[Clinical analysis of 309 hospitalized children with pertussis-associated pneumonia].

Objective: To investigate the clinical characteristics of pertussis-associated pneumonia and analyze it's risk factors. Methods: Clinical data were taken from Shenzhen Children's Hospital with Bordetella pertussis infection and confirmed by culture or real-time polymerase chain reaction (PCR) of nasopharyngeal secretion from October 2013 to December 2015. Patients were divided into two groups, those with radiologically confirmed pneumonia in the course of their disease and those with not. Clinical data were retrospectively analyzed and compared. T test, Rank sum test or chi square test were used for comparison between groups. Risk factors were analyzed by unconditional Logistic regression analysis. Results: A total of 501 children hospitalized with Bordetella pertussis infection were included. Among them, 309 patients were diagnosed with pneumonia. The median age was 3 (2, 6) months. Symptoms were paroxysmal cough ( n= 252, 81.6%), tachypnea ( n= 69, 22.3%), and cyanosis ( n= 105, 34.0%). The time from onset of cough to radiologically confirmed pneumonia was between 1 and 66 days with a median of 9 (5.5, 15.0) days. The most common pathogen of coinfection was respiratory syncytial virus (RSV)(20 cases). Macrolides were used in 306 cases for (8.2±3.6) days. All cases showed significant improvement. There were more male children (62.1% (192/309) vs. 50.3% (95/189) , χ(2)=6.768, P= 0.009), and more instances of comorbidities (13.3% (41/309) vs .5.8% (11/189) , χ(2)=6.957, P= 0.008) in the pneumonia group than in the other. The age was younger (3 (2,6) vs .4 (2,6) months, Z= 32.91, P= 0.000) in pneumonia group than in the other. Male sex, younger age, and underlying disease were independent risk factors for pertussis-associated pneumonia ( OR= 1.648, 1.486, 2.695, P= 0.008, 0.036, 0.005). Conclusions: Pneumonia, as a complication of pertussis, is very easy to see in hospitalized children. The duration of hospitalization is extensive. It is more likely to happen in children who are male, young, and having underlying diseases. Pneumonia is easy to occur in the first 2 weeks of the course of disease.