A descriptive analysis of asthma in the U.S. Navy Submarine Force.

BACKGROUND: The U.S. Navy Submarine Force offers a unique opportunity to study asthma because of the relative socioeconomic and physical homogeneity of the population and the closed environment occupational exposure. Currently, asthma is disqualifying from submarine service, which results in a significant loss of experienced personnel. METHODS: We performed a retrospective analysis of 119 U.S. Navy submariner disqualification packages for asthma between 1989-1993. RESULTS: We found a 0.16% annual period prevalence of asthma in the active duty enlisted Atlantic Fleet Submarine Force. Two groups of asthma disqualifications were identified with a significant increase above their proportional representation in the fleet: enlisted personnel (p < 0.01) and submarine recruits (p < 0.0001). The proportion of African-American personnel also had a tendency toward increased asthma disqualification (p < 0.08). There were no differences in prevalence of asthma between crews of ballistic missile submarines or fast attack submarines. Asthma risk factors reported in the civilian literature (childhood history of asthma, family history of asthma and non-drug allergies) were highly represented in our study (41%, 46% and 68% of submariners, respectively). Most disqualified submariners had "mild" asthma based on the diagnostic work-up. The methacholine challenge test appeared to carry a disproportionate diagnostic weight despite its low specificity. CONCLUSION: Although the period prevalence of asthma is low in the U.S. Navy Submarine Force, submariners disqualified for asthma have similar historical and ethnic risk factors as the civilian population.

Prevalence of Helicobacter pylori in United States Navy submarine crews.

Helicobacter pylori prevalence is elevated in German submarine crews and in United States Navy (USN) surface fleet personnel, but H. pylori prevalence in USN submariners was unknown. The goal of the study was to determine the prevalence of H. pylori in the crews of USN nuclear submarines compared to other military personnel and to the general US population. The presence of H. pylori IgG antibodies was determined in serum samples using a commercial ELISA. Only 47 out of 451 submariners (9.4%) were H. pylori positive, which is similar to that of the US general population with a similar level of education. In contrast, H. pylori prevalence is significantly higher in US Army recruits (26%), USN surface fleet personnel (25%), and German diesel submariners (38%). These data demonstrate that submarine service (and by inference activity requiring isolation and close contact, per se) is not a risk factor for H. pylori infection.