Risk factors and pathogenic significance of bacteremic pneumonia in adult patients with community-acquired pneumococcal pneumonia

Bloodstream infections due to multi-drug resistant bacteria in the emergency department: prevalence, risk factors and outcomes-a retrospective observational study

Multidrug-resistant organisms (MDROs) are prevalent in patients admitted to the Emergency Department (ED) and increase the risk of inappropriate empirical antibiotic therapy. Risk stratification for MDRO infection is essential to early identify patients requiring empirical broad-spectrum antibiotic therapy, but it remains challenging for emergency physicians. This study aimed to evaluate prevalence, risk factors, and outcomes of patients admitted to the ED with a bloodstream infection (BSI) caused by MDROs. A retrospective observational study enrolling all consecutive adult patients admitted with a BSI to the ED of Niguarda Hospital, Italy, from January 2019 to December 2021 was performed. 757 patients were enrolled, 14.1% with septic shock. 156 (20%) patients had a BSI caused by MDRO: extended-spectrum beta-lactamase (ESBL) producing Enterobacterales were the most prevalent followed by methicillin-resistant Staphylococcus aureus (MRSA). Risk factors for BSI due to MDRO and specifically for ESBL were chronic renal failure (OR 2.2; 95%CI 1.4-3.6), nursing home residency (OR 4.4; 95%CI 1.9-10.2) and antibiotic therapy in the last 90-days (OR 2.6; 95%CI 1.7-4), whereas for MRSA were dialysis (OR 12.3; 95%CI 1.8-83), antibiotic therapy and/or hospital admission in the past 90-days (OR 3.6; 95%CI 1.2-10.6) and ureteral stent or nephrostomy (OR 7.8; 95%CI 1.5-40.9). Patients with BSI due to MDRO had a higher rate of inappropriate empirical antibiotic therapy (50%) and longer length of stay, but no higher in-hospital mortality. Among patients admitted to the ED with a BSI, MDROs are frequent and often associated with inappropriate empirical antibiotic therapy. Specific updated risk factors for MDRO may help clinicians to better identify patients requiring a broader antibiotic therapy in the ED, while awaiting microbiological results.

The causal relationship between bacterial pneumonia and diabetes: a two-sample mendelian randomization study

BACKGROUND

Previous observational studies have established the high prevalence of bacterial pneumonia in diabetic patients, which in turn leads to increased mortality. However, the presence of a causal connection between bacterial pneumonia and diabetes remains unobserved.

METHODS

We chose genome-wide significant (Ρ < 1 × 10-5 and Ρ < 1 × 10-6) and independent (r2 < 0.001) single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) to proceed a bidirectional two-sample MR study. The extracted SNPs explored the relationship between bacterial pneumonia and diabetes by Inverse variance weighted (IVW), MR-Egger, and weighted median methods. In addition, we conducted the Heterogeneity test, the Pleiotropy test, MR-presso and the Leave-one-out (LOO) sensitivity test to validate the reliability of results.

RESULTS

In an MR study with bacterial pneumonia as an exposure factor, four different types of diabetes as outcome. It was observed that bacterial pneumonia increases the incidence of GDM (OR = 1.150 (1.027-1.274, P = 0.011) and T1DM (OR = 1.277 (1.024-1.531), P = 0.016). In the reverse MR analysis, it was observed that GDM (OR = 1.112 (1.023-1.201, P = 0.009) is associated with an elevated risk of bacterial pneumonia. However, no significant association was observed bacterial pneumonia with T1DM and other types of diabetes (P > 0.05).

CONCLUSION

This study utilizing MR methodology yields robust evidence supporting a bidirectional causal association between bacterial pneumonia and GDM. Furthermore, our findings suggest a plausible causal link between bacterial pneumonia and T1DM.

Lung-innervating nociceptor sensory neurons promote pneumonic sepsis during carbapenem-resistant Klebsiella pneumoniae lung infection

Carbapenem-resistant Klebsiella pneumoniae (CRKP) causes Gram-negative lung infections and fatal pneumonic sepsis for which limited therapeutic options are available. The lungs are densely innervated by nociceptor sensory neurons that mediate breathing, cough, and bronchoconstriction. The role of nociceptors in defense against Gram-negative lung pathogens is unknown. Here, we found that lung-innervating nociceptors promote CRKP pneumonia and pneumonic sepsis. Ablation of nociceptors in mice increased lung CRKP clearance, suppressed trans-alveolar dissemination of CRKP, and protected mice from hypothermia and death. Furthermore, ablation of nociceptors enhanced the recruitment of neutrophils and Ly6Chi monocytes and cytokine induction. Depletion of Ly6Chi monocytes, but not of neutrophils, abrogated lung and extrapulmonary CRKP clearance in ablated mice, suggesting that Ly6Chi monocytes are a critical cellular population to regulate pneumonic sepsis. Further, neuropeptide calcitonin gene-related peptide suppressed the induction of reactive oxygen species in Ly6Chi monocytes and their CRKP-killing abilities. Targeting nociceptor signaling could be a therapeutic approach for treating multidrug-resistant Gram-negative infection and pneumonic sepsis.

