Jiangsu Province, China: a multicenter retrospective study

Background

It has been reported that the emergence of coronavirus disease 2019 (COVID-19) has changed the epidemiological characteristics of many pathogens, but the epidemiological characteristics of Mycoplasma (MP) infection in hospitalized children with community-acquired pneumonia (CAP) are not clear. The aim of this study was to answer this question.

Methods

Children with CAP in three tertiary hospitals (hospitals A, B and C) from 2018 to 2023 were selected. Data on gender, age, number and date of MP infection were obtained from the medical record. The intensity of the epidemic was measured as a percentage of the number of CAP.

Results

In hospitals A and B, before the pandemic (in 2018 and 2019), the number of hospitalized children with MP pneumonia and the proportion of total pneumonia had shown a significant upward trend, but the control measures led to a slight decline. In hospital C, the number and percentage of hospitalized children with MP pneumonia were low before and during the COVID-19 period. After the epidemic control was lifted, the number and percentage of children with MP pneumonia in the three hospitals increased sharply, and the proportion of children aged more than 7 years old increased significantly in 2022 and 2023.

Conclusions

From 2018 to 2019, there was already an epidemic trend of MP in the study hospital. From 2020 to 2022, after the outbreak of COVID-19, the incidence of MP pneumonia stabilized, but after the epidemic control was lifted, it broke out. This may be due to the severe restrictive measures taken early during the COVID-19 pandemic that effectively controlled the spread of MP, pausing its pandemic.

Effectiveness of Antiviral Treatment with Intravenous Peramivir and Oral Oseltamivir for Seasonal Influenza in Children

BACKGROUND/OBJECTIVES

Influenza poses significant risks in children, causing complications like febrile seizures and hospitalizations. Antiviral treatments include oseltamivir and peramivir, both FDA-approved neuraminidase inhibitors. This study aims to compare the effectiveness of intravenous peramivir and oral oseltamivir in pediatric patients presenting to an emergency department, with a primary focus on the revisit rate within 72 h post-treatment.

METHODS

A retrospective study analyzed 1327 children aged 1-15 years diagnosed with influenza A or B between 1 January 2019 and 29 February 2020, at a single urban hospital. Patients were divided into oseltamivir (n = 1243) and peramivir (n = 84) groups. Data included demographics, clinical symptoms, emergency department stays, and revisit rates. Fisher's exact test was used for analysis, with p-values < 0.05 considered significant.

RESULTS

A total of 1327 pediatric patients were included, with 1243 receiving oseltamivir and 84 receiving peramivir. Patients in the peramivir group were older (median age 5.88 years vs. 4.54 years, p = 0.002) and had higher rates of gastrointestinal symptoms. The emergency department length of stay was significantly longer in the peramivir group (167 min vs. 63 min, p < 0.001). The revisit rate within 3 days was 5.63% for oseltamivir and 9.52% for peramivir, with no statistically significant difference (p = 0.22).

CONCLUSIONS

Peramivir presents as an effective alternative treatment for influenza in children, particularly in situations where oral administration is not feasible due to gastrointestinal intolerance, highlighting the importance of an alternative route of antiviral administration.

Insights from respiratory virus co-infections

Respiratory viral co-infections present significant challenges in clinical settings due to their impact on disease severity and patient outcomes. Current diagnostic methods often miss these co-infections, complicating the epidemiology and management of these cases. Research, primarily conducted in vitro and in vivo, suggests that co-infections can lead to more severe illnesses, increased hospitalization rates, and greater healthcare utilization, especially in high-risk groups such as children, the elderly, and immunocompromised individuals. Common co-infection patterns, risk factors, and their impact on disease dynamics highlight the need for advanced diagnostic techniques and tailored therapeutic strategies. Understanding the virological interactions and immune response modulation during co-infections is crucial for developing effective public health interventions and improving patient outcomes. Future research should focus on the molecular mechanisms of co-infection and the development of specific therapies to mitigate the adverse effects of these complex infections.

Safety, Efficacy, and Effectiveness of Maternal Vaccination against Respiratory Infections in Young Infants

Lower respiratory tract infection (LRTI) is a major cause of neonatal morbidity and mortality worldwide. Maternal vaccination is an effective strategy in protecting young infants from LRTI, particularly in the first few months after birth when infant is most vulnerable, and most primary childhood vaccinations have not been administered. Additionally, maternal vaccination protects the mother from illness during pregnancy and the postnatal period, and the developing fetus from adverse outcomes such as stillbirth and prematurity. In this paper, we review the safety, efficacy, and effectiveness of maternal vaccines against LRTIs, such as pertussis, influenza, coronavirus disease 2019, and respiratory syncytial virus.

