Community-acquired pneumonia requiring hospitalization among U.S. children

Abstract

Background: Incidence estimates of hospitalizations for community-acquired pneumonia among children in the United States that are based on prospective data collection are limited. Updated estimates of pneumonia that has been confirmed radiographically and with the use of current laboratory diagnostic tests are needed.

Methods: We conducted active population-based surveillance for community-acquired pneumonia requiring hospitalization among children younger than 18 years of age in three hospitals in Memphis, Nashville, and Salt Lake City. We excluded children with recent hospitalization or severe immunosuppression. Blood and respiratory specimens were systematically collected for pathogen detection with the use of multiple methods. Chest radiographs were reviewed independently by study radiologists.

Results: From January 2010 through June 2012, we enrolled 2638 of 3803 eligible children (69%), 2358 of whom (89%) had radiographic evidence of pneumonia. The median age of the children was 2 years (interquartile range, 1 to 6); 497 of 2358 children (21%) required intensive care, and 3 (<1%) died. Among 2222 children with radiographic evidence of pneumonia and with specimens available for bacterial and viral testing, a viral or bacterial pathogen was detected in 1802 (81%), one or more viruses in 1472 (66%), bacteria in 175 (8%), and both bacterial and viral pathogens in 155 (7%). The annual incidence of pneumonia was 15.7 cases per 10,000 children (95% confidence interval [CI], 14.9 to 16.5), with the highest rate among children younger than 2 years of age (62.2 cases per 10,000 children; 95% CI, 57.6 to 67.1). Respiratory syncytial virus was more common among children younger than 5 years of age than among older children (37% vs. 8%), as were adenovirus (15% vs. 3%) and human metapneumovirus (15% vs. 8%). Mycoplasma pneumoniae was more common among children 5 years of age or older than among younger children (19% vs. 3%).

Conclusions: The burden of hospitalization for children with community-acquired pneumonia was highest among the very young, with respiratory viruses the most commonly detected causes of pneumonia. (Funded by the Influenza Division of the National Center for Immunization and Respiratory Diseases.).

Figure 1. Study Enrollment and Final Pneumonia Cases

Figure 2. A/B: Pathogen Detection among U.S. Children with Community-acquired Pneumonia Requiring Hospitalization, 2010-2012

Panel A shows the proportion of pathogen types detected from January 1, 2010 through June 30, 2012 among 2222 hospitalized children with radiographic pneumonia who had 1) blood (bacterial culture or real-time polymerase chain reaction [PCR]) or pleural fluid (bacterial culture or PCR), endotracheal aspirate (bacterial culture), or bronchoalveolar lavage (bacterial culture); 2) and naso/oropharyngeal swab (viral and atypical bacterial PCR) or viral serology results available. Panel B shows number and percent of children with specific pathogen detections for all ages in the bar graph. There were 1802 patients who had a viral and/or bacterial pathogen detected among 2222 patients who had available tests for both bacterial and viral detection; there were two patients in whom Histoplasma was detected. Because patients could have more than one pathogen detected, there were a total of 2533 total detections. Darker and lighter shading in the bar graph indicates single and co-pathogen detection, respectively. Proportions of detections (single and co-detection) by age group are depicted on the pie graphs.

Figure 3

A/B: Pathogen Detection by Month and Year among U.S. Children with Community-acquired Pneumonia Requiring Hospitalization, January 1, 2010 through June 30, 2012. Panel A includes respiratory syncytial virus (RSV), human rhinovirus (HRV), human metapneumovirus (HMPV), adenovirus (AdV), and influenza A/B (Flu). Panel B includes M. pneumoniae (M. pn), parainfluenza viruses 1-3 (PIV), coronaviruses (CoV), and S. pneumoniae (S. pn.).

Figure 3

A/B: Pathogen Detection by Month and Year among U.S. Children with Community-acquired Pneumonia Requiring Hospitalization, January 1, 2010 through June 30, 2012. Panel A includes respiratory syncytial virus (RSV), human rhinovirus (HRV), human metapneumovirus (HMPV), adenovirus (AdV), and influenza A/B (Flu). Panel B includes M. pneumoniae (M. pn), parainfluenza viruses 1-3 (PIV), coronaviruses (CoV), and S. pneumoniae (S. pn.).

Figure 3

A/B: Pathogen Detection by Month and Year among U.S. Children with Community-acquired Pneumonia Requiring Hospitalization, January 1, 2010 through June 30, 2012. Panel A includes respiratory syncytial virus (RSV), human rhinovirus (HRV), human metapneumovirus (HMPV), adenovirus (AdV), and influenza A/B (Flu). Panel B includes M. pneumoniae (M. pn), parainfluenza viruses 1-3 (PIV), coronaviruses (CoV), and S. pneumoniae (S. pn.).