Association between depression and HIV treatment outcomes in a US military population with HIV infection.

BACKGROUND: Depression is common among HIV-infected individuals and may contribute to suboptimal adherence to antiretroviral therapy (ART) and subsequent inability to attain viral load (VL) suppression. We evaluated associations between depression, self-reported adherence, and longitudinal HIV treatment outcomes in US Military HIV Natural History Study (NHS) participants with and without depression. METHODS: Male NHS participants with available ICD-9 data for mental health diagnoses, Center for Epidemiological Studies Depression (CES-D) measures, and self-reported adherence (SRA) were included. ART use was defined as ART initiation between 2006 and 2010, with follow-up through 2015. SRA was defined as taking 95% of ART doses and continuous ART was defined as longitudinal ART use with gaps < 30 days. Continuous VL suppression was defined as maintaining VLs < 200 c/mL on ART. To analyse the association between depression and HIV treatment outcomes, latent class analysis was used to create classes of depression trajectories: low depression (LD), recent onset depression (ROD) and high Depression (HD). RESULTS: Participants had a mean age of 32 (± 8.3) years at HIV diagnosis, and similar proportions were Caucasian (44.3%) or African American (40.8%). Overall, older participants at HIV diagnosis had greater odds of having 95% self-reported adherence (OR 1.06, 95% CI 1.02-1.12), and African Americans had lower odds (OR 0.41, 95% CI 0.22-0.76) compared to Caucasians (OR 1.49, 95% CI 0.52-4.28). However, there was no difference in SRA by depression trajectory. Participants with HD had an increased odds of taking ART continuously (OR 1.75, 95% CI 0.99-3.09), and those with ROD had significantly higher odds of virologic failure (OR 0.58, 95% CI 0.38-0.91). CONCLUSIONS: Although there was no observed association between depression and SRA, participants with ROD had lower odds of attaining the HIV treatment goal of VL suppression. Continued efforts to identify and aggressively manage mental health disorders is important to success along the HIV care continuum.

Antiretroviral Therapy and Viral Suppression Among Active Duty Service Members with Incident HIV Infection - United States, January 2012-June 2018.

Human immunodeficiency virus (HIV) infection is a deployment-limiting medical condition for U.S. armed forces in the Department of Defense (DoD) (1). HIV management using contemporary antiretroviral therapy (ART) regimens permits effective suppression of viremia among persons in clinical care. Although service members with HIV infection can remain in military service, treatment outcomes have not been fully described. Data from the Defense Medical Surveillance System (DMSS) were analyzed to estimate ART use and viral suppression among DoD service members with diagnosed HIV infection during January 2012-June 2018 (2). Among 1,050 service members newly diagnosed with HIV infection during January 1, 2012-December 31, 2017, 89.4% received ART within 6 months of HIV diagnosis, 95.4% within 12 months, and 98.7% by the end of the surveillance period on June 30, 2018. Analyses determined that, among 793 persons who initiated ART and remained in military service for ≥1 year, 93.8% received continuous ART, 99.0% achieved viral suppression within 1 year after ART initiation, and 96.8% were virally suppressed at receipt of their last viral load test. The DoD model of HIV care demonstrates that service members with HIV infection who remain in care receive timely ART and can achieve both early and sustained viral suppression.

HIV Preexposure Prophylaxis in the U.S. Military Services - 2014-2016.

Human immunodeficiency virus (HIV) infection is a substantial health concern for the U.S. Department of Defense (DoD) and for service members stationed throughout the world. Each year, approximately 350 new HIV infections are diagnosed in members of the U.S. military services, with most infections acquired within the United States (1). The DoD populations most affected by HIV mirror those in the U.S. civilian population; the highest rates of new military diagnoses are in men and blacks or African Americans (blacks) (1). Blacks are disproportionally affected, and most new diagnoses occur among men who have sex with men (MSM). HIV preexposure prophylaxis (PrEP) is approximately 90% effective in preventing HIV infection when used properly (2), and an increasing number of active duty personnel have used HIV prevention services and PrEP in the military health system since the repeal of "Don't Ask, Don't Tell"* in 2011 (3). Military health system and service records were reviewed to describe HIV PrEP use among military personnel, and military health care providers were surveyed to assess HIV PrEP knowledge and attitudes. Among 769 service members prescribed PrEP during February 1, 2014-June 10, 2016, 60% received prescriptions from an infectious disease provider, 19% were black men, and 42% were aged >28 years. Half of surveyed military health care providers self-rated their PrEP knowledge as poor. DoD is developing new policy to address access to care challenges by defining requirements and establishing pathways for universal patient access to PrEP.

