The Department of Defense Medical Mortality Registry.

The Department of Defense Medical Mortality Registry is being implemented at the Office of the Armed Forces Medical Examiner, Armed Forces Institute of Pathology, providing the first comprehensive medical mortality surveillance for the Department of Defense. The Registry attempts to obtain complete medical and circumstantial information on every military active duty death for medical surveillance and prevention research. Medical records, autopsy reports, eyewitness accounts, and investigative reports are reviewed to validate and synthesize medical, circumstantial, and risk factor information on each death. All military active duty deaths since 1980 are currently identified and classified by manner of death (accident, suicide, homicide, illness, hostile, undetermined). Military death rates have decreased during the past two decades by nearly half. About three-quarters of military deaths are attributable to injury (accident, suicide, homicide). The Registry creates new opportunities for prevention-oriented research as it collects detailed information on every military death.

The asthma accession standard: a survival analysis of military recruits, 1995 to 1997.

Asthma has a significant impact on U.S. military expenditures and readiness. Every year approximately 1,000 recruits are discharged for asthma during their first 6 months of service. This study was done to evaluate the practice of allowing some individuals with a history of asthma to enter military service (waiving). A survival analysis was performed to compare length of time until discharge and asthma-related failure for individuals waived for asthma (cases) and individuals not disqualified for asthma (controls). Cases were 587 recruit applicants initially disqualified who received waivers for asthma and accessed in the years 1995 to 1997. Controls were 1,761 matched enlisted recruits starting basic training in those years. No significant differences were found with respect to general attrition. The statistical differences for asthma-related hospitalization or discharge did not translate into practical differences. Waiving for asthma was not a significant occupational liability in terms of asthma-related hospitalization or early military attrition.

Cost-effective syphilis screening in military recruit applicants.

A cost-effectiveness analysis of syphilis screening was performed. Strategies included no screening, universal testing at military entrance processing stations, universal testing at basic training centers, and contracting centralized screening. Probabilities derived from data retained on recruit applicants from 1989 through 1991 (N = 1,588,143) and from the published literature were used. Cost estimates were derived from costs incurred by the military and costs projected from implementing new strategies. Sensitivity analyses were performed. Modifying the existing contract for human immunodeficiency virus screening to include syphilis screening would maximize the effectiveness of screening at a cost to the Department of Defense of $9.52 per additional year of service received. The no-screening option was significantly more cost-saving than the current method of testing. Syphilis is rare and treatable, and individuals with syphilis will be identified by other means in many cases. Syphilis screening of recruit applicants at the military entrance processing stations should cease, saving the military $2,541,000 per year.

Climate and satellite indicators to forecast Rift Valley fever epidemics in Kenya.

All known Rift Valley fever virus outbreaks in East Africa from 1950 to May 1998, and probably earlier, followed periods of abnormally high rainfall. Analysis of this record and Pacific and Indian Ocean sea surface temperature anomalies, coupled with satellite normalized difference vegetation index data, shows that prediction of Rift Valley fever outbreaks may be made up to 5 months in advance of outbreaks in East Africa. Concurrent near-real-time monitoring with satellite normalized difference vegetation data may identify actual affected areas.

Reducing medical attrition: the role of the Accession Medical Standards Analysis and Research Activity.

This paper illustrates how adding an epidemiologic perspective to medical accession policy development allows the Department of Defense to address unacceptably high rates of premature attrition, lost duty time, avoidable medical care costs, sick leave, disability, and various wasteful, inefficient practices. The Accession Medical Standards Analysis and Research Activity is a major new epidemiologic entity. Historically, military medical accession policy and waiver deliberations were based heavily on expert opinion. A common limitation of expert opinion is that although experience teaches much about individuals with certain conditions who develop problems, it does not teach about individuals with the same conditions who remain well. The Accession Medical Standards Analysis and Research Activity produces the analyses of epidemiologic data necessary for the joint personnel and medical flag-level Department of Defense Accessions Medical Standards Steering Committee to make evidence-based accession policy decisions.

