Automation of an interferon-γ release assay and comparison to the tuberculin skin test for screening basic military trainees for Mycobacterium tuberculosis infection.

We automated portions of the QuantiFERON-TB Gold In-Tube test (QFT-GIT) and assessed its quality when performed concurrently with the tuberculin skin test (TST) among U.S. Air Force basic military trainees (BMTs). The volume of blood collected for QFT-GIT was monitored. At least one of the three tubes required for QFT-GIT had blood volume outside the recommended 0.8- to 1.2-mL range for 688 (29.0%) of 2,373 subjects who had their blood collected. Of the 2,124 subjects who had TST and QFT-GIT completed, TST was positive for 0.6%; QFT-GIT was positive for 0.3% and indeterminate for 2.0%. Among 2,081 subjects with completed TST and determinate QFT-GIT results, overall agreement was 99.5% but positive agreement was 5.6%. Specificity among the 1,546 low-risk BMTs was identical (99.7%). Indeterminate QFT-GIT results were 2.7 times more likely when mitogen tubes contained >1.2 mL blood than when containing 0.8- to 1.2-mL blood. Automation can facilitate QFT-GIT completion, especially if the recommended volume of blood is collected. Mycobacterium tuberculosis infection prevalence among BMTs based on TST and QFT-GIT is similar and low. Selectively testing those with significant risk may be more appropriate than universal testing of all recruits.

Suicide burden in the U.S. Air Force: 1990-2004.

OBJECTIVE: To measure indirectly standardized active duty Air Force (ADAF) suicide rates. METHODS: The study period was 1990-2004. ADAF suicide deaths were obtained from the Air Force Mortality Registry. ADAF population counts were obtained from the Defense Manpower and Data Center. Suicide rates for the U.S. general population were obtained from the National Center for Health Statistics. RESULTS: The standardized mortality ratios (SMRs), adjusted for age, gender, and race, were: all enlisted personnel, 0.64 (95% CI: 0.59-0.69) and all officers, 0.14 (95% CI: 0.10-0.20). Adjusted for age and race, the SMRs were: enlisted men, 0.63 (95% CI: 0.58-0.68); enlisted women, 0.95 (95% CI: 0.66-1.33); officer men, 0.12 (95% CI: 0.08-0.17); and officer women, 0.67 (95% CI: 0.27-1.36). CONCLUSIONS: There were significant deficits of suicides in overall enlisted personnel and in overall officers. When analyzed further by gender and rank, there were significant deficits only in enlisted men and officer men. Suicide mortality in enlisted and officer women was not significantly less compared to their general population counterparts.

Motor vehicle driver death and high state maximum speed limits: 1991-1993.

OBJECTIVE: To measure the association between motor vehicle crash (MVC) driver death and high state maximum speed limits. METHODS: This study used a case-control design and assessed driver deaths from three major types of MVCs: non-collision; collision with motor vehicles in transit; and collision with stationary objects. The study period was 1991-1993. For each type of crash, case subject populations of fatally injured drivers were obtained from the U.S. Department of Transportation Fatality Analysis Reporting System. Four control subject populations, each associated with a different cause of death, were obtained from a U.S. national death certificate database (the causes of death were unintentional poisoning, non-Hodgkin lymphoma, drowning, and diabetes mellitus). Subjects were considered exposed if the state in which they crashed (for cases) or died (for controls) had a maximum speed limit greater than 55 mph. Each of the three case subject populations was compared against each of the four control subject populations. Odds ratios (ORs) were adjusted for age and gender. RESULTS: For non-collision driver death, ORs ranged from 3.06 to 6.56, depending on the year and control group; all the ORs were significant. For collision with motor vehicles in transit driver death, ORs ranged from 1.12 to 2.22; all the ORs were significant. For collision with stationary objects driver death, ORs ranged from 0.87 to 1.83. CONCLUSIONS: There was a moderately strong and significant association between non-collision driver death and high state maximum speed limits. For collision with motor vehicles in transit driver death, the association was somewhat milder but still consistent. For collision with stationary objects driver death, the presence of an association was unclear. During 1991-1993, the effects of high state maximum speed limits may have been different for different types of MVCs.

Obesity in civilian adults: potential impact on eligibility for U.S. military enlistment.