Comparative analysis between genotypes of adenovirus isolates from hospitalized children with acute respiratory tract infections and clinical manifestations in Wuhan, China, from June 2022 to September 2023

Acute respiratory tract infections (ARTIs) are among the leading causes of morbidity and mortality in children worldwide. Human adenovirus (HAdV) infections are estimated to account for at least 5% of pediatric ARTIs. The circulated genotypes of HAdV and the correlation between genotype and clinical manifestations in Wuhan, China, before and after the complete relaxation of nonpharmaceutical interventions against severe acute respiratory syndrome coronavirus 2, remain unknown. Here, 101 HAdV strains were isolated from throat swab samples collected from hospitalized children with ARTIs who tested positive for HAdV nucleic acid. Of these, sixty-six strains from 2022 and 23 strains from 2023 were successfully genotyped and subjected to phylogenetic analysis based on the hexon, penton base, and fiber genes. Six genotypes, B3, C1, C2, C5, C104, and C108 were identified. HAdV-B3 (84.85%) was the most prevalent type in 2022, while HAdV-C (86.96%), including C1, C2, C108, and C104, was the most prevalent in 2023. These strains were phylogenetically related to strains from Japan, China, and the United States in recent years. When comparing clinical characteristics, pediatric patients infected with B3, C1, C2, C5, C104, or C108 exhibited similar clinical manifestations, primarily fever and cough, but varying interleukin (IL)-10 levels. In conclusion, from June 2022 to September 2023, the circulated genotypes of HAdV in Wuhan included B3, C1, C2, C108, C5, and C104. The endemic pattern of HAdV in Wuhan, China, shifted from species B as the dominant type in 2022 to species C in 2023.

Pulmonary thromboembolism due to Mycoplasma pneumoniae in children: a case report and literature review

BACKGROUND

Mycoplasma pneumoniae (MP) is a common respiratory pathogen in children that can sometimes lead to extrapulmonary manifestations. Among these, pediatric pulmonary thromboembolism (PE) is clinically rare but carries significant implications. However, it is often underrecognized, and its diagnosis and treatment are not well understood.

CASE PRESENTATION

We report a case of PE associated with MP pneumonia in a 6-year-old girl who presented with recurrent hyperpyrexia, cough, extensive consolidation in the upper lobe of the left lung, and pulmonary artery thrombi in the right lung. Following prompt diagnosis of PE and appropriate antibiotic therapy combined with anticoagulation treatment, the child recovered well and remained healthy at follow-up. The diagnostic and treatment processes were analyzed, and previously reported cases of pediatric MP-related PE were reviewed.

CONCLUSION

PE should be considered in pediatric patients with MP pneumonia who do not improve or whose condition worsens despite standard therapy. The outcomes of pediatric MP-related PE are generally favorable if prompt diagnosis and appropriate treatment are provided.

Risk factors for complications of Mycoplasma pneumoniae pneumonia in hospitalized children in China: a systematic review and meta-analysis

BACKGROUND

Mycoplasma pneumoniae pneumonia (MPP) is a common respiratory disease in children. Some patients may develop long-term respiratory issues such as chronic cough and wheezing due to complications. These complications increase the health burden for children with MPP, highlighting the need to understand their risk factors in order to improve disease prognosis. This study aims to assess the risk factors for complications in hospitalized children with MPP in China.

METHODS

A comprehensive review of Chinese and English databases was conducted up to April 2024 to retrieve studies focusing on complications in hospitalized children with MPP. Pooled effect sizes were calculated using random-effects or fixed-effects models. Statistical analyses were performed using R software and RevMan 5.3.

RESULTS

This meta-analysis encompassed a total of 17 studies. We analyzed multiple risk factors associated with complications, including prolonged fever (OR: 3.79, aOR: 1.64), pleural effusion (OR: 3.71, aOR: 6.70), extensive lung infiltration (OR: 5.52, aOR: 3.57), ≥ 2/3 consolidation in a single lung lobe (OR: 4.29, aOR: 4.52), right upper lung lesion (OR: 4.84, aOR: 3.57), extrapulmonary manifestations (OR: 3.20, aOR: 1.89), hypoxemia (OR: 7.58, aOR: 12.43), delayed administration of glucocorticoids (OR: 7.93, aOR: 6.67), and delayed administration of macrolides (OR: 2.75, aOR: 3.84).

CONCLUSION

Hospitalized children with SMPP and RMPP may have a higher risk of complications, and it is important to identify risk factors early and provide appropriate treatment to minimize complications. The current level of evidence is relatively low and may not accurately reflect the actual clinical situation in China. Further high-quality studies are needed to validate and clarify these findings.

TRIAL REGISTRATION

Our protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (registration number: CRD42024534397).

