Helicopter mishap attributed to single seizure.

A case report is presented of a 36-year-old U.S. Coast Guard aviator who had a single seizure while operating a helicopter on the ground. His seizure activity produced a loss of consciousness during which he pushed the cyclic to the left anterior quadrant that resulted in a ground mishap. No risk factors were identified in an extensive neurological workup. The current guidance for handling seizures in military aviation personnel is reviewed, along with considerations for treatment. Although the military aviation selection process carefully screens applicants for seizure history and potential, occasional seizures in the aviation population remain possible. Such events may result in military aircraft mishaps despite careful risk factor surveillance, as demonstrated by this case.

Hearing thresholds for U.S. Marines: comparison of aviation, combat arms, and other personnel.

INTRODUCTION: Aviation personnel in the U.S. Marine Corps are exposed to auditory trauma that may produce hearing loss in excess of personnel with other work exposures. METHODS: U.S. Marine Corps personnel in the Navy and Marine Corps Hearing Conservation Database (1995-1999; n = 20,645) were analyzed. The outcome variable was a hearing threshold at 4000 Hz in the left ear greater than 25 dB for annual and periodic audiograms. Personnel were characterized by gender, officer status, 5-yr age groups, and by military occupational skills (MOS) groups of "aviation," "combat arms," and "other." RESULTS: After adjustment by logistic regression for age group, gender, and officer status, the "aviation" group was not different from the "other" category, while the "combat arms" group was more likely to have elevated hearing thresholds. Officers and women demonstrated significantly lower rates for elevated thresholds. DISCUSSION: These findings provide information for personnel planning and assessing military hearing conservation programs.

U.S. Navy and Marine Corps conversion rates for tuberculosis skin testing (1999-2002), with literature review.

We examined tuberculosis skin conversion rates for U.S. Navy and Marine Corps personnel for 1999 to 2002, using information submitted to the Navy Environmental Health Center (Portsmouth, Virginia). The screening of 1,190,866 Navy and Marine Corps personnel with tuberculosis skin testing found 17,439 (1.46%) new reactors. The annual conversion rate increased from 1.35% in 1999 to 1.33% in 2000, 1.54% in 2001, and 1.61% in 2003 [chi2 for trend (df = 1) = 102.368; p = 0.000]. The overall conversion rate for aircraft carriers was 0.52%, with significantly higher rates for amphibious ships (1.76%; relative risk, 3.33; 95% confidence interval, 2.98-3.71; p = 0.000) and Marine units (1.13%; relative risk, 2.17; 95% confidence interval, 1.98-2.38; p = 0.000). Annual conversion rates increased significantly over the period for aircraft carriers [chi2 for trend (df = 1) = 4.950; p = 0.02608] and decreased significantly for amphibious ships [chi2 for trend (df = 1) = 40.197; p = 0.000]. Conversion rates were consistent with the recent historical values for the Navy and Marine Corps.

Navy Asbestos Medical Surveillance Program 1990-1999: demographic features and trends in abnormal radiographic findings.

A 10-year cross-sectional analysis was conducted for 233,353 radiographic examinations performed as part of the Navy Asbestos Medical Surveillance Program. Demographic and temporal trends in abnormal radiographs were assessed during this analysis. Abnormal radiograph prevalence increased significantly with age, and abnormal radiographs were nearly 30 times more likely to occur among participants 60 to 69 years of age, compared with participants < 20 years of age (odds ratio, 27.57; 95% confidence interval, 14.75-51.53). Men were 5 times more likely than women to have an abnormal radiograph (odds ratio, 5.84; 95% confidence interval, 5.02-6.80); after controlling for differences in age, this gender association remained significant only for participants > 30 years of age. The proportion of abnormal radiographs decreased significantly over the study period [chi2 (df = 1) test for trend, chi2 = 198.7, p < 0.0001], although the cohort mean age increased. Despite aging of the Asbestos Medical Surveillance Program population, the overall prevalence of radiographic abnormalities is declining; future studies should examine the reasons for this observation.

Needle-stick epidemiology in Navy health care workers based on INJTRAK reports (2001-2002).

We provide a descriptive epidemiological analysis of needlestick injuries in Navy medical personnel from the Naval Safety Center database (INJTRAK) for a 1-year period (October 2001 through September 2002). The reports of needle sticks were reviewed on the basis of the Bureau of Labor Statistics Occupational Injury and Illness Classification system for exposure code 3431 (N = 265). Most of the reported needle sticks occurred in men (60.8%) and were from personnel <30 years of age (73.8%). Hospital corpsmen represented the most common work group (57%). Fingers were the most commonly reported anatomical location (77%) for needle sticks. The information suggests several focus areas for reducing needle-stick injuries and improving training. The analysis also reinforces the importance of timely and accurate reporting of injuries related to medical apparatus to the Naval Safety Center.

