Predictive signature of murine and human host response to typical and atypical pneumonia.

BACKGROUND: Pneumonia due to typical bacterial, atypical bacterial and viral pathogens can be difficult to clinically differentiate. Host response-based diagnostics are emerging as a complementary diagnostic strategy to pathogen detection. METHODS: We used murine models of typical bacterial, atypical bacterial and viral pneumonia to develop diagnostic signatures and understand the host's response to these types of infections. Mice were intranasally inoculated with Streptococcus pneumoniae, Mycoplasma pneumoniae, influenza or saline as a control. Peripheral blood gene expression analysis was performed at multiple time points. Differentially expressed genes were used to perform gene set enrichment analysis and generate diagnostic signatures. These murine-derived signatures were externally validated in silico using human gene expression data. The response to S. pneumoniae was the most rapid and robust. RESULTS: Mice infected with M. pneumoniae had a delayed response more similar to influenza-infected animals. Diagnostic signatures for the three types of infection had 0.94-1.00 area under the receiver operator curve (auROC). Validation in five human gene expression datasets revealed auROC of 0.82-0.96. DISCUSSION: This study identified discrete host responses to typical bacterial, atypical bacterial and viral aetiologies of pneumonia in mice. These signatures validated well in humans, highlighting the conserved nature of the host response to these pathogen classes.

Multicentre case-control study of pneumococcal infections among children with pneumonia in Peninsular Malaysia (MY-Pneumo): a study protocol.

BACKGROUND: S. pneumoniae (SPN) is the most common cause of pneumonia. The disease can be effectively prevented through immunisation. Since December 2020, the Malaysian Government has included the 10-valent pneumococcal conjugate vaccine (PCV10) for all infants born on or after 1 January 2020 as part of the National Immunisation Programme (NIP). However, the epidemiology of pneumonia remains poorly understood. To fill the knowledge gap, we established a multicentre surveillance study to understand the burden of pneumococcal pneumonia among young children in Peninsular Malaysia. METHODS: MY-Pneumo is a multicentre prospective case-control study conducted in three sentinel sites located in three different states of Peninsular Malaysia - Kuala Lumpur, Pahang, and Kelantan. A cohort of at least 500 incident cases and 500 controls is enrolled beginning in October 2021 and matched for age. Cases are hospitalised children < 5 years with radiologically confirmed pneumonia, and the controls are children without any features suggestive of pneumonia. Clinical samples, including nasopharyngeal swabs (NPS) and urine, are collected according to the study protocol. Biological fluids such as blood, cerebrospinal fluid (CSF) and pleural fluid are obtained from invasive pneumonia disease (IPD) patients, if available. All children are tested for SPN using polymerase chain reaction (PCR) and pneumococcal urine antigen test (PUAT) using BinaxNow. DISCUSSION: Surveillance data, including carriage rate, serotype variations and the phylogeny data structure of SPN among young children in Malaysia during PCV implementation, will be generated from this study. Trends and patterns of pneumococcal serotypes by different regions are important for targeted public health strategies. Our data will provide baseline information for estimating the impact of PCV10 implementation and will influence policymakers' decisions regarding the upgrade from PCV10 to a higher-valency conjugate vaccine in Malaysia. TRIAL REGISTRATION: This project was registered at ClinicalTrials.gov (NCT04923035) on 2021, June 11. The study protocol was approved by the International Medical University Joint-Committee on Research & Ethics (4.15/JCM-216/2021) and the Institutional Review Board at sentinel sites (USM/JEPeM/21020190, IREC 2021-114, MREC ID No: 2021128-9769) and University of Southampton's Ethics and Research Governance (ERGo II 64844).

Effectiveness of pneumococcal vaccination in adults with common immune-mediated inflammatory diseases in the UK: a case-control study.

