An Outbreak of Covid-19 on an Aircraft Carrier.

BACKGROUND: An outbreak of coronavirus disease 2019 (Covid-19) occurred on the U.S.S. Theodore Roosevelt, a nuclear-powered aircraft carrier with a crew of 4779 personnel. METHODS: We obtained clinical and demographic data for all crew members, including results of testing by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). All crew members were followed up for a minimum of 10 weeks, regardless of test results or the absence of symptoms. RESULTS: The crew was predominantly young (mean age, 27 years) and was in general good health, meeting U.S. Navy standards for sea duty. Over the course of the outbreak, 1271 crew members (26.6% of the crew) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by rRT-PCR testing, and more than 1000 infections were identified within 5 weeks after the first laboratory-confirmed infection. An additional 60 crew members had suspected Covid-19 (i.e., illness that met Council of State and Territorial Epidemiologists clinical criteria for Covid-19 without a positive test result). Among the crew members with laboratory-confirmed infection, 76.9% (978 of 1271) had no symptoms at the time that they tested positive and 55.0% had symptoms develop at any time during the clinical course. Among the 1331 crew members with suspected or confirmed Covid-19, 23 (1.7%) were hospitalized, 4 (0.3%) received intensive care, and 1 died. Crew members who worked in confined spaces appeared more likely to become infected. CONCLUSIONS: SARS-CoV-2 spread quickly among the crew of the U.S.S. Theodore Roosevelt. Transmission was facilitated by close-quarters conditions and by asymptomatic and presymptomatic infected crew members. Nearly half of those who tested positive for the virus never had symptoms.

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.

Next-generation sequencing of HIV-1 single genome amplicons.

The analysis of HIV-1 sequences has helped understand the viral molecular epidemiology, monitor the development of antiretroviral drug resistance, and design candidate vaccines. The introduction of single genome amplification (SGA) has been a major advancement in the field, allowing for the characterization of multiple sequences per patient while preserving linkage among polymorphisms in the same viral genome copy. Sequencing of SGA amplicons is performed by capillary Sanger sequencing, which presents low throughput, requires a high amount of template, and is highly sensitive to template/primer mismatching. In order to meet the increasing demand for HIV-1 SGA amplicon sequencing, we have developed a platform based on benchtop next-generation sequencing (NGS) (IonTorrent) accompanied by a bioinformatics pipeline capable of running on computer resources commonly available at research laboratories. During assay validation, the NGS-based sequencing of 10 HIV-1 env SGA amplicons was fully concordant with Sanger sequencing. The field test was conducted on plasma samples from 10 US Navy and Marine service members with recent HIV-1 infection (sampling interval: 2005-2010; plasma viral load: 5,884-194,984 copies/ml). The NGS analysis of 101 SGA amplicons (median: 10 amplicons/individual) showed within-individual viral sequence profiles expected in individuals at this disease stage, including individuals with highly homogeneous quasispecies, individuals with two highly homogeneous viral lineages, and individuals with heterogeneous viral populations. In a scalability assessment using the Ion Chef automated system, 41/43 tested env SGA amplicons (95%) multiplexed on a single Ion 318 chip showed consistent gene-wide coverage >50×. With lower sample requirements and higher throughput, this approach is suitable to support the increasing demand for high-quality and cost-effective HIV-1 sequences in fields such as molecular epidemiology, and development of preventive and therapeutic strategies.

Costs and consequences: Hepatitis C seroprevalence in the military and its impact on potential screening strategies.

UNLABELLED: Knowledge of the contemporary epidemiology of hepatitis C viral (HCV) infection among military personnel can inform potential Department of Defense screening policy. HCV infection status at the time of 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 2007-2010. A cost model was developed from the perspective of the Department of Defense for a military applicant screening program. Return on investment was based on comparison between screening program costs and potential treatment costs avoided. The prevalence of HCV antibody-positive and chronic HCV infection at accession among younger recently deployed military personnel born after 1965 was 0.98/1000 (95% confidence interval 0.45-1.85) and 0.43/1000 (95% confidence interval 0.12-1.11), respectively. Among these, service-related incidence was low; 64% of infections were present at the time of accession. With no screening, the cost to the Department of Defense of treating the estimated 93 cases of chronic HCV cases from a single year's accession cohort was $9.3 million. Screening with the HCV antibody test followed by the nucleic acid test for confirmation yielded a net annual savings and a $3.1 million dollar advantage over not screening. CONCLUSIONS: Applicant screening will reduce chronic HCV infection in the force, result in a small system costs savings, and decrease the threat of transfusion-transmitted HCV infection in the battlefield blood supply and may lead to earlier diagnosis and linkage to care; initiation of an applicant screening program will require ongoing evaluation that considers changes in the treatment cost and practice landscape, screening options, and the epidemiology of HCV in the applicant/accession and overall force populations.

Perceived risk of watery diarrhea and dysentery and intended compliance with chemoprophylaxis among a deployed military population.

BACKGROUND: Infectious diseases are a leading cause of morbidity among travelers to resource-limited regions and primary prevention is a cornerstone to risk reduction. Chemoprophylaxis has been successfully utilized for specific diseases. METHODS: We assessed self-reported compliance to daily chemoprophylaxis among deployed US military personnel. A 21 item self-completed questionnaire was completed by military personnel during mid-deployment. RESULTS: The perception of high disease risk was associated with an increased likelihood of compliance with daily chemoprophylaxis. However, 60 % of respondents stated they would not comply with a daily regimen. CONCLUSIONS: These data highlight the complexity of perceived risk and the difficulties with prophylactic interventions.

Pathogenicity and phenotypic characterization of enterotoxigenic Escherichia coli isolates from a birth cohort of children in rural Egypt.

Enterotoxigenic Escherichia coli (ETEC) has consistently been the predominant bacterial cause of diarrhea in many birth cohort- and hospital-based studies conducted in Egypt. We evaluated the pathogenicity of ETEC isolates in a birth cohort of children living in a rural community in Egypt. Between 2004 and 2007, we enrolled and followed 348 children starting at birth until their second year of life. A stool sample and two rectal swabs were collected from children during twice-weekly visits when they presented with diarrhea and were collected every 2 weeks if no diarrhea was reported. From routine stool cultures, five E. coli-like colonies were screened for ETEC enterotoxins using a GM1 enzyme-linked immunosorbent assay (ELISA). The isolates were screened against a panel of 12 colonization factor antigens (CFAs) by a dot blot assay. A nested case-control study evaluated the association between initial or repeat excretion of ETEC and the occurrences of diarrhea. The pathogenicity of ETEC was estimated in symptomatic children compared to that in asymptomatic controls. ETEC was significantly associated with diarrhea (crude