Severity of influenza A 2009 (H1N1) pneumonia is underestimated by routine prediction rules. Results from a prospective, population-based study

Clinical features that predict the mortality risk in older patients with Omicron pneumonia: the MLWAP score

In December 2022, the Chinese suffered widespread Omicron of SARS-CoV-2 with variable symptom severity and outcome. We wanted to develop a scoring model to predict the mortality risk of older Omicron pneumonia patients by analyzing admission data. We enrolled 227 Omicron pneumonia patients aged 60 years and older, admitted to our hospital from December 15, 2022, to January 16, 2023, and divided them randomly into a 70% training set and a 30% test set. The former were used to identify predictors and develop a model, the latter to verify the model, using the area under the receiver operating characteristic curve (AUC), the Hosmer-Lemeshow goodness-of-fit test, a calibration curve to test its performance and comparing it to the existing scores. The MLWAP score was calculated based on a multivariate logistic regression model to predict mortality with a weighted score that included immunosuppression, lactate ≥ 2.4, white blood cell count ≥ 6.70 × 109/L, age ≥ 77 years, and PaO2/FiO2 ≤ 211. The AUC for the model in the training and test sets was 0.852 (95% CI, 0.792-0.912) and 0.875 (95% CI, 0.789-0.961), respectively. The calibration curves showed a good fit. We grouped the risk scores into low (score 0-7 points), medium (8-10 points), and high (11-13 points). This model had a sensitivity of 0.849, specificity of 0.714, and better predictive ability than the CURB-65 and PSI scores (AUROC = 0.859 vs. 0.788 vs. 0.801, respectively). The MLWAP-mortality score may help clinicians to stratify hospitalized older Omicron pneumonia patients into relevant risk categories, rationally allocate medical resources, and reduce the mortality.

Additional risk factors improve mortality prediction for patients hospitalized with influenza pneumonia: a retrospective, single-center case-control study

BACKGROUND

Severe influenza, especially influenza pneumonia, causes large numbers of deaths each year. Some patients who develop severe influenza have no known risk factors. In this study we investigated risk factors for mortality of patients with influenza A-related pneumonia who have different basic conditions. We also evaluated the power of pneumonia severity assessment tools in Chinese patients hospitalized with influenza A-related pneumonia. Together, these results could provide a basis for a screening method that has improved ability for the early identification of critical patients who will have poor prognoses in clinical practice.

METHODS

This single-center, retrospective case-control study included 152 adult patients with severe influenza over six influenza seasons. Data for diagnoses and demographics, as well clinical data, laboratory findings, treatment methods, 30-day and 60-day outcomes of the patients were collected. Patients who had any of the risk factors for severe influenza were included in the high-risk group, and those that had no known risk factors were included in the low-risk group.

RESULTS

The PSI, CURB-65 and PIRO-CAP tools all underestimated the mortality rate of patients hospitalized with influenza A-related pneumonia, and this underestimate was more pronounced for low-risk patients. D-dimer (Odds ratio [OR] = 1.052, 95% confidence interval [CI] 1.001-1.106, p = 0.045) and direct bilirubin (OR = 1.143, 95%CI 1.049-1.246, p = 0.002) were independent risk factors for mortality of patients with influenza A-related pneumonia. When used in combination with ferritin and D-dimer, the area under receiver operator characteristic curve (AUC_ROC) was 0.851 (95%CI 0.780-0.922, p < 0.001), 0.840 (95%CI 0.763-0.916, p < 0.001) and 0.829 (95%CI 0.748-0.911, p < 0.001) for PSI, CURB-65 and PIRO-CAP, respectively, which was higher than that obtained using PSI, CURB-65 and PIRO-CAP alone.

CONCLUSIONS

The findings demonstrate that currently used community-acquired pneumonia (CAP) scoring systems could underestimate the risk of influenza A-related pneumonia mortality. D-dimer was shown to be an independent risk factor of mortality for influenza A-related pneumonia in hospitalized patients, and a combination of D-dimer with ferritin could improve the predictive value of PSI, CURB-65 and PIRO-CAP for adverse prognoses of patients with influenza A-related pneumonia.

