Influenza Pneumonia Patients Research Articles

Impact of pulmonary hypertension on outcomes of influenza pneumonia patients: A nationwide analysis

Background: Pulmonary hypertension can be a significant cause of morbidity and mortality for influenza pneumonia (IP) patients. We performed analysis from the multicentric National Inpatient Sample (NIS) datasets to study the influence of disorders of pulmonary hypertension on the outcomes in IP patients. Methods: We used NIS 2016–2019 to identify IP hospitalizations (between 22–90 years of age) and divided them into with and without pulmonary hypertension (herein PHDPC). We analyzed for differences in demographics, primary (all-cause mortality) and other secondary outcomes. Results: Of 353,460 IP hospitalizations, 6.5% had PHDPC. The PHDPC cohort had more elderly, females, African Americans, and Medicare enrollees predominantly with more hospitalizations to large bed sizes and urban teaching hospitals, and higher cardiovascular comorbidities than non-PHDPC cohort. PHDPC had higher primary outcomes for in-hospital mortality (8.9% vs. 5.8%, adjusted OR 1.4, 95% CI: 1.21–1.61). PHDPC also had higher secondary outcomes for sepsis, septic shock, cardiogenic shock and need for mechanical ventilation, prolonged ventilation, hospital resource utilization for longer mean length of stay, mean hospitalization cost, transfer to other facilities or need for home health care, and high risk for 30-day readmission than the non-PHDPC cohort. Conclusions: With our study, we provide contemporary data for the outcomes of IP inpatients with pulmonary hypertension and depict worse outcomes for mortality, complications, and hospital resource utilization. Although our study does not include stratification for vaccination status for the outcome, primary care physicians, cardiologists, and pulmonologists should pro-actively educate patients on preventive strategies during the flu season.

Bacterial Co- or Superinfection in Patients Treated in Intensive Care Unit with COVID-19- and Influenza-Associated Pneumonia.

Viral pneumonia is frequently complicated by bacterial co- or superinfection (c/s) with adverse effects on patients' outcomes. However, the incidence of c/s and its impact on the outcomes of patients might be dependent on the type of viral pneumonia. We performed a retrospective observational study in patients with confirmed COVID-19 pneumonia (CP) or influenza pneumonia (IP) from 01/2009 to 04/2022, investigating the incidence of c/s using a competing risk model and its impact on mortality in these patients in a tertiary referral center using multivariate logistic regressions. Co-infection was defined as pulmonary pathogenic bacteria confirmed in tracheal aspirate or bronchoalveolar lavage within 48 h after hospitalization. Superinfection was defined as pulmonary pathogenic bacteria detected in tracheal aspirate or bronchoalveolar lavage 48 h after hospitalization. We examined 114 patients with CP and 76 patients with IP. Pulmonary bacterial co-infection was detected in 15 (13.2%), and superinfection was detected in 50 (43.9%) of CP patients. A total of 5 (6.6%) co-infections (p = 0.2269) and 28 (36.8%) superinfections (p = 0.3687) were detected in IP patients. The overall incidence of c/s did not differ between CP and IP patients, and c/s was not an independent predictor for mortality in a study cohort with a high disease severity. We found a significantly higher probability of superinfection for patients with CP compared to patients with IP (p = 0.0017).

Prevalence and patient risk factors for pneumothorax in COVID-19 and in influenza pneumonia: a nationwide comparative analysis.

