Incidence of Respiratory Pathogens in Naval Special Warfare SEAL Candidates with Swimming-Induced Pulmonary Edema.

ABSTRACT

BACKGROUND: Swimming-Induced Pulmonary Edema (SIPE) is a respiratory condition frequently seen amongst Naval Special Warfare (NSW) trainees. The incidence of positive respiratory panels (RPs) in trainees diagnosed with SIPE is currently unknown. RESEARCH QUESTION Is there a significant difference in the incidence of respiratory pathogens in nasopharyngeal samples of NSW candidates with SIPE and a control group? STUDY DESIGN AND METHODS: Retrospective analysis of clinical information from NSW Sea Air and Land (SEAL) candidates diagnosed with SIPE over a 12-month period. Candidates who presented with the common signs and symptoms of SIPE received a nasopharyngeal swab and RP test for common respiratory pathogens. SIPE diagnoses were supported by two-view chest radiograph. RP tests were obtained for a selected control group of 1st phase trainees without SIPE. RESULTS: 45 of 1048 SEAL candidates were diagnosed with SIPE (4.3%). 5 had superimposed pneumonia. 36 of 45 tested positive for at least one microorganism on the RP (80%). In the study group, human rhinovirus/enterovirus (RV/EV) was the most frequently detected organism (37.8%), followed by coronavirus OC43 (17.8%), and parainfluenza virus 3 (17.8%). 16 of 68 candidates from the control group had positive RPs (24%). Patients with SIPE and positive RPs reported dyspnea (94%), pink-frothy sputum (44%), and hemoptysis (22%) more frequently than the controls with positive RPs. Those who reported respiratory infection symptoms in both the study and control groups had higher incidences of positive RPs (P=.046). INTERPRETATION: We observed that 80% of trainees diagnosed with SIPE tested positive on a point of care RP. This positivity rate was significantly higher than RP test results from the control cohort. These findings suggest an association between colonization with a respiratory pathogen and the development of SIPE in NSW candidates.