Burden of viral respiratory infections in the pediatric intensive care unit: age, virus distribution, and the impact of the COVID-19 pandemic

Though usually self-limiting, viral respiratory infections can escalate to severe cases requiring admission to a pediatric intensive care unit (PICU). This study aims to examine the proportional incidence, affected age ranges, viral pathogens involved, associated severity measures, and the impact of the COVID-19 pandemic on their incidence and virus distribution. This retrospective cohort study conducted in a tertiary care center (2011-2021) reviewed all pediatric patients admitted to PICU with laboratory-confirmed viral respiratory infection. The study included 312 patients, comprising 5.5% of all PICU admissions; 45% were males; 52% had underlying conditions. The median age was 1.1 (IQR 0.3-2.8) years; 18% were born prematurely. The most common viruses were respiratory syncytial virus (35%), adenovirus (26%), influenza (10%), parainfluenza (11%), and human metapneumovirus (11%). All viruses displayed a seasonal pattern, except year-round occurrence in adenovirus. The seasonality pattern was disrupted by COVID-19 pandemic-related restrictions. Mechanical ventilation was required for 46% of patients; 27% required other non-invasive respiratory support. Thirty-day mortality was documented in 18 (5.8%) patients. Underlying conditions, particularly immunosuppression, neuromuscular diseases, and genetic/metabolic syndromes, were associated with increased mortality (p = 0.001, 0.006, and 0.001, respectively). Adenovirus was also linked to higher mortality (p = 0.04), hMPV to prolonged ventilation (p = 0.004) and prolonged PICU stay (p = 0.009), and SARS-CoV-2 to extended ventilation (p = 0.04). During COVID-19, patients were older (p = 0.001), RSV cases decreased (p = 0.006), ventilation duration increased (p = 0.03), and cardiologic complications rose (p = 0.02). No influenza A or B cases appeared post-pandemic.

CONCLUSION

Viral respiratory infections can lead to severe complications. Their high prevalence in infants and young children highlights the need to extend vaccination age ranges for vaccine-preventable viral infections, monitor uptake in at-risk children, and implement public health interventions in daycare settings.

WHAT IS KNOWN

• Viral respiratory infections in children are a significant cause of illness and mortality.

WHAT IS NEW

• Severe infections in children beyond current vaccine eligibility suggest the need to expand vaccination to broader age groups. • SARS-CoV-2 dominance during the COVID-19 pandemic altered disease characteristics of respiratory infections.

A Phase 3 Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of V116 in Pneumococcal Vaccine-Experienced Adults 50 Years of Age or Older (STRIDE-6)

BACKGROUND

Pneumococcal diseases cause considerable morbidity and mortality in adults. V116 is an investigational 21-valent pneumococcal conjugate vaccine (PCV) specifically designed to protect adults from pneumococcal serotypes responsible for the majority of residual pneumococcal diseases. This phase 3 study evaluated safety, tolerability, and immunogenicity of V116 in pneumococcal vaccine-experienced adults aged ≥50 years.

METHODS

A total of 717 adults were enrolled to receive a single dose of pneumococcal vaccine as follows: cohort 1 (n = 350) previously received 23-valent pneumococcal polysaccharide vaccine (PPSV23) and were randomized 2:1 to receive V116 or PCV15, respectively; cohort 2 (n = 261) previously received PCV13 and were randomized 2:1 to receive V116 or PPSV23, respectively; cohort 3 (n = 106) previously received PPSV23 + PCV13, PCV13 + PPSV23, PCV15 + PPSV23, or PCV15 and all received open-label V116. Immunogenicity was evaluated 30 days postvaccination using opsonophagocytic activity (OPA) geometric mean titers (GMTs) and immunoglobulin G (IgG) geometric mean concentrations (GMCs) for all V116 serotypes. Safety was evaluated as the proportion of participants with adverse events (AEs).

RESULTS

V116 was immunogenic across all 3 cohorts as assessed by serotype-specific OPA GMTs and IgG GMCs postvaccination for all 21 serotypes. V116 elicited comparable immune responses to serotypes shared with PCV15 (cohort 1) or PPSV23 (cohort 2), and higher immune responses to serotypes unique to V116. The proportions of participants with solicited AEs were generally comparable across cohorts.

CONCLUSIONS

V116 is well tolerated with a safety profile comparable to currently licensed pneumococcal vaccines and generates IgG and functional immune responses to all V116 serotypes, regardless of prior pneumococcal vaccine received.

CLINICAL TRIALS REGISTRATION

NCT05420961; EudraCT 2021-006679-41.

Molecular detection of respiratory viruses: an observational study on respiratory co-infections in children and adults

Respiratory tract infection (RTI) is the most important cause of visiting both public and private medical care services. During the decade preceding Covid-19, in developing countries, there was a gap in the epidemiology of respiratory viral infections, probably due to the difficulty of detecting viral agents in clinical microbiology laboratories routine, at that time. In this context, the aim of this study was to describe the occurrence of virus, demographic factors associated and the likelihood of coinfections detection by multiplex PCR methods. The target also was to determine the involvement of respiratory viruses other than SARS-CoV-2 as agents of upper respiratory tract infections (URTIs) using rapid respiratory panels by multiplex real time PCR with flow chip methodology. Samples of SARSs patients, 530 in total, were tested between 2022 and 2023, obtained from nasopharyngeal swabs, nasopharyngeal exudates or nasopharyngeal aspirates. Of 530 tests, 30% was human rhinovirus, the most prevalent, followed by respiratory syncytial virus B (21.5%) and human adenovirus (17.4%). Among the total of positive samples, 83.8% belonged to patients aged between 0 and 10 years, 62.6% of whom were aged between 1 and 10 years. Multiple virus detection was found in 50.4% of the samples tested, 93.1% of which were from patients under the age of 18. Viral co-infection was evident in the finding and was higher (88.7%) in patients under the age of 18 yeas.