Diabetes Mellitus and Pneumococcal Pneumonia

Currently, there are more than 500 million people suffering from diabetes around the world. People aged 65 years or older are the most affected by this disease, and it is estimated that approximately 96% of diabetes cases worldwide are type 2 diabetes. People with diabetes mellitus are at an increased risk of infections such as pneumonia, due to a series of factors that may contribute to immune dysfunction, including hyperglycemia, inhibition of neutrophil chemotaxis, impaired cytokine production, phagocytic cell dysfunction, altered T cell-mediated immune responses and the co-existence of chronic comorbidities. Rates of infection, hospitalization and mortality in diabetic patients are reported to be higher than in the general population. Research into the risk of infectious diseases such as pneumonia in these patients is very important because it will help improve their management and treatment.

Risk Factors for 30-Day Mortality in Patients with Bacteremic Pneumonia Caused by Escherichia coli and Klebsiella pneumoniae: A Retrospective Study

Objective

Escherichia coli and Klebsiella pneumoniae are prevalent Gram-negative microorganisms responsible for pneumonia, as well as the primary Enterobacteriaceae pathogens causing bacteremic pneumonia. The objective of this research is to analyze the risk factors associated with bacteremic pneumonia caused by these pathogens and develop a predictive model.

Patients and Methods

This retrospective investigation encompassed a cohort of 252 patients diagnosed with Escherichia coli or Klebsiella pneumoniae-induced bacteremic pneumonia between 2018 and 2022. The primary endpoint was 30-day mortality, which was analyzed using multifactorial logistic regression, nomogram construction, and Bootstrap validation.

Results

Among the 252 patients diagnosed with Escherichia coli and Klebsiella pneumoniae, 65 succumbed to the disease while 187 survived. The overall 30-day mortality was found to be 25.8%. A multifactorial logistic regression analysis revealed that diastolic blood pressure, cerebrovascular diseases/transient ischemic attacks (TIA), immunosuppression, blood urea nitrogen, Pitt score, and CURB-65 score were statistically significant factors. The Nomogram model demonstrated an AUC of 0.954, which closely aligns with the Bootstrap-derived mean AUC of 0.953 (95% CI: 0.952-0.954).

Conclusion

In patients with bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae, Low diastolic blood pressure (≤61 mmHg), pre-existing cerebrovascular disease/ transient ischemic attacks (TIA), immunosuppression status, elevated blood urea nitrogen levels (≥8.39 mmol/L), high Pitt score (≥3), and a high CURB-65 score (≥2) are all independent risk factors for Escherichia coli and Klebsiella pneumoniae bacteremic pneumonia, among which the first three warrant particular attention.

Acute organ injury and long-term sequelae of severe pneumococcal infections

Streptococcus pneumoniae (Spn) is a major public health problem, as it is a main cause of otitis media, community-acquired pneumonia, bacteremia, sepsis, and meningitis. Acute episodes of pneumococcal disease have been demonstrated to cause organ damage with lingering negative consequences. Cytotoxic products released by the bacterium, biomechanical and physiological stress resulting from infection, and the corresponding inflammatory response together contribute to organ damage accrued during infection. The collective result of this damage can be acutely life-threatening, but among survivors, it also contributes to the long-lasting sequelae of pneumococcal disease. These include the development of new morbidities or exacerbation of pre-existing conditions such as COPD, heart disease, and neurological impairments. Currently, pneumonia is ranked as the 9^th leading cause of death, but this estimate only considers short-term mortality and likely underestimates the true long-term impact of disease. Herein, we review the data that indicates damage incurred during acute pneumococcal infection can result in long-term sequelae which reduces quality of life and life expectancy among pneumococcal disease survivors.

Invasive Pneumococcal Disease and COVID-19 Coinfection: A Series of Cases Admitted to an Intensive Care Unit

Pneumococcal infection is still a frequent disease. It can be classified as invasive when pneumococcus is isolated in a generally sterile fluid. Pneumonia is the most common infectious source of adult invasive pneumococcal disease (IPD), and several risk factors for IPD are well known. This case report presents three clinical cases of different manifestations of IPD. The two most severe cases had coinfection by SARS-CoV-2 at hospital admission.

ESTIMATING THE RISK OF BACTERAEMIA IN HOSPITALISED PATIENTS WITH PNEUMOCOCCAL PNEUMONIA

Objective To construct a prediction model for bacteraemia in patients with pneumococcal community-acquired pneumonia (P-CAP) based on variables easily obtained at hospital admission. MethodsThis prospective observational multicentre derivation-validation study was conducted in patients hospitalised with P-CAP between 2000-2020. All cases were diagnosed based on positive urinary antigen tests in the emergency department and had blood cultures taken on admission. A risk score to predict bacteraemia was developed. Results We included 1783 patients with P-CAP (1195 in the derivation and 588 in the validation cohort). A third (33.3%) of the patients had bacteraemia. In the multivariate analysis, the following were identified as independent factors associated with bacteraemia: no influenza vaccination the last year, no pneumococcal vaccination in the last 5 years, blood urea nitrogen (BUN) ≥30 mg/dL, sodium <130 mmol/L, lymphocyte count <800/µl, C-reactive protein ≥200 mg/L, respiratory failure, pleural effusion and no antibiotic treatment before admission. The score yielded good discrimination (AUC 0.732; 95% CI: 0.695-0.769) and calibration (Hosmer-Lemeshow p-value 0.801), with similar performance in the validation cohort (AUC 0.764; 95% CI:0.719-0.809). Conclusions We found nine predictive factors easily obtained on hospital admission that could help achieve early identification of bacteraemia. The prediction model provides a useful tool to guide diagnostic decisions.