Pneumothorax is a rare but deadly complication in patients who require mechanical ventilation. As with any condition associated with acute respiratory distress syndrome (ARDS), coronavirus disease 2019 (COVID-19) is known to be associated with pneumothorax. However, in the literature, comparative data on the risk factors for pneumothorax in COVID-19 and other diseases like influenza are limited. The aim of this study is to determine the prevalence and risk factors for pneumothorax in hospitalized COVID-19 patients and compare them with influenza pneumonia patients. This study is a retrospective analysis of the National Inpatient Sample (NIS) 2020 database cohort. Univariate and multivariate logistic regression were used to identify the prevalence and risk factors for pneumothorax in COVID-19 patients and compared with the risk of pneumothorax in influenza patients. The NIS 2020 database includes 1,608,980 hospitalizations of COVID-19 patients, of which 22,545 [95% confidence interval (CI): 21,491-23,598] (1.4%) developed pneumothorax. On multivariate analysis, factors associated with pneumothorax in COVID-19 included patient age of 41-64 years; male sex; Hispanics, Native Americans, and other races; hospitals with large-bed size; privately owned hospitals; urban teaching hospitals; hospitals in the southern United States (US); stroke; malnutrition; chronic obstructive pulmonary disease (COPD); bronchiectasis; pulmonary fibrosis; liver disease; non-invasive and invasive ventilation; and extracorporeal membrane oxygenation (ECMO). Of 184,980 influenza patients, 1,630 (95% CI: 1,448-1,811) (0.88%) developed pneumothorax. The prevalence of pneumothorax was higher (1.4%) in COVID-19 patients compared to patients with influenza pneumonia (0.88%). COVID-19 patients who develop pneumothorax have a poor prognosis. Several risk factors for the development of pneumothorax were identified. Patients with these risk factors should be prioritized in applying evidence-based guidelines to prevent pneumothorax.

Simultaneous profiling and quantification of 25 eicosanoids in human serum by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry

The eicosanoid metabolic pathway is responsible for mediating the production of various inflammatory factors that are closely related to the development and resolution of inflammation. In biological matrices, the major quantifying obstacles were shown to be the oxidation and low quantities of eicosanoids and their metabolites. This study aimed to develop a reliable, sensitive ultrahigh-performance liquid chromatography coupled to a tandem mass spectrometry (UPLC–MS/MS) method to quantify eicosanoids in human serum. Solid-phase extraction (SPE) was used for sample preparation. The approach employed continuous ionization polarity switching. The target eicosanoids showed good linearity over the investigated concentration range (r2 > 0.99). The recovery rates were over 64.5%, and the matrix effects ranged from 73.0 to 128.0%. The limits of quantification were 0.048 ~ 0.44 ng/mL. For the broad concentration range, the CV % for accuracy and precision were less than ± 20%. We successfully applied this method to rapidly analyse 74 serum samples from severe influenza pneumonia, severe bacterial pneumonia and healthy individuals. Eicosanoid-related metabolite concentrations were quantified within a range similar to those of previously published articles. Compared to healthy individuals, our application found that 20-HETE, 14,15-EET and 11,12-EET were upregulated in severe influenza pneumonia patients, while LTB4 was downregulated. 8-HETE and 5-HETE were upregulated in severe bacterial pneumonia patients, while LTE4 was downregulated. This approach provides a means for monitoring the low quantities of eicosanoids in biological matrices, and our finding that different characteristic metabolite profiles may help discriminate the induction of severe pneumonia patients.

Distinguishing COVID-19 From Influenza Pneumonia in the Early Stage Through CT Imaging and Clinical Features