Understanding serum inflammatory markers in pediatric Mycoplasma pneumoniae pneumonia

This editorial reflects on the research, which investigates the potential of serum markers to predict the severity of Mycoplasma pneumoniae infections. Mycoplasma pneumoniae pneumonia (MPP) is a prevalent cause of respiratory infections in children, often leading to significant morbidity. Predicting the severity of MPP can significantly enhance patient management and outcomes. This editorial reviews the role of specific laboratory markers: (1) Lactate dehydrogenase; (2) Interleukin (IL)-6; (3) IL-10; (4) Tumor necrosis factor-α; and (5) D-dimer in predicting the severity of MPP in pediatric patients. Elevated levels of these markers are strongly associated with severe cases of MPP, providing clinicians with valuable tools for early diagnosis and targeted intervention.

Electronic Clinical Decision Support Tools: Strategies to Improve the Management of Lower Respiratory Tract Infections in Low-Resource Settings

Lower respiratory tract infection (LRTI) is a common reason for hospitalization and antibacterial use globally. There is considerable overlap in the clinical presentation of bacterial and viral LRTIs. Low- or middle-income countries (LMICs) face the dual challenge of appropriately targeting antibacterials for bacterial LRTI while reducing inappropriate antibacterials for viral LRTI. We propose a framework by which an electronic clinical decision support tool (eCDST) for diagnosing LRTI and reducing unnecessary antibacterial use may be developed, validated, and prospectively evaluated in an LMIC. The developed tool would be data driven, low-cost, feasible in the local setting, adaptable based on resource availability, and updated in real time, with prospective assessment to identify its clinical impact. We draw upon our team's recent experience developing an eCDST for LRTI management in Sri Lanka. Publicly sharing such processes and data is valuable, such that we can collectively improve clinical care in LMICs and other settings.

Testing and Treatment Thresholds for Pediatric Pneumonia in the Emergency Department

BACKGROUND

Clinical prediction models for pediatric community-acquired pneumonia (CAP) may standardize management. Understanding physician risk thresholds is important for model implementation. We aimed to elucidate physician-derived thresholds for chest radiograph performance and empirical antibiotic treatment of CAP among children presenting to the emergency department with respiratory illness before and after knowledge of results of a validated clinical prediction model.

METHODS

Pediatric emergency physicians were surveyed through the American Academy of Pediatrics Pediatric Emergency Medicine Collaborative Research Committee and provided 8 clinical vignettes for children with respiratory symptoms. Respondents were asked to indicate their probability of radiographic CAP and choose whether they would obtain a chest radiograph or give empirical antibiotics before and after being provided with the probability of radiographic CAP based on a validated prediction model. We used logistic regression to establish testing and treatment thresholds, defined as the disease probability at which half of physicians acted.

RESULTS

Two-hundred and eight (44.3%) of 469 physicians completed the survey. Most were attending physicians (96.0%) practicing in a freestanding children's hospital (76.8%). Testing and treatment thresholds for CAP were 17.6% (95% confidence interval [CI] 16.4% to 18.8%) and 66.1% (95% CI 60.1% to 72.5%), respectively, before knowledge of the model-estimated probability. With knowledge of the prediction model, testing and treatment thresholds were 13.5% (95% CI 12.3% to 14.7%) and 58.0% (95% CI 53.2-62.8).

CONCLUSIONS

We elucidated physician thresholds for testing and treatment of CAP, which may be integrated into future pneumonia risk models to improve acceptability and incorporation into practice.

Laboratory diagnosis and treatment of Mycoplasma pneumoniae infection in children: a review

Mycoplasma pneumoniae (MP) is the cause of Mycoplasma pneumoniae pneumonia (MPP) in children and adolescents, with the clinical manifestations highlighted by intermittent irritating cough, accompanied by headache, fever and muscle pain. This paper aimed to study the research status and focal points in MP infection, especially the common laboratory diagnostic methods and clinical treatment of Mycoplasma pneumoniae. Laboratory diagnostic methods include molecular assay, serological antibody detection, rapid antigen detection and isolation and culture. Polymerase chain reaction (PCR) is the gold standard with high sensitivity and specificity. The serological antibody can detect various immune antibodies qualitatively or quantitatively in serum. Rapid antigen can be detected faster, with no equipment environment requirements, which can be used for the early diagnosis of MP infection. While the culture growth cycle is long and insensitive, not recommended for routine diagnosis. Macrolides were the preferred drug for children with MPP, while the drug resistance rate was rising in China. Tetracycline can be substituted but was not recommended for children under 8 years of age, quinolone drugs are not necessary, severe MPP can be combined with glucocorticoids, involving the nervous or immune system can choose gamma globulin. Other treatments for MPP including symptomatic treatment which can alleviate symptoms, improve lung function and improve prognosis. A safe and effective vaccine needed to be developed which can provide protective immunity to children and will reduce the incidence of MPP.