Prepandemic viral community-acquired pneumonia: Diagnostic sensitivity and specificity of nasopharyngeal swabs and performance of clinical severity scores

The objectives of this work were to assess the diagnostic sensitivity and specificity of nasopharyngeal (NP) swabs for viral community-acquired pneumonia (CAP) and the performance of pneumonia severity index (PSI) and CURB-65 severity scores in the viral CAP in adults. A prospective observational cohort study of consecutive 341 hospitalized adults with CAP was performed between January 2018 and March 2020. Demographics, comorbidities, symptoms/signs, analytical data, severity scores, antimicrobials, and outcomes were recorded. Blood, NP swabs, sputum, and urine samples were collected at admission and assayed by multiplex real time-PCR, bacterial cultures, and Streptococcus pneumoniae and Legionella pneumophila antigens detection, to determine the etiologies and quantify the viral load. The etiology was identified in 174 (51.0%) patients, and in 85 (24.9%) it was viral, the most frequent rhinovirus and influenza virus. The sensitivity of viral detection in sputum (50.7%) was higher than in NP swabs (20.9%). Compared with sputum, the positive predictive value and specificity of NP swabs for viral diagnosis were 95.8% and 96.9%, respectively. Performance of PSI and CURB-65 scores in all CAP with etiologic diagnosis were as expected, with mortality associated with higher values, but they were not associated with mortality in patients with viral pneumonia. NP swabs have lower sensitivity but high specificity for the diagnosis of viral CAP in adults compared with sputum, reinforcing the use NP swabs for the diagnostic etiology work-up. The PSI and CURB-65 scores did not predict mortality in the viral CAP, suggesting that they need to be updated scores based on the identification of the etiological agent.

Derivation and external validation of a simple prediction rule for the development of respiratory failure in hospitalized patients with influenza

BACKGROUND

Influenza viruses cause seasonal epidemics worldwide with a significant morbimortality burden. Clinical spectrum of Influenza is wide, being respiratory failure (RF) one of its most severe complications. This study aims to elaborate a clinical prediction rule of RF in hospitalized Influenza patients.

METHODS

A prospective cohort study was conducted during two consecutive Influenza seasons (December 2016-March 2017 and December 2017-April 2018) including hospitalized adults with confirmed A or B Influenza infection. A prediction rule was derived using logistic regression and recursive partitioning, followed by internal cross-validation. External validation was performed on a retrospective cohort in a different hospital between December 2018 and May 2019.

RESULTS

Overall, 707 patients were included in the derivation cohort and 285 in the validation cohort. RF rate was 6.8% and 11.6%, respectively. Chronic obstructive pulmonary disease, immunosuppression, radiological abnormalities, respiratory rate, lymphopenia, lactate dehydrogenase and C-reactive protein at admission were associated with RF. A four category-grouped seven point-score was derived including radiological abnormalities, lymphopenia, respiratory rate and lactate dehydrogenase. Final model area under the curve was 0.796 (0.714-0.877) in the derivation cohort and 0.773 (0.687-0.859) in the validation cohort (p < 0.001 in both cases). The predicted model showed an adequate fit with the observed results (Fisher's test p > 0.43).

CONCLUSION

we present a simple, discriminating, well-calibrated rule for an early prediction of the development of RF in hospitalized Influenza patients, with proper performance in an external validation cohort. This tool can be helpful in patient's stratification during seasonal Influenza epidemics.

Burden of primary influenza and respiratory syncytial virus pneumonia in hospitalized adults: insights from a two-year multi-centre cohort study (2017-2018)

This two-year (2017-2018) multi-centre study on 356 adults hospitalized for influenza A/B and RSV pneumonia analysed factors associated with non-invasive ventilation (NIV) failure and in-hospital death (IHD.) Patients with both obstructive sleep apnoea or obesity hypoventilation syndrome and influenza-A virus pneumonia showed a higher risk for NIV failure (OR 4.66; 95% CI 1.42-15.30). Patients submitted to NIV showed a higher risk for IHD, regardless of comorbidities (influenza-A OR 3.00; 95% CI 1.35-6.65, influenza-B OR 4.52; 95% CI 1.13-18.01, RSV OR 5.61; 95% CI 1.26-24.93). The increased knowledge of influenza-A/B and RSV pneumonia burden may contribute to a better management of patients with viral pneumonia. This article is protected by copyright. All rights reserved.

Prehospital hypoxemia, measured by pulse oximetry, predicts hospital outcomes during the New York City COVID-19 pandemic

OBJECTIVE

To determine if oxygen saturation (out-of-hospital SpO2), measured by New York City (NYC) 9-1-1 Emergency Medical Services (EMS), was an independent predictor of coronavirus disease 2019 (COVID-19) in-hospital mortality and length of stay, after controlling for the competing risk of death. If so, out-of-hospital SpO2 could be useful for initial triage.