Humanitarian Mission at Home: Walter Reed National Military Medical Center's Experience in Operation Allies Refuge and Operation Allies Welcome.

Military medicine has a long history of humanitarian efforts globally, including responses to natural disasters and as planned medical civil action projects. However, ending two decades of war in Afghanistan, Walter Reed National Military Medical Center (WRNMMC) was tasked to receive up to 63 injured patients with less than 96-hour notice on August 27, 2021. As part of Operation Allies Refuge and transition to Operation Allies Welcome, this article highlights the complicated cross-organizational and multidisciplinary response at WRNMMC where ultimately 277 Afghan patients and nonmedical attendants received medical care and other requirements for resettlement. Lessons learned from coordinating the complex short suspense medical, cultural, and logistic efforts are noted as considerations and practical recommendations for future missions.

Risk of sexually transmitted infections among U.S. military service members in the setting of HIV pre-exposure prophylaxis use.

BACKGROUND: The evidence for an increased incidence of sexually transmitted infections (STIs) among patients utilizing HIV pre-exposure prophylaxis (PrEP) has been inconsistent. We assessed the risk of incident STI while on PrEP compared to periods off PrEP among military service members starting PrEP. METHODS: Incidence rates of chlamydia, gonorrhea, syphilis, hepatitis C virus, and HIV were determined among military service members without HIV prescribed daily oral tenofovir disoproxil fumarate and emtricitabine for HIV PrEP from February 1, 2014 through June 10, 2016. Hazard ratios for incident STIs were calculated using an Anderson-Gill recurrent event proportional hazard regression model. RESULTS: Among 755 male service members, 477 (63%) were diagnosed with incident STIs (overall incidence 21.4 per 100 person-years). Male service members had a significantly lower risk of any STIs (adjusted hazard ratio (aHR) 0.21, 95% CI 0.11-0.40) while using PrEP compared to periods off PrEP after adjustment for socio-demographic characteristics, reasons for initiating PrEP, surveillance period prior to PrEP initiation, and the effect of PrEP on site and type of infection in multivariate analysis. However, when stratifying for anatomical site and type of infection, the risk of extragenital gonorrhea infection (pharyngeal NG: aHR 1.84, 95% CI 0.82-4.13, p = 0.30; rectal NG: aHR 1.23, 95% CI 0.60-2.51, p = 1.00) and extragenital CT infection (pharyngeal CT: aHR 2.30, 95% CI 0.46-11.46, p = 0.81; rectal CT: aHR 1.36, 95% CI 0.81-2.31, p = 0.66) was greater on PrEP compared to off PrEP although these values did not reach statistical significance. CONCLUSIONS: The data suggest entry into PrEP care reduced the overall risk of STIs following adjustment for anatomical site of STI and treatment. Service members engaged in PrEP services also receive more STI prevention counseling, which might contribute to decreases in STI risk while on PrEP.

Patients with HIV-associated cancers have evidence of increased T cell dysfunction and exhaustion prior to cancer diagnosis.

BACKGROUND: People living with HIV (PLWH) have increased risk of developing cancers after controlling traditional risk factors and viral suppression. This study explores whether T cells can serve as a marker of risk for cancer among HIV-infected virally suppressed patients. METHODS: A nested case control study design was pursued with 17 cancer cases and 73 controls (PLWH without cancer)ouidentified among the US Military HIV Natural History Study cohort, and were matched for CD4 + count, duration of HIV infection, and viral suppression. Cells were obtained from PLWH on an average of 12 months prior to clinical cancer diagnosis. Expression of inhibitory receptors (PD-1, CD160, CD244, Lag-3, and TIGIT), and transcription factors (T-bet, Eomesodermin, TCF-1, and (TOX) was measured on CD8 +T cells from that early time point. RESULTS: We found that cases have increased expression of PD-1 +CD160+CD244+ ('triple positive') on total and effector CD8 + compared with controls (p=0.02). Furthermore, CD8 +T cells that were both PD-1 +CD160+CD244+ and T-betdimEomeshi were significantly elevated in cases at time point before cancer detection, compared with controls without cancer (p=0.008). This was driven by the finding that transcriptional factor profile of cells was altered in cancers compared with controls. Triple-positive cells were noted to retain the ability for cytotoxicity and cytokine secretion mediated by expression of CD160 and PD-1, respectively. However, triple-positive cells demonstrated high expression of TOX-1, a transcription factor associated with T cell exhaustion. CONCLUSION: In conclusion, we have found a subset of dysfunctional CD8 +T cells, PD-1 +CD160+CD244+T-betdimEomeshi, that is elevated 12 months before cancer diagnosis, suggesting that peripheral T cell alterations may serve as a biomarker of increased cancer risk among PLWH.