Prevalence of antibodies to adenovirus serotypes 4 and 7 among unimmunized US Army trainees: results of a retrospective nationwide seroprevalence survey.

The 1996 production halt of adenovirus types 4 and 7 vaccines prompted concerns about the resurgence of large respiratory disease outbreaks among US military basic trainees. This serosurvey was conducted to assess the current susceptibility of the trainee population to these viruses. A stratified, random sample (n=303) of trainees' sera was tested using a quantitative colorimetric microneutralization assay to demonstrate antibody titers considered to provide immunologic protection against each adenovirus type. Results were analyzed for relationships between susceptibility and 4 demographic factors-gender, race, prior military service, and age. Results showed that 66% and 73% of trainees were susceptible to serotypes 4 and 7, respectively. Nearly 90% were susceptible to at least one serotype. Susceptibility was significantly (P<.05) related to lack of prior military service and younger age. Consistent with a serosurvey conducted 20 years ago, these results demonstrated significant susceptibility to two vaccine-preventable causes of disease. These findings may have civilian implications.

Deployed US Army soldiers' knowledge and use of personal protection measures to prevent arthropod-related casualties.

The recommendation to use personal protection measures (PPMs) to prevent arthropod-related diseases and nuisance bites is a common element of travel medicine consultation.1-3 Prevention of arthropod-related casualties is especially important to the military, given the often intense exposure of service members to biting arthropods and the threat of personnel losses to mission success. In the 1980s, 75% deet (N,N-diethyl-m-toluamide) was the US military-issue insect repellent for use on skin and clothing. Collaboration between military and civilian researchers led to the implementation in 1991 of the current US military system of PPMs which has three components: topical application of 33% extended-duration deet, treatment of field uniforms with permethrin, and proper wearing of field uniforms.4-6 Compared to military-issue 75% topical deet, 33% extended-duration deet prevents bites up to three times longer (as long as 12 hours), is less greasy, and has lower plasticizing properties. Field uniforms treated with the contact toxicant, permethrin, are also necessary to minimize bites from crawling arthropods such as ticks and chiggers. Implementation of all three components of this system is a safe and effective means of reducing the threat posed by biting arthropods.7 We conducted a questionnaire survey to assess the degree of deployed soldiers' knowledge of the US military's system of PPMs and use of PPMs in general. Survey results may promote the development of better ways to advise and teach military and civilian travelers about the proper use of PPMs given the multitude of available products and practices.

Vaccine-preventable disease susceptibility in a young adult Micronesian population.

Current US military recruit vaccination policy presumes that recruits have had a complete childhood immunization series. This assumption may not be appropriate for recruits from Micronesia, who may have had limited access to modern health care, including immunization programs. During 1988 and 1990, a cross-sectional serosurvey was conducted among 66 US military recruits, 56 from the Federated States of Micronesia and 10 from the Republic of the Marshall Islands, collectively referred to as Micronesia. Antibody seronegativity levels for 12 vaccine-preventable (or potentially so) diseases were: measles (52%), mumps (14%), rubella (21%), varicella (38%), diphtheria (39%) tetanus (0%), polio type 1 (4%), polio type 2 (0%), polio type 3 (14%), hepatitis A (9%), hepatitis B (17%), and hepatitis C (98%). Compared with Army recruits in general, Micronesian recruits were significantly more likely to be seronegative for measles and varicella and seropositive for hepatitis types A and B. Personal histories of disease were felt to be inadequate in predicting antibody status.

Seroprevalence of Helicobacter pylori infections in a cohort of US Army recruits.