BACKGROUND: People with immune-mediated inflammatory disease are at increased risk of pneumococcal pneumonia. The effectiveness of pneumococcal vaccination in people with immune-mediated inflammatory diseases has not been evaluated. We investigated the effectiveness of pneumococcal vaccination in preventing morbidity and mortality associated with pneumonia in patients with immune-mediated inflammatory diseases. METHODS: In this matched case-control study, we used primary-care electronic health record data from the Clinical Practice Research Datalink Gold database in the UK, with linked hospitalisation and mortality data. Adults with incident common immune-mediated inflammatory diseases diagnosed between April 1, 1997, and Dec 31, 2019, were followed up from the first diagnosis date to the occurrence of an outcome or date of last follow-up. Cases (ie, those with an outcome of interest) were age-matched and sex-matched to up to ten contemporaneous controls by use of incidence density sampling. Outcomes were hospitalisation due to pneumonia, death due to pneumonia, or primary-care consultation for lower respiratory tract infection requiring antibiotics. We defined hospital admission for pneumonia using hospital discharge diagnoses, death due to pneumonia using death certification data, and lower respiratory tract infection as present when primary-care consultation and antibiotic prescription occurred on the same date. We used multivariable, unconditional, logistical regression and constructed three models to examine the association between pneumococcal vaccination as an exposure and each of the three outcomes. FINDINGS: The first nested case-control analysis included 12 360 patients (7326 [59·3%] women and 5034 [40·7%] men): 1884 (15·2%) who were hospitalised due to pneumonia and 10 476 (84·8%) who were not admitted to hospital due to pneumonia. The second analysis included 5321 patients (3112 [58·5%] women and 2209 [41·5%] men): 781 (14·7%) who died due to pneumonia and 4540 (85·3%) who were alive on the index date. The third analysis included 54 530 patients (33 605 [61·6%] women and 20 925 [38·4%] men): 10 549 (19·3%) with lower respiratory tract infection treated with antibiotics and 43 981 (80·7%) without infection. In the multivariable analysis, pneumococcal vaccination was negatively associated with hospitalisation due to pneumonia (adjusted odds ratio 0·70 [95% CI 0·60-0·81]), death due to pneumonia (0·60 [0·48-0·76]), and lower respiratory tract infection treated with antibiotics (0·76 [0·72-0·80]). INTERPRETATION: Pneumococcal vaccination is associated with protection against hospitalisation and death due to pneumonia in patients with immune-mediated inflammatory diseases, without apparent residual confounding. However, residual unmeasured confounding cannot be fully excluded in observational research, which includes nested case-control studies. These findings should also be corroborated with data from other countries, given that this study used UK-based data. FUNDING: National Institute for Health and Care Research.

Mice fatal pneumonia model induced by less-virulent Streptococcus pneumoniae via intratracheal aerosolization.

Aim: Animal models of fatal pneumonia caused by Streptococcus pneumoniae (Spn) have not been reliably generated using many strains of less virulent serotypes.Materials & methods: Pulmonary infection of a less virulent Spn serotype1 strain in the immunocompetent mice was established via the intratracheal aerosolization (ITA) route. The survival, local and systemic bacterial spread, pathological changes and inflammatory responses of this model were compared with those of mice challenged via the intratracheal instillation, intranasal instillation and intraperitoneal injection routes.Results: ITA and intratracheal instillation both induced fatal pneumonia; however, ITA resulted in better lung bacterial deposition and distribution, pathological homogeneity and delivery efficiency.Conclusion: ITA is an optimal route for developing animal models of severe pulmonary infections.

What is this article about? Streptococcus pneumoniae (Spn), a type of bacteria, can cause serious illness and death in otherwise healthy people. One way that we study pneumonia is using animals. However, pneumonia in animals infected with Spn in the laboratory does not mimic that in humans very well. To study this illness, we need a new way to set up a proper animal model.What were the results? This study set up a method called intratracheal aerosolization (ITA). In ITA, bacteria can form small droplets called aerosols and reach the deepest parts of a mouse's lung. ITA can cause deadly illness in mice infected with Spn, even if the mice are healthy.What do the results of the study mean? The ITA method could be a useful tool to set up animal models of serious pneumonia with less virulent bacteria.