High frequency of potential phosphodiesterase type 5 inhibitor drug interactions in males with HIV infection and erectile dysfunction.

OBJECTIVES: We sought to determine the prevalence of phosphodiesterase type 5 inhibitor (PDE-5) mediated drug-drug interactions (DDIs) in males with HIV infection receiving antiretroviral therapy (ART) and identify factors associated with PDE-5-mediated DDIs. METHODS: Male US Military HIV Natural History Study participants diagnosed with erectile dysfunction (ED) and having a PDE-5 inhibitor and potentially-interacting ART co-dispensed within 30 days were included. DDIs were defined according to criteria found in published guidelines and drug information resources. The primary outcome of interest was overall PDE-5 inhibitor-mediated DDI prevalence and episode duration. A secondary logistic regression analysis was performed on those with and without DDIs to identify factors associated with initial DDI episode. RESULTS: A total of 235 male participants with ED met inclusion criteria. The majority were White (50.6%) or African American (40.4%). Median age at medication co-dispensing (45 years), duration of HIV infection (14 years), and duration of ED (1 year) did not differ between the two groups (p>0.05 for all). PDE-5 inhibitors included sildenafil (n = 124), vardenafil (n = 99), and tadalafil (n = 14). ART regimens included RTV-boosted protease inhibitors (PIs) atazanavir (n = 83) or darunavir (n = 34), and COBI-boosted elvitegravir (n = 43). Potential DDIs occurred in 181 (77.0%) participants, of whom 122 (67.4%) had multiple DDI episodes. The median DDI duration was 8 (IQR 1-12) months. In multivariate analyses, non-statistically significant higher odds of DDIs were observed with RTV-boosted PIs or PI-based ART (OR 2.13, 95% CI 0.85-5.37) and in those with a diagnosis of major depressive disorder (OR 1.74, 95% CI 0.83-3.64). CONCLUSIONS: PDE-5-mediated DDIs were observed in the majority of males with HIV infection on RTV- or COBI-boosted ART in our cohort. This study highlights the importance of assessing for DDIs among individuals on ART, especially those on boosted regimens.

Antiretroviral Therapy Anchor-based Trends in Body Mass Index Following Treatment Initiation Among Military Personnel with HIV.

INTRODUCTION: Weight gain and obesity in people living with HIV have been associated with increased risk for non-AIDS-related comorbidities, and integrase strand transfer inhibitor (INSTI)-based regimens may lead to comparatively more weight gain than other regimens. We evaluated body mass index (BMI) following antiretroviral therapy (ART) initiation among participants in the U.S. Military HIV Natural History Study (NHS). MATERIALS AND METHODS: NHS participants with available baseline weight and height data initiating ART from 2006 to 2017 were considered for analysis. Antiretroviral therapy was categorized by anchor class to include INSTIs, non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs). Linear growth-curve modeling was used to predict BMI changes from ART initiation through 2 years of follow-up in participants stratified by baseline BMI (<25 vs ≥25 kg/m2) at ART start and anchor drug class. These models were adjusted for demographic- and HIV-related characteristics. RESULTS: Of 961 NHS participants started on initial ART between 2006 and 2017, 491 men who had available baseline BMI data and were virally suppressed (<200 c/mL) at 1 and 2 years of follow-up were included. Overall, the predicted BMI increased at each time point over 2 years regardless of baseline BMI. There was a trend toward less weight gain for non-INSTI regimens regardless of demographic- or HIV-related factors (-0.65 kg/m2/yr, P = .070). In participants with BMI <25, all regimens were associated with BMI gains except in those with high viral load (≥100,000 copies/mL) started on PI regimens (-1.91 kg/m2/yr, P = .000; n = 13). For those participants with BMI ≥25, only INSTI- and PI-based regimens were significantly associated with increased BMI (INSTI 0.54 kg/m2/y, P = .000; PI 0.39 kg/m2/yr, P = .006). Non-nucleoside reverse transcriptase inhibitors were not associated with weight gain regardless of race- or HIV-related characteristics. African Americans with BMI ≥25 were more likely to gain weight as compared to Whites (0.99 kg/m2/yr, P = .016). Specific anchor drug-based predictions revealed that only INSTI use among African Americans was significantly associated with BMI gains (1.85 kg/m2/yr, P = .007); NNRTI- and PI-related weight change was not significant as compared to Whites. CONCLUSIONS: In our cohort of young military members with HIV infection, those with BMI <25 experienced BMI gains across all ART classes. Among those with BMI ≥25, African Americans on INSTI regimens had the greatest BMI gains. Further studies are needed to determine whether NNRTI regimens should be considered in certain individuals at risk for INSTI-associated weight gain.

