Investigation On Etiology And Clinical Characteristics Of 685 Hospitalized Children With Community-acquired Pneumonia

Objective: To estimate the prevalence of common respiratory pathogens among children with CAP in Zunyi City,Guizhou,China,and to assess whether the presence of common respiratory pathogens in patients is associated with disease severity.Methods: Subjects: This retrospective study enrolled hospitalized infants and children aged 1 month to 5 years with radiologically confirmed CAP in the Third Affiliated Hospital of Zunyi Medical University between April 2017 and March 2018.Data collection: demographic characteristics,CT images,clinical signs,and symptoms were collected on the day of admission.In the morning of the day after admission,venous blood was collected for liver function,renal function,myocardial zymogram and other tests;nasopharyngeal swabs were collected within 24 hours after admission for respiratory virus detection;sputum or nasopharyngeal aspirate samples were collected for bacterial culture before the use of antibiotics.The diagnosis of pneumonia was supported by chest X-ray or chest CT examination.Data analysis: differences in epidemiological characteristics of common respiratory pathogens were analyzed by Microsoft Excel 2007 or SPSS 18.0.The association between severe CAP and the presence of respiratory pathogens was determined using multivariate logistic regression models.Results:1.Of all 685 children enrolled,at least one virus was detected in 410 cases,with a positive rate of 59.9%.Respiratory syncytial virus(RSV)was the most common viral pathogen,with a prevalence rate of 39.9%(273/685),followed by PIV of 11.8%,Flu of10.7% and hAdV of 1.9%.2.At least one bacterial agent was detected in 393 samples,with a positive rate of57.4%.H.in was the most commonly detected bacterial pathogen,with a prevalence rate of15.3%(105/685),followed by S.pn of 14.2% and S.au of 12.4%.3.Compared with other months,the detection rate of respiratory viruses and bacteriawas higher in autumn and winter months(from November to February of the following year).4.The positive rate of RSV(63.4%,P=0.000)and S.aureus(78.8%,P=0.000)was the highest in children aged 1 to 6 months,respectively,while the positive rate of Flu(39.7%,P=0.000)was the highest in children aged 7 to 12 months.5.Compared with children in other virus groups,children with RSV had a faster pulse rate(median 145 bite per min,P=0.001),higher respiratory rate(median 45 bite per min,P=0.004),and higher frequency of wheezing(54.6%,P=0.002)and dyspnea(52.0%,P=0.003).The signs of dullness and fever were more frequently found in children infected with hAdV(52.0%,P=0.006)and(68.5%,P=0.000)than other virus,respectively.Myocardial damage was more common in children with RSV(63.7%,P=0.021)and PIV(64.2%,P=0.021).6.Children were younger than in mixed infection than RSV infection alone(median age 4 years old vs 5 years old,P=0.015),and the length of stay was longer in mixed infection than viral infection alone(median 9 days vs 8 days,P=0.000).Fever was more common in children with PIV mixed infection than PIV infection alone(48.8% vs 15.8%,P=0.015).7.Multiple clinical symptoms and complications were more frequent in children with SCAP than children with MCAP.The presence of RSV(adjusted odds ratio(aOR)1.9;95% confidence interval(CI)1.3–2.8)and Staphylococcus aureus(aOR 13.7;95% CI5.5-33.9)in children with CAP was associated with severe pneumonia.Conclusion: In a cohort of Zunyi infants and children hospitalized with CAP,RSV was the most common pathogen,and the presence of RSV in the upper respiratory tracts is associated with SCAP.