METHODS

A population-based longitudinal study of adult patients transported by EMS to emergency departments (ED) between March 5 and April 30, 2020 (the NYC COVID-19 peak period). Inclusion required EMS prehospital SpO2 measurement while breathing room air, transport to emergency department, and a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction test. Multivariable logistic regression modeled mortality as a function of prehospital SpO2, controlling for covariates (age, sex, race/ethnicity, and comorbidities). A competing risk model also was performed to estimate the absolute risks of out-of-hospital SpO2 on the cumulative incidence of being discharged from the hospital alive.

RESULTS

In 1673 patients, out-of-hospital SpO2 and age were independent predictors of in-hospital mortality and length of stay, after controlling for the competing risk of death. Among patients ≥66 years old, the probability of death was 26% with an out-of-hospital SpO2 >90% versus 54% with an out-of-hospital SpO2 ≤90%. Among patients <66 years old, the probability of death was 11.5% with an out-of-hospital SpO2 >90% versus 31% with an out-of-hospital SpO2 ≤ 90%. An out-of-hospital SpO2 level ≤90% was associated with over 50% decreased likelihood of being discharged alive, regardless of age.

CONCLUSIONS

Out-of-hospital SpO2 and age predicted in-hospital mortality and length of stay: An out-of-hospital SpO2 ≤90% strongly supports a triage decision for immediate hospital admission. For out-of-hospital SpO2 >90%, the decision to admit depends on multiple factors, including age, resource availability (outpatient vs inpatient), and the potential impact of new treatments.

Using a machine learning approach to predict mortality in critically ill influenza patients: a cross-sectional retrospective multicentre study in Taiwan

OBJECTIVES

Current mortality prediction models used in the intensive care unit (ICU) have a limited role for specific diseases such as influenza, and we aimed to establish an explainable machine learning (ML) model for predicting mortality in critically ill influenza patients using a real-world severe influenza data set.

STUDY DESIGN

A cross-sectional retrospective multicentre study in Taiwan SETTING: Eight medical centres in Taiwan.

PARTICIPANTS

A total of 336 patients requiring ICU-admission for virology-proven influenza at eight hospitals during an influenza epidemic between October 2015 and March 2016.

PRIMARY AND SECONDARY OUTCOME MEASURES

We employed extreme gradient boosting (XGBoost) to establish the prediction model, compared the performance with logistic regression (LR) and random forest (RF), demonstrated the feature importance categorised by clinical domains, and used SHapley Additive exPlanations (SHAP) for visualised interpretation.

RESULTS

The data set contained 76 features of the 336 patients with severe influenza. The severity was apparently high, as shown by the high Acute Physiology and Chronic Health Evaluation II score (22, 17 to 29) and pneumonia severity index score (118, 88 to 151). XGBoost model (area under the curve (AUC): 0.842; 95% CI 0.749 to 0.928) outperformed RF (AUC: 0.809; 95% CI 0.629 to 0.891) and LR (AUC: 0.701; 95% CI 0.573 to 0.825) for predicting 30-day mortality. To give clinicians an intuitive understanding of feature exploitation, we stratified features by the clinical domain. The cumulative feature importance in the fluid balance domain, ventilation domain, laboratory data domain, demographic and symptom domain, management domain and severity score domain was 0.253, 0.113, 0.177, 0.140, 0.152 and 0.165, respectively. We further used SHAP plots to illustrate associations between features and 30-day mortality in critically ill influenza patients.

CONCLUSIONS

We used a real-world data set and applied an ML approach, mainly XGBoost, to establish a practical and explainable mortality prediction model in critically ill influenza patients.