Provider Knowledge Gaps in HIV PrEP Affect Practice Patterns in the US Navy.

INTRODUCTION: Although HIV pre-exposure prophylaxis (PrEP) is available at no cost to personnel in the United States (U.S.) military, uptake has been lower than expected. An online survey was conducted assessing current knowledge, perceptions, and attitudes of primary care providers in the U.S. Navy. MATERIALS AND METHODS: A cross-sectional anonymous online survey was conducted among U.S. Navy healthcare providers in active service. Providers' demographics, medical practice and PrEP experience, and attitudes regarding PrEP were assessed by self-rated PrEP knowledge. RESULTS: Greater than half of respondents reported being knowledgeable about PrEP and a majority (78%) supported the provision of PrEP in the military health system. However, only 19% had ever prescribed PrEP. Self-reports of having been questioned by a patient about PrEP, having high levels of comfort discussing sexual risk behaviors, and being in a specialty of infectious disease, occupational health, or preventive medicine were associated with increased knowledge about PrEP. The more knowledgeable a provider was about PrEP, the more likely they were to prescribe it (29% vs. 6%). CONCLUSIONS: Although Navy providers were supportive of the provision of PrEP by the military, knowledge gaps remain. Training to address the knowledge deficit as well as improving sexual history taking are potential areas to target in implementing PrEP in primary care specialties.

Cell-Mediated Immunity Generated in Response to a Purified Inactivated Vaccine for Dengue Virus Type 1.

Dengue is the most prevalent arboviral disease afflicting humans, and a vaccine appears to be the most rational means of control. Dengue vaccine development is in a critical phase, with the first vaccine licensed in some countries where dengue is endemic but demonstrating insufficient efficacy in immunologically naive populations. Since virus-neutralizing antibodies do not invariably correlate with vaccine efficacy, other markers that may predict protection, including cell-mediated immunity, are urgently needed. Previously, the Walter Reed Army Institute of Research developed a monovalent purified inactivated virus (PIV) vaccine candidate against dengue virus serotype 1 (DENV-1) adjuvanted with alum. The PIV vaccine was safe and immunogenic in a phase I dose escalation trial in healthy, flavivirus-naive adults in the United States. From that trial, peripheral blood mononuclear cells obtained at various time points pre- and postvaccination were used to measure DENV-1-specific T cell responses. After vaccination, a predominant CD4+ T cell-mediated response to peptide pools covering the DENV-1 structural proteins was observed. Over half (13/20) of the subjects produced interleukin-2 (IL-2) in response to DENV peptides, and the majority (17/20) demonstrated peptide-specific CD4+ T cell proliferation. In addition, analysis of postvaccination cell culture supernatants demonstrated an increased rate of production of cytokines, including gamma interferon (IFN-γ), IL-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Overall, the vaccine was found to have elicited DENV-specific CD4+ T cell responses as measured by enzyme-linked immunosorbent spot (ELISpot), intracellular cytokine staining (ICS), lymphocyte proliferation, and cytokine production assays. Thus, together with antibody readouts, the use of a multifaceted measurement of cell-mediated immune responses after vaccination is a useful strategy for more comprehensively characterizing immunity generated by dengue vaccines.IMPORTANCE Dengue is a tropical disease transmitted by mosquitoes, and nearly half of the world's population lives in areas where individuals are at risk of infection. Several vaccines for dengue are in development, including one which was recently licensed in several countries, although its utility is limited to people who have already been infected with one of the four dengue viruses. One major hurdle to understanding whether a dengue vaccine will work for everyone-before exposure-is the necessity of knowing which marker can be measured in the blood to signal that the individual has protective immunity. This report describes an approach measuring multiple different parts of immunity in order to characterize which signals one candidate vaccine imparted to a small number of human volunteers. This approach was designed to be able to be applied to any dengue vaccine study so that the data can be compared and used to inform future vaccine design and/or optimization strategies.

