A retrospective cohort study of military deployment and postdeployment medical encounters for respiratory conditions.

Deployed military personnel are exposed to inhalational hazards that may increase their risk of chronic lung conditions. This evaluation assessed associations between Operation Iraqi Freedom (OIF) deployment and postdeployment medical encounters for respiratory symptoms and medical conditions. This retrospective cohort study was conducted among military personnel who, between January 2005 and June 2007, were deployed to either of two locations with burn pits in Iraq, or to either of two locations without burn pits in Kuwait. Incidence rate ratios (IRRs) were estimated using two nondeployed reference groups. Rates among personnel deployed to burn pit locations were also compared directly to those among personnel deployed to locations without burn pits. Significantly elevated rates of encounters for respiratory symptoms (IRR = 1.25; 95% confidence interval [CI]: 1.20-1.30) and asthma (IRR = 1.54; 95% CI: 1.33-1.78) were observed among the formerly deployed personnel relative to U.S.-stationed personnel. Personnel deployed to burn pit locations did not have significantly elevated rates for any of the outcomes relative to personnel deployed to locations without burn pits. These results are consistent with the hypothesis that OIF deployment is associated with subsequent risk of respiratory conditions. Elevated medical encounter rates were not uniquely associated with burn pits.

Short communication: Investigation of incident HIV infections among U.S. army soldiers deployed to Afghanistan and Iraq, 2001-2007.

The U.S. Army initiated an investigation in response to observations of a possible increase in HIV incidence among soldiers deployed to combat. Human immunodeficiency virus (HIV)-infected U.S. Army soldiers are not eligible to deploy. Combat presents a health hazard to HIV-infected soldiers and they pose a threat to the safety of the battlefield blood supply and their contacts. All soldiers are routinely screened for HIV every 2 years and those who deploy are also screened both prior to and after deployment. Seroconversion rates were estimated for all soldiers who deployed to Afghanistan or Iraq in the period 2001-2007 and all active duty soldiers who did not. Seroconverters with an estimated date of infection, based on calculation of the midpoint between the last seronegative and first seropositive test date, that was either before or during deployment were eligible for inclusion. Confidential interviews and medical record reviews were conducted to determine the most likely time, geographic location, and mode of infection. Reposed predeployment samples were tested for HIV ribonucleic acid. The HIV seroconversion rate among all soldiers who deployed was less than the rate among those who did not deploy: 1.04 and 1.42 per 10,000 person-years, respectively. Among 48 cases, most were determined to have been infected in the United States or Germany and prior to deployment (n=20, 42%) or during rest and relaxation leave (n=13, 27%). Seven seronegative acute infections were identified in the predeployment period. Subtype was determined for 40 individuals; all were subtype B infections. All were acquired through sexual contact. These findings can inform development of preventive interventions and refinement of existing screening policy to further reduce HIV-infected deployed soldier person time.

Serosurvey of bacterial and viral respiratory pathogens among deployed U.S. service members.

BACKGROUND: Respiratory illnesses can cause substantial morbidity during military deployments. Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus, parainfluenza, and respiratory syncytial virus (RSV) are hypothesized causes. PURPOSE: To determine pathogen-specific seroprevalence prior to and after deployment in support of Operation Enduring Freedom (OEF). METHODS: A retrospective cohort study of 1000 service members deployed between June 30, 2004, and June 30, 2007, was conducted from 2008 through 2009. Pre- and post-deployment sera were tested for the presence of antibody to each pathogen. RESULTS: Pre-deployment IgG seropositivity was high for adenovirus, RSV, and parainfluenza (98.7%, 97.8%, and 81.6%, respectively), whereas seropositivity for B. pertussis, M. pneumoniae, and C. pneumoniae was 14.2%, 21.9%, and 65.1%, respectively. As defined by seroconversion in 1000 subjects, the following were identified: 43 new parainfluenza infections (24% of susceptibles); 37 new pertussis infections (4% of susceptibles); 33 new C. pneumoniae infections (10% of susceptibles); and 29 new M. pneumoniae infections (4% of susceptibles). B. pertussis seroconversion was two to four times higher than reports for the general U.S. population. Overall, 14.2% of the service members seroconverted to at least one of these six pathogens; this increased to 30.1% seroconversion when influenza was included. However, serologic testing was not clearly associated with clinical illness in this report. CONCLUSIONS: Serologic evidence for respiratory infections was common among the 2004-2007 OEF-deployed military, sometimes at a higher rate than the general U.S. population. Awareness of this risk and implementation of preventive measures should be emphasized by leadership prior to and during deployment.