Unveiling the dynamics of respiratory infections revealed by multiplex PCR testing during the COVID-19 pandemic in Taiwan, 2020-2023

BACKGROUND

The emergence of SARS-CoV-2 in late 2019 sparked the global COVID-19 pandemic, leading to varied vaccine policies worldwide. The evolving patterns of respiratory pathogens, aside from SARS-CoV-2, during the pandemic have had a significant impact on the development of vaccine strategies.

METHODS

This study explores the landscape of respiratory pathogens, encompassing SARS-CoV-2, respiratory syncytial virus (RSV), and influenza viruses, through a retrospective analysis of data obtained from the BioFire Respiratory Panel 2.1 (RP 2.1) at China Medical University Hospital (Taichung, Taiwan) spanning from January 2020 to November 2023.

RESULTS

Among the 7950 respiratory samples studied, pediatric cases exhibited higher positivity (64.9%, 2488/3835) and mixed detection rates (43.8%, 1090/2488) than adults. Annual mixed detection rates increased (27.9-48%). Prevalence analysis revealed diverse patterns across age groups, with higher rates in pediatrics. Notably, human rhinovirus/enterovirus predominated (48.1%). Mixed detection illustrated viral co-detections, notably with parainfluenza viruses and adenovirus. Government policies and pandemic dynamics influenced infection patterns, with RSV resurgence after May 2022. Age-specific RSV detection demonstrated a shift, influencing vaccine considerations. Amid global vaccine initiatives, RSV's increasing trend in adults warrants attention.

CONCLUSIONS

This comprehensive analysis emphasizes the importance of multiplex PCR testing in shaping targeted vaccination strategies during evolving respiratory pathogen landscapes.

Predicting the impact of non-pharmaceutical interventions against COVID-19 on Mycoplasma pneumoniae in the United States

The introduction of non-pharmaceutical interventions (NPIs) against COVID-19 disrupted circulation of many respiratory pathogens and eventually caused large, delayed outbreaks, owing to the build up of the susceptible pool during the intervention period. In contrast to other common respiratory pathogens that re-emerged soon after the NPIs were lifted, longer delays (> 3 years) in the outbreaks of Mycoplasma pneumoniae (Mp), a bacterium commonly responsible for respiratory infections and pneumonia, have been reported in Europe and Asia. As Mp cases are continuing to increase in the US, predicting the size of an imminent outbreak is timely for public health agencies and decision makers. Here, we use simple mathematical models to provide robust predictions about a large Mp outbreak ongoing in the US. Our model further illustrates that NPIs and waning immunity are important factors in driving long delays in epidemic resurgence.

Sentinel surveillance in bacterial pneumonia in children under 5 years old in a fourth-level pediatric hospital in Colombia 2016-2022

Objectives

Sentinel surveillance for bacterial pneumonia (SSBP) allows the monitoring of immunopreventable diseases. The results of the SSBP carried out at HOMI, Fundación Hospital pediátrico de la Misericordia, are presented.

Methods

The daily active search for cases was carried out in accordance with the protocol of the Pan American Health Organization from January 2016 to December 2022.

Results

There were 6970 suspected cases of bacterial pneumonia (BP). Among the 3048 (43.7%) patients with probable BP, cultures were obtained from 2777 (91.1%), and BP was confirmed in 190 (6.2%). The causes were Streptococcus pneumoniae in 98 (51.6%) cases, Spn19A in 47 (48%), Spn3 in 16 (16%), and Spn6C in 4 (4%). Haemophilus influenzae was found in 32 (16.8%) cases: non-typeable H. influenzae in 20 (62.5%), H. influenzae type b in five (15.6%), and H. influenzae type a in two (6.2%). Other bacteria were found in 60 (31.6%) cases. A total of 51.6% and 42.9% of patients with S. pneumoniae had decreased sensitivity to penicillin and ceftriaxone, respectively.

Conclusions

The serotypes included in the conjugate vaccines for pneumococcus and H. influenzae b decreased significantly, and serotype turnover was observed. Among the S. pneumoniae cases, Spn19A, Spn3, and Spn6C were the most frequent serotypes and associated with multiresistance. The SSBP allows us to determine the clinical behavior of the disease and to detect the serotypes emergence.

Detection of community-acquired respiratory viruses during COVID-19 pandemic in subtropical region in Japan

PURPOSE

Coronavirus disease 2019 (COVID-19) pandemic changed the dynamics of other community-acquired respiratory viruses (CARVs), however, information regarding the frequency of CARV detection during COVID-19 pandemic in subtropical regions is limited. Additionally, studies comparing the diagnostic accuracy between multiplex and monoplex PCR for the diagnosis of COVID-19 are scarce.

METHODS

We evaluated samples collected from patients suspected of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Okinawa, a subtropical climate in Japan, from March 2020 to March 2021. For SARS-CoV-2, results obtained from monoplex (NIID method) and multiplex (Allplex™ SARS-CoV-2 Assay) PCR were compared.

