PNEUMONIA IN MILITARY RECRUITS

Lower respiratory disease is a major source of morbidity in military r ecruits, with hospitalization rates for pneumonia more than 30 times t hat of the non-recruit population. The etiologic agent remains unknown in over 75% of cases. This study prospectively examined the etiology of pneumonia among recruits at Naval Training Center, San Diego, Calif ornia. Recruits presenting with cough, fever, or shortness of breath a nd pulmonary infiltrates on chest X-ray were eligible for enrollment. A standardized scoring form and focused physical exam were completed o n each subject. Sputum specimens were obtained for Gram's stain and cu lture, DNA probing for Legionella and Mycoplasma species, and direct f luorescent antibody staining for Legionella. Acute and convalescent se rologies were performed for adenovirus, influenza A and B, Mycoplasma pneumoniae, Chlamydia group, and respiratory syncytial virus. Of 110 e ligible patients, 100 consented to enrollment and 75 patients complete d the study. Etiologic diagnoses were obtained in 40 of the patients ( 53%). M. pneumoniae, Haemophilus influenzae, and viruses accounted for the majority of infections. Mixed infections were seen in six patient s. Forty-seven percent of patients had no diagnosis established. Pneum onia in this series of military recruits was frequently caused by M. p neumoniae and H. influenzae. Fifty percent of cases were undiagnosed w ith routinely available laboratory methods. Further studies are warran ted to more clearly define the etiologic agents of recruit pneumonia a nd the utility of prophylactic measures.