Transfusion-transmissible viral infections among US military recipients of whole blood and platelets during Operation Enduring Freedom and Operation Iraqi Freedom.

BACKGROUND: Current US military clinical practice guidelines permit emergency transfusions of non-Food and Drug Administration (FDA)-compliant freshly collected blood products in theaters of war. This investigation aimed to characterize the risks of transfusion-transmitted infections (TTIs) associated with battlefield transfusions of non-FDA-compliant blood products. STUDY DESIGN AND METHODS: US Service members who received emergency transfusion products in Iraq and Afghanistan (March 1, 2002-September 30, 2007) were tested for hepatitis C virus (HCV), human immunodeficiency virus (HIV), and hepatitis B virus (HBV) infections using reposed pre- and posttransfusion sera. Selected regions of viral genomes from epidemiologically linked infected recipients and their donors were sequenced and compared. RESULTS: Of 761 US Service members who received emergency transfusion products, 475 were tested for HCV, 472 for HIV, and 469 for HBV. One transfusion-transmitted HCV infection (incidence rate of 2.1/1000 persons) was identified. The pretransfusion numbers (prevalence per 1000 persons) were HCV-four (8/1000), HIV-zero (0/1000), chronic HBV-two (4 /1000), and naturally immune (antibody to HBV core antigen)-nine (19/1000). CONCLUSION: One HCV TTI was determined to be associated with emergency blood product use. The pretransfusion HCV and HBV prevalence in transfusion recipients, themselves members of the potential donor population, indicates better characterization of the deployed force's actual donor population, and further investigations of the TTI prevalence in these donors are needed. These data will inform countermeasure development and clinical decision making.

Active tuberculosis and recent overseas deployment in the U.S. military.

BACKGROUND: The risk of active TB resulting from military deployment to endemic areas is unknown. It has typically been assumed that the risk of TB approximates the risk among local nationals in that country. PURPOSE: This nested case-control study assesses the putative association of overseas deployment with active tuberculosis among active-component U.S. military service members. METHODS: Deployment histories and other exposures among 578 active TB cases and 2312 controls matched on year of entry into service and length of service between 1990 and 2006 were compared in 2009 using multivariate conditional logistic regression. Multiple imputation methods were used to account for missing data. RESULTS: The matched OR of active TB for military deployers as compared to nondeployers was 1.18 (95% CI=0.91, 1.52). A significant association of deployments of 90-179 days was found, but this was inconsistent with the overall negative result. Significant associations were seen with foreign birth and nonwhite racial or ethnic groups. Overseas stationing in Korea was also found to be associated with active TB. CONCLUSIONS: No strong or consistent association was found between active TB and deployment, but an association was seen with long-term residence in TB-endemic countries (Korea). The strongest risk factors for active TB in the U.S. military population were found to exist prior to accession into military service. These conclusions were robust in sensitivity analysis.

Malaria in the Republic of Korea, 1993-2007. Variables related to re-emergence and persistence of Plasmodium vivax among Korean populations and U.S. forces in Korea.

Malaria was eradicated and the Republic of Korea (ROK) declared "malaria free" in 1979. However, in 1993, a temperate strain of vivax malaria, expressing both latent and nonlatent disease populations, re-emerged near the demilitarized zone (DMZ), rapidly spread to civilian sectors near the DMZ, and increased exponentially in ROK military, veteran, and civilian populations through 1998. Malaria among all ROK populations decreased 5-fold from a high of 4142 cases in 2000 to a low of 826 cases in 2004, before increasing again to 2180 cases by 2007. Each malaria case in the ROK is reported in the metropolitan area/province where the diagnosis is made, which may be at some distance from the area where infection occurred. Therefore, it is difficult to ascertain transmission sites since approximately 60% of vivax malaria in Korea is latent with symptoms occurring >1 month to 24 months after infection. A review of case diagnosis for civilian, veteran, and military populations shows that nearly all malaria south of Gyeonggi and Gangwon Provinces is the result of veterans exposed in malaria high-risk areas along the DMZ and returning to their hometowns where they later develop malaria. Thus, malaria currently remains localized near the DMZ with limited transmission in provinces south of Seoul and has not spread throughout Korea as previously hypothesized. This report describes the reemergence of vivax malaria cases in civilian and military ROK populations and U.S. military personnel and assesses variables related to its transmission and geographic distribution.

Comparison of the trivalent live attenuated vs. inactivated influenza vaccines among U.S. military service members.