Streptococcus pneumoniae Coinfection in COVID-19 in the Intensive Care Unit: A Series of Four Cases

Bacterial coinfections in patients infected with SARS-CoV-2 pneumonia are uncommon, when compared to coinfections with other respiratory viruses. For example, the prevalence of bacterial coinfections in hospitalized seasonal influenza patients can exceed 30%, whereas the prevalence of bacterial coinfections in SARS-CoV-2 infection is less than 4%. Bacterial coinfections increase the severity of respiratory viral infections and have been associated with higher mortality and morbidity. Current literature shows that diagnostic testing and antibiotic therapy for bacterial infections are not necessary upon admission in majority of patients with SARS-CoV-2 patients. It is however important for the clinician to be cognizant of these coinfections since missing the diagnosis may pose a substantial risk to vulnerable COVID-19 patients. In that light, we present four cases of Streptococcus pneumoniae coinfections complicating confirmed SARS-CoV-2 infections.

Mortality changes for patients with pneumococcal pneumonia from 2012 to 2017 in Japan

INTRODUCTION

Pneumococcal pneumonia has a high morbidity and mortality in adults, especially those ≥65 years old. In the past decade, pneumococcal vaccination programs have been initiated worldwide, however, few data concerning mortality changes are available in pneumococcal pneumonia patients and there are no reports clarifying these current changes in Japan.

METHODS

Japanese patients ≥65 years old hospitalized with pneumococcal pneumonia between April 2012 and March 2018 were analyzed using the Diagnostic Procedure Combination database. In-hospital mortality was evaluated, and the odds ratios for this outcome in each fiscal year compared with that in 2012 was analyzed using multivariable logistic regression models.

RESULTS

Between 2012 and 2017, data of 47,375 pneumococcal pneumonia patients ≥65 years old were extracted. The incidence per 1000 person-years for in-hospital mortality was 60.4 in 2012, 56.8 in 2013, 63.2 in 2014, 56.1 in 2015, 73.0 in 2016, and 67.4 in 2017 and the odds ratios for in-hospital mortality in 2013, 2014, 2015, 2016, and 2017 compared with that in 2012 were 1.00, 1.05, 1.04, 1.06, and 0.98, respectively. There were no significant differences between 2012 and each year from 2013 to 2017. Low BMI; low ADL score; high A-DROP score; comorbid malignancy and heart failure; the coexistence of invasive pneumococcal infection; and the use of invasive mechanical ventilation were independent risk factors for in-hospital mortality.

CONCLUSIONS

There were no changes in in-hospital mortality in pneumococcal pneumonia patients between 2012 or each year from 2013 to 2017 and further epidemiological observations are necessary.

Low-dose methylprednisolone treatment in critically ill patients with severe community-acquired pneumonia

Purpose

Severe community-acquired pneumonia (CAP) requiring intensive care unit admission is associated with significant acute and long-term morbidity and mortality. We hypothesized that downregulation of systemic and pulmonary inflammation with prolonged low-dose methylprednisolone treatment would accelerate pneumonia resolution and improve clinical outcomes.

Methods

This double-blind, randomized, placebo-controlled clinical trial recruited adult patients within 72–96 h of hospital presentation. Patients were randomized in 1:1 ratio; an intravenous 40 mg loading bolus was followed by 40 mg/day through day 7 and progressive tapering during the 20-day treatment course. Randomization was stratified by site and need for mechanical ventilation (MV) at the time of randomization. Outcomes included a primary endpoint of 60-day all-cause mortality and secondary endpoints of morbidity and mortality up to 1 year of follow-up.

Results

Between January 2012 and April 2016, 586 patients from 42 Veterans Affairs Medical Centers were randomized, short of the 1420 target sample size because of low recruitment. 584 patients were included in the analysis. There was no significant difference in 60-day mortality between the methylprednisolone and placebo arms (16% vs. 18%; adjusted odds ratio 0.90, 95% CI 0.57–1.40). There were no significant differences in secondary outcomes or complications.

Conclusions

In patients with severe CAP, prolonged low-dose methylprednisolone treatment did not significantly reduce 60-day mortality. Treatment was not associated with increased complications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06684-3.

Burden of pneumococcal disease among adults in Southern Europe (Spain, Portugal, Italy, and Greece): a systematic review and meta-analysis

The aim was to summarize pneumococcal disease burden data among adults in Southern Europe and the potential impact of vaccines on epidemiology. Of 4779 identified studies, 272 were selected. Invasive pneumococcal disease (IPD) incidence was 15.08 (95% CI 11.01-20.65) in Spain versus 2.56 (95% CI 1.54-4.24) per 100,000 population in Italy. Pneumococcal pneumonia incidence was 19.59 (95% CI 10.74-35.74) in Spain versus 2.19 (95% CI 1.36-3.54) per 100,000 population in Italy. Analysis of IPD incidence in Spain comparing pre-and post- PCV7 and PCV13 periods unveiled a declining trend in vaccine-type IPD incidence (larger and statistically significant for the elderly), suggesting indirect effects of childhood vaccination programme. Data from Portugal, Greece and, to a lesser extent, Italy were sparse, thus improved surveillance is needed. Pneumococcal vaccination uptake, particularly among the elderly and adults with chronic and immunosuppressing conditions, should be improved, including shift to a higher-valency pneumococcal conjugate vaccine when available.