Inhibition of the PI3K/AKT Signaling Pathway or Overexpression of Beclin1 Blocks Reinfection of Streptococcus pneumoniae After Infection of Influenza A Virus in Severe Community-Acquired Pneumonia

Streptococcus pneumoniae (S. pneumoniae) and viruses are considered as primary risks of community-acquired pneumonia (CAP), and the effects of co-infection bacterial and virus in the prognosis of patients with severe CAP (SCAP) are poorly described. Therefore, this study is conducted to investigate the regulation of Beclin1-PI3K/AKT axis in reinfection of S. pneumoniae after influenza A virus in mice model of bronchoalveolar lavage fluid (BALF). Samples of sputum and BALF were collected from patients with SCAP for etiological detection. The expression of each gene was determined by RT-qPCR and western blot analysis. Influenza A/PR/8/34 and S. pneumoniae were used to establish the mice model of reinfection pneumonia. The virus quantity, expression levels of inflammatory factors, bacterial load, and myeloperoxidase (MPO) activity were tested. HE staining was applied to observe histopathology of lung tissue. The expression of Beclin1 was downregulated and the PI3K/AKT pathway was activated in viral pneumonia. In vivo experiment, the reinfection of S. pneumoniae following influenza A virus infection increased the number of S. pneumoniae population, the activity of MPO, and the expression of TNF-α, IL-6, and IFN-γ in BALF of mice. In contrast, inhibition of the PI3K/AKT pathway or overexpression of Beclin1 reduced the number of S. pneumoniae population, the activity of MPO, and the expression of TNF-α, IL-6, and IFN-γ in BALF of mice reinfected with S. pneumoniae after influenza A virus infection. Collectively, our study demonstrates that inhibition of the PI3K/AKT signaling pathway or overexpressed Beclin1 alleviates reinfection of S. pneumoniae after influenza A virus infection in SCAP.

Clinical Features Predicting Mortality Risk in Patients With Viral Pneumonia: The MuLBSTA Score

Objective

The aim of this study was to further clarify clinical characteristics and predict mortality risk among patients with viral pneumonia.

Methods

A total of 528 patients with viral pneumonia at RuiJin hospital in Shanghai from May 2015 to May 2019 were recruited. Multiplex real-time RT-PCR was used to detect respiratory viruses. Demographic information, comorbidities, routine laboratory examinations, immunological indexes, etiological detections, radiological images and treatment were collected on admission.

Results

76 (14.4%) patients died within 90 days in hospital. A predictive MuLBSTA score was calculated on the basis of a multivariate logistic regression model in order to predict mortality with a weighted score that included multilobular infiltrates (OR = 5.20, 95% CI 1.41–12.52, p = 0.010; 5 points), lymphocyte ≤ 0.8^∗10⁹/L (OR = 4.53, 95% CI 2.55–8.05, p < 0.001; 4 points), bacterial coinfection (OR = 3.71, 95% CI 2.11–6.51, p < 0.001; 4 points), acute-smoker (OR = 3.19, 95% CI 1.34–6.26, p = 0.001; 3 points), quit-smoker (OR = 2.18, 95% CI 0.99–4.82, p = 0.054; 2 points), hypertension (OR = 2.39, 95% CI 1.55–4.26, p = 0.003; 2 points) and age ≥60 years (OR = 2.14, 95% CI 1.04–4.39, p = 0.038; 2 points). 12 points was used as a cut-off value for mortality risk stratification. This model showed sensitivity of 0.776, specificity of 0.778 and a better predictive ability than CURB-65 (AUROC = 0.773 vs. 0.717, p < 0.001).

Conclusion

Here, we designed an easy-to-use clinically predictive tool for assessing 90-day mortality risk of viral pneumonia. It can accurately stratify hospitalized patients with viral pneumonia into relevant risk categories and could provide guidance to make further clinical decisions.

Influenza A H1N1 Community-Acquired Pneumonia: Characteristics and Risk Factors-A Case-Control Study

Introduction

Influenza A H1N1 community-acquired pneumonia (CAP) is a quite frequent respiratory disease. Despite being considered more serious than other CAPs, there are very few studies comparing its characteristics with noninfluenza CAP. We aim to establish the differences between pneumonia due to H1N1 virus and pneumonia not caused by H1N1 influenza virus and to determine the probability that a pneumonia is due to an H1N1 virus infection based on the most relevant variables.

Methods

We used a case-control study where cases were H1N1 CAP patients with confirmed microbiological diagnosis and controls were patients with CAP admitted to hospital. H1N1 and other influenza types were discarded among controls. We calculated the probability of being a case or control using multivariate logistic regression.

Results

We included 99 cases and 270 controls. Cases were younger than controls (53 vs 71 years, respectively). Mortality was much higher for H1N1 patients (13% vs 0.3%), and admission to intensive care unit was more frequent for H1N1 cases. The variables most associated with presenting H1N1 CAP were bilateral affectation on chest X-rays (OR: 5.70; 95% CI 2.69-10.40), followed by presence of arthromyalgias, with cases presenting close to three times more arthromyalgias compared to controls. Low leukocytes count and high AST values were also significantly associated with H1N1 CAP. H1N1 CAPs are characterized by bilateral affectation, low leukocyte count, presence of arthromyalgias, and high AST.

