Serosurvey of Bacterial and Viral Respiratory Pathogens Among Deployed U.S. Service Members

BackgroundRespiratory illnesses can cause substantial morbidity during military deployments. Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus, parainfluenza, and respiratory syncytial virus (RSV) are hypothesized causes.PurposeTo determine pathogen-specific seroprevalence prior to and after deployment in support of Operation Enduring Freedom (OEF).MethodsA retrospective cohort study of 1000 service members deployed between June 30, 2004, and June 30, 2007, was conducted from 2008 through 2009. Pre- and post-deployment sera were tested for the presence of antibody to each pathogen.ResultsPre-deployment IgG seropositivity was high for adenovirus, RSV, and parainfluenza (98.7%, 97.8%, and 81.6%, respectively), whereas seropositivity for B. pertussis, M. pneumoniae, and C. pneumoniae was 14.2%, 21.9%, and 65.1%, respectively. As defined by seroconversion in 1000 subjects, the following were identified: 43 new parainfluenza infections (24% of susceptibles); 37 new pertussis infections (4% of susceptibles); 33 new C. pneumoniae infections (10% of susceptibles); and 29 new M. pneumoniae infections (4% of susceptibles). B. pertussis seroconversion was two to four times higher than reports for the general U.S. population. Overall, 14.2% of the service members seroconverted to at least one of these six pathogens; this increased to 30.1% seroconversion when influenza was included. However, serologic testing was not clearly associated with clinical illness in this report.ConclusionsSerologic evidence for respiratory infections was common among the 2004–2007 OEF-deployed military, sometimes at a higher rate than the general U.S. population. Awareness of this risk and implementation of preventive measures should be emphasized by leadership prior to and during deployment.