Invasive Pneumococcal Disease in a Patient With COVID-19: A Case Report

The spread of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has resulted in a global health pandemic and caused profound morbidity and mortality worldwide. The virus is known to cause severe hypoxemic respiratory failure and has been associated with extrapulmonary manifestations and end-organ dysfunction in the setting of extensive inflammatory response. Recently, the association between COVID-19 and pneumococcal pneumonia co-infection or superinfections has gained increasing interest. In this report, we present the case of a 58-year-old man with a past medical history significant for pulmonary tuberculosis, diagnosed over two decades ago, who presented with pleuritic chest pain, myalgia, intermittent fevers, chills, and productive cough and was found to have invasive pneumococcal disease and COVID-19. To our knowledge, this is the first reported case of invasive pneumococcal infection in a patient with COVID-19.

International prevalence and risk factors evaluation for drug-resistant Streptococcus pneumoniae pneumonia

OBJECTIVE

Streptococcus pneumoniae is the most frequent bacterial pathogen isolated in subjects with Community-acquired pneumonia (CAP) worldwide. Limited data are available regarding the current global burden and risk factors associated with drug-resistant Streptococcus pneumoniae (DRSP) in CAP subjects. We assessed the multinational prevalence and risk factors for DRSP-CAP in a multinational point-prevalence study.

DESIGN

The prevalence of DRSP-CAP was assessed by identification of DRSP in blood or respiratory samples among adults hospitalized with CAP in 54 countries. Prevalence and risk factors were compared among subjects that had microbiological testing and antibiotic susceptibility data. Multivariate logistic regressions were used to identify risk factors independently associated with DRSP-CAP.

RESULTS

3,193 subjects were included in the study. The global prevalence of DRSP-CAP was 1.3% and continental prevalence rates were 7.0% in Africa, 1.2% in Asia, and 1.0% in South America, Europe, and North America, respectively. Macrolide resistance was most frequently identified in subjects with DRSP-CAP (0.6%) followed by penicillin resistance (0.5%). Subjects in Africa were more likely to have DRSP-CAP (OR: 7.6; 95%CI: 3.34-15.35, p<0.001) when compared to centres representing other continents.

CONCLUSIONS

This multinational point-prevalence study found a low global prevalence of DRSP-CAP that may impact guideline development and antimicrobial policies.

Protection against fatal pneumonia through mucosal and subcutaneous immunization with the pneumococcal SP0148 protein

Streptococcus pneumoniae infection is associated with very high morbidity and mortality throughout the world. Vaccines are an effective measure for the reduction of S. pneumoniae infection. In particular, protein vaccines are attracting increasing attention because of their good immunogenicity and wide coverage of serotypes. Therefore, identifying effective protein vaccine targets is important for protein vaccine development. SP0148 is a promising protein vaccine target for S. pneumoniae and is capable of reducing S. pneumoniae colonization in the nasopharynx of mice through the IL-17A pathway. However, the protective effects of SP0148 in fatal pneumococcal infection have not been evaluated. This study used subcutaneous and nasal immunization routes to systematically evaluate the protective effects of the SP0148 protein in fatal pneumococcal infection. Subcutaneous and nasal mucosal immunization with recombinant SP0148 protein produced effective immune protection against infection with a lethal dose of S. pneumoniae and significantly prolonged survival time and increased the survival rate of mice. Furthermore, nasal immunization with SP0148 induced mouse splenocytes to secrete high levels of the cytokines IFN-γ and IL-17A. Both recombinant SP0148 protein and its antiserum inhibited the adhesion of S.pneumoniae D39 to A549 human lung epithelial cells in a dose-dependent manner. In summary, SP0148 induced mice to produce protective immune responses to fatal S. pneumoniae infection, and our results could contribute to the accumulating data on the use of SP0148 protein vaccines.

Cost-effectiveness analysis of 13-valent pneumococcal conjugate vaccine versus 23-valent pneumococcal polysaccharide vaccine in an adult population in South Korea

In South Korea, the National Immunization Program offers a 23-valent pneumococcal polysaccharide vaccine (PPSV23) for the elderly; however, the 13-valent pneumococcal conjugate vaccine (PCV13) is not included, and vaccination is not offered to younger, at-risk populations. This study offers a comparative analysis of PCV13 and PPSV23 in Korea's adults, stratified by age and risk group. A Markov model with a lifetime horizon was developed from the healthcare perspective. Data sources included the Health Insurance Review & Assessment Service, Korea Centre for Disease Control & Prevention and Korean medical institutions. An expert panel tested data validity. The CAPiTA trial and Cochrane meta-analysis were used to obtain vaccine effectiveness data. Regardless of co-morbidity, when the sequential PCV13-PPSV23 strategy was compared to that using PPSV23-only, in elderly populations, the incremental cost-effectiveness ratio (ICER) was 3,300 USD per quality-adjusted life years (QALY). For the risk group aged ≥65 years, the ICER of the addition of PCV13 over the existing PPSV23-only strategy was 3,404 USD/QALY. However, on replacing PPSV23 with PCV13, for all elderly populations, an ICER of 1,421 USD/QALY resulted; for the risk group aged ≥65 years, the ICER was 1,736 USD/QALY. For the 18-64 year-old risk group, the sequential PCV13-PPSV23 strategy yielded an ICER of 3,629 USD/QALY over the PPSV23-only strategy, and 6,643 USD/QALY compared to no vaccination. Thus, the PCV13→PPSV23 combination strategy for elderly populations was found to be a cost-effective alternative to the current National Immunization Program regardless of co-morbidity. This finding was the same as that for younger, at-risk populations.