To study the prevalence and risk factors of Helicobacter pylori infection in healthy young adults, sera were collected from a nationwide sample of 404 females and 534 males (mean age, 20.2; range, 17-26 years) at induction into the US Army at Fort Jackson, South Carolina, during the fall of 1990. An enzyme-linked immunosorbent assay (PYLORI STAT, BioWhittaker, Inc., Walkersville, MD) was used to detect H. pylori-specific immunoglobulin G antibodies. Demographic data were obtained from a personnel database and by linking US census information to the subject's home address. The observed crude seropositivity rate was 26.3% (95% confidence interval 23.2-28.9). The direct sex-, race-, and geographic region-adjusted seropositivity rate was 20.8% (95% confidence interval 17.9-23.7). Seropositivity rates for blacks, Hispanics, and whites were 44%, 38%, and 14%, respectively, (chi 2, p < 0.001), and rates increased progressively from 24% in the age group 17-18 years to 43% in the age group 24-26 years (chi 2 for trend, p < 0.001). The age trends remained strong after controlling for race Median income was also an important predictive variable for seropositivity (chi 2, p < 0.0001). Sex, the percent urbanization, and population density of the home county were not significant predictors of seropositivity when age and race-ethnic group were controlled in a statistical model. The sharp increase in seroprevalence in this narrow age range suggests that the incidence rates are higher in young adults than previously reported.

Decreases in invasive Haemophilus influenzae diseases in US Army children, 1984 through 1991.

OBJECTIVE: To document trends in the incidence of invasive Haemophilus influenzae diseases in young children of US Army active duty soldiers following the publication of H influenzae type b immunization recommendations for young children between 1985 and 1990. DESIGN: A population-based surveillance of hospital discharge diagnoses for H influenzae invasive diseases. SETTING: Military and civilian medical treatment facilities around the world. PATIENTS: There was a mean population of nearly 200,000 US Army health care beneficiaries younger than 5 years of age each year of the study. OUTCOME MEASURES: Annual total and age-specific incidences of the six most common H influenzae invasive diseases in this population (meningitis, epiglottitis, septicemia, pneumonia, cellulitis, and septic arthritis). RESULTS: The annual number of cases of H influenzae invasive diseases decreased from a high of 188 in 1986 to 43 in 1991. The incidence in the age group at highest risk for H influenzae disease, those 6 to 11 months of age, decreased from 355 per 100,000 children in 1986 to 116 per 100,000 in 1991 (P < .0001, chi 2 for trend). The incidence for H influenzae meningitis declined from 59 per 100,000 children in 1986 to 6 per 100,000 in 1991 (P < .0001, chi 2 for trend). CONCLUSIONS: The decrease in H influenzae invasive diseases closely follows the dates of H influenzae type b vaccine licensure for use in progressively younger age groups. Some age groups, however, experienced a decline in disease rates even before becoming eligible for vaccination.

A brief review of the epidemiology of HIV in the U.S. Army.

The Department of Defense has conducted extensive HIV testing for over 5 years. We summarize the epidemiology of the HIV infection in the total Army. While screening of civilian applicants effectively ensures seronegativity of enlistees, there are approximately 220 new HIV infections each year among active duty soldiers. High-risk demographic groups in the Army include single soldiers, males, those age 25-35, blacks, and Hispanics (including black and Hispanic females). While preventive efforts in the Army should reflect the higher risk experienced by these groups, all soldiers should be made aware of their susceptibility as the epidemic evolves to include more women and heterosexual men.

The susceptibility of young adult Americans to vaccine-preventable infections. A national serosurvey of US Army recruits.

OBJECTIVE: Due to recent resurgences of measles, mumps, and rubella among young US adults, we sought to generate antibody prevalence data for national and military immunization policy evaluations. DESIGN: We used a questionnaire and serological survey of Army recruits to assess antibody status to measles, mumps, rubella, and varicella by enzyme-linked immunosorbent assay and to poliovirus types 1, 2, and 3 by microneutralization assay. SETTING: Basic training reception centers at Fort Benning, Ga., and Fort Jackson, SC. PATIENTS: The study included 1547 US Army recruits who were inducted during September and October 1989. OUTCOME MEASURES: Seronegativity by various demographic factors. RESULTS: Seronegativity rates, directly adjusted to the 15- to 24-year-old US population in 1980, were 20.7% for measles, 15.6% for mumps, 17.5% for rubella, and 6.9% for varicella. For measles, mumps, and rubella, susceptibility was less in females, blacks, and college-educated recruits, and varicella susceptibility was greater in females and blacks. Recruitment who were born after 1969 lacked measles, mumps, and rubella antibodies more often than older recruits. The adjusted seronegativity rates for poliovirus types 1, 2, and 3 were 2.3%, 0.6%, and 14.6%, respectively; trends by age, sex, and race-ethnicity were generally unremarkable. CONCLUSIONS: Among young adult Americans, susceptibility to measles, mumps, and rubella is unevenly distributed and may be substantial. Our findings support national objectives to further improve immunization coverage in school-age and adult populations and provide further impetus for legislation requiring college entrants to present evidence of having received at least two doses of measles vaccine, with one on or after entry into elementary school.