Disease nonbattle injury surveillance for commander, Joint Task Force Haiti, 2004.

We analyzed weekly disease nonbattle injury data from the Joint Task Force in Haiti during 2004. Surveillance found 908 initial visits during 17,938 person-weeks, for an overall rate of 5.1% (95% confidence interval, 4.7-5.4%), above the reference rate of 4% suggested by the Chairman of the Joint Chiefs of Staff. Rates of dermatological (1%), respiratory (0.8%), and other medical/surgical (0.9%) conditions were above suggested rates, whereas rates of work injuries (0.6%) and recreational injuries (0.8%) were below suggested rates. Leading causes of light duty (n = 1,079; 6.01 days per 100 person-weeks) were recreational injuries (39%) and work-related injuries (36%), followed by other medical/surgical conditions (12%). One case of malaria was reported during the deployment. These rates are lower than disease nonbattle injury rates of 9.2% to 13% reported for multinational forces from previous operations in Haiti. They are also lower than rates of 7.1% to 8.1% reported from Bosnia and Kosovo in the late 1990s.

Navy physical readiness test scores and body mass index (Spring 2002 cycle).

Physical performance and risk factors from the U.S. Navy physical readiness test (PRT) were analyzed in a retrospective, cross-sectional, population-based study using data from the Spring 2002 cycle. PRT scores were available for 22,314 active duty women and 131,287 men, and risk factor information was available for 4,254 women and 31,503 men. For risk factors, self-reported smoking rates were higher for men than women, and decreased with increasing age. Self-reported rates for elevated cholesterol and joint problems increased with increasing age. Linear regression showed body mass index increased with age for men (constant = 25.6, increasing 0.0,765 per year of age over 18 years, p = 0.000) and were increasing at a lower rate for women (constant = 24.5 increasing 0.0,159 per year of age over 18 years, p = 0.000). Increasing body mass index was associated with decreasing PRT performance. This analysis provides population-based information on the PRT risk factors, body mass index, and physical fitness for Navy personnel.

Trends in pleural radiographic findings in the Navy Asbestos Medical Surveillance Program (1990-1999).

The U.S. Navy Asbestos Medical Surveillance Program is a comprehensive effort to decrease exposure to asbestos, a known health hazard. This study was part of a programmatic review of the Asbestos Medical Surveillance Program database, which included 233,353 radiographic examinations from 1990 to 1999. The initial review focused on incidental findings recorded by B-readers for 23,460 radiographs. Abnormalities reported included bullae (0.68%), cancer (0.56%), cardiac size/ shape abnormalities (1.36%), emphysema (0.74%), subpleural fat (2.62%), fractured ribs (1.24%), hilar adenopathy (0.13%), ill-defined diaphragm (0.46%), ill-defined heart border (0.29%), Kerley lines (0.06%), pleural thickening (2.35%), and tuberculosis (0.27%). The rates by age cohort for pleural abnormalities decreased significantly (30-39 years, chi2 for trend = 23.49, df = 1; 40-49 years, chi2 for trend = 176.21; 50-59 years, chi2 for trend = 401.87), but findings were not significantly different for those > or =60 years of age. This suggests that sequential age cohorts in the program are developing fewer pleural abnormalities; pleural abnormalities have historically been associated with asbestos exposure.

Occupational Interstitial Lung Diseases.

OBJECTIVE: Evidence-based diagnostic and treatment guidelines for occupationally related interstitial lung diseases (ILDs) have been developed and are summarized herein. METHODS: Comprehensive literature reviews were conducted with article abstraction, critiquing, objective grading, and evidence table compilation. A multidisciplinary expert panel drafted evidence- and consensus-based guidance. External peer-review was incorporated. RESULTS: Recommendations for diagnosis (n = 12) and management (n = 4) of ILD were developed. Spirometric testing, chest radiographs, and high-resolution computerized tomographic scans were recommended based upon evidence. In addition to a detailed clinical history, carbon monoxide diffusion capacity, sputum sampling, exposure assessment, 6-minute walk test, and bronchoalveolar lavage were also recommended. There was no recommendation regarding chest magnetic resonance imaging due to lack of evidence. CONCLUSIONS: Recommendations for diagnosis and management of ILD are supported by quality evidence. These guidelines may be useful to help guide providers who are tasked with diagnosing and/or treating patients with occupationally related ILD.

Work-Related Asthma.