A model for predicting bacteremia in patients with community-acquired pneumococcal pneumonia: a retrospective observational study

Background

Pneumococcal pneumonia causes high morbidity and mortality among adults. This study aimed to identify risk factors for bacteremic pneumococcal pneumonia, and to construct a prediction model for the development of bacteremia in patients with community-acquired pneumococcal pneumonia.

Methods

We retrospectively analyzed data from patients hospitalized with community-acquired pneumococcal pneumonia between April 2007 and August 2015. Logistic regression models were applied to detect risk factors for pneumococcal bacteremia, and a receiver operating characteristic curve was used to devise a prediction model.

Results

Based on the results of sputum cultures, urine antigen tests, and/or blood cultures, 389 patients were diagnosed with pneumococcal pneumonia, 46 of whom had bacteremia. In the multivariate analysis, age < 65 years, serum albumin level < 3.0 g/dL, need for intensive respiratory or vasopressor support (IRVS), and C-reactive protein level > 20 mg/dL were identified as independent risk factors for the development of pneumococcal bacteremia. The bacteremia prediction score based on receiver operating characteristic curve analysis had a sensitivity of 0.74 and a specificity of 0.78 in patients with two risk factors. The area under the receiver operating characteristic curve was 0.77 (95% confidence interval (CI), 0.70–0.85).

Conclusions

Age < 65 years, hypoalbuminemia, IRVS, and high C-reactive protein level on admission are independent risk factors for the development of bacteremia in patients with community-acquired pneumococcal pneumonia. A prediction model based on these four risk factors could help to identify patients with community-acquired pneumococcal pneumonia at high risk of developing bacteremia; this can be used to guide antibiotic choices.

Trial registration

UMIN-CTR UMIN 000004353. Registered 7 October 2010. Retrospectively registered.

Predictive and prognostic factors in patients with blood-culture-positive community-acquired pneumococcal pneumonia

In patients with pneumococcal community-acquired pneumonia (CAP), the risk factors for bacteraemia and its impact on outcomes are not fully elucidated. We aimed to compare characteristics of patients with blood-culture-positive versus blood-culture-negative pneumococcal CAP, and to characterise bacteraemic serotypes.We describe a prospective, observational study on nonimmunocompromised patients with pneumococcal CAP, from 1996 to 2013. We define severe pneumonia according to American Thoracic Society/Infectious Diseases Society of America guidelines.Of a total of 917 patients with pneumococcal CAP, 362 had blood-culture-positive pneumococcal pneumonia (BCPPP; 39%). High C-reactive protein (CRP) (≥20 mg·dL(-1)) (odds ratio (OR) 2.36, 95% CI 1.45-3.85), pleural effusion (OR 2.03, 95% CI 1.13-3.65) and multilobar involvement (OR 1.69, 95% CI 1.02-2.79) were independently associated with bacteraemic CAP, while nursing home resident (OR 0.12, 95% CI 0.01-1.00) was found as a protective factor. Despite the clinical differences, BCPPP showed similar outcomes to blood-culture-negative pneumococcal pneumonia (BCNPP). 14% of the serotypes (period 2006-2013) causing bacteraemia are included in pneumococcal conjugate vaccine PVC7, 74% in pneumococcal conjugate vaccine PVC13 and 83% in pneumococcal polysaccharide vaccine PPSV23.Pleural effusion, a high level of CRP and multilobar involvement predicted an increased risk of BCPPP. Although BCPPP patients were more severely ill at admission, mortality was not significantly greater than in BCNPP patients.

Bacteremic pneumococcal pneumonia: clinical outcomes and preliminary results of inflammatory response

PURPOSE

Further examination of clinical outcomes and inflammatory response of bacteremic pneumococcal community-acquired pneumonia (CAP) is of great interest to enhance the care of patients with pneumococcal CAP.

METHODS

This is a secondary analysis of the Community Acquired Pneumonia Organization (CAPO) to compare the time to clinical stability (TCS), length of hospital stay (LOS), and in-hospital mortality of hospitalized pneumococcal CAP patients with and without bacteremia. To measure the effect of bacteremia in pneumococcal CAP patients on outcomes, we modeled all-cause in-hospital mortality using a Poisson regression model, and TCS and LOS using Cox proportional hazards models. Adjusted multivariate regression models were also used to predict the probability of occurrence of each of the study outcomes. To investigate the inflammatory response, we measured the plasma levels of pro- and anti-inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1rα, IL-6, IL-8, IL-10], inflammatory biomarkers [C-reactive protein (CRP), pro-calcitonin (PCT), and B-type natriuretic peptide (BNP)], and peripheral blood neutrophil responses in 10 patients, 4 bacteremic and 6 non-bacteremic pneumococcal CAP, upon admission and every other day during the first 6 days of hospitalization. Functional data were presented as median and standard error of the median (SEM); due to small number of samples no statistical comparisons were performed between groups.

RESULTS

From 833 pneumococcal CAP patients, 394 patients (47 %) were bacteremic. Bacteremic pneumococcal CAP were less likely to reach TCS with an adjusted hazard ratio (AHR) of 0.82 (95 % CI 0.69-0.97; p = 0.02) and had higher in-hospital mortality with an AHR of 1.63 (95 % CI 1.06-2.50, p = 0.026). Bacteremic pneumococcal CAP patients had a longer LOS than non-bacteremic pneumococcal CAP (p < 0.003). Higher plasma levels of CRP, PCT, and BNP were found in bacteremic than in non-bacteremic patients. The bacteremic group had consistently higher plasma levels of both pro- and anti-inflammatory cytokines. The blood neutrophil functional responses were similar in both groups of patients.

