Methods: Clinical and laboratory data were collected from subjects diagnosed with pneumonia from four U.S. military recruit camps between February 2004 and January 2015. Serum, throat swabs, and nasopharyngeal swabs were tested for a variety of respiratory pathogens, including adenovirus, influenza A and B viruses, parainfluenza viruses (PIV) 1–3, enterovirus, herpes simplex virus (HSV), respiratory syncytial virus, Mycoplasma pneumoniae, Streptococcus pneumoniae, Chlamydophila pneumoniae, Bordetella pertussis, and Legionella pneumophila. Additionally, positivity rates among those tested were compared during the pre-(2004-2011) and post- adenovirus vaccines (2012-2015) periods.
Results: During the 11 years of this study, 2355 individuals with pneumonia were enrolled. The most commonly detected pathogen was adenovirus (36%), followed by M. pneumoniae (35%), rhinovirus (34%), C. pneumoniae (20%), S. pneumoniae (7%), enterovirus (3%), HSV (2%), influenza A (2%) and PIV 3 (1%). Co-infections among adenovirus, M. pneumoniae, and C. pneumoniae were common, with 4-12% of cases being positive for two pathogens and 3% having all three. Differences in pathogen distribution were noted after the adenovirus vaccines were resumed, most notably a precipitous decline in adenovirus infections.
Conclusion: Adenovirus, M. pneumoniae, rhinovirus, and C. pneumoniae were the major contributing pathogens in young adults diagnosed with pneumonia at military training sites, and may be relevant to pneumonia epidemiology in other institutional settings containing young adults.
A. Hawksworth, None
R. Lee, None