Two-component regulatory system TCS08 of a serotype 4 strain in pneumococcal pneumonia pathogenesis.

OBJECTIVES: Streptococcus pneumoniae, a human respiratory pathogen, causes diseases with severe morbidity and mortality rates worldwide. The two-component regulatory system (TCS) is an important signaling pathway that enables regulation of gene expression in response to environmental cues, thereby allowing an organism to adapt to a variety of host niches. Here we examined the contribution of pneumococcal TCS08 to bacterial colonization, the development of pneumonia, and pulmonary dysfunction. METHODS: We employed an hk08 knockout mutant (Δhk08) with a background of the TIGR4 wild-type (WT) strain to verify whether TCS08 is associated with bacterial colonization and the development of pneumonia in a murine infection model. To clarify the association of hk08 inactivation-induced phenotypic changes with their virulence, we examined pneumococcal capsule production, colony morphology, and surface-displayed protein profiles. RESULTS: Pneumococcal TCS08 was involved in bacterial colonization in the respiratory tract. Interruption of the signaling pathway of TCS08 by hk08 inactivation impaired mouse survival and increased the bacterial burden within the respiratory tract. Furthermore, a histopathological examination revealed massive inflammatory cell infiltration, edema formation, and diffuse alveolar damage in the lung tissues of mice infected with Δhk08 versus the WT or complemented strain. Interestingly, virulence-associated phenotype changes, including capsule production, increased chain length, and surface-displayed protein profile, were observed in the Δhk08 strain. CONCLUSIONS: The present findings indicate that TCS08 contributes to pneumococcal colonization and pulmonary dysfunction by assisting adaptation to the respiratory tract milieu, leading to the development of pneumonia.

Catching the Culprit: Benzylpenicillin Neurotoxicity Confirmed by Therapeutic Drug Monitoring in a Critically Ill Patient With Continuous Venovenous Hemofiltration.

ABSTRACT: We present the case of a 65-year-old patient who was treated with high-dose benzylpenicillin for severe invasive pneumococcal pneumonia, complicated by acute renal failure managed with continuous venovenous hemofiltration. After cessation of continuous venovenous hemofiltration, the patient experienced multiple tonic-clonic seizures. Therapeutic drug monitoring revealed high total serum concentrations of benzylpenicillin, identifying it as the likely cause of the neurotoxicity. This case study presents the first documented total serum benzylpenicillin concentration associated with neurotoxicity.

Elixhauser comorbidity method in predicting death of Spanish inpatients with asplenia and pneumococcal pneumonia.

BACKGROUND: Pneumococcal pneumonia (PP) is a serious infection caused by Streptococcus pneumoniae (pneumococcus), with a wide spectrum of clinical manifestations. The aim of this study was to analyze the comorbidity factors that influenced the mortality in patients with asplenia according to PP. METHODS: Discharge reports from the Spanish Minimum Basic Data Set (MBDS) was used to retrospectively analyze patients with asplenia and PP, from 1997 to 2021. Elixhauser Comorbidity Index (ECI) was calculated to predict in-hospital mortality (IHM). RESULTS: 97,922 patients with asplenia were included and 381 cases of PP were identified. The average age for men was 63.87 years and for women 65.99 years. In all years, ECI was larger for splenectomized than for non-splenectomized patients, with men having a higher mean ECI than women. An association was found between risk factors ECI, splenectomy, age group, sex, pneumococcal pneumonia, and increased mortality (OR = 0.98; 95% CI: 0.97-0.99; p < 0.001). The IHM increased steadily with the number of comorbidities and index scores in 1997-2021. CONCLUSIONS: Asplenia remain a relevant cause of hospitalization in Spain. Comorbidities reflected a great impact in patients with asplenia and PP, which would mean higher risk of mortality.

[Mortality in bacterial pneumonia due to pneumococcus]. / Mortalidad en neumonía bacteriémica por neumococo.

