Objective To explore the distribution of bacteria among community acquired lower respiratory tract infection (LRTI) inpatients with underlying chronic respiratory tract diseases.Methods The clinical data，sputum culture and drug susceptibility results of 212 community acquired LRTI patients who were hospitalized during the period 2001-2005 were retrospectively analyzed.All patients had various underlying chronic respiratory tract diseases.Results A total of 229 strains of pathogens were detected，with the majority being gram negative bacteria.In pathogens of acute exacerbation of chronic obstructive pulmonary disease，gram negative bacteria occupied 73.9%.And Pseudomonas aeruginosa and Klebsiella pneumoniae were the most common pathogens，with each occupying 18.2% and 13.6% respectively.Gram positive bacteria occupied 23.8%，mainly Staphylococcus aureus (10.2%) and Streptococcus pneumoniae (9.1%).In patients with bronchiectasis exacerbated by bacterial infection，86.2% were caused by gram negative bacteria，the top three being，in descending order，Pseudomonas aeruginosa (27.5%)，Haemophilus parainfluenzae (13.7%)，and Haemophilus influenzae (11.8%).Bronchiectasis was the major risk factor of getting Pseudomonas aeruginosa infection (OR=5.590，95%CI 2.792~11.192).The risk factors of getting Acinetobacter baumanii infection were antacid usage within 1 month (OR=9.652，95%CI 2.792~11.192) and hypoalbuminemia (OR=2.679，95%CI 1.108~6.476).For enterobacters infections，including Klebsiella pneumoniae，Enterobacter cloacae and Escherichia coli，the risk factors were antibiotic usage within 1 month (OR=4.236，95%CI 1.982~9.057)，having renal diseases (OR=4.305，95%CI 1.090~17.008) and diabetes mellitus (OR=2.836，95%CI 1.339~6.009).Conclusions Gram negative bacteria were the main pathogens of community acquired LRTI in hospitalized patients with underlying chronic respiratory tract diseases.The pathogens were influenced by underlying diseases，severity of diseases and drug usage history of patients.
ObjectiveThe aim of this study was to assess the disease burden of non-COVID-19 lower respiratory infection (LRI) in China during the period 1990−2021, particularly during the period 2019−2021. MethodsData on the burden of disease for LRI in China were obtained from the GBD 2021 database. A Joinpoint regression model was used to describe the changes in disease burden trends of LRI in China from 1990 to 2021, and the results are presented in terms of average annual percentage change (AAPC). ResultsIn 2021, the age-standardized incidence rate of LRI in China was 2 853.31/100 000, the age-standardized rate of DALY was 347.67/100 000, and the age-standardized mortality rate was 14.03/100 000. Compared with 1990, the AAPC were −2.13%, −6.89% and −4.10% respectively. In contrast, during the COVID-19 pandemic, both showed a decreasing and then increasing trend, except for the age-standardized incidence rate, which showed a decreasing trend. Children under 5 years of age have experienced the greatest reduction in the burden of disease over the past decades, while the burden of disease has increased in absolute terms for the elderly over 70 years of age. Compared with 1990, the disease burden of LRI in China due to each pathogenic microorganism has decreased. And during 2019−2021, all pathogens showed an increasing trend, except for ASMR caused by influenza (APC=−55.21%) and respiratory syncytial virus (APC=−53.35%). In 2021, the primary attributable risk factors for LRI mortality in China shifted from household air pollution due to solid fuels, childhood underweight, and childhood stunting in 1990 to ambient particulate matter pollution, smoking, and secondhand smoke. ConclusionThe disease burden of LRIs in China showed an overall decreasing trend from 1990 to 2021, but with large variations between age groups and pathogens. During the two years following the outbreak of the COVID-19 pandemic, the incidence of LRI in China, along with the disease burden caused by influenza and respiratory syncytial virus, significantly declined. Over the past few decades, the attributable risk factors for mortality and DALYs have undergone substantial changes. To address this phenomenon, targeted measures should be implemented to reduce the burden of LRI on the population caused by air pollution and smoking.