Conclusions

A few and easy to obtain clinical parameters might be extremely useful to distinguish H1N1 CAP from CAPs of other origin.

Incidence, Etiology, and Outcomes of Community-Acquired Pneumonia: A Population-Based Study

Background

The microbial etiology of community-acquired pneumonia (CAP) is often unclear in clinical practice, and previous studies have produced variable results. Population-based studies examining etiology and incidence are lacking. This study examined the incidence and etiology of CAP requiring hospitalization in a population-based cohort as well as risk factors and outcomes for specific etiologies.

Methods

Consecutive admissions due to CAP in Reykjavik, Iceland were studied. Etiologic testing was performed with cultures, urine-antigen detection, and polymerase chain reaction analysis of airway samples. Outcomes were length of stay, intensive care unit admission, assisted ventilation, and mortality.

Results

The inclusion rate was 95%. The incidence of CAP requiring hospitalization was 20.6 cases per 10000 adults/year. A potential pathogen was detected in 52% (164 of 310) of admissions and in 74% (43 of 58) with complete sample sets. Streptococcuspneumoniae was the most common pathogen (61 of 310, 20%; incidence: 4.1/10000). Viruses were identified in 15% (47 of 310; incidence: 3.1/10000), Mycoplasmapneumoniae were identified in 12% (36 of 310; incidence: 2.4/10000), and multiple pathogens were identified in 10% (30 of 310; incidence: 2.0/10000). Recent antimicrobial therapy was associated with increased detection of M pneumoniae (P < .001), whereas a lack of recent antimicrobial therapy was associated with increased detection of S pneumoniae (P = .02). Symptoms and outcomes were similar irrespective of microbial etiology.

Conclusions

Pneumococci, M pneumoniae, and viruses are the most common pathogens associated with CAP requiring hospital admission, and they all have a similar incidence that increases with age. Symptoms do not correlate with specific agents, and outcomes are similar irrespective of pathogens identified.

Diagnosis and treatment of community-acquired pneumonia in adults: 2016 clinical practice guidelines by the Chinese Thoracic Society, Chinese Medical Association

Community‐acquired pneumonia (CAP) in adults is an infectious disease with high morbidity in China and the rest of the world. With the changing pattern in the etiological profile of CAP and advances in medical techniques in diagnosis and treatment over time, Chinese Thoracic Society of Chinese Medical Association updated its CAP guideline in 2016 to address the standard management of CAP in Chinese adults. Extensive and comprehensive literature search was made to collect the data and evidence for experts to review and evaluate the level of evidence. Corresponding recommendations are provided appropriately based on the level of evidence. This updated guideline covers comprehensive topics on CAP, including aetiology, antimicrobial resistance profile, diagnosis, empirical and targeted treatments, adjunctive and supportive therapies, as well as prophylaxis. The recommendations may help clinicians manage CAP patients more effectively and efficiently. CAP in pediatric patients and immunocompromised adults is beyond the scope of this guideline. This guideline is only applicable for the immunocompetent CAP patients aged 18 years and older. The recommendations on selection of antimicrobial agents and the dosing regimens are not mandatory. The clinicians are recommended to prescribe and adjust antimicrobial therapies primarily based on their local etiological profile and results of susceptibility testing, with reference to this guideline.

Clinical Features and Courses of Adenovirus Pneumonia in Healthy Young Adults during an Outbreak among Korean Military Personnel

Background

The number of pneumonia patients increased suddenly in Korean military hospitals in late December 2014, indicating the urgent need for an epidemic outbreak investigation.

Methods

We conducted a prospective study of pneumonia etiology among immunocompetent young adults admitted to Daejeon Armed Forces hospital. Patient blood and sputum samples were subjected to conventional culture, serology, and polymerase chain reaction tests for respiratory viruses and atypical pathogens.