INTRODUCTION: Despite improvements in health care, pneumonia-associated mortality remains high. The objective of this study was to analyze the factors associated with mortality in bacteremic pneumonia caused by pneumococcus. METHODS: Retrospective cohort study in adult patients with pneumonia diagnosis and isolation of pneumococcus in blood cultures, between January 2012 and May 2021, was carried out. Clinical and laboratory variables, radiological involvement, evolution and mortality during hospitalization were analyzed. The group of deceased patients was compared with that of survivors. RESULTS: 152 patients were included. Median age: 58 years; men: 58.9%; 33% presented a CURB-65 > than 2 at admission. Overall mortality: 34% (n=52). Deceased patients were more tachypneic on admission (respiratory rate 26 vs. 22; p=0.003), presented sensory alteration more frequently (58% vs. 14%; p< 0.001), PaO2/fraction of inspired oxygen ratio < 250 (58% vs. 22%; p<0.001), bilateral radiological compromise (50% vs. 32%; p=0.03), needed mechanical ventilation (50% vs 12%; p< 0.001), higher blood creatinine values (1.6 vs. 1.15; p=0.01), lower white blood cell count (10 900 vs 17 400; p=0.002), a lower glucose dosage (111 vs. 120; p=0.01), and fewer days of hospital stay (6 vs. 9; p=0.015). In logistic regression model, significant differences were maintained in the following factors associated with mortality: mechanical ventilation (OR=3.54), altered mental status (OR=5.95), chest X-ray with bilateral compromise (OR 3.20) and PAFI less than 250 (OR=3.62). CONCLUSION: In our series, the factors related to mortality, despite the presence of bacteremia, do not differ from those published in the literature and which are part of the different prognostic scores used in routine practice.

Introducción: A pesar de las mejoras en los cuidados de la salud, la mortalidad asociada a neumonía continúa siendo alta. El objetivo de este estudio fue analizar los factores asociados a mortalidad en neumonía bacteriémica por neumococo. Métodos: Estudio de cohorte retrospectiva en pacientes adultos con diagnóstico de neumonía y neumococo aislado en hemocultivos, entre enero 2012 y mayo 2021. Se analizaron: variables clínicas y de laboratorio, compromiso radiológico, evolución y mortalidad durante la internación. Se comparó el grupo de pacientes fallecidos con el de sobrevivientes. Resultados: Se incluyeron 152 pacientes. La mediana de edad fue de 58 años y el 58.9% fueron hombres. El 33% presentó un CURB-65 mayor a 2 al momento de internación. La mortalidad global fue 34% (n=52). Los pacientes fallecidos se encontraban más frecuentemente taquipneicos al ingreso (frecuencia respiratoria 26 vs. 22; p=0.003), presentaban más frecuentemente alteración del sensorio (58% vs. 14%; p< 0.001), PaO2/fracción inspirada de oxígeno (PAFI) < 250 (58% vs. 22%; p<0.001), compromiso radiológico bilateral (50% vs. 32%; p=0.03), necesidad de asistencia respiratoria mecánica (ARM) (50% vs. 12%; p< 0.001), mayor valor de creatinina en sangre (1.6 vs. 1.15; p=0.01), menor recuento de glóbulos blancos (10 900 vs. 17 400; p=0.002), menor valor de glucemia (111 vs. 120; p=0.01) y menos días de estancia hospitalaria (6 vs. 9; p=0.015). En el análisis de regresión logística multivariable se mantuvieron diferencias significativas en los siguientes factores asociados a mortalidad: ventilación mecánica (OR=3.54), confusión (OR=5.95), radiografía con compromiso bilateral (OR= 3.20) y PAFI < 250 (OR=3.62). Conclusión: Los factores relacionados con mortalidad, a pesar de la presencia de bacteriemia, no difieren de los publicados en la literatura y forman parte de los scores pronósticos de práctica habitual.

IL-33 controls IL-22-dependent antibacterial defense by modulating the microbiota.

