Epidemiology of contemporary seroincident HIV infection in the Navy and Marine corps.

Human Immunodeficiency Virus (HIV) infection continues at a steady rate among U.S. Sailors and Marines. This study provides the first service-specific description of HIV infection demographics. All Sailors and Marines identified as HIV infected between January 2005 and August 2010 were included. The project compared personnel and epidemiologic data, and tested reposed sera in the Department of Defense Serum Repository. This group comprised 410 Sailors and 86 Marines, predominantly men. HIV infected Marines were more likely to be foreign born than their Navy counterparts, 42% versus 10%, p < 0.001. Approximately half of the patients had deployed including to the wars in Iraq or Afghanistan. Nearly half of each group was infected by the age of 25. Similar to the U.S. epidemic, Black race was over-represented. Unlike national rates, Hispanic Sailors and Marines were not over-represented. Demographics were distinct for those of specific occupational specialties. Certain ship classes carried lower incidences. Clustering of HIV infection risk occurred around deployment. The Navy and Marine Corps have different patterns of HIV infection, which may merit distinct approaches to prevention. The Navy may have unique targets for prevention efforts to include pipeline training and first assignment as well as particular occupational environments.

A closed-loop reduced oxygen breathing device for inducing hypoxia in humans.

BACKGROUND: Hypoxia poses a documented threat to aerospace and diving operations in healthy people and is a component of many clinical conditions. Practical training for aircrew, and research on clinically relevant hypoxic conditions frequently rely exclusively on large, expensive hypobaric chambers. PURPOSE: Here we describe and report the efficacy of a compact, economical, closed-loop rebreather-type reduced-oxygen breathing device (ROBD) for hypoxia induction in humans. METHODS: Subjects were four healthy student Naval flight surgeons. During baseline, subjects breathed normoxic air (21% O2, equivalent to sea-level). Baseline was followed by an altitude period, during which participants were exposed to hypoxic air (about 10% O2, approximating 5,486 m [18,000 ft mean sea-level]) for 30 min followed by a normoxic recovery period. Subjects' peripheral arterial oxygen saturation (SpO2), BP, impedance cardiography, cardiac output, and systemic vascular resistance served as dependent measures along with the fraction of inspired oxygen (FiO2). RESULTS: Circuit FiO2 and subjects' SpO2 were significantly lower during the altitude period than the baseline and recovery periods. HR and cardiac output were significantly higher, and systemic vascular resistance was significantly lower, during hypoxic air exposure than during baseline or recovery. CONCLUSIONS: These data support the closed-loop ROBD as a potentially useful device for training and research involving acute hypoxia in healthy and clinical populations.