BackgroundBoth coronavirus disease 2019 (COVID-19) and influenza pneumonia are highly contagious and present with similar symptoms. We aimed to identify differences in CT imaging and clinical features between COVID-19 and influenza pneumonia in the early stage and to identify the most valuable features in the differential diagnosis.MethodsSeventy-three patients with COVID-19 confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and 48 patients with influenza pneumonia confirmed by direct/indirect immunofluorescence antibody staining or RT-PCR were retrospectively reviewed. Clinical data including course of disease, age, sex, body temperature, clinical symptoms, total white blood cell (WBC) count, lymphocyte count, lymphocyte ratio, neutrophil count, neutrophil ratio, and C-reactive protein, as well as 22 qualitative and 25 numerical imaging features from non-contrast-enhanced chest CT images were obtained and compared between the COVID-19 and influenza pneumonia groups. Correlation tests between feature metrics and diagnosis outcomes were assessed. The diagnostic performance of each feature in differentiating COVID-19 from influenza pneumonia was also evaluated.ResultsSeventy-three COVID-19 patients including 41 male and 32 female with mean age of 41.9 ± 14.1 and 48 influenza pneumonia patients including 30 male and 18 female with mean age of 40.4 ± 27.3 were reviewed. Temperature, WBC count, crazy paving pattern, pure GGO in peripheral area, pure GGO, lesion sizes (1–3 cm), emphysema, and pleural traction were significantly independent associated with COVID-19. The AUC of clinical-based model on the combination of temperature and WBC count is 0.880 (95% CI: 0.819–0.940). The AUC of radiological-based model on the combination of crazy paving pattern, pure GGO in peripheral area, pure GGO, lesion sizes (1–3 cm), emphysema, and pleural traction is 0.957 (95% CI: 0.924–0.989). The AUC of combined model based on the combination of clinical and radiological is 0.991 (95% CI: 0.980–0.999).ConclusionCOVID-19 can be distinguished from influenza pneumonia based on CT imaging and clinical features, with the highest AUC of 0.991, of which crazy-paving pattern and WBC count play most important role in the differential diagnosis.

Predicting acute respiratory distress syndrome in influenza pneumonia patients using delta mean platelet volume

BackgroundPatients with influenza pneumonia are at high risk of rapid progression to acute respiratory distress syndrome (ARDS). Mean platelet volume (MPV), which reflects platelet size, is considered to be a crucial inflammatory marker. The study aim was to investigate the role of delta mean platelet volume (delta MPV) in predicting ARDS in patients with influenza pneumonia.MethodsThis retrospective study was conducted in a tertiary care centre in southern Thailand. Adult patients diagnosed with influenza pneumonia were enrolled from January 2015 to December 2020. Demographic data, laboratory investigations including delta MPV (MPV on day 2 minus MPV on day 1), management records, and clinical outcomes were collected for analysis. The study population was divided into two groups according to the development of ARDS.ResultsDuring the study, 1240 patients with laboratory-confirmed influenza were screened and 212 pneumonia patients were enrolled. Fifty-six patients (26.4%) met the diagnostic criteria for ARDS during hospitalization. Delta MPV was significantly higher in the ARDS group compared to that in the non-ARDS group (1.0 fL vs 0.2 fL, p < 0.001). Multivariable logistic regression revealed that delta MPV is an independent predictor of ARDS (OR 17.37; 95% CI 6.5–46.4; p < 0.001). Receiver operating characteristic curve analysis indicated a cut-off value of 0.7 fL for delta MPV (sensitivity 80.36%, specificity 80.77%) to predict ARDS in patients with influenza pneumonia.ConclusionsDelta MPV strongly predicts ARDS in influenza pneumonia patients. Implementation of delta MPV may be useful in identifying at-risk patients who will require intensive care and ARDS prevention.

Comparison of clinical features and outcomes in COVID-19 and influenza pneumonia patients requiring intensive care unit admission

BackgroundLittle is known in distinguishing clinical features and outcomes between coronavirus disease-19 (COVID-19) and influenza (FLU).Materials/methods Retrospective, single-centre study including patients with COVID-19 or FLU pneumonia admitted to the Intensive care Unit (ICU) of Policlinico Umberto I (Rome). Aims were: (1) to assess clinical features and differences of patients with COVID-19 and FLU, (2) to identify clinical and/or laboratory factors associated with FLU or COVID-19 and (3) to evaluate 30-day mortality, bacterial superinfections, thrombotic events and invasive pulmonary aspergillosis (IPA) in patients with FLU versus COVID-19.ResultsOverall, 74 patients were included (19, 25.7%, FLU and 55, 74.3%, COVID-19), median age 67 years (58–76). COVID-19 patients were more male (p = 0.013), with a lower percentage of COPD (Chronic Obstructive Pulmonary Disease) and chronic kidney disease (CKD) (p = 0.001 and p = 0.037, respectively) than FLU. SOFA score was higher (p = 0.020) and lymphocytes were significantly lower in FLU than in COVID-19 [395.5 vs 770.0 cells/mmc, p = 0.005]. At multivariable analysis, male sex (OR 6.1, p < 0.002), age > 65 years (OR 2.4, p = 0.024) and lymphocyte count > 725 cells/mmc at ICU admission (OR 5.1, p = 0.024) were significantly associated with COVID-19, whereas CKD and COPD were associated with FLU (OR 0.1 and OR 0.16, p = 0.020 and p < 0.001, respectively). No differences in mortality, bacterial superinfections and thrombotic events were observed, whereas IPA was mostly associated with FLU (31.5% vs 3.6%, p = 0.0029).ConclusionsIn critically ill patients, male sex, age > 65 years and lymphocytes > 725 cells/mmc are related to COVID-19. FLU is associated with a significantly higher risk of IPA than COVID-19.