CONCLUSIONS

Bacteremic pneumococcal CAP patients were significantly associated with higher in-hospital mortality, lower TCS, and longer LOS. HIV-infected patients showed a greater mortality which was not statistically significant. Bacteremic pneumococcal CAP patients had higher levels of biomarkers and systemic cytokines.

Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease

Pneumococcal disease (including community-acquired pneumonia and invasive pneumococcal disease) poses a burden to the community all year round, especially in those with chronic underlying conditions. Individuals with COPD, asthma or who smoke, and those with chronic heart disease or diabetes mellitus have been shown to be at increased risk of pneumococcal disease compared with those without these risk factors. These conditions, and smoking, can also adversely affect patient outcomes, including short-term and long-term mortality rates, following pneumonia. Community-acquired pneumonia, and in particular pneumococcal pneumonia, is associated with a significant economic burden, especially in those who are hospitalised, and also has an impact on a patient's quality of life. Therefore, physicians should target individuals with COPD, asthma, heart disease or diabetes mellitus, and those who smoke, for pneumococcal vaccination at the earliest opportunity at any time of the year.

Influence of chronic illnesses and underlying risk conditions on the incidence of pneumococcal pneumonia in older adults

OBJECTIVE

To investigate hospitalizations from pneumococcal pneumonia in older adults with specific underlying chronic conditions, evaluating the influence of these conditions in developing pneumonia.

METHODS

Population-based cohort study involving 27,204 individuals ≥ 60 years old in Southern Catalonia, Spain. All cases of hospitalization from pneumococcal pneumonia (bacteremic and nonbacteremic) were collected since 01/12/2008 until 30/11/2011. Cox regression was used to calculate hazards ratio (HR) and estimate the association between baseline conditions and the risk of developing pneumococcal pneumonia.

RESULTS

Maximum incidences (per 1000 person-years) appeared among patients with history of prior pneumonia (14.6), nursing home residents (12.8), persons with immunodeficiency/asplenia (7.7) and patients with chronic pulmonary disease (7.6). In multivariable analysis, age (HR: 1.05), nursing home residence (HR: 4.59), history of prior pneumonia (HR: 3.58), stroke (HR: 2.50), chronic heart disease (HR: 1.53), chronic pulmonary disease (HR: 4.09), diabetes mellitus (HR: 1.66), smoking (HR: 1.69) and immunosuppressive medication (HR: 1.87) appeared significantly associated with an increased risk of pneumococcal pneumonia.

CONCLUSION

Our data support that nursing home residence, chronic pulmonary disease and immunocompromising conditions are the underlying conditions most strongly associated with an increasing risk of pneumococcal pneumonia in older adults. This data underline the need for better prevention strategies among these persons.

Results of high-risk neutropenia therapy of hematology-oncology patients in a university hospital in Uruguay

Background

Febrile neutropenia is an important cause of mortality and morbidity in hematology–oncology patients undergoing chemotherapy. The management of febrile neutropenia is typically algorithm-driven. The aim of this study was to assess the results of a standardized protocol for the treatment of febrile neutropenia.

Methods

A retrospective cohort study (2011–2012) was conducted of patients with high-risk neutropenia in a hematology–oncology service.

Results

Forty-four episodes of 17 patients with a median age of 48 years (range: 18–78 years) were included. The incidence of febrile neutropenia was 61.4%. The presence of febrile neutropenia was associated with both the duration and severity of neutropenia. Microbiological agents were isolated from different sources in 59.3% of the episodes with bacteremia isolated from blood being the most prevalent (81.3%). Multiple drug-resistant gram-negative bacilli were isolated in 62.5% of all microbiologically documented infections. Treatment of 63% of the episodes in which the initial treatment was piperacillin/tazobactam needed to be escalated to meropenem. The mortality rate due to febrile neutropenia episodes was 18.5%.

Conclusion

The high rate of gram-negative bacilli resistant to piperacillin/tazobactam (front-line antibiotics in our protocol) and the early need to escalate to carbapenems raises the question as to whether it is necessary to change the current protocol.

Decrease in mortality in severe community-acquired pneumococcal pneumonia: impact of improving antibiotic strategies (2000-2013)

OBJECTIVE

The objective of the present study was to compare antibiotic prescribing practices and survival in the ICU for patients with pneumococcal severe community-acquired pneumonia (SCAP) between 2000 and 2013.

METHODS

This was a matched case-control study of two prospectively recorded cohorts in Europe. Eighty patients from the Community-Acquired Pneumonia en la Unidad de Cuidados Intensivos (CAPUCI) II study (case group) were matched with 80 patients from CAPUCI I (control group) based on the following: shock at admission, need of mechanical ventilation, COPD, immunosuppression, and age.