Limited effectiveness data are available comparing live attenuated influenza vaccine (LAIV) to inactivated influenza vaccine (TIV) among adults. To compare the incidence of influenza-like illness following immunization of adults with LAIV vs. TIV, we conducted a retrospective cohort analysis of active component U.S. military personnel for the 2005-2006 and 2006-2007 influenza seasons. Recruits experienced a much higher burden of disease compared to non-recruits, with crude incidence rates of influenza-like illness 2-16 times higher than non-recruits depending on the season and cohort. For both seasons, a slightly greater protection from influenza-like illness was found for non-recruits who received TIV compared to LAIV (adjusted incidence rate ratio, 1.17 (95% CI, 1.14-1.20) and 1.33 (95% CI, 1.30-1.36), 2005-2006 and 2006-2007 influenza seasons, respectively). However, for Army and Air Force recruits, LAIV was found to provide significantly greater protection from influenza-like illnesses compared to TIV, with adjusted incidence rates of influenza-like illness 22-51% and 18-47% lower among LAIV compared to TIV recipients for the 2005-2006 and 2006-2007 influenza seasons, respectively. Possible reasons for differences in recruit and non-recruit findings include differences in pre-existing influenza antibody levels, differing respiratory disease burden, and/or unmeasured confounding. Consideration of these findings should be made when developing influenza immunization policies.

Injury reduction effectiveness of selecting running shoes based on plantar shape.

Popular running magazines and running shoe companies suggest that imprints of the bottom of the feet (plantar shape) can be used as an indication of the height of the medial longitudinal foot arch and that this can be used to select individually appropriate types of running shoes. This study examined whether or not this selection technique influenced injury risk during United States Army Basic Combat Training (BCT). After foot examinations, BCT recruits in an experimental group (E: n = 1,079 men and 451 women) selected motion control, stability, or cushioned shoes for plantar shapes judged to represent low, medium, or high foot arches, respectively. A control group (C: n = 1,068 men and 464 women) received a stability shoe regardless of plantar shape. Injuries during BCT were determined from outpatient medical records. Other previously known injury risk factors (e.g., age, fitness, and smoking) were obtained from a questionnaire and existing databases. Multivariate Cox regression controlling for other injury risk factors showed little difference in injury risk between the E and C groups among men (risk ratio (E/C) = 1.01; 95% confidence interval = 0.88-1.16; p = 0.87) or women (risk ratio (E/C) = 1.07; 95% confidence interval = 0.91-1.25; p = 0.44). In practical application, this prospective study demonstrated that selecting shoes based on plantar shape had little influence on injury risk in BCT. Thus, if the goal is injury prevention, this selection technique is not necessary in BCT.

Suspected pulmonary tuberculosis exposure at a remote U.S. army camp in northeastern Afghanistan, 2007.

Military personnel serving at remote camps in the border regions of northeastern Afghanistan may experience crowded living conditions and may have frequent interaction with local national (LN) workers, increasing the risk of exposure to multiple endemic diseases including tuberculosis (TB). In January 2007, pulmonary TB was clinically suspected in a LN worker who had close contact with a company of 92 U.S. Army personnel at a remote camp in Konar province, Afghanistan, over 4 months. This report describes the results of the contact investigation conducted by the U.S. Army, in which four U.S. personnel were found to have evidence of TB exposure. This investigation raises concerns arising from the high prevalence of drug-resistant TB in the region and in neighboring North West Frontier Province, Pakistan, and demonstrates the challenges of conducting contact investigations and using LN workers in deployed wartime environments.

Incidence rates of pelvic inflammatory disease diagnoses among Army and Navy recruits potential impacts of Chlamydia screening policies.

BACKGROUND: U.S. Navy policy requires Chlamydia trachomatis screening of all women upon entry to recruit training in conjunction with an educational session, and yearly screening thereafter until age 25. Army policy directs only annual screening of asymptomatic women aged <25. Hence, screening of Army recruits may not occur for up to 12 months following accession. Using routinely collected surveillance data, the rates of outpatient pelvic inflammatory disease (PID) following accession into the Army or Navy were compared to assess the potential implications of these policies. METHODS: The population at risk comprised active-component women aged <25 who accessioned to either the U.S. Army or Navy between January 1, 2001, and December 31, 2005. Subjects were followed up to 60 months from accession, either until a first outpatient PID diagnosis occurred or they departed from military service. Data were collected from 2001 to 2006 and analyzed in 2007. Multiple Poisson regression was used to assess the effects of potentially important covariates. Time-to-event analysis was employed to characterize risk over time. RESULTS: There were 1276 and 546 incident outpatient diagnoses of PID among 58,088 Army and 33,046 Navy accessions during 93,918 and 65,863 person-years of follow-up, respectively. The crude incident rate was 64% higher in the Army (13.6/1000 person-years) than the Navy (8.3/1000 person-years). Risk for the Army increased soon after accession, followed by a decline, while risk for the Navy remained comparatively uniform. CONCLUSIONS: PID rates were higher in the Army than Navy during the first years of active service. A comprehensive study to elucidate the source of this observed difference is warranted.