IL-22 plays a critical role in defending against mucosal infections, but how IL-22 production is regulated is incompletely understood. Here, we show that mice lacking IL-33 or its receptor ST2 (IL-1RL1) were more resistant to Streptococcus pneumoniae lung infection than wild-type animals and that single-nucleotide polymorphisms in IL33 and IL1RL1 were associated with pneumococcal pneumonia in humans. The effect of IL-33 on S. pneumoniae infection was mediated by negative regulation of IL-22 production in innate lymphoid cells (ILCs) but independent of ILC2s as well as IL-4 and IL-13 signaling. Moreover, IL-33's influence on IL-22-dependent antibacterial defense was dependent on housing conditions of the mice and mediated by IL-33's modulatory effect on the gut microbiota. Collectively, we provide insight into the bidirectional crosstalk between the innate immune system and the microbiota. We conclude that both genetic and environmental factors influence the gut microbiota, thereby impacting the efficacy of antibacterial immune defense and susceptibility to pneumonia.

Neutrophil reduction attenuates the severity of lung injury in the early phase of pneumococcal pneumonia in mice.

Neutrophils are the first leukocytes to be recruited to sites of inflammation in response to chemotactic factors released by activated macrophages and pulmonary epithelial and endothelial cells in bacterial pneumonia, a common cause of acute respiratory distress syndrome (ARDS). Although neutrophilic inflammation facilitates the elimination of pathogens, neutrophils also may cause bystander tissue injury. Even though the presence of neutrophils in alveolar spaces is a key feature of acute lung injury and ARDS especially from pneumonia, their contribution to the pathogenesis of lung injury is uncertain. The goal of this study was to elucidate the role of neutrophils in a clinically relevant model of bacterial pneumonia. We investigated the effect of reducing neutrophils in a mouse model of pneumococcal pneumonia treated with antibiotics. Neutrophils were reduced with anti-lymphocyte antigen 6 complex locus G6D (Ly6G) monoclonal antibody 24 h before and immediately preceding infection. Mice were inoculated intranasally with Streptococcus pneumoniae and received ceftriaxone 12 h after bacterial inoculation. Neutrophil reduction in mice treated with ceftriaxone attenuated hypoxemia, alveolar permeability, epithelial injury, pulmonary edema, and inflammatory biomarker release induced by bacterial pneumonia, even though bacterial loads in the distal air spaces of the lung were modestly increased as compared with antibiotic treatment alone. Thus, when appropriate antibiotics are administered, lung injury in the early phase of bacterial pneumonia is mediated in part by neutrophils. In the early phase of bacterial pneumonia, neutrophils contribute to the severity of lung injury, although they also participate in host defense.NEW & NOTEWORTHY Neutrophil accumulation is a key feature of ARDS, but their contribution to the pathogenesis is still uncertain. We investigated the effect of reducing neutrophils in a clinically relevant mouse model of pneumococcal pneumonia treated with antibiotics. When appropriate antibiotics were administered, neutrophil reduction with Ly6G antibody markedly attenuated lung injury and improved oxygenation. In the early phase of bacterial pneumonia, neutrophils contribute to the severity of lung injury, although they also participate in host defense.

Evaluation of Acute and Convalescent Antibody Concentration Against Pneumococcal Capsular Polysaccharides for the Diagnosis of Pneumococcal Infection in Children with Community-Acquired Pneumonia.

We evaluated whether the quantification of IgG to pneumococcal capsular polysaccharides is an accurate diagnostic test for pneumococcal infection in children with pneumonia in Nepal. Children with pneumococcal pneumonia did not have higher convalescent, or higher fold change, IgG to pneumococcal polysaccharides than children with other causes of pneumonia. Caution is needed in interpreting antibody responses in pneumococcal infections.

Biological effects of corticosteroids on pneumococcal pneumonia in Mice-translational significance.