Objective To study the incidence and etiological distribution of lower respiratory tract infection (LRTI) after airway metal stent implantation in patients with malignant central airway obstruction (MCAO). Methods The clinical data of 149 patients with MCAO who underwent airway metal stent implantation in Department of Pulmonary and Critical Care Medicine of Hunan Provincial People's Hospital from April 2014 to April 2021 were selected for a retrospective study. The incidence of LRTI after treatment was counted. According to whether LRTI occurred after operation, they were divided into infected group and uninfected group. The clinical data of the two groups were compared and the influencing factors of LRTI were analyzed. Sputum samples and/or bronchoalveolar lavage fluid samples from patients infected with LRTI were collected for pathogen detection and drug susceptibility test, and the distribution and drug resistance of main pathogens were analyzed. Results A total of 149 patients who met the criteria were included in this study and the incidence of LRTI was 21.48%. People in the infected group was older than that in the uninfected one, and the proportion of people with a history of smoking, chemoradiotherapy, covered metal stents, and stent-related granulation tissue proliferation was higher, and the proportion of people with postoperative standardized aerosol inhalation was lower (P<0.05). Age, smoking history, chemoradiotherapy, covered metal stents, stent-related granulation tissue hyperplasia and postoperative standardized aerosol inhalation were all influencing factors of LRTI in these patients (P<0.05). A total of 38 pathogens were detected in 32 patients with LRTI. Gram negative bacteria, gram positive bacteria and fungi accounted for 68.42% (26/38), 21.05% (8/38) and 10.53% (4/38) respectively. Pseudomonas aeruginosa, the main Gram-negative bacteria, had no resistance to tobramycin, gentamicin and amikacin, but had high resistance to compound sulfamethoxazole, tigecycline and ampicillin; Klebsiella pneumoniae had low resistance to tobramycin, amikacin and tigecycline, and high resistance to cefotaxime, ciprofloxacin and cefepime; the main Gram-positive Staphylococcus aureus had no drug resistance to vancomycin, linezolid, compound sulfamethoxazole and quinuptin/dafuptin, but had high drug resistance to tetracycline, penicillin G, levofloxacin, oxacillin and ciprofloxacin; the main fungi Candida albicans showed no resistance to fluconazole, itraconazole, voriconazole, 5-fluorocytosine and amphotericin B. These results of pathogenic detection and drug susceptibility test contributed to the improvement of the rational application rate of antibiotics. Conclusions LRTI occurs in about a quarter of patients with MCAO after airway metal stent implantation. The pathogens are mainly Pseudomonas aeruginosa and Staphylococcus aureus. Antimicrobial treatment should be based on the results of etiological detection and drug susceptibility test.
Objective To investigate the relations between the human beta defensin-2 (HBD-2) and systemic inflammatory responses in patients with lower respiratory tract infection（LRTI）. Methods Eighty-one patients with confirmed LRTI including community-acquired pneumonia，acute exacerbation of chronic obstructive pulmonary disease or concurrent lung infection，and bronchiectasis concurrent infection were enrolled，and twenty healthy volunteers were included as control. Plasma concentrations of HBD-2，IL-1β，and IL-8 were assayed with ELISA method in all patients and controls. Furthermore the patients were divided into three groups according to the onset of disease:,ie.group A （shorter than 7 days），group B （7 to 14 days），and group C （more than 14 days）. The differences between these groups were compared. Correlation between HBD-2 and IL-1β or IL-8 concentrations was analyzed. Results HBD-2，IL-1β，white blood cell （WBC） of the peripheral blood in the patients with LRTI were all significantly higher than those in the healthy controls. HBD-2 and IL-1β increased in group A and group B，and decreased in group C comparing to the control group （Plt;0.05 respectively）. There was no significant difference of IL-8 in group A，B and C. HBD-2 showed a positive linear correlation with IL-1β （r=0.313，P=0.030） and no correlation with IL-8（Pgt;0.05）. Conclusions The plasma HBD-2 concentration is increased in LRTI patients，which may be a biomarker of systemic inflammation in the early or relative early course of LRTI.