Results

From January to May 2015, we enrolled 191 (189 male) adults with pneumonia; the mean age was 20.1 ± 1.3 years. Five patients had severe pneumonia, and one died. Pathogenic human adenoviruses were most common (HAdV, 153/191 [80.1%]), indicating a HAdV pneumonia outbreak. Genotyping of 35 isolates indicated that 34 matched HAdV-55 and one matched HAdV-2. HAdV pneumonia infected recruit trainees most frequently. High and prolonged fever, nasal congestion, sore throat, and pharyngeal inflammation were significantly more common in the HAdV pneumonia group, compared to patients with other or unknown causes of pneumonia. Only 12% of HAdV pneumonia patients displayed leukocytosis, whereas febrile leukopenia (62.7%) and thrombocytopenia (41%) were commonly observed. HAdV pneumonia patient chest CT scans displayed ground glass opacity (with or without septal thickness) with consolidation in 50.0% of patients.

Conclusions

An outbreak of HAdV respiratory infection occurred at the Korean military training center. HAdV pneumonia exhibited specific laboratory and clinical features, and although most patients were cured without complication, some progressed to respiratory failure and fatality. Therefore, HAdV vaccine should be provided to military trainees in Korea.

The frequency of influenza and bacterial coinfection: a systematic review and meta-analysis

Aim

Coinfecting bacterial pathogens are a major cause of morbidity and mortality in influenza. However, there remains a paucity of literature on the magnitude of coinfection in influenza patients.

Method

A systematic search of MeSH, Cochrane Library, Web of Science, SCOPUS, EMBASE, and PubMed was performed. Studies of humans in which all individuals had laboratory confirmed influenza, and all individuals were tested for an array of common bacterial species, met inclusion criteria.

Results

Twenty‐seven studies including 3215 participants met all inclusion criteria. Common etiologies were defined from a subset of eight articles. There was high heterogeneity in the results (I² = 95%), with reported coinfection rates ranging from 2% to 65%. Although only a subset of papers were responsible for observed heterogeneity, subanalyses and meta‐regression analysis found no study characteristic that was significantly associated with coinfection. The most common coinfecting species were Streptococcus pneumoniae and Staphylococcus aureus, which accounted for 35% (95% CI, 14%–56%) and 28% (95% CI, 16%–40%) of infections, respectively; a wide range of other pathogens caused the remaining infections. An assessment of bias suggested that lack of small‐study publications may have biased the results.

Conclusions

The frequency of coinfection in the published studies included in this review suggests that although providers should consider possible bacterial coinfection in all patients hospitalized with influenza, they should not assume all patients are coinfected and be sure to properly treat underlying viral processes. Further, high heterogeneity suggests additional large‐scale studies are needed to better understand the etiology of influenza bacterial coinfection.

Viral Infection in Adults with Severe Acute Respiratory Infection in Colombia

OBJECTIVES

To identify the viral aetiology in adult patients with severe acute respiratory infection (SARI) admitted to sentinel surveillance institutions in Bogotá in 2012.

DESIGN

A cross-sectional study was conducted in which microarray molecular techniques for viral identification were used on nasopharyngeal samples of adult patients submitted to the surveillance system, and further descriptions of clinical features and relevant clinical outcomes, such as mortality, need for critical care, use of mechanical ventilation and hospital stay, were obtained.

SETTING

Respiratory infections requiring hospital admission in surveillance centres in Bogotá, Colombia.

PARTICIPANTS

Ninety-one adult patients with acute respiratory infection (55% were female).

MEASUREMENTS

Viral identification, intensive care unit admission, hospital stay, and mortality.

RESULTS

Viral identification was achieved for 63 patients (69.2%). Comorbidity was frequently identified and mainly involved chronic pulmonary disease or pregnancy. Influenza, Bocavirus and Adenovirus were identified in 30.8%, 28.6% and 18.7% of the cases, respectively. Admission to the intensive care unit occurred in 42.9% of the cases, while mechanical ventilation was required for 36.3%. The average hospital stay was 9.9 days, and mortality was 15.4%. Antibiotics were empirically used in 90.1% of patients.

CONCLUSIONS

The prevalence of viral aetiology of SARI in this study was high, with adverse clinical outcomes, intensive care requirements and high mortality.

Mortality prediction to hospitalized patients with influenza pneumonia: PO2 /FiO2 combined lymphocyte count is the answer

INTRODUCTION

Community-acquired pneumonia (CAP) severity scores perform well in predicting mortality of CAP patients, but their applicability in influenza pneumonia is powerless.

OBJECTIVES

The aim of our research was to test the efficiency of PO₂ /FiO₂ and CAP severity scores in predicting mortality and intensive care unit (ICU) admission with influenza pneumonia patients.

