Outbreak of Pneumonia in the Setting of Fatal Pneumococcal Meningitis among US Army Trainees: Potential Role of Chlamydia pneumoniae Infection
1 Epidemic Intelligence Service, Office of Workforce and Career Development assigned to Influenza Epidemiology and Prevention Branch, Influenza Division, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, Georgia, 30333, USA
2 U.S. Army Center for Health Promotion and Preventive Medicine, 5158 Blackhawk Road, Aberdeen Proving Ground, Maryland, 21010, USA
3 General Leonard Wood Army Community Hospital, Preventive Medicine Division, 126 Missouri Avenue, Fort Leonard Wood, Missouri, 65473, USA
4 Naval Health Research Center, PO Box 85122, San Diego, California, 92106, USA
5 Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, Georgia, 30333, USA
6 General Leonard Wood Army Community Hospital, 126 Missouri Avenue, Fort Leonard Wood, Missouri, 65473, USA
BMC Infectious Diseases 2011, 11:157 doi:10.1186/1471-2334-11-157Published: 2 June 2011
Compared to the civilian population, military trainees are often at increased risk for respiratory infections. We investigated an outbreak of radiologically-confirmed pneumonia that was recognized after 2 fatal cases of serotype 7F pneumococcal meningitis were reported in a 303-person military trainee company (Alpha Company).
We reviewed surveillance data on pneumonia and febrile respiratory illness at the training facility; conducted chart reviews for cases of radiologically-confirmed pneumonia; and administered surveys and collected nasopharyngeal swabs from trainees in the outbreak battalion (Alpha and Hotel Companies), associated training staff, and trainees newly joining the battalion.
Among Alpha and Hotel Company trainees, the average weekly attack rates of radiologically-confirmed pneumonia were 1.4% and 1.2% (most other companies at FLW: 0-0.4%). The pneumococcal carriage rate among all Alpha Company trainees was 15% with a predominance of serotypes 7F and 3. Chlamydia pneumoniae was identified from 31% of specimens collected from Alpha Company trainees with respiratory symptoms.
Although the etiology of the outbreak remains unclear, the identification of both S. pneumoniae and C. pneumoniae among trainees suggests that both pathogens may have contributed either independently or as cofactors to the observed increased incidence of pneumonia in the outbreak battalion and should be considered as possible etiologies in outbreaks of pneumonia in the military population.