RESULTS

Demographic data were comparable in the two groups. Combined antibiotic therapy increased from 66.2% to 87.5% (P < .01), and the percentage of patients receiving the first dose of antibiotic within 3 h increased from 27.5% to 70.0% (P < .01). ICU mortality was significantly lower (OR, 0.82; 95% CI, 0.68-0.98) in cases, both in the whole population and in the subgroups of patients with shock (OR, 0.67; 95% CI, 0.50-0.89) or receiving mechanical ventilation (OR, 0.73; 95% CI, 0.55-0.96). In the multivariate analysis, ICU mortality increased in patients requiring mechanical ventilation (OR, 5.23; 95% CI, 1.60-17.17) and decreased in patients receiving early antibiotic treatment (OR, 0.36; 95% CI, 0.15-0.87) and combined therapy (OR, 0.19; 95% CI, 0.07-0.51).

CONCLUSIONS

In pneumococcal SCAP, early antibiotic prescription and use of combination therapy increased. Both were associated with improved survival.

A leukocyte score to improve clinical outcome predictions in bacteremic pneumococcal pneumonia in adults

In multivariate analysis, a leukocyte score that adds 1 point each for neutropenia, lymphopenia and monocytopenia was associated with 30-day mortality in 192 patients with bacteremic pneumococcal pneumonia. By reflecting immunoparalysis, this score could improve clinical outcome predictions in BPP.

Background

 Bacteremic pneumococcal pneumonia (BPP) is associated with high and early mortality. A simple procedure to predict mortality is crucial.

Methods

 All adult patients with BPP admitted from 2005 through 2013 to the University Hospital of Dijon, France, were enrolled to study 30-day mortality and associated factors, particularly leukocyte counts. A simple leukocyte score was created by adding 1 point each for neutropenia (<1500 cells/mm³), lymphopenia (<400), and monocytopenia (<200).

Results

 One hundred and ninety-two adult patients (mean age, 69 years; standard deviation [SD], 19 years) who had developed and were hospitalized for BPP (58% community-acquired) were included. The 30-day crude mortality rate was 21%. The mean Pneumonia Severity Index score was high at 127.3 (SD = 41.3). Among the 182 patients who had a white blood cell count, 34 (19%) had a high leukocyte score (≥2). Multivariate analysis revealed that mortality was significantly associated with a high leukocyte score (odds ratio, 6.28; 95% confidence interval, 2.35–16.78), a high respiratory rate, a low serum bicarbonate level, and an altered mental status (all P < .05). The leukocyte score was not significantly dependent on the previous state of immunosuppression, alcoholism, or viral coinfection, but it did correlate with an acute respiratory distress syndrome and a low serum bicarbonate level.

Conclusions

 This new leukocyte score, in combination with the well known predictive factors, seems of interest in predicting the risk of death in BPP. A high score correlated with organ dysfunction and probably reflects the level of immunoparalysis. Its predictive value has to be confirmed in other cohorts.

Clinical management of infections caused by multidrug-resistant Enterobacteriaceae

Enterobacteriaceae showing resistance to cephalosporins due to extended-spectrum β-lactamases (ESBLs) or plasmid-mediated AmpC enzymes, and those producing carbapenemases have spread worldwide during the last decades. Many of these isolates are also resistant to other first-line agents such as fluoroquinolones or aminoglycosides, leaving few available options for therapy. Thus, older drugs such as colistin and fosfomycin are being increasingly used. Infections caused by these bacteria are associated with increased morbidity and mortality compared with those caused by their susceptible counterparts. Most of the evidence supporting the present recommendations is from in vitro data, animal studies, and observational studies. While carbapenems are considered the drugs of choice for ESBL and AmpC producers, recent data suggest that certain alternatives may be suitable for some types of infections. Combined therapy seems superior to monotherapy in the treatment of invasive infections caused by carbapenemase-producing Enterobacteriaceae. Optimization of dosage according to pharmacokinetics/pharmacodynamics data is important for the treatment of infections caused by isolates with borderline minimum inhibitory concentration due to low-level resistance mechanisms. The increasing frequency and the rapid spread of multidrug resistance among the Enterobacteriaceae is a true and complex public health problem.

Bacteraemic and non-bacteraemic/urinary antigen-positive pneumococcal community-acquired pneumonia compared

The diagnosis of invasive pneumococcal pneumonia is based mainly on bacteraemia. Episodes without bacteraemia, but with a positive urinary antigen test (UAT), are considered non-invasive. We determined differences in outcome between patients with bacteraemic and non-bacteraemic/UAT-positive pneumococcal community-acquired pneumonia (CAP). Adult patients with clinical and radiological evidence of CAP with blood cultures and UAT tests performed at presentation in three Dutch laboratories between June 2008 and May 2010 were included. Clinical characteristics were retrospectively extracted from hospital records. Overall, 168 patients had non-bacteraemic/UAT-positive pneumococcal CAP and 123 had bacteraemic pneumococcal CAP. The day-30 mortality was 9% and 13% for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively [risk difference -4%, 95% confidence interval (CI) -11% to +3%, p = 0.28]. In a multivariable logistic regression model, age ≥ 65 years, admission to the intensive care unit/coronary care unit (ICU/CCU) and presence of an immunocompromising condition were associated with day-30 mortality. A non-significant association with mortality was found for bacteraemia [odds ratio (OR) 2.21, 95% CI 0.94-5.21, p = 0.07). No such trend was found for UAT positivity. The median lengths of hospital stay were 8 [interquartile range (IQR) 5-14] and 10 (IQR 6-18) days for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively (p = 0.05). As compared to non-bacteraemic/UAT-positive pneumococcal CAP, bacteraemic pneumococcal CAP has a stronger association with day-30 mortality.