Differentiation of Chest CT Findings Between Influenza Pneumonia and COVID-19: Interobserver Agreement Between Radiologists

ObjectivesTo investigate the chest CT and clinical characteristics of COVID-19 pneumonia and H1N1 influenza, and explore the radiologist diagnosis differences between COVID-19 and influenza.Materials and methodsThis cross-sectional study included a total of 43 COVID-19-confirmed patients (24 men and 19 women, 49.90 ± 18.70 years) and 41 influenza-confirmed patients (17 men and 24 women, 61.53 ± 19.50 years). Afterwards, the chest CT findings were recorded and 3 radiologists recorded their diagnoses of COVID-19 or of H1N1 influenza based on the CT findings.ResultsThe most frequent clinical symptom in patients with COVID-19 and H1N1 pneumonia were dyspnea (96.6%) and cough (62.5%), respectively. The CT findings showed that the COVID-19 group was characterized by GGO (88.1%), while the influenza group had features such as GGO (68.4%) and consolidation (66.7%). Compared to the influenza group, the COVID-19 group was more likely to have GGO (88.1% vs. 68.4%, p = 0.032), subpleural sparing (69.0% vs. 7.7%, p <0.001) and subpleural band (50.0% vs. 20.5%, p = 0.006), but less likely to have pleural effusion (4.8% vs. 33.3%, p = 0.001). The agreement rate between the 3 radiologists was 65.8%.ConclusionConsidering similarities of respiratory infections especially H1N1 and COVID-19, it is essential to introduce some clinical and para clinical modalities to help differentiating them. In our study we extracted some lung CT scan findings from patients suspected to COVID-19 as a newly diagnosed infection comparing with influenza pneumonia patients.

Differential circRNA expression profiles in peripheral blood mononuclear cells among mild and severe influenza-associated pneumonia patients

Objective: To explore the difference in the expression profile of circular RNA in peripheral blood mononuclear cells between patients with mild and severe influenza pneumonia. Methods: From December 2018 to March 2019, 10 inpatients with mild and 10 inpatients with severe influenza pneumonia admitted to the Department of Infection and Clinical Microbiology of Beijing Chaoyang Hospital were included. Clariom™ D gene chip was used to explore the circRNA expression profiles of peripheral blood mononuclear cells (PBMC) isolated from the patients. The absolute value of the fold change (FC value)>2 and P<0.05 were used as the criteria to screen the differentially expressed circRNA, and the gene ontology (GO) enrichment analysis and the Kyoto Encyclopedia of Gene and Genome database (Kyoto Encyclopedia of Genes and Genomes, KEGG) signal pathway enrichment analysis were also performed. Results: The age of mild patients [M (P25, P75)] was 62.0 (34.5, 69.8) years old, including 4 males; the age of severe patients [M (P25, P75)] was 50.0 (37.0, 60.0) years old, all were males. A total of 137 differentially expressed circRNAs in PBMCs of mild and severe patients were screened. The numbers of up-regulated and down-regulated circRNAs in mild patients were 101 and 36, respectively. Among them, hsa_circ_0091073 (FC value=160.898, P<0.05) was the most significantly up-regulated circRNA and hsa_circ_0092219 (FC value =-17.630, P<0.05) was the most significantly down-regulated circRNA. GO enrichment analysis showed that a total of 111 secondary GO items were significantly associated with related differential expression of circRNA (P<0.05). The GO terms associated with upregulated circRNAs included DNA-templated transcription, regulation of DNA-templated transcription, regulation of transcription from RNA polymerase Ⅱ promoter, etc.; The GO terms associated with downregulated circRNAs included neutrophil degranulation, killing of cells of other organism, defense response to fungus, etc. KEGG signaling pathway analysis showed that there were 37 metabolic pathways related to differentially expressed circRNAs (P<0.05). Signaling pathways related to up-regulated circRNAs included nuclear factor-κB (NF-κB) signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, tumor necrosis factor (TNF) signaling pathway, etc. Signaling pathways related to down-regulation of circRNAs included cancer transcription disorders, folate carbon pool, and other types of O-glycan biosynthesis. Conclusion: The expression of circRNA in PBMC of mild and severe influenza pneumonia patients is significantly different, and it may play a role in the pathogenic mechanism of influenza pneumonia through multiple signal pathways.