RESULTS

In total, 744 samples were collected and 238 viruses were detected in 205 specimens, of which 22 showed viral co-infection. Viral co-infection was more common in patients aged 10 and under than in older patients (p = 0.0054). For CARV, 142 viruses were detected in 127 specimens (17.1%), and human rhinovirus (HRV) was most common. Overall concordance rate for two SARS-CoV-2 assays was 94.1%; 7 and 37 specimens were detected only by NIID and Allplex™ SARS-CoV-2 Assay, respectively. The median cycling threshold values of the 44 samples that were only positive for either the NIID or Allplex™ SARS-CoV-2 Assay were 37.91 for E gene, 38.13 for RdRp/S gene, 38.21 for N gene and 39.16 for N2 gene.

CONCLUSION

HRV was continuously detected during COVID-19 pandemic in the subtropical region and viral co-infection was more common in younger patients. For the diagnosis of COVID-19, multiplex PCR was more reliable, especially in samples with low viral load.

Risk association model for atelectasis complication in Mycoplasma pneumoniae pneumonia patients following standardized treatment

Background

Mycoplasma pneumoniae pneumonia (MPP) is a common disease of childhood pneumonia, and atelectasis is a serious comorbidity. Traditional diagnostic methods for MPP are limited by low accuracy, emphasizing the need for improved diagnostic approaches. This study aimed to establish a predictive scoring model for early detection of MPP complicated with atelectasis following standardized treatment.

Methods

A total of 572 children were retrospectively enrolled, including 40 patients with MPP complicated by atelectasis despite standardized treatment and 532 patients in the non-atelectasis group. Clinical, laboratory, and imaging data within 24 h of admission were collected, including demographic information and various biomarkers. Multivariate logistic regression analysis was employed to identify risk factors and construct a predictive model, evaluated using receiver operating characteristic (ROC) curve analysis.

Results

Significant differences were observed between the MPP complicated with atelectasis group and the non-atelectasis group in terms of age, hospital admission time, fever duration, neutrophil percentage and count, CRP, ALT, and LDH levels (P < 0.05). According to the multivariate logistic regression analysis, length of fever, neutrophil ratio, platelet count, ALT, LDH, age were incorporated into the nomogram. The predictive model exhibited a sensitivity of 87.97% and specificity of 77.50% according to the ROC curve.

Conclusion

Our study presents a preliminary risk association model incorporating clinical indicators such as fever duration, neutrophil ratio, platelet count, ALT value, LDH value, and age to aid in the early prediction of atelectasis in children with MPP. Given the methodological limitations, the generalizability of our findings is constrained, and this model should be viewed as an initial framework for clinical assessment rather than a definitive tool.

Significance of respiratory virus coinfection in children with Mycoplasma pneumoniae pneumonia

OBJECTIVE

Mycoplasma pneumoniae is a major causative pathogen in community-acquired pneumonia. Respiratory viral coinfections in children with Mycoplasma pneumoniae pneumonia (MPP) are not uncommon and cause severe clinical manifestations. This study aims to investigate the impacts of viral coinfection in MPP patients and hopes to offer novel insights for discriminating between MPP and MPP coinfection.

METHODS

This study recruited 748 children hospitalized for MP pneumonia between January 2021 and October 2023. Patients were classified into two groups: MPP coinfected with respiratory virus group and MPP group. All children underwent polymerase chain reaction testing for respiratory pathogens. Baseline clinical features and demographic data were obtained retrospectively through medical records.

RESULTS

The retrospective study included 748 patients, with a viral coinfection rate of 38.75%. Patients in the MPP coinfected with respiratory virus group have a higher disease burden than those in the non-coinfection group. Our findings indicate that patients with Mycoplasma pneumonia co-infected with respiratory viruses had longer hospital stays and prolonged fever post-admission, as well as more severe conditions and a higher incidence of extrapulmonary complications. MPP coinfection was associated with the following factors: patients with extrapulmonary complications of gastroenteritis (OR = 4.474, 95%CI = 1.733-11.554, P = 0.002), longer hospital stay (OR = 1.109, 95%CI = 1.012-1.217, P = 0.027), longer days of fever after admission (OR = 1.215 95%CI = 1.006-1.469, P = 0.043), elevated white blood cell count (OR = 1.332 95%CI = 1.082-1.640, P = 0.007), decreased neutrophil count (OR = 0.768 95%CI = 0.602-0.981, P = 0.035), higher fibrinogen levels (OR = 1.652 95%CI = 1.138-2.398, P = 0.008), and raised lactate dehydrogenase levels (OR = 1.007 95%CI = 1.003-1.011, P = 0.001).

CONCLUSIONS

We determined the clinical significance of respiratory viral coinfection in children with MPP. Timely identification of MPP coinfection and provision of early and comprehensive therapeutic measures are vital in shortening the disease severity and improving prognosis.