Objective To investigate the differences in bacteria distribution and drug resistance of pathogens in patients with lower respiratory tract infection between respiratory general wards and respiratory intensive care unit ( RICU) .Methods All the clinical isolates fromsputumor secretion of lower respiratory tract from2007. 1-2010. 10 were analyzed retrospectively. Antibiotic susceptibility was tested by Kirby-Bauer method. Results The total number of isolated strains was 3202. Among 1254 strains isolated from respiratory general wards, Gram-positive bacteria accounted for 2. 63% , Gram-positive bacteria accounted for 42. 42% , and fungi accounted for 54. 95% . Streptococcus pneumoniae ranked first place among Gram-positive bacteria, accounting for 51. 52% . Haemophilus parainfluenzae bacillus ranked first place among Gramnegative bacteria, accounting for 21. 99% . Both were sensitive to the most commonly used antibiotics. Among 1948 strains isolated from RICU ward, Gram-positive bacteria accounted for 4. 52% , Gram-positive bacteria accounted for 37.73% , and fungi accounted for 57. 75% . Staphylococcus aureus ranked first place among Gram-positive bacteria, accounting for 52. 27% . Acinetobacter baumannii ranked first place in Gramnegative bacteria, accounting for 27. 35% . Both were resistant to most commonly used antibiotics. Pseudomonas aeruginosa had a higher rate of infection both in the general wards and RICU, and was resistant to most commonly used antibiotics.Conclusions In lower respiratory tract infection of respiratory general ward, Gram-positive bacteria with Streptococcus pneumoniae mainly and Gram-negative bacteria with Haemophilus parainfluenzae mainly are both sensitive to the most commonly used antibiotics. While in the RICU ward, Gram-positive bacteria infections with Staphylococcus aureus mainly and Gram-negative bacteria infections with Acinetobacter baumannii mainly are both resistant to most commonly used antibiotics.
ObjectiveTo investigate the distribution and drug resistance of pathogens in neonates with lower respiratory tract infection, and provide evidence for clinical rational antibiotic use. MethodsA retrospective analysis on 998 strains isolated from 5 486 sputum samples during January 1, 2009 to December 31, 2012 collected from hospitalized neonates was performed. ResultsOf the 998 isolated strains, the common pathogens were Klebsiella pneumoniae (23.1%), Escherichia coli (E. coli) (21.2%), Staphylococcus aureus (19.4%), and Enterobacter cloacae (8.4%). Klebsiella pneumonia, E. coli and Enterobacter cloacae were generally resistant to penicillin, but enzyme inhibitors could reduce the resistance rate. A large proportion of Klebsiella pneumonia was resistant to the third generation cephalosporins (78.4%), while E. coli and Enterobacter cloacae had a lower resistance rate (46.7% and 46.5%, respectively). There were 7 strains (3.0%) of Klebsiella pneumoniae and 1 (1.2%) strain of Enterobacter cloacae resistant to imipenem. Twenty-three strains (13.6%) of Klebsiella pneumoniae, 1 strain (0.7%) of E.coli and 1 strain (2.5%) of Enterobacter cloacae were resistant to ertapenem. A total of 97.0% of Staphylococcus aureus was resistant to penicillin, but only 11.0% was resistant to oxacillin, and all the isolates were sensitive to vancomycin. ConclusionGram negative bacteria are the common pathogens in the hospitalized neonates in our hospital. Klebsiella pneumonia, E. coli and Staphylococcus aureus are the common pathogens. The common pathogens show a high resistant level to antibiotics. Clinicians should evaluate the potential pathogens of infections based on the results presented in our study, in order to select antibiotics rationally when treating infections.