Sociodemographic, Clinical Characteristics, and Outcomes of Influenza Pneumonia Patients Admitted in a Tertiary Care Hospital in Karachi, Pakistan: Findings from a Cross-sectional Study.

To determine the sociodemographic, clinical characteristics, and outcomes of influenza pneumonia patients in tertiary care hospital, Karachi Pakistan. A cross-sectional study. The Aga Khan University Hospital Karachi Pakistan from January 2013 to December 2018. Methodology: All adult patients who were older than 18 years and suspected to have viral pneumonia were included in the study. Data were abstracted on 105 patientsand were entered on preformed proforma after reviewing the files of patients. Ninety-four (89.5%) patients were influenza positive and 15.2% (n=16) had been vaccinated. Around 92.4% (n=97), 81.9% (n=86) and 61.9% (n=65) patients had cough, fever and shortness of breath, respectively; and 63.8% (n=67), 16.2% (n=17), and 2.9% (n=3) patients had consolidation, nodules, and cavitation, respectively. Almost 91.4% (n=96) patients were given treatment and discharged home; however, 7.6% (n=8) died. Procalcitonin, creatinine, HCO3 , lactate, and bilirubin level were increased in 2nd group (mortality group) after 48 hours; however, the results were only significant for HCO3 (p = 0.035). Influenza pneumonia is very common in our population and older people are more likely to be affected by this disease. Patients can be prevented from adverse outcomes and complications, if diagnosed and treated in time. Key Words: Influenza, Clinical characteristics, Outcome, Patients.

Impact of Corticosteroid Administration within 7 Days of the Hospitalization for Influenza Pneumonia with Respiratory Failure: A Propensity Score Analysis Using a Nationwide Administrative Database.

Influenza pneumonia, which causes acute respiratory distress syndrome and multiple organ failure, has no established management protocol. Recently, corticosteroid therapy was used to treat coronavirus disease 2019 with respiratory failure; however, its effectiveness as a treatment for influenza pneumonia remains controversial. To investigate the impact of corticosteroid therapy for the early phase of severe influenza pneumonia, we compared influenza pneumonia patients with respiratory failure treated with or without corticosteroids within 7 days after hospital admission using a Japanese nationwide administrative database. The primary endpoint was the mortality rate. The secondary endpoints were duration of intensive-care unit management, invasive mechanical ventilation, and hospital stay. The inverse probability weighting method with estimated propensity scores was used to minimize the data collection bias. We included 3519 patients with influenza pneumonia with respiratory failure. Of these, 875 were treated with corticosteroids. There was no significant difference between the groups regarding 30-day and 90-day mortality, duration of intensive-care unit management, invasive mechanical ventilation, and hospital stay. However, the in-hospital mortality rate was higher in the corticosteroid group. The use of systematic corticosteroid therapy in patients with influenza pneumonia was associated with a higher in-hospital mortality rate.