Immunogenicity achieved by the intradermal hepatitis B vaccination programme for US Army soldiers in Korea.

Hepatitis B virus (HBV) infections are a significant threat to the 30,000 US Army soldiers stationed in South Korea. Hepatitis B surface antigen carrier rates in some Korean populations may run as high as 15%, and HBV incidence estimates for US soldiers in Korea have ranged from 0.6 to 6% per year. In response to this threat, on 1 October 1986 the US Army instituted a mandatory three-dose (0, 30-60, and 60+ days), 0.1 ml per dose, intradermal (i.d.) immunization regimen for all soldiers bound for permanent assignments in Korea. Although shown to be immunogenic in experimental studies, the i.d. route had never been attempted on as large a scale as in this operational setting. During September 1987, an evaluation of programme compliance and immune response was conducted. For those who received three doses according to schedule, antibody response was similar to that reported by previous controlled trials that used the i.d. approach. The three-dose i.d. series appeared to provide protective antibody levels in at least 67% of soldiers, but, consistent with previous trials, antibody levels were approximately one-half those obtained following intramuscular vaccination. We conclude that, as a cost-reduction strategy, wide-scale use of intradermal hepatitis B vaccine may be useful in situations characterized by short-term increased HBV infection risk.

Increasing incidence of varicella hospitalizations in United States Army and Navy personnel: are today's teenagers more susceptible? Should recruits be vaccinated?

Hospital records for 10,687 United States Army and Navy adult varicella (chickenpox) admissions were reviewed. Annual hospital admission rates for varicella increased more than fourfold in the active-duty army during 1980 to 1988 and more than 18-fold among active-duty navy enlisted personnel during 1975 to 1988. Fifty-seven percent of varicella admissions occurred in the most junior military members, aged 17 to 20. More than half of the total varicella admissions occurred in personnel with less than a year of military service. Multivariate analysis of the navy data confirmed increasing time-related trends of risk, suggesting a national temporal trend of increased varicella susceptibility in US teenagers and young adults. Administering a safe and effective varicella vaccine to army and navy recruits could prevent more than 7260 hospital-bed days during the first year of use.

Human immunodeficiency virus seropositivity among members of the active duty US Army 1985-89.

Between October 1985 and June 1989, most active duty US Army soldiers were screened for human immunodeficiency virus (HIV) antibody. Of 648,032 screened soldiers in this analysis, 1,588 were HIV-antibody positive. In a multivariate analysis, correlates of positivity included: age [Adjusted Odds Ratios (ref less than 20 years) = 20-24 years, 3.7; 25-29, 9.3; 30-34, 15.7; greater than or equal to 35, 15.9]; being male, [4.2]; being Black or Hispanic (vs white) [3.7 and 3.0, respectively]; being single (vs married) [3.8]; assignment to an HIV endemic location [1.7], and having a medical occupation [2.7, 2.7, and 2.6 for negligible, low, and high blood exposure professions, respectively]. Seropositivity rate ratios for medical vs non-medical personnel were 0.7 [95% CI = 0.4, 1.4] for females and 2.9 [95% CI = 2.5, 3.3] for males. For male medical personnel, being single (vs married) correlated strongly with antibody positivity [prevalence ratio = 3.4, 95% CI = 2.6, 4.6]. Excess HIV risk among medical personnel appeared largely attributable to factors other than occupational exposures.