Hepatitis B seroprevalence in the U.S. military and its impact on potential screening strategies.

INTRODUCTION: Knowledge of the contemporary epidemiology of hepatitis B virus (HBV) infection among military personnel can inform potential Department of Defense (DoD) screening policy and infection and disease control strategies. MATERIALS AND METHODS: HBV infection status at accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period from 2007 to 2010. A cost model was developed from the perspective of the Department of Defense for a program to integrate HBV infection screening of applicants for military service into the existing screening program of screening new accessions for vaccine-preventable infections. RESULTS: The prevalence of chronic HBV infection at accession was 2.3/1,000 (95% CI: 1.4, 3.2); most cases (16/21, 76%) identified after deployment were present at accession. There were 110 military service-related HBV infections identified. Screening accessions who are identified as HBV susceptible with HBV surface antigen followed by HBV surface antigen neutralization for confirmation offered no cost advantage over not screening and resulted in a net annual increase in cost of $5.78 million. However, screening would exclude as many as 514 HBV cases each year from accession. CONCLUSIONS: Screening for HBV infection at service entry would potentially reduce chronic HBV infection in the force, decrease the threat of transfusion-transmitted HBV infection in the battlefield blood supply, and lead to earlier diagnosis and linkage to care; however, applicant screening is not cost saving. Service-related incident infections indicate a durable threat, the need for improved laboratory-based surveillance tools, and mandate review of immunization policy and practice.

HIV PrEP in the Military: Experience at a Tertiary Care Military Medical Center.

Objectives: We evaluated human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) administration at the Walter Reed National Military Medical Center (WRNMMC), which serves a geographic area at high risk of HIV infection. Methods: Medical records were reviewed for all patients initiating PrEP at WRNMMC from November 1, 2013, to March 30, 2016. Demographic, laboratory, clinical, and risk exposure characteristics and outcomes were described. Results: One hundred fifty-nine patients received PrEP; 133 (84%) patients were active duty, 95 (60%) patients were over 28 yr old. The majority were non-Hispanic Whites (n = 87, 55%). The median men who have sex with men (MSM) risk index score was 18.0 (IQR 12.0-22.0); 20 patients scored less than 10. One hundred and thirty-one (82%) patients remained on PrEP through the evaluation period. Patients mainly discontinued PrEP for service-related or toxicity reasons. Incident STIs occurred in 31 (19%) patients. No cases of HIV seroconversion were observed. Conclusions: In this first description of PrEP utilization in a U.S. military health care system, a significant number of patients were non-Hispanic Whites, well-educated, were older, or were otherwise at low risk for HIV acquisition. Further effort is needed to enhance PrEP use among the higher risk young African-American MSM population, and further studies are needed to determine the cost-effectiveness of PrEP in individuals who are not categorized as high risk.

Sepsis Mimicker in an Human Immunodeficiency Virus-Infected Patient.

A 22-year-old human immunodeficiency virus-infected male presented with fever, rash, hypotension, and renal insufficiency 18 days following initiation of therapy with an efavirenz-based antiretroviral regimen. Although rash is a common side effect of efavirenz, severe hypersensitivity reactions are rare. Systemic symptoms can include hepatic toxicity and pneumonitis, and in one instance death. Corticosteroids are the mainstay of treatment.

Knowledge, attitudes, and beliefs about HIV pre-exposure prophylaxis among US Air Force Health Care Providers.

Providers are central to effective implementation of HIV pre-exposure prophylaxis (PrEP). Primary care providers (PCP) and infectious disease physicians (ID) in the US Air Force (USAF) participated in a cross-sectional survey regarding knowledge, attitudes, and beliefs toward HIV PrEP. Characteristics associated with PrEP knowledge were assessed in univariate and multivariate analyses.Among 403 (40% of 1015 providers) participants, 9% (PCP 383, ID 20) ever prescribed PrEP. In univariate analysis, years in practice, number of HIV-infected patients treated in the past 12 months, past prescription of antiretrovirals for HIV prevention, frequency of prescribing PrEP in the past 12 months, and ever being questioned by a patient about PrEP were associated with PrEP knowledge (P < 0.05). In multivariate analysis, providers who had ever prescribed antiretrovirals to prevent HIV (AOR: 2.37, 95% CI: 1.27-4.42) had greater odds of high PrEP knowledge. Despite concerns about medication side effects (overall 67%: PCP 68%, ID 85%) and prescribing PrEP without clear evidence (overall 60%: PCP 65%, ID 62%), 64% (PCP 65%, ID 85%) of participants indicated PrEP should be offered in the Military Health System and 68% (PCP 70%, ID 100%) disagreed with the statement that their patient population was not at risk for HIV infection.Successful PrEP implementation in the USAF will require continued education and training of primary care providers to improve knowledge and mitigate concerns about PrEP.