Effect of metagenomic next-generation sequencing on clinical outcomes in adults with severe pneumonia post-cardiac surgery: a single-center retrospective study

Reports on the application of metagenomic next-generation sequencing (mNGS) in adult patients with severe pneumonia after cardiac surgery remain limited. This study aimed to evaluate the clinical outcomes of mNGS analysis of bronchoalveolar lavage fluid (BALF) in such patients.A retrospective cohort study was conducted on adult patients with severe pneumonia after cardiac surgery. Samples were collected from patients in the surgical intensive care unit (SICU) of Sichuan Provincial People's Hospital between January 2019 and March 2024. Upon diagnosis of severe pneumonia, bronchoalveolar lavage fluid was obtained via bronchoscopy within 24 h. The mNGS group was composed of patients tested using mNGS and conventional microbiological tests. BALF was detected only by the conventional microbiological test (CMT) method in the CMT group, which involved examining bacterial and fungal smears and cultures at least. We reviewed a total of 4,064 cardiac surgeries, and based on the inclusion criteria, a total of 113 adult patients with severe pneumonia after cardiac surgery were included in this study. The overall positive rate detected by mNGS was significantly higher than that of the culture method (98% vs. 58%, P<0.0001). After receipt of the microbiological results, the mNGS group exhibited a higher incidence of antibiotic adjustments in comparison to the CMT group (P = 0.0021). After adjusting the treatment plan based on microbial testing results, the mNGS group showed an improvement in ventilator-free days within 28 days (P = 0.0475), with a shorter duration of invasive ventilation compared to the CMT group (P = 0.0208). The detection of mNGS can significantly improve the Acute Physiology and Chronic Health Evaluation-II (APACHE II) score (P = 0.0161) and Sequential Organ Failure Assessment (SOFA) score (P = 0.0076) on the 7th day after admission to the SICU. In this study, the mNGS group showed signs of having a positive impact on the length of stay in ICU (median: 9 days, IQR: 7-10 days vs. median: 10 days, IQR: 8-13.75 days, P = 0.0538), length of stay in Hospital (median: 20 days, IQR: 17-28 days vs. median: 25 days, IQR: 18-29 days, P = 0.1558), mortality in 28 days (19% vs. 20%, P = 0.8794), in-hospital mortality (19% vs. 22%, P = 0.7123); however, statistical analysis did not confirm these differences to be significant. mNGS could serve as a valuable complement to conventional diagnostic approaches in adult patients with severe pneumonia after cardiac surgery, potentially improving diagnostic accuracy and leading to more precise and timely interventions, with significant potential to inform clinical decision-making and enhance patient outcomes.

Alterations in Gut Microbiota and Serum Metabolites in Children with Mycoplasma pneumoniae Pneumonia

Background

Over the past years, there has been a significant increase in the incidence of Mycoplasma pneumoniae (MP) infections, particularly among pediatric patients, nationwide. An emerging body of research has established a link between dysbiosis of the host microbiome and the metabolic functioning of the host, which contributes to the development of respiratory diseases.

Methods

A total of 25 children were included in the study, comprising 15 pneumonia patients and 10 healthy children. Stool samples were collected from all participants to analyze the 16S ribosomal RNA (16S rRNA) gene, while serum samples were prepared for untargeted metabolomics to qualitatively and quantitatively assess short-chain fatty acids.

Results

The gut microbial composition of individuals with Mycoplasma pneumoniae pneumonia (MPP) exhibited significant differences compared to healthy children. Notably, diseased children demonstrated higher microbial diversity and an enrichment of opportunistic pathogens, such as Erysipelatoclostridium and Eggerthella. Analysis revealed elevated levels of two specific short-chain fatty acids, namely acetic acid and isobutyric acid, in the MPP group, suggesting their potential as biomarkers for predicting MP infection. Metabolomic signature analysis identified a significant increase in major classes of glycerophospholipids in the MPP group. Moreover, we identified a total of 750 significant correlations between gut microbiota and circulating serum metabolites. MPP enriched genera Erysipelatoclostridium and Eggerthella, exhibited negative associations with indole-3-butyric acid. Additionally, Eggerthella showed a positive correlation with inflammatory metabolites LPC (18:0).

Discussion

Collectively, these findings provide novel insights into the selection of potential biomarkers and the pathogenesis of MPP in children based on the gut microbiota and systemic circulating metabolites.

Incidence of pneumococcal disease in children in Germany, 2014-2019: a retrospective cohort study

BACKGROUND

Novel, expanded valency pneumococcal conjugate vaccines (PCVs) are in development to reduce the burden of pneumococcal disease (PD) in children. To understand the potential value of new vaccines in Germany, this study estimated the residual burden of PD in children < 16 years old from 2014 to 2019, using administrative health data from a large German claims database.

METHODS

Outpatient and inpatient cases of all-cause pneumonia (ACP), pneumococcal pneumonia (PP) and invasive pneumococcal disease (IPD) were identified in the InGef database. Incidence rates (IRs) with 95% confidence intervals (CI) were calculated as number of episodes/person-years (PY) at risk. The Mann-Kendall test assessed time trends in incidence.