Diagnostic value of peripheral hematologic markers for coronavirus disease 2019 (COVID-19): A multicenter, cross-sectional study.

BackgroundTo determine the diagnostic value of hematologic markers for coronavirus disease 2019 (COVID‐19) and explore their relationship with disease severity.MethodsSubjects included 190 COVID‐19 patients, 190 healthy subjects, and 105 influenza pneumonia (IP) patients. COVID‐19 patients were divided into the ARDS and non‐ARDS groups. Routine blood examination, biochemistry indicator, days in hospital, body temperature, pneumonia severity index (PSI), CURB‐65, and MuLBSTA were recorded. Correlations between variables were assessed using Spearman's correlation analysis. Receiver operating characteristic (ROC) curves were used to study the accuracy of the various diagnostic tests.ResultsCompared with healthy subjects, COVID‐19 patients had lower white blood cell (WBC), lymphocyte, platelet, and hemoglobin levels; higher percentages of neutrophils and monocytes; lower percentages of lymphocytes and higher neutrophil‐to‐lymphocyte ratio (NLR), monocyte‐to‐lymphocyte ratio (MLR), and platelet‐to‐lymphocyte ratio (PLR) values (P < .05). COVID‐19 patients had higher WBC and neutrophil levels and lower percentages of lymphocytes compared to IP (P < .05). ROC curve analysis revealed that MLR had a high diagnostic value in differentiating COVID‐19 patients from healthy subjects, but not from IP patients. NLR showed significant positive correlations with PSI, CURB‐65, and MuLBSTA. Lymphocyte count was lower in the ARDS group and yielded a higher diagnostic value than the other variables.ConclusionsMonocyte‐to‐lymphocyte ratio showed an acceptable efficiency to separate COVID‐19 patients from healthy subjects, but failed to rule out IP patients. NLR may be a reliable marker to evaluate the disease severity of COVID‐19. Lymphocyte count may be useful to establish the early diagnosis of ARDS in the COVID‐19 patients.

Outcomes of severe H1N1 pneumoniae: A retrospective study at intensive care units

The incidence of acute respiratory distress syndrome (ARDS) and the mortality rate of H1N1 influenza pneumonia are unclear. The aim of this study is to investigate the clinical features and outcomes of adult patients admitted to intensive care units (ICUs) with H1N1 pneumonia related ARDS. This retrospective study included patients with confirmed H1N1 influenza pneumonia admitted to the ICUs of a medical center between July 2009 and May 2014. We investigated the patients' characteristics, clinical presentations, illness severities, and outcomes. Sixty-six patients were confirmed to have H1N1 influenza pneumonia requiring mechanical ventilation. Fifty-four of those patients (82%) developed ARDS, while their hospital mortality rate was 33% (22/66). There were no significant differences in the ICU and hospital mortality rates of the ARDS and non-ARDS patients. Among the ARDS patients, there were higher rates of solid malignant disease (22.8% vs. 2.8%, p=0.038) and sepsis (66.7% vs. 33.3%, p=0.020) and a higher mean tidal volume (8.9±1.8 vs. 7.8±1.9ml/kg, p=0.032) in the non-survivors than the survivors. Logistic regression analysis revealed that a high tidal volume (odds ratio=1.448, 95 % CI=1.033-2.030; p=0.032) and sequential organ failure assessment (SOFA) score (odds ratio=1.233, 95% CI=1.029-1.478; p=0.023) were the risk factors of hospital mortality. For H1N1 influenza pneumonia patients admitted to ICUs with mechanical ventilation, there is a high probability of developing ARDS with a modest mortality rate. For patients with ARDS due to H1N1 influenza pneumonia, the tidal volume and SOFA score are the predictors of hospital mortality.

Clinical features of Mycoplasma pneumoniae coinfection and need for its testing in influenza pneumonia patients.