Pseudoepidemics of tuberculin skin test conversions in the U.S. Army after recent deployments.

RATIONALE: The tuberculin skin test (TST) has many sources of error. These can lead to predominantly false-positive reactions when used in low-risk populations. The U.S. Army deploys to areas considered at high risk for tuberculosis (TB) infection, but often has limited contact with the local population. OBJECTIVES: We describe the investigation of eight pseudoepidemics of TST conversions in U.S. Army populations, five of which were associated with overseas deployments. METHODS: Outbreak investigations of these pseudoepidemics consisted of several components: evaluation of active and latent TB surveillance data, review of medical records, investigation and interviews of active TB cases and their contacts, evaluation of materials and personnel screening procedures, and placement and reading of repeat skin testing. MEASUREMENTS AND MAIN RESULTS: Initially reported risk of conversion in the outbreaks ranged from 1.3 to 15%. Repeat testing of converters (positives) found that 30 to 100% were negative on retesting. Several sources of false-positive results were identified in these pseudoepidemics, including variability in reading and administration, product variability, and cross-reactions to nontuberculous mycobacteria. CONCLUSIONS: Pseudoepidemics of TST conversions are a common occurrence after U.S. Army deployments and in U.S. Army populations. U.S. Army forces generally have a low risk of TB infection resulting from deployments due to limited exposure to local nationals with active TB, and universal testing in this population has a low positive-predictive value.

Trends in overweight and obesity among 18-year-old applicants to the United States military, 1993-2006.

We examined trends in overweight and obesity among 756,269 18-year-old civilian applicants to the United States military from 1993-2006. The prevalence of overweight increased from 22.8% in 1993 to 27.1% in 2006, and obesity increased from 2.8% to 6.8%. We conclude the U.S. military is recruiting from an increasingly overweight population.

Mental health impact of 9/11 Pentagon attack: validation of a rapid assessment tool.

BACKGROUND: Following the tragic events of 9/11/2001, the Pentagon Post Disaster Health Assessment (PPDHA) survey was created to identify healthcare needs and concerns among Pentagon personnel and to assure that appropriate care and information was provided. The PPDHA was fielded from October 15, 2001, to January 15, 2002. Fundamental in this assessment was the evaluation of the mental health impact as a result of the attack. METHODS: Although a number of standardized instruments exist for mental health domains, most are lengthy and could not be used as a rapid health assessment. Instead, a short screening instrument consisting of 17 questions was developed that covered important mental health symptom domains, mental health functioning, and possible predictive risk factors. High-risk groups for post-traumatic stress disorder (PTSD), depression, panic attacks, generalized anxiety, and alcohol abuse were assessed, and validation of risk groups was assessed across functional levels. RESULTS: Overall, 1837 (40%) respondents met the screening criteria for any of the symptom domains of interest 1 to 4 months after the attack: PTSD (7.9%), depression (17.7%), panic attacks (23.1%), generalized anxiety (26.9%), or alcohol abuse (2.5%). Mental health risk groups were highly correlated with self-reported reduced daily functioning and use of counseling services. Additionally, risk factors known to be associated with mental health problems after traumatic events were strongly predictive of the high-risk categories identified. CONCLUSIONS: Mental health concerns were common among Pentagon employees in the 4 months after the 9/11 attack. Data from this study suggested that the short mental health screening instrument had validity and can serve as a prototype for rapid public health assessment of the mental health impact of future traumatic events.

Development of a brief questionnaire to measure mental health outcomes among Pentagon employees following the September 11, 2001 attack.

In the aftermath of the terrorist action at the Pentagon there was a critical operational need to understand and document the extent of injuries, illnesses, and exposures sustained by Service members and civilian employees at the Pentagon. It was decided to develop and administer a brief questionnaire to the Pentagon employees that would contain questions about exposures, new or worsening injuries or illnesses, mental health, and factors suggested by the literature to increase risk or be protective for these outcomes. This report describes the development the mental health portion of this questionnaire. Most mental health instruments are very lengthy, limiting their usefulness as rapid public health assessment tools. This brief instrument was designed to cover four main symptom domains, as well as key risk/protective factors, thought to be most important following the terrorist attack. The symptom domains were: acute and post-traumatic stress symptoms, depression, anxiety/panic attacks, and alcohol abuse. Further analyses will assess the usefulness of this questionnaire as a public health tool for rapid assessment of mental health symptoms following the attack.