Risk factors for levofloxacin-nonsusceptible Streptococcus pneumoniae in community-acquired pneumococcal pneumonia: a nested case-control study

This study was performed to evaluate the clinical features of community-onset levofloxacin-nonsusceptible pneumococcal pneumonia and to identify risk factors for levofloxacin resistance. Using the database of a surveillance study of community-acquired pneumococcal infections in Asian countries, we conducted a nested case-control study to identify risk factors for levofloxacin-nonsusceptible S. pneumoniae in community-acquired pneumonia in adults. Of 981 patients with pneumococcal pneumonia, 46 (4.7 %) had levofloxacin-nonsusceptible S. pneumoniae, of whom 39 evaluable cases were included in the analysis. All cases were from Korea, Taiwan, and Hong Kong. Among patients with levofloxacin-susceptible S. pneumoniae, 490 controls were selected based on patient country. Of the 39 cases of levofloxacin-nonsusceptible pneumococcal pneumonia, 23 (59.0 %) were classified as healthcare-associated, while 164 (33.5 %) of the 490 controls of levofloxacin-susceptible S. pneumoniae (P = 0.001) were classified as healthcare-associated. Multivariate analysis showed that previous treatment with fluoroquinolones, cerebrovascular disease, and healthcare-associated infection were significantly associated with levofloxacin-nonsusceptible pneumococcal pneumonia (all P < 0.05). Levofloxacin-nonsusceptible pneumococci pose an important new public health threat in our region, and more information on the emergence and spread of these resistant strains will be necessary to prevent spread throughout the population.

30-day mortality in UK patients with bacteraemic community-acquired pneumonia

OBJECTIVES

To determine 7 and 30-day mortality in consecutive patients with bacteraemic community-acquired pneumonia (CAP) and the association between predicted variables and likelihood of death.

METHODS

From August 2007 to July 2011, demographic, clinical and microbiological data were prospectively collected on patients with bacteraemic CAP. Patients were followed until death, hospital discharge or recovery from infection. Univariate and multivariate analysis was performed to determine the association between predictor variables and 30-day mortality.

RESULTS

7-day mortality was 61/252 [24.4%, 95% confidence interval (CI) 19.1-30.0%] and by 30 days, this had risen to 77/252 (30.6%, 95% CI 24.9-36.6%). In univariate analysis, factors associated with 30-day mortality were age, speciality within 48 h of admission, blood culture isolate and Charlson co-morbidity index (CCI). In multivariate analysis, age and CCI remained significantly associated. There was also a trend towards significance for meticillin-sensitive Staphylococcus aureus (MSSA) and Pseudomonas aeruginosa blood culture isolates compared to Streptococcus pneumoniae.

CONCLUSIONS

Overall, bacteraemic CAP was associated with high inpatient mortality. Because of their association with poor outcomes, patients with MSSA and P. aeruginosa bacteraemic CAP require further study.

Clinical and economic burden of invasive pneumococcal disease in adults: a multicenter hospital-based study

BACKGROUND

Streptococcus pneumoniae causes a broad spectrum of illnesses ranging from mild upper respiratory tract infections to invasive pneumococcal disease (IPD). Quantitative data on the burden of pneumococcal disease, important for the establishment of appropriate vaccination strategies, is currently lacking in adults.

METHODS

This multicenter, retrospective cohort study was designed to estimate the clinical and economic burden of IPD in adults over the last decade. Data were collected from patients with IPD at 10 university hospitals in South Korea. We estimated the proportion of IPD among all hospitalized patients, the case fatality rate, and the direct medical costs of IPD. Data were further analyzed according to age and risk groups.

RESULTS

During the study period, 970 patients with IPD were identified. The mean age for all patients was 60.9 years; patients aged 50-64 years (33.0%) were most numerous, followed by those aged 65-74 years (27.4%). Overall, the proportion of IPD was 0.36 cases/1000 hospitalized patients and the case fatality rate was 30.9%, which increased significantly with age (p < 0.01). The mean direct medical costs were estimated to be US $7,452 without a difference between age and risk groups. On multivariate analysis, old age, advanced ECOG performance status, bacteremic pneumonia, and nosocomial infection were independent risk factors of 30-day case fatality.

CONCLUSIONS

The clinical disease burden of IPD increased significantly with age and direct medical costs from IPD were substantial, regardless of age and co-morbid conditions. The current age-based vaccination strategy appears to be appropriate.

Antimicrobial resistance in Asia: current epidemiology and clinical implications

Antimicrobial resistance has become one of the most serious public health concerns worldwide. Although circumstances may vary by region or country, it is clear that some Asian countries are epicenters of resistance, having seen rapid increases in the prevalence of antimicrobial resistance of major bacterial pathogens. In these locations, however, the public health infrastructure to combat this problem is very poor. The prevalence rates of methicillin-resistant Staphylococcus aureus (MRSA), macrolide-resistant Streptococcus pneumoniae, and multidrug-resistant enteric pathogens are very high due to the recent emergence of extremely drug-resistant gram-negative bacilli in Asia. Because antimicrobial options for these pathogens are extremely limited, infections caused by antimicrobial-resistant bacteria are often associated with inappropriate antimicrobial therapy and poor clinical outcomes. Physicians should be aware of the current epidemiological status of resistance and understand the appropriate use of antimicrobial agents in clinical practice. This review focuses on describing the epidemiology and clinical implications of antimicrobial-resistant bacterial infections in Asian countries.