OBJECTIVE: This study measures the prevalence in the civilian adult population of obesity for military enlistment. METHODS: The National Health and Nutrition Examination Survey for 2001-2004 was used to obtain a sample of civilian adults 17 to 42 years of age. Weight standards for each branch of service were applied to determine the proportion of subjects who were over maximal weight limits and thus ineligible for enlistment. RESULTS: Depending on the branch of service and the age range, 17.9% to 54.4% of men and 20.8% to 54.9% of women were overweight for enlistment. Generally, there were higher prevalence rates in the older age groups and among women. Prevalence rates for non-Caucasian subjects were not higher among men but were higher among women. CONCLUSION: Large proportions of civilian adults are over the weight limits for military enlistment. The currently increasing prevalence of obesity in the civilian population may pose a challenge for military recruitment programs.

Cancer incidence in the U.S. Air Force: 1989-2002.

BACKGROUND: Cancer incidence in U.S. Air Force active duty (AFAD) personnel is unknown. Defining the epidemiology may support more effective prevention and clinical services. METHODS: Standardized incidence ratios (SIRs) for invasive cancer in AFAD personnel during 1989-2002 were determined using U.S. national incidence rates as the reference. SIRs were adjusted for age and race. Cutaneous squamous and basal cell carcinomas (CAs) were excluded. RESULTS: There were 2750 cases: 1986 in men and 764 in women. The all-cancers SIRs were for men, 0.50 (95% CI: 0.48-0.53), and for women, 0.96 (95% CI: 0.89-1.03). Among men, the 10 most frequent cancers (77.6% of total) were, in descending order: melanoma; testicular CA; prostate CA; non-Hodgkin lymphoma; follicular/papillary thyroid CA; Hodgkin's Disease; colorectal CA; brain neuroepithelial CA; and (tied) bladder CA and oral squamous cell CA. Among women, the 10 most frequent cancers (88.1% of total) were, in descending order: breast CA; cervical CA; follicular/papillary thyroid CA; melanoma; Hodgkin's Disease; colorectal CA; (tied) non-Hodgkin lymphoma and ovarian epithelial CA; vulvar CA; and (tied) brain neuroepithelial CA and oral squamous cell CA. Compared with the U.S. population, cancer type-specific SIRs were significantly increased for cervical CA, prostate CA, and vulvar CA (range, 1.44-3.54). SIRs were significantly decreased for bladder CA (men), brain neuroepithelial CA, colorectal CA (men), Hodgkin's Disease (men), non-Hodgkin lymphoma, oral squamous cell CA (men), and testicular CA (range, 0.31-0.68). The remaining SIRs were not significantly different from unity. CONCLUSIONS: The cancer experience of the AFAD population differs substantially from that of the U.S. population.

Testicular carcinoma in U.S. Air Force aviators: a case-control study.

BACKGROUND: Previous descriptive studies have suggested an increased risk of testicular carcinoma in military aviators. The association between testicular carcinoma and aviation in the U.S. Air Force was measured using a case-control study design. METHODS: A Department of Defense hospitalization database was used to obtain a set of testicular carcinoma cases (seminomas, embryonal cell carcinomas, teratocarcinomas, and choriocarcinomas) and an unmatched set of male appendicitis controls from October 1988 to February 1999. A centralized U.S. Air Force personnel database was used to obtain demographic and flying history data on the subjects. Multiple logistic regression was used to obtain odds ratios (OR) and confidence intervals (CI) for the following exposure factors: total flight time, rank, crew position, and general type of aircraft. Study subjects were restricted to white active duty officers. RESULTS: For one or more total flight hours, the age-adjusted OR was 1.74 (95% CI 1.04-2.92). Age-adjusted OR's for 1-499, 500-1999, and 2000 or more flight hours were, respectively, 1.37, 1.92, and 1.67. These OR's were not statistically significant. Age- and flight hour-adjusted OR's were increased for the navigator crew position and for bomber/tanker/ transport/reconnaissance type aircraft (2.13 and 1.67, respectively), but the ratios were not statistically significant. OR's were not increased for senior rank, fighter/trainer type aircraft, and rotary-wing aircraft. CONCLUSIONS: There is an association between testicular carcinoma and flight time in U.S. Air Force officers. There was a suggestion of a dose-response effect; however, the OR's were not statistically significant.