OBJECTIVE: Summarize developed evidence-based diagnostic and treatment guidelines for work-related asthma (WRA). METHODS: Comprehensive literature reviews conducted with article critiquing and grading. Guidelines developed by a multidisciplinary expert panel and peer-reviewed. RESULTS: Evidence supports spirometric testing as an essential early test. Serial peak expiratory flow rates measurement is moderately recommended for employees diagnosed with asthma to establish work-relatedness. Bronchial provocation testing is moderately recommended. IgE and skin prick testing for specific high-molecular weight (HMW) antigens are highly recommended. IgG testing for HMW antigens, IgE testing for low-molecular weight antigens, and nitric oxide testing for diagnosis are not recommended. Removal from exposure is associated with the highest probability of improvement, but may not lead to complete recovery. CONCLUSION: Quality evidence supports these clinical practice recommendations. The guidelines may be useful to providers who diagnose and/or treat WRA.

Navy and Marine Corps active duty mortality patterns for 1995 to 1999.

The authors analyze all Navy and Marine Corps active duty deaths from January 1, 1995 through December 31, 1999 (Navy, N=1231; Marine Corps, N=701). Data were obtained from official Navy and Marine Corps sources, including the Report of Casualty (DD form 1300) and the Navy Personnel Casualty Report (Control Symbol NMPC 1770-4) or the Marine Corps Personnel Casualty Report (MC-3040-02), as appropriate. Overall fatality rates were 68.2 per 100,000 active duty Navy personnel and 84.2 for active duty Marine Corps personnel. Rates were generally lower than those noted in previous studies and lower than comparable civilian groups. The officer fatality rates were strongly affected by aircraft mishap-related deaths. The only subgroup displaying higher rates than their civilian counterparts was mishap-related deaths for enlisted Marines age 17 to 24 years old.

Disease and nonbattle injury patterns: afloat data from the U.S. Fifth Fleet (2000-2001).

Disease and nonbattle injury (DNBI) patterns were analyzed for reports from the Commander Fifth Fleet for 2000-2001 covering 217,972 person-weeks. The overall DNBI rate was 4.38 visits per 100 person-weeks with the largest subcategory being "other medical/surgical" conditions (1.36 visits/100 person-weeks and over 30% of the initial patient visits). This was followed by dermatological (0.89 visits/100 person-weeks) and respiratory conditions (0.65 visits/100 person-weeks). Collapsing total injuries would have created the third largest incidence category. The mean DNBI rate for cruisers/destroyers/ frigates (4.23 visits/100 person-weeks; SD, 2.64 visits) was not significantly different from aircraft carriers (4.76 visits/100 person-weeks; SD, 1.60, t(df = 207) = -0.91, p = 0.363) but was statistically different from supply ships (8.93 visits/100 person-weeks; SD, 2.44, t(df = 191) = -6.23, p = 0.000) and amphibious support ships (8.07 visits/100 person-weeks; SD, 3.99, t(df = 190) = -4.72, p = 0.000). These results are compared with historical data from land-based units, and the limitations in shipboard DNBI reporting are discussed.

Effects of pediatric blood lead surveillance on Navy population health (1995-2001).

Navy medicine instituted a pediatric lead surveillance program in 1995 because of a public health concern over pediatric blood lead levels. This program included local sampling of pediatric populations and a central database at the Navy Environmental Health Center. That database contains 38,502 samples from 1995 through 2001 with 1.6% above 10 microg/dL. The number of samples submitted and percentage with elevated lead levels has steadily decreased during the 6-year reporting period. Rates above 10 microg/dL for children considered at high risk were similar for those residing on (2.4%) and off base (2.5%). Rates above 10 microg/dL for children considered at low risk, living off base, were 1.3%, whereas those living on base were 0.4% (relative risk = 3.44, p = 0.00, 95% confidence interval = 2.34-5.20). Several locations were identified as having higher risk for elevated blood levels that warrant continued surveillance.

Navy Asbestos Medical Surveillance Program (1991-1999): linear regression analysis for the effect of asbestos exposure on pulmonary function testing.

The effect of asbestos exposure on pulmonary function was studied using data from the Navy Asbestos Medical Surveillance Program. Records were selected for Caucasian men from 1991 to 1999 (N = 89,318) and were analyzed using a cross-sectional, linear regression model. Dependent variables were forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), with independent continuous variables of age, height, weight, smoking, and asbestos history. Overall, the continuous variable for asbestos exposure demonstrated significant protection of +1.1 cm3/year (t = 3.278, p = 0.001) for FEV1 and +1.6 cm3/year (t = 4.225, p = 0.000) for FVC. There was significant interaction between asbestos exposure and smoking history (FEV1, -0.09 cm3/year2, t = -6.467, p = 0.000; FVC, -0.097 cm3/year2, t = -5.663, p = 0.000). This study suggests that workers within the program demonstrated minimal additional pulmonary function changes during the period, particularly if they do not smoke tobacco. The study also supports continuing smoking cessation efforts for all asbestos-exposed workers.

Hearing health risk in a population of aircraft carrier flight deck personnel.