METHODS

We reviewed all patients with positive influenza virus RNA detection in Beijing Chao-Yang Hospital during the 2009-2014 influenza seasons. Outpatients, inpatients with no pneumonia and incomplete data were excluded. We used receiver operating characteristic curves (ROCs) to verify the accuracy of severity scores or indices as mortality predictors in the study patients.

RESULTS

Among 170 hospitalized patients with influenza pneumonia, 30 (17.6%) died. Among those who were classified as low-risk (predicted mortality 0.1%-2.1%) by pneumonia severity index (PSI) or confusion, urea, respiratory rate, blood pressure, age ≥65 year (CURB-65), the actual mortality ranged from 5.9 to 22.1%. Multivariate logistic regression indicated that hypoxia (PO₂ /FiO₂  ≤ 250) and lymphopenia (peripheral blood lymphocyte count <0.8 × 10⁹ /L) were independent risk factors for mortality, with OR value of 22.483 (95% confidence interval 4.927-102.598) and 5.853 (95% confidence interval 1.887-18.152), respectively. PO₂ /FiO₂ combined lymphocyte count performed well for mortality prediction with area under the curve (AUC) of 0.945, which was significantly better than current CAP severity scores of PSI, CURB-65 and confusion, respiratory rate, blood pressure, age ≥65 years for mortality prediction (P < 0.001). The scores or indices for ICU admission prediction to hospitalized patients with influenza pneumonia confirmed a similar pattern and PO₂ /FiO₂ combined lymphocyte count was also the best predictor for predicting ICU admission.

CONCLUSION

In conclusion, we found that PO₂ /FiO₂ combined lymphocyte count is simple and reliable predictor of hospitalized patients with influenza pneumonia in predicting mortality and ICU admission. When PO₂ /FiO₂  ≤ 250 or peripheral blood lymphocyte count <0.8 × 10⁹ /L, the clinician should pay great attention to the possibility of severe influenza pneumonia.

Children hospitalised with influenza-associated pneumonia during the 2009 pandemic displayed increased disease severity

AIM

The precise role of the influenza virus in the morbidity of hospitalised paediatric pneumonia cases is unknown. We identified how many cases hospitalised during the 2009 pandemic had influenza-associated pneumonia and assessed their severity.

METHODS

Children admitted to three Israeli medical centres during the 2009 influenza pandemic with radiologically confirmed pneumonia were prospectively screened for influenza. We compared the clinical, laboratory and radiologic findings for positive and negative cases.

RESULTS

The pandemic H1N1 virus was detected in 89 (30%) of the 297 patients hospitalised for pneumonia and 55% of the Paediatric Intensive Care Unit admissions for pneumonia. There were no significant differences in the rates of underlying disease between the two groups. Logistic regression analysis revealed that children with pandemic H1N1 virus-associated pneumonia had significantly increased disease severity than those without, with a higher incidence of hypoxemia (41.6% versus 24%) with a relative risk (RR) of 2.2, higher rate of paediatric intensive care unit admission (16.9% versus 5.8%, RR of 2.7) and higher rate of mechanical ventilation (10.1% versus 2.4%, RR:4.4).

CONCLUSION

During the 2009 influenza pandemic, 30% of children hospitalised for pneumonia had the influenza infection and these children displayed increased disease severity.

Mortality in healthcare-associated pneumonia in a low resistance setting: a prospective observational study

BACKGROUND

The classification of pneumonia as community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP) has implications for selection of initial antimicrobial therapy. HCAP has been associated with an increased prevalence of multidrug-resistant (MDR) pathogens and with high mortality leading to recommendations for broad empiric therapy.

METHODS

We performed a prospective, population-based study on consecutive adults (≥ 18 years) admitted for pneumonia over 1 calendar year. Patients were classified by pneumonia type and severity. Microbial etiologic testing was performed on all patients. Treatment, length of stay, and mortality rates were compared.

RESULTS

A total of 373 admissions were included, 94% of all eligible patients. They were classified as CAP (n = 236, 63%) or HCAP (n = 137, 37%). Chronic underlying disease was more commonly found among patients with HCAP compared with CAP (74% vs 51%, p < 0.001). Mycoplasma pneumoniae was more common among CAP patients (p < 0.01), while gram-negative bacteria were more often found among HCAP patients (p = 0.02). No MDR pathogens were detected, and rates of Staphylococcus aureus were similar in the two groups. HCAP patients were not more likely to receive ineffective initial antimicrobial therapy. HCAP patients had worse prognostic scores on admission and higher in-house mortality than CAP patients (10% vs 1%, respectively, p < 0.01).