BACKGROUND: Streptococcus pneumoniae is the most common bacterial cause of community acquired pneumonia and the acute respiratory distress syndrome (ARDS). Some clinical trials have demonstrated a beneficial effect of corticosteroid therapy in community acquired pneumonia, COVID-19, and ARDS, but the mechanisms of this benefit remain unclear. The primary objective of this study was to investigate the effects of corticosteroids on the pulmonary biology of pneumococcal pneumonia in a mouse model. A secondary objective was to identify shared transcriptomic features of pneumococcal pneumonia and steroid treatment in the mouse model and clinical samples. METHODS: We carried out comprehensive physiologic, biochemical, and histological analyses in mice to identify the mechanisms of lung injury in Streptococcus pneumoniae with and without adjunctive steroid therapy. We also studied lower respiratory tract gene expression from a cohort of 15 mechanically ventilated patients (10 with Streptococcus pneumoniae and 5 controls) to compare with the transcriptional studies in the mice. RESULTS: In mice with pneumonia, dexamethasone in combination with ceftriaxone reduced (1) pulmonary edema formation, (2) alveolar protein permeability, (3) proinflammatory cytokine release, (4) histopathologic lung injury score, and (5) hypoxemia but did not increase bacterial burden. Transcriptomic analyses identified effects of steroid therapy in mice that were also observed in the clinical samples. CONCLUSIONS: In combination with appropriate antibiotic therapy in mice, treatment of pneumococcal pneumonia with steroid therapy reduced hypoxemia, pulmonary edema, lung permeability, and histologic criteria of lung injury, and also altered inflammatory responses at the protein and gene expression level. The transcriptional studies in patients suggest that the mouse model replicates some of the features of pneumonia in patients with Streptococcus pneumoniae and steroid treatment. Overall, these studies provide evidence for the mechanisms that may explain the beneficial effects of glucocorticoid therapy in patients with community acquired pneumonia from Streptococcus Pneumoniae.

Post-resolution macrophages shape long-term tissue immunity and integrity in a mouse model of pneumococcal pneumonia.

Resolving inflammation is thought to return the affected tissue back to homoeostasis but recent evidence supports a non-linear model of resolution involving a phase of prolonged immune activity. Here we show that within days following resolution of Streptococcus pneumoniae-triggered lung inflammation, there is an influx of antigen specific lymphocytes with a memory and tissue-resident phenotype as well as macrophages bearing alveolar or interstitial phenotype. The transcriptome of these macrophages shows enrichment of genes associated with prostaglandin biosynthesis and genes that drive T cell chemotaxis and differentiation. Therapeutic depletion of post-resolution macrophages, inhibition of prostaglandin E2 (PGE2) synthesis or treatment with an EP4 antagonist, MF498, reduce numbers of lung CD4+/CD44+/CD62L+ and CD4+/CD44+/CD62L-/CD27+ T cells as well as their expression of the α-integrin, CD103. The T cells fail to reappear and reactivate upon secondary challenge for up to six weeks following primary infection. Concomitantly, EP4 antagonism through MF498 causes accumulation of lung macrophages and marked tissue fibrosis. Our study thus shows that PGE2 signalling, predominantly via EP4, plays an important role during the second wave of immune activity following resolution of inflammation. This secondary immune activation drives local tissue-resident T cell development while limiting tissue injury.

Retrospective study on the health and economic burden of hospitalized patients due to pneumonia and invasive pneumococcal infections in Belgium settings.

INTRODUCTION: pneumococcal infections are associated with high morbidity, hospitalisation and mortality. The objective of this study was to investigate the health and economic burden of all-cause pneumonia and invasive pneumococcal disease in Belgian hospital settings, by patient's age and risk profile. METHODS: This descriptive retrospective study was conducted in 17 Belgian hospitals. Univariate and multivariate logistic linear regression models were performed. The Health Insurance and patient's cost perspectives were considered because a few studies report these costs. RESULTS: The analysis has included 4,712 hospital admissions over the year 2018. Median hospitalization costs were higher for invasive pneumococcal infection diagnosis than for all-cause pneumonia (p < 0,001), respectively 4,051€ and 3,362€. Other factors associated with higher hospitalization cost were patient's high-risk profile, admission to emergency unit, transfer from nursing home, admission to intensive care unit and length of stay. CONCLUSION: Streptococcus pneumoniae infections remain a public health problem with significant cost for the Health Insurance and poor prognosis. Invasive pneumococcal infections are associated with longer hospital stays and required more intensive care than all other causes of pneumonia, in addition to be more costly, which justifies more attention for vaccination. This study also suggests an increase of economic and health burden with age and presence of underlying conditions.