Objective To investigate the viral etiology of acute lower respiratory tract infection in adult inpatients. Methods 192 adult inpatients suffering from community-acquired pneumonia, acute bronchitis, or acute exacerbation of chronic obstructive pulmonary disease, admitted from October 2007 to October 2008, were enrolled in the study. Swabs from the nasopharynxes were collected. Multiple polymerase chain reaction was employed to identify the 7 common species of respiratory virus ( including 11subspecies) . Serumspecific IgM against several viruses were detected by indirect immunofluorescence. 106 healthy volunteers were enrolled as control. Results Only 4 cases were found to be infected with virus in 106 healthy volunteers. Viruses were identified in 80 ( 41. 6% ) cases of 192 inpatients and 99 ( 51. 5% )viral strains were detected. The most common viruses identified in the inpatients were influenza virus A ( FluA) , rhinovirus ( RhV) , and parainfluenza virus 1 ( PIV1) . The ratio of the 3 virus strains to the all strains identified was 81. 8% ( 81/99) . Serumspecific IgM was positive in 61 ( 31. 7% ) inpatients and 73 ( 38. 0% ) viral strains were detected. The most common viruses identified in the inpatients were FluA, PIV1,and respiratory syncytial virus ( RSV) . When summing up the data from the swabs and serum, 91 ( 47. 3% )cases had viral infection in 192 inpatients and 110 ( 57. 2% ) viral strains were detected. Conclusion The rate of viral infection is relatively high in the adult inpatients with acute lower respiratory tract infection, and the most common species are FluA, RhV, and PIV1.
Objective To explore the application value of Mycoplasma pneumoniae （MP） rapid culture technique for diagnosis of lower respiratory tract infections （LRTIs ） inpatients. Methods 120 LRTIs inpatients in respiratory ward，Anzhen hospital from January 1，2010 to December 31，2010，were recruited in this study. Their pharynx swabs were obtained for rapid MP culture and the serum antibody detection of MP was performed by Gelatin particle agglutination method. Results There were 33 positive yields in 120 LRTIs patients by rapid culture method and 24 positive yields by serological assay. The positive rates were 27.5% and 20.0% respectively. There was no significant difference in the two detecting methods （Pgt;0.05）. Conclusions MP rapid culture method is a better early diagnostic method at the present. MP rapid culture method combined with serological detection can improve the positive yield and avoid missed diagnosis.
ObjectiveTo investigate clinical characteristics and influencing factors of lower respiratory tract infection of Acinetobacter baumannii (AB-LRTI) in respiratory intensive care unit (RICU).MethodsClinical data were collected from 204 RICU patients who were isolated Acinetobacter baumannii (AB). The bacteriological specimens were derived from sputum, bronchoscopic endotracheal aspiration, bronchoalveolar lavage fluid, pleural effusion and blood. The definition of bacterial colonization was based on the responsible criteria from Centers for Disease Control and Prevention/National Medical Safety Network (CDC/NHSN). The patients were divided into three groups as follows, AB colonization group (only AB was isolated, n=40); simple AB-LRTI group (only AB was isolated and defined as infection, n=63), AB with another bacteria LRTI group (AB and another pathogen were isolated simultaneously, n=101). The epidemiology, clinical characteristics and influencing factors of each group were analyzed and compared. ResultsCompared with the AB colonization group, the AB with another bacteria LRTI group had higher proportion of patients with immunosuppression, specimens from sputum and bronchoalveolar lavage fluid, more than 4 invasive procedures, 90-day mortality, white blood cell count >10×109/L (or <4×109/L), neutrophil percent >75% (or <40%), lymphocyte count <1.1×109/L, platelet count <100×109/L, albumin <30 g/L, high sensitivity C-reactive protein >10 mg/L, and neutrophil-to-lymphocyte ratio (NLR). The frequency of bronchoscopy and days of infusing carbapenem within 90 days before isolating AB, the Acute Physiology and Chronic Health Evaluation Ⅱ score, the proportion of patients with invasive mechanical ventilation and the duration of invasive mechanical ventilation in the AB with another pathogen LRTI group were higher than those in the AB colonization group (all P<0.05). Days of infusing carbapenem and β-lactams/β-lactamase inhibitors within 90 days before isolating AB, proportion of septic shock, NLR and 90-day mortality of the patients from the AB with another pathogen LRTI group were more than those in the simple AB-LRTI group (all P<0.05). After regression analysis, more than 4 invasive procedures, or immunosuppression, or with more days of infusing carbapenem within 90 days before isolating AB were all the independent risk factors for AB-LRTI.ConclusionsThere are significant differences in epidemiology, clinical symptoms and laboratory indicators between simple AB-LRTI, AB with another pathogen LRTI and AB colonization in RICU patients. For RICU patients, who suffered more than 4 invasive procedures, immunosuppression, or with more days of infusing carbapenem within 90 days before isolating AB, are more susceptible to AB-LRTI.