Care of the aging HIV patient.

Thanks to antiretroviral therapy, human immunodeficiency virus (HIV) infection has become a controllable chronic disease, and many infected patients are now living into their 60s and beyond. In addition, many patients with newly diagnosed HIV infection are over age 50. The subsequent rising prevalence of HIV infection in older adults presents several challenges for primary care clinicians. This article promotes increased HIV screening in older adults and highlights the need to recognize polypharmacy and the various comorbidities inherent in the aging HIV population.

Safety and Immunogenicity of a Dengue Virus Serotype-1 Purified-Inactivated Vaccine: Results of a Phase 1 Clinical Trial.

We describe the results from a human clinical trial of a dengue virus serotype-1, purified-inactivated vaccine (DENV-1 PIV) adjuvanted with aluminum hydroxide. This first-in-man, Phase 1, open-label clinical trial consisted of two groups of flavivirus-naïve healthy adult volunteers that received two intramuscular vaccine doses of either 2.5 µg or 5 µg of DENV-1 PIV administered on days 0 and 28. Following vaccination, both vaccine doses exhibited an acceptable safety profile with minimal injection site and systemic reactions. By study day 42, 2 weeks following the second vaccine dose, all volunteers in both vaccine groups developed serum-neutralizing antibodies against DENV-1. Additional testing using an enzyme-linked immunosorbent assay demonstrated induction of a humoral immune response following both vaccine doses. The DENV-1 PIV was safe and immunogenic in a small number of volunteers supporting development and further testing of a tetravalent DENV PIV formulation.

Whooping cough in 2014 and beyond: an update and review.

Pertussis, or whooping cough, has had a dramatic resurgence in the past several years and is the most common vaccine-preventable disease in the world. The year 2012 marked the most cases in the United States in > 50 years. Large outbreaks have occurred in multiple states, and infant deaths have drawn the attention of not only health-care providers but also the media. Although the disease is theoretically preventable by vaccination, it remains a challenge to control. New vaccination strategies have been implemented across different age groups and populations of patients, but vaccine coverage remains dismally low. Acellular vaccines, although safe, do not afford the same long-lasting immunity as the previously used whole-cell vaccine. Ultimately, improvements in the development of vaccines and in vaccination coverage will be essential to decrease the burden of pertussis on society. This article provides a review of pertussis infection and discusses advances related to the epidemiology, diagnosis, treatment, and prevention of infection, as well as continued areas of uncertainty.

Seroprevalence of Dengue Fever in US Army Special Operations Forces: Initial Results and the Way Ahead.

The endemicity of dengue fever (DF) and, consequently, sequelae of DF are increasing worldwide. The increases are largely a result of widespread international travel and the increased range of the mosquito vectors. US Army Special Operations Command (USASOC) personnel are at an increased risk of exposure to dengue based on their frequent deployments to and presence in dengue endemic areas worldwide. Repeated deployments to different endemic areas can increase the risk for developing the more serious sequelae of dengue: dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Information about the seroprevalence rate of dengue in USASOC personnel, in particular, is lacking and is critical to assessing the risk, tailoring preventive medicine countermeasures, leveraging field diagnostics, and maintaining mission capability. In the first part of a two-part project to assess baseline seroprevalence in USASOC units, a random, unit-stratified sample of 500 anonymous serum specimens from personnel assigned to the highest-risk units in USASOC were screened for dengue using a microneutralization assay. Of the 500 specimens screened, 56 (11.2%) of 500 had neutralizing titers (NT) (MN50≥10) against at least one DENV serotype. Subsequent sample titration resulted in 48 (85.7%) of 56 of the samples with NT (MN50≥10) against at least one dengue serotype for an overall dengue exposure rate of 9.6% (48 of 500). The second part of the ongoing project, started in 2012, was a multicenter, serosurveillance project using predeployment and postdeployment sera collected from USASOC personnel deployed to South and Central America, Africa, and Southeast Asia. Preliminary results show a 13.2% (55 of 414) seropositivity rate. The significance of these findings as they relate to personal risk and operational impact is discussed.