Protective effect of PCV13 against all-cause hospitalized pneumonia in children in Beijing, China: real-world evidence.

BACKGROUND: The study evaluated the protective effect of 13-valent pneumococcal polysaccharide conjugate vaccine (PCV13) against all-cause hospitalized pneumonia in children in Beijing. METHODS: Based on the vaccination record and inpatient medical record database of Beijing, children born in 2017 in Beijing, matched by age, gender, and district of the children with the ratio of 1:4, were selected as the vaccinated and unvaccinated groups according whether if vaccinated with PCV13. The incidence rate and 95 % confidence interval (95 %CI), vaccine effectiveness (VE) and direct medical costs of all-cause hospitalized pneumonia were calculated and compared within the same period of 12 months, 18 months, 24 months and 30 months after the birth of the child. RESULTS: The decreased incidence rates of all-cause hospitalized pneumonia were observed at the four points in the PCV13 vaccinated group compared to the unvaccinated group, which were significant at the points of 12 months (0.42 % vs. 0.72 %, P = 0.001), 18 months (0.90 % vs. 1.26 %, P = 0.002) and 24 months (1.37 % vs. 1.65 %, P = 0.046). The VE of PCV13 against all-cause hospitalized pneumonia within 12 months was the highest as 41.9 % (95 % CI 19.6 %, 58.0 %), followed by 29.3 % (95 % CI 11.4 %, 43.5 %) within 18 months, 17.1 % (95 % CI 0.3 %, 31.1 %) within 24 months and it almost disappeared within 30 months. The VE of 4-dose vaccination within 18 months and 24 months were 39.9 % (95 % CI 20.3 %, 54.7 %) and 27.2 % (95 % CI 8.6 %, 42.0 %), respectively. The median hospitalization cost of the children in the vaccinated group was higher at the four points but without significance. CONCLUSIONS: PCV13 had a certain protective effect on all-cause hospitalized pneumonia, and the booster immunization strategy had the best protective effect with great public health significance to enter the immunization program.

Early predictors of delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae in children: a retrospective study in China.

BACKGROUND: Lobar pneumonia caused by Mycoplasma pneumoniae is a relatively difficult-to-treat pneumonia in children. The time of radiographic resolution after treatment is variable, a long recovery time can result in several negative effects, and it has attracted our attention. Therefore, exploring factors associated with delayed radiographic resolution will help to identify these children at an early stage and prepare for early intervention. METHODS: The data of 339 children with lobar pneumonia caused by Mycoplasma pneumoniae were collected from the Department of Pediatrics of Fu Yang People's Hospital, China from January 2021 to June 2022. After discharge, the children were regularly followed up in the outpatient department and on the WeChat platform for > 8 weeks. According to whether pulmonary imaging (chest radiography or plain chest computed tomography) returned to normal within 8 weeks, the children were divided into the delayed recovery group (DRG) (n = 69) and the normal recovery group (NRG) (n = 270). The children's general information, laboratory examination findings, bronchoscopy results, and imaging findings were retrospectively analyzed. Single-factor analysis was performed to identify the risk factors for delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae, and the factors with statistically significant differences underwent multiple-factor logistic regression analysis. Receiver operating characteristic (ROC) analysis was then performed to calculate the cutoff value of early predictive indicators of delayed radiographic resolution. RESULTS: Single-factor analysis showed that the following were significantly greater in the DRG than NRG: total fever duration, the hospitalization time, C-reactive protein (CRP) level, lactate dehydrogenase (LDH) level, D-dimer level, pulmonary lesions involving two or more lobes, a large amount of pleural effusion, the time to interventional bronchoscopy, and mucus plugs formation. Multivariate logistic regression analysis showed that the hospitalization time, CRP level, LDH level, pulmonary lesions involving two or more lobes, and a large amount of pleural effusion were independent risk factors for delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae. The cutoff values on the receiver operating characteristic curve were a hospitalization time of ≥ 10.5 days, CRP level of ≥ 25.92 mg/L, and LDH level of ≥ 378 U/L. CONCLUSION: If patients with lobar pneumonia caused by Mycoplasma pneumoniae have a hospitalization time of ≥ 10.5 days, CRP level of ≥ 25.92 mg/L, and LDH level ≥ 378 U/L, the time of radiographic resolution is highly likely to exceed 8 weeks. Pediatricians must maintain a high level of vigilance for these factors, control the infection as early as possible, strengthen airway management, and follow up closely to avoid complications and sequelae of Mycoplasma pneumoniae pneumonia.