CONCLUSIONS

Even in a low resistance setting, patients with HCAP have increased mortality compared with patients with CAP. This is most likely explained by a higher prevalence of co-morbidities. Our data do not support broad-spectrum empiric antibiotic therapy for HCAP.

Mortality and severity evaluation by routine pneumonia prediction models among Japanese patients with 2009 pandemic influenza A (H1N1) pneumonia

BACKGROUND

Influenza-related pneumonia, referred to as influenza pneumonia, was reported relatively more frequently during a recent influenza pandemic in 2009. The validity of adapting routine pneumonia severity prediction models for various types of pneumonia is unclear.

METHODS

We conducted a nationwide survey to evaluate influenza pneumonia among adult patients in Japan. Questionnaires were sent to physicians working in departments of respiratory medicine at 2491 hospitals. Both the outcome and pneumonia severity, using invasive positive pressure ventilation (IPPV) as an indicator, were evaluated by routine pneumonia severity index (PSI), CURB-65 (confusion, urea, respiratory rate, blood pressure, and age ≥ 65 years), and A-DROP (age, dehydration, respiration, disorientation, and blood pressure).

RESULTS

Data collected from 320 patients with influenza pneumonia, including 25 cases (7.8%) of death and 43 (13.4%) of IPPV, were analyzed. Although all routine prediction models showed that higher mortality tended to be associated with a higher risk class/grade, the actual mortality rates were higher than predicted. The risk class of mortality calculated by the PSI was influenced by pneumonia patterns. Although pneumonia severity was similarly predicted, the types of pneumonia also affected severity in all prediction models. A-DROP showed the highest accuracy on receiver operating characteristic analysis for both mortality and severity.

CONCLUSIONS

CURB-65 and A-DROP are fair predictors of mortality regardless of pneumonia patterns. However, the current pneumonia prediction models may underestimate the severity and appropriate site of care for patients with influenza pneumonia.

Complications and factors associated with severity of influenza in hospitalized children and adults during the pandemic wave of A(H1N1)pdm2009 infections--the Fluco French cohort

BACKGROUND

The emergence of novel A(H1N1)pdm2009 virus threatened to lead to frequent severe manifestations.

OBJECTIVES

To describe the clinical, virological, and biological characteristics of the disease and identify the factors associated with severe presentations.

STUDY DESIGN

This prospective multicenter study recruited consecutive hospitalized patients with confirmed A(H1N1)pdm2009 disease. Clinical, virological and biological assessments were carried out at inclusion and 30 days post-inclusion. Disease manifestations were assessed by an adjudication committee using pre-identified definitions of complications and severity scores.

RESULTS

The study analyzed from November 30th, 2009 to February 8th, 2010, 40 hospitalized patients, 21 children and 19 adults. Eighteen (45%) were considered to have severe presentations. Except age, main characteristics in children and adults did not differ. The majority (18/21) of children and all adults had a respiratory presentation; extra-respiratory manifestations tended to be more frequent in children (12 vs. 6, P=0.10). Two children against 5 adults presented acute respiratory distress syndrome (ARDS, P=0.23), but more children suffered respiratory failure (7 vs. 1, P=0.046) without ARDS. At day 30, one death had occurred in each group. The main factor associated with non-severe presentation was an early (<48 h) implementation of oseltamivir treatment (P=0.038).

CONCLUSIONS

Although the study failed to achieve its main objective, due mainly to the difficulty of carrying a study of this nature in the midst of a pandemic, it allowed the description of a panel of unusual and complicated forms and confirmed the added value of early oseltamivir treatment in limiting severity in hospitalized children and adults.

Hospital admission decision for patients with community-acquired pneumonia

Where to treat patients is probably the single most important decision in the management of community-acquired pneumonia (CAP), with a substantial impact on both patients' outcomes and health-care costs. Several factors can contribute to the decision of the site of care for CAP patients, including physicians' experience and clinical judgment and severity scores developed to predict mortality, as well as social and health-care-related issues. The recognition, both in the community and in the emergency department, of the presence of severe sepsis and acute respiratory failure and the coexistence with unstable comorbidities other than CAP are indications for hospital admission. In all the other cases, physician's choice to admit CAP patients should be validated against at least one objective tool of risk assessment, with a clear understanding of each score's limitations.