Comparison Of Bacterial And Viral Distribution Characteristics And Clinical Features In Patients With Diabetes Mellitus Complicated With Community Acquired Pneumonia

Objective: Analyze the pathogenic distribution characteristics and clinical features of patients with diabetes mellitus(DM)complicated with community acquired pneumonia(CAP),in order to provide a theoretical basis for early and effective anti-infective treatment.Methods: A total of 128 patients of T2 DM complicated with CAP(11.7%)were enrolled from the 1095 patients with acute respiratory infection who were treated in the hospital from March 2012 to March 2017.The lower respiratory tract specimens of the 128 cases were collected and the pathogens were detected by the traditional culture methods and real-time quantitative polymerase chain reaction(Real-time PCR).Analysis of its pathogenic distribution characteristics,epidemiology,and the relationship between different blood glucose levels and pathogen infection.Grouped the cases into bacterial group,viral group,mixed infection group and negative group according to the pathogen.Compared the clinical features and risk factors between groups to filter indicators for determining viral/bacterial infections by combined with clinical data.Results: The total positive rate of pathogen detection was 34.4%(44/128)among 128 patients with type 2 diabetes mellitus complicated with CAP,including 12 cases(9.4%)with single bacterial infection;31 cases(24.2%)with viral infection,including 28 cases with single virus infection,three cases with two viruses infection,one case(0.8%)was mixed with bacterial virus.Among the bacteria detected,Gram-negative bacteria were the most common(69.2%),of which the most common was Klebsiella pneumoniae(4 strains,30.8%),followed by Pseudomonas aeruginosa 3 strains(23.1%),two strain of Streptococcus and Staphylococcus aureus(15.4%),and one strain of Acinetobacter baumannii and Pseudomonas maltophilia.For the viruses,influenza A virus was the most common virus(55.9%),followed by human cytomegalovirus 23.5%,adenovirus 8.8%,and respiratory syncytial virus 5.9%,human influenza virus type 1 and Boca virus 2.9%.The influenza A virus showed an epidemic peak from June to July and from November to January,and occasionally distributed in the rest months of the year.128 patients with T2 DM combined with CAP were divided into 31 cases of viral infection group,12 cases of bacterial infection group,1 case of mixed infection group and 84 cases of negative group according to the etiological test results.Analysis of clinical features found that there was no significant difference in blood glucose levels between these groups.And there was also no significant difference in pathogen spectrum at different blood glucose levels.We found that with the increase of fasting blood glucose,bacterial infection gradually increased,but the difference was not statistically significant.We found that the rate of chronic obstructive pulmonary disease was significantly higher in the viral infection group than in the negative group(P=0.022,OR=2.817,95% CI: 1.177-6.743),and the incidence of viral infection combined with chronic obstructive pulmonary disease(42.2%)was also higher than the bacterial infection group(16.7%),but there was no statistically significant difference between thesse two groups(P=0.158);the incidence of bacterial infection combined with bronchiectasis was higher than that of the viral infection group and the negative group(P=0.017,OR=6.750,95% CI: 1.422-31.604;P=0.004,OR=9.286,95% CI: 2.252-38.283).In terms of clinical symptoms,myalgia was much more common in the viral infection group than that in the bacterial infection group and the negative group(P=0.019;P=0.003,OR=4.674,95% CI: 1.756-12.440);while chill was more common than the virus-infected group(P=0.017,OR=15.000,95% CI: 1.465-153.546).In the auxiliary examination we found that the white blood cell count of the bacterial infection group was significantly higher than that of the viral infection group(Mann–Whitney U=100,P=0.020)and the negative group(Mann–Whitney U=287,P=0.016).The procalcitonin value was also higher in the bacterial infection group than the viral infection group(Mann–Whitney U=101,P=0.027)and the negative group(Mann–Whitney U=227,P=0.007).In lung imaging performance,the ground-glass opacities is more common in Flu-A viral pneumonia.Conclusions: Among T2 DM patients complicated with CAP,the detection rate of virus was high(24.2%),among which the influenza A virus was the most common virus.In addition,Gram-negative bacteria was majority in bacterial detection(69.2%),especially the Klebsiella pneumoniae,pseudomonas aeruginosa was common.We found no significant difference in the distribution of pathogen spectrum between the different blood glucose levels,but we found the bacterial infection gradually increased with the increase of fasting blood glucose,and it still need a further research to confirm because of the cases in this study is small.Comparing clinical features between the groups we found that combined with chronic obstructive pulmonary disease,myalgia,normal white blood cell count and no or only mild increase in PCT can be used as an indicator to predict viral infection.While the combination of bronchiectasis,the elevated white blood cell count and PCT may be associated with bacterial pneumonia.In addition,the ground-glass opacities of lung is more common in Flu-A viral pneumonia,it is helpful for early clinical judgement of the pathogen infection.