c Recently, the newly emerged hypervirulent Klebsiella pneumoniae strain (hvKP) has caused great concern globally, but the clinical features and molecular characteristics of bacteremia caused by hvKP are rarely reported in mainland China. Seventy patients with K. pneumoniae bacteremia were investigated to study the clinical features of hvKP infection from 2008 till 2012 in Beijing Chao-Yang Hospital. The molecular characteristics of the hvKP strains were also studied using PCR, multilocus sequence typing, and pulsed-field gel electrophoresis (PFGE) methods. hvKP was identified in 31.4% of the patients with K. pneumoniae bacteremia, which displayed 4 serotypes (K1, K2, K20, and K57). Patients with hvKP infection tended to have no underlying diseases compared to those with classic K. pneumoniae (cKP). More hvKP-positive patients (95.5%) had community-acquired infection than did cKP-infected patients (35.4%) (P < 0.001). The 30-day mortality rate was lower in hvKP-infected patients than in cKPinfected patients (4.5% compared to 16.7%). Resistance to tested antimicrobials was significantly greater in cKP-than in hvKPinfected patients. Two extended-spectrum-beta-lactamase (ESBL)-producing hvKP strains were found. Seven novel sequence types (STs) and 4 new alleles of K. pneumoniae were revealed. A strong correlation was found between two STs (ST23, ST1265) and the K1 serotype. The hvKP isolates (n ‫؍‬ 22) had 14 different PFGE patterns, and among them 10 K1 isolates shared similar PFGE patterns. The emerging hvKP strain was prevalent in patients with severe community-acquired infections in healthy individuals in China. Identification of ESBL-producing hvKP strains in hvKP-infected patients will facilitate clinical management of hvKP infection.

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.

BackgroundBetter knowledge of distribution of respiratory viruses (RVs) in adolescents and adults with community-acquired pneumonia (CAP) is needed.MethodsTo investigate the RVs etiology among adolescents and adults with CAP, according to age and pneumonia severity index (PSI), a multi-center, prospective study was conducted from November 2010 to April 2012. Fifteen RVs were tested by polymerase chain reaction (PCR). Bacteria were detected by urinary antigen, conventional culture and PCR.ResultsMean (SD) age and median (IQR) PSI score of 954 patients enrolled was 45.2 (19.5) years (range 14–94) and 42 (36). RVs were found in 262 patients (27.5%): influenza virus A (IFV A, 9.9%) comprised of pandemic H1N1 (6.7%) and seasonal H3N2 (3.5%), human rhinovirus (4.3%), adenovirus (4.2%), human metapneumovirus (1.8%), parainfluenza virus 1, 3 and 2 (1.7%, 1.5% and 1.2%). Influenza virus B, enterovirus, respiratory syncytial virus, human coronavirus and parainfluenza virus 4 were rarely detected (<1%). Frequency of IFV A was highest among patients aged between 45–64 years (p < 0.001), while adenovirus among patients aged 14–17 years (p < 0.001), no differences was found in other RVs. The proportion of pandemic H1N1 increased with severity of pneumonia evaluated by PSI (P < 0.05).ConclusionsThe proportion of RVs in CAP is higher than previously reported. IFV A pneumonia are usually found in patients older than 45 years, while, adenovirus pneumonia are common in adolescents and young adults. Pandemic H1N1 virus is still recognized by PSI as a high-severity pathogen. The findings contribute baseline data on viral CAP study in China.

IntroductionComparisons of the characteristics between the influenza A (H1N1) pdm09 and common seasonal influenza are important for both clinical management and epidemiological studies. However, the differences between pandemic and seasonal influenza during the post-pandemic period are poorly understood.ObjectivesThe aim of our research was to investigate clinical and immune response differences between patients with influenza A (H1N1) pdm09 pneumonia and seasonal influenza A (H3N2) pneumonia in the post-pandemic period.MethodsDuring the first flu season in post-pandemic period, patients from Beijing Network for Adult Community-Acquired Pneumonia present A (H1N1) pdm09 or A (H3N2) influenza were compared concurrently in the aspects of clinical characteristics and inflammatory profile in acute phase.ResultPatients with A (H1N1) pdm09 influenza pneumonia showed a close mean age to A (H3N2) pneumonia (51 ± 20 vs 53 ± 16, mean ± standard deviation, years) but tended to have more underlying diseases (32.8% vs 10%, P = 0.036). Although clinical characteristics were similar, no statistical difference were found in pneumonia severity index (PSI) score or intensive care unit admission rate or mortality, patients in A (H1N1) pdm09 cohort present higher levels of aspartate aminotransferase, lactase dehydrogenase (P = 0.006, 0.018, respectively) in blood and also longer duration of fever than A (H3N2) cohort. Levels of interleukin (IL)-10 and IL-12 (p70) were higher in A (H1N1) pdm09 cohort (P = 0.031, 0.047, respectively).ConclusiosDuring the first post-pandemic flu season, patients with the A (H1N1) pdm09 pneumonia showed similar clinical characteristics but slightly higher disease severity and stronger systemic inflammatory response than A (H3N2) pneumonia.