Prior pneumococcal vaccination improves in-hospital mortality among elderly population hospitalized due to community-acquired pneumonia.

BACKGROUND: Pneumococcal vaccination is a preventive method to reduce pneumonia related mortality. However, real-world data on efficacy of the pneumococcal vaccine in reducing mortality is lacking, especially in elderly patients. This study was conducted to assess the effects of prior pneumococcal vaccination in elderly pneumonia patients. METHODS: The data was procured from the Health Insurance Review and Assessment and Quality Assessment database. Hospitalized patients who met the criteria of community-acquired pneumonia (CAP) were included and they were grouped according to vaccination state. Patients were aged ≥ 65 years and treated with beta-lactam, quinolone, or macrolide. Patients were excluded when treatment outcomes were unknown. RESULTS: A total of 4515 patients were evaluated, and 1609 (35.6%) of them were vaccinated prior to hospitalization. Mean age was 77.0 [71.0;82.0], 54.2% of them were male, and mean Charlson comorbidity index (CCI) was 3.0. The patients in the vaccinated group were younger than those in the unvaccinated group (76.0 vs. 78.0 years; P < 0.001), and showed higher in-hospital improvement (97.6 vs. 95.0%; P < 0.001) and lower 30-day mortality (2.6 vs. 5.3%; P < 0.001). After adjusting confounding factors such as age, gender, CURB score and CCI score, the vaccinated group demonstrated a significant reduction in 30-day mortality (hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.41-0.81; P < 0.01) and in-hospital mortality (HR 0.53, 95% CI0.37-0.78; P < 0.001) compared to the unvaccinated group in multivariate analysis. Vaccinated group showed better 30-day survival than those in non-vaccinated group (log-rank test < 0.05). CONCLUSIONS: Among elderly hospitalized CAP patients, prior pneumococcal vaccination was associated with improved in-hospital mortality and 30-day mortality.

Unveiling the role of preceding seasonal influenza in the development of bacteremic pneumococcal pneumonia in older adults before the COVID-19 pandemic in Japan.

OBJECTIVE: We aimed to investigate the impact of preceding seasonal influenza on the clinical characteristics of adult patients with invasive pneumococcal disease (IPD) in Japan. METHODS: Data for 1722 adult patients with IPD were analyzed before (2017-2019) and during the COVID-19 pandemic (2020-2022). RESULTS: The seasonal influenza epidemic disappeared soon after the emergence of the pandemic. Compared with that before the pandemic (66.7%), we observed a lower bacteremic pneumonia proportion in patients with IPD during the pandemic (55.6%). The clinical presentations of IPD cases significantly differed between those with and without preceding influenza. The proportion of bacteremic pneumonia was higher in IPD patients with preceding influenza than in those without in both younger (44.9% vs 84.2%) and older adults (65.5% vs 87.0%) before the pandemic. The case fatality rate was significantly higher in IPD patients with preceding influenza (28.3%) than in those without (15.3%) in older adults before the pandemic (P = 0.020). Male and aging are high risk factors for death in older patients with IPD who had preceding influenza. CONCLUSION: Our study reveals that preceding seasonal influenza plays a role in the development of bacteremic pneumococcal pneumonia, increasing the risk of death in older adults.