To investigate the clinical features of coinfection due to Mycoplasma pneumoniae (M. pneumoniae), a common copathogen in influenza, in influenza pneumonia patients. We reviewed 4,465 patients with influenza who visited a tertiary care hospital emergency department in Seoul (Korea) from 2010 through 2016, and underwent immunoglobulin M (IgM) serology or polymerase chain reaction (PCR) for M. pneumoniae. Influenza pneumonia was defined as laboratory-confirmed influenza plus radiographic pneumonia. Patients with healthcare-associated pneumonia or non-mycoplasma bacterial coinfection were excluded. Clinical, laboratory, and radiographic findings and outcomes of the influenza pneumonia patients with and without M. pneumoniae coinfection were compared. Multivariable logistic regression analysis was performed to identify factors associated with the coinfection. Of 244 influenza pneumonia patients, 41 (16.8%) had M. pneumoniae coinfection. These patients were younger with a higher frequency of age of 5-10 years, and had higher white blood cell (WBC) and lymphocyte counts; lower concentration of C-reactive protein (CRP). The coinfection had no association with specific radiographic findings and poor outcome. Multivariable analysis showed the age of 5-10 years (adjusted odds ratio, 18.83; 95% confidence interval, 5.899-60.08; P<0.001) as the factor associated with the coinfection. M. pneumoniae coinfection in influenza pneumonia may be associated with the age of 5-10 years, and otherwise clinically indistinct from influenza pneumonia without the coinfection. This finding suggests the need for M. pneumoniae testing in patients aged 5-10 years with influenza pneumonia.

Characteristics of influenza pneumonia patients admitted to the ICU due to hypoxemic respiratory failure.

Hypoxemic respiratory failure due to influenza pneumonia during epidemic seasons sometimes may require mechanical ventilation support and intensive care unit (ICU) stay. We aimed to evaluate the characteristics and risk factors of influenza pneumonia patients admitted to our ICU due to hypoxemic respiratory failure. Patients admitted to our ICU between December 2015 and March 2016 who had hypoxemic respiratory failure due to clinically and radiologically suspected influenza pneumonia were enrolled. Twenty two patients (11 male) met the enrollment criteria. Median age and APACHE II score was 45 (36-63) years and 19 (13-25) respectively. Maximum set PEEP levels during mechanical ventilation was significantly lower in patients who survived [10 (8-10) vs 13 (10-16), p= 0.025)]. Deceased patients spent more time under a PaO2/FiO2 ratio below 100 [72 (24-90) vs. 0 (0-48) hours, p= 0.024]. Survival rate was 88% (7/8) in patients who had noninvasive ventilation (NIV) success while it was only 7% (1/14) in patients who had undergone invasive mechanical ventilation (p< 0.001). Overall mortality was 64%. Viral pneumonia may result in severe hypoxemic respiratory failure and ARDS especially during epidemic seasons. NIV success, time spent under a PaO2/FiO2 ratio below 100 and low serum albumin levels at admission may be predictors of severity of the disease and mortality.

Integrated, Multi-cohort Analysis Identifies Conserved Transcriptional Signatures across Multiple Respiratory Viruses

Respiratory viral infections are a significant burden to healthcare worldwide. Many whole genome expression profiles have identified different respiratory viral infection signatures, but these have not translated to clinical practice. Here, we performed two integrated, multi-cohort analyses of publicly available transcriptional data of viral infections. First, we identified a common host signature across different respiratory viral infections that could distinguish (1) individuals with viral infections from healthy controls and from those with bacterial infections, and (2) symptomatic from asymptomatic subjects prior to symptom onset in challenge studies. Second, we identified an influenza-specific host response signature that (1) could distinguish influenza-infected samples from those with bacterial and other respiratory viral infections, (2) was a diagnostic and prognostic marker in influenza-pneumonia patients and influenza challenge studies, and (3) was predictive of response to influenza vaccine. Our results have applications in the diagnosis, prognosis, and identification of drug targets in viral infections.