This study evaluated the risk to hearing health associated with duty on the flight deck of a Nimitz class aircraft carrier. Descriptive data includes time-weighted average noise exposure and an evaluation of temporary threshold shift for a group of nonaviator flight deck personnel (FD), and a comparison of accrued permanent threshold shift among three shipboard occupational groups that had been matched for years of military service. The study participants included 76 FD personnel in a high-exposure group, 77 engineers in a moderate-exposure group, and 52 administrative personnel who were considered to have low occupational noise exposure. The study found a mean FD time weighted average of 109 dBA over workdays averaging 11.5 hours. Only 2 (4%) of 52 administrative personnel had any appreciable hearing loss (defined as worse than 20 dB at any frequency 1,000 through 4,000 Hz), whereas FD and engineers demonstrated 17% and 27% hearing impairment, respectively.

Lyme disease reporting for Navy and Marine Corps (1997-2000).

Reported cases of Lyme disease for Navy and Marine Corps personnel during 1997-2000 are presented from data collected in the Naval Disease Reporting System and the Defense Medical Epidemiological Database. Naval Disease Reporting System identified 210 case subjects; 60% were men, 49% were family members, and 37% were active duty, and most originated in the second quarter of the calendar year. States reporting the greatest number of reports were Connecticut (44%), North Carolina (16%), Rhode Island (10%), and Virginia (10%), which was generally consistent with national figures and the concentration of military populations. Incidence rates from Defense Medical Epidemiological Database for Lyme disease were generally higher for active duty personnel than reported civilian rates. Areas for improvement for Naval Disease Reporting System are identified and include additional emphasis on complete reporting on patient history and on Lyme disease antibody testing results. These findings suggest that Lyme disease is an important disease in military medicine, particularly in the eastern United States.

Navy Hearing Conservation Program: 1995-1999 retrospective analysis of threshold shifts for age, sex, and officer/enlisted status.

This study provides a cross-sectional, population-based analysis of significant threshold shifts (STS) from over 83,000 audiograms on active duty members in the Navy Hearing Conservation Program Database for 1995-1999. Crude STS rates were lower for women than men (odds ration [OR], 0.82; 95% confidence interval [CI], 0.76-0.89; p = 0.0000) and lower for officer than enlisted (OR, 0.71; 95% CI, 0.66-0.76; p = 0.000000). STS rates also increased significantly with increasing age (chi2 for trend, 134; p = 0.0000). Compared with historical information, STS rates for officers were significantly lower (OR, 0.23; 95% CI, 0.18-0.27; p = 0.00000). Adjustment by logistic regression found STS rates were lower for women (OR, 0.837; 95% CI, 0.773-0.905; p = 0.000) and officer status (OR, 0.670; 95% CI, 0.619-0.725; p = 0.0000), and increased significantly with age. These findings warrant further investigation because they have programmatic implications on Navy hearing conservation and force health protection.

Analysis of Navy Physical Evaluation Board diagnoses (1998-2000).

An analysis is provided from 19,265 Physical Evaluation Board diagnoses from 10,406 Navy personnel from 1998 to 2000. The leading diagnostic categories were musculoskeletal and mental disorders as well as for subgroups of women and officers. Musculoskeletal conditions were 41.6% of the diagnoses and decreased with advancing age (42.9% for <30 years; 41.1% for 30-40 years; 37.6% for >40 years; chi2 for trend [1 df] = 26.4; p = 0.000). Mental disorders were 11.8% of the diagnoses and also decreased with advancing age (14.1% for <30 years; 10.4% for 30-40 years; 8.8% for >40 years; chi2 for trend [1 df] = 84; p = 0.000). Diagnoses for injury and poisoning (8.9%), nervous system (7.6%), and ill-defined conditions (4.7%) completed the top five categories below age 40 years, whereas circulatory disorders were evident after age 40 years. These findings suggest priorities for reducing overall medical disability losses in our active duty Navy forces.

Navy Asbestos Medical Surveillance Program (1984-1990): linear regression analysis for effect of asbestos exposure on pulmonary function testing.

This study examined records from the Navy Asbestos Medical Surveillance Program for 1984 through 1990 for Caucasian men (N = 129,598) using a population-based, cross-sectional, linear regression model. Continuous dependent variables were forced expiratory volume in 1 s and forced vital capacity (FVC), and continuous independent variables were age, height, weight, and tobacco use. A mid-period estimate of asbestos exposure was used because those values were reported as categorical variables. With asbestos exposure, forced expiratory volume in 1 s changed -3.2 cm3/year (t = -8.6, p = 0.000), and forced vital capacity changed -5.1 cm3/year (t = -11.8, p = 0.00). Those with more than 5 years of asbestos exposure demonstrated impairment over those with less exposure, and those with more than 15 years of exposure demonstrated even more impairment. These findings support the association of pulmonary function impairment with asbestos exposure for workers studied during this period.