RESULTS

There were no significant trends in IRs of IPD or PP from 2014 to 2019. For ACP, IRs declined from 2014 to 2019; 2,213 (CI 2,176-2,250) to 1,503 (CI 1,472-1,534) per 100,000 PY (p = 0.017). IRs of ACP and PP were highest among children aged 12-23 months; 4,672 (CI 4,584-4,762) and 20.8 (CI 15.3-27.5) per 100,000 PY, respectively. For IPD, children 5-11 months-old had the highest IRs, at 14.7 (CI 9.0-22.7) per 100,000 PY.

CONCLUSIONS

From 2014 to 2019 there were no discernible trends in the IRs of PP or IPD, but the IRs of ACP declined in children aged < 16 years. The highest IRs of ACP, PP and IPD were observed in children < 2 years of age, highlighting the importance of infant pneumococcal vaccination in the prevention of pediatric PD. The clinical burden of pediatric PD in Germany persists. Continued surveillance of changing pneumococcal burden, serotype distribution, antimicrobial resistance and vaccination status is critical to better understand the factors driving incidence of PD and to inform future vaccination strategies.

Enhanced insights into the neutrophil-driven immune mechanisms during Mycoplasma pneumoniae infection

Mycoplasma pneumoniae (MP) infections represent a significant component of community-acquired pneumonia, especially in children, invoking a complex neutrophil-mediated immune response, crucial for host defense. This review consolidates current knowledge on the role of neutrophils in MP infection, focusing on their recruitment, migration and activation, as well as the molecular mechanisms underpinning these processes. Significant findings indicate that specific bacterial components, notably CARDS toxin and lipoproteins, intensify neutrophil recruitment via signaling pathways, including the IL-23/IL-17 axis and G-CSF. Furthermore, neutrophils engage in a series of responses, including phagocytosis, degranulation and NETosis, to combat infection effectively. However, dysregulated neutrophil activity can lead to exacerbated lung injury, highlighting the delicate balance required in neutrophil responses. Age and immunodeficiency also emerge as critical factors influencing the severity of MP infections. This review emphasizes the dual role of neutrophils in both defending against and exacerbating MP infections, suggesting that targeted therapeutic strategies could mitigate the adverse effects while enhancing beneficial neutrophil functions.

Early-life upper airway microbiota are associated with decreased lower respiratory tract infections

BACKGROUND

Microbial interactions mediating colonization resistance play key roles within the human microbiome, shaping susceptibility to infection from birth. The role of the nasal and oral microbiome in the context of early life respiratory infections and subsequent allergic disease risk remains understudied.

OBJECTIVES

Our aim was to gain insight into microbiome-mediated defenses and respiratory pathogen colonization dynamics within the upper respiratory tract during infancy.

METHODS

We performed shotgun metagenomic sequencing of nasal (n = 229) and oral (n = 210) microbiomes from our Wisconsin Infant Study Cohort at age 24 months and examined the influence of participant demographics and exposure history on microbiome composition. Detection of viral and bacterial respiratory pathogens by RT-PCR and culture-based studies with antibiotic susceptibility testing, respectively, to assess pathogen carriage was performed. Functional bioassays were used to evaluate pathogen inhibition by respiratory tract commensals.

RESULTS

Participants with early-life lower respiratory tract infection were more likely to be formula fed, attend day care, and experience wheezing. Composition of the nasal, but not oral, microbiome associated with prior lower respiratory tract infection, namely lower alpha diversity, depletion of Prevotella, and enrichment of Moraxella catarrhalis including drug-resistant strains. Prevotella originating from healthy microbiomes had higher biosynthetic gene cluster abundance and exhibited contact-independent inhibition of M catarrhalis.

CONCLUSIONS

These results suggest interbacterial competition affects nasal pathogen colonization. This work advances understanding of protective host-microbe interactions occurring in airway microbiomes that alter infection susceptibility in early life.

Laboratory validation of a clinical metagenomic next-generation sequencing assay for respiratory virus detection and discovery

Tools for rapid identification of novel and/or emerging viruses are urgently needed for clinical diagnosis of unexplained infections and pandemic preparedness. Here we developed and clinically validated a largely automated metagenomic next-generation sequencing (mNGS) assay for agnostic detection of respiratory viral pathogens from upper respiratory swab and bronchoalveolar lavage samples in <24 h. The mNGS assay achieved mean limits of detection of 543 copies/mL, viral load quantification with 100% linearity, and 93.6% sensitivity, 93.8% specificity, and 93.7% accuracy compared to gold-standard clinical multiplex RT-PCR testing. Performance increased to 97.9% overall predictive agreement after discrepancy testing and clinical adjudication, which was superior to that of RT-PCR (95.0% agreement). To enable discovery of novel, sequence-divergent human viruses with pandemic potential, de novo assembly and translated nucleotide algorithms were incorporated into the automated SURPI+ computational pipeline used by the mNGS assay for pathogen detection. Using in silico analysis, we showed that after removal of all human viral sequences from the reference database, 70 (100%) of 70 representative human viral pathogens could still be identified based on homology to related animal or plant viruses. Our assay, which was granted breakthrough device designation from the US Food and Drug Administration (FDA) in August of 2023, demonstrates the feasibility of routine mNGS testing in clinical and public health laboratories, thus facilitating a robust and rapid response to the next viral pandemic.