Incidence, seasonality and mortality associated with influenza pneumonia in Thailand: 2005-2008.

BackgroundData on the incidence, seasonality and mortality associated with influenza in subtropical low and middle income countries are limited. Prospective data from multiple years are needed to develop vaccine policy and treatment guidelines, and improve pandemic preparedness.MethodsDuring January 2005 through December 2008, we used an active, population-based surveillance system to prospectively identify hospitalized pneumonia cases with influenza confirmed by reverse transcriptase–polymerase chain reaction or cell culture in 20 hospitals in two provinces in Thailand. Age-specific incidence was calculated and extrapolated to estimate national annual influenza pneumonia hospital admissions and in-hospital deaths.ResultsInfluenza was identified in 1,346 (10.4%) of pneumonia patients of all ages, and 10 influenza pneumonia patients died while in the hospital. 702 (52%) influenza pneumonia patients were less than 15 years of age. The average annual incidence of influenza pneumonia was greatest in children less than 5 years of age (236 per 100,000) and in those age 75 or older (375 per 100,000). During 2005, 2006 and 2008 influenza A virus detection among pneumonia cases peaked during June through October. In 2007 a sharp increase was observed during the months of January through April. Influenza B virus infections did not demonstrate a consistent seasonal pattern. Influenza pneumonia incidence was high in 2005, a year when influenza A(H3N2) subtype virus strains predominated, low in 2006 when A(H1N1) viruses were more common, moderate in 2007 when H3N2 and influenza B co-predominated, and high again in 2008 when influenza B viruses were most common. During 2005–2008, influenza pneumonia resulted in an estimated annual average 36,413 hospital admissions and 322 in-hospital pneumonia deaths in Thailand.ConclusionInfluenza virus infection is an important cause of hospitalized pneumonia in Thailand. Young children and the elderly are most affected and in-hospital deaths are more common than previously appreciated. Influenza occurs year-round and tends to follow a bimodal seasonal pattern with substantial variability. The disease burden varies significantly from year to year. Our findings support a recent Thailand Ministry of Public Health (MOPH) decision to extend annual influenza vaccination to older adults and suggest that children should also be targeted for routine vaccination.

Severe human influenza infections in Thailand: oseltamivir treatment and risk factors for fatal outcome.

BackgroundInfluenza is often not recognized as an important cause of severe or fatal disease in tropical and subtropical countries in Southeast Asia. The extent to which Oseltamivir treatment may protect against a fatal outcome in severe influenza infections is not known. Thailand's National Avian Influenza Surveillance (NAIS) system affords a unique opportunity to describe the epidemiology of laboratory-confirmed severe and fatal human influenza infections.Methodology/Principal FindingsDuring January 2004 through December 2006, 11,641 notifications to the NAIS were investigated in 73 of 76 Thai provinces. Clinical and demographic data and respiratory swab specimens were collected and tested by PCR for influenza. Using the NAIS database, we identified all patients with laboratory confirmed human influenza (A/H3N2, A/H1N1 and Type B) infection. A retrospective medical record review was conducted on all fatal cases with laboratory confirmed influenza and from a sample of hospitalized cases in 28 provinces. The association of underlying risk factors, Oseltamivir treatment and risk of a fatal outcome were examined. Human influenza infections were identified in 2,075 (18%) cases. Twenty-two (1%) deaths occurred including seven deaths in children less than ten years of age. Thirty-five percent of hospitalized human influenza infections had chest X-ray confirmed pneumonia. Current or former smoking; advanced age, hypertension and underlying cardiovascular, pulmonary or endocrine disease were associated with a fatal outcome from human influenza infection. Treatment with Oseltamivir was statistically associated with survival with a crude OR of .11 (95% CI: 0.04–0.30) and .13 (95% CI: 0.04–0.40) after controlling for age.ConclusionsSevere and fatal human influenza infections were commonly identified in the NAIS designed to identify avian A/H5N1 cases. Treatment with Oseltamivir is associated with survival in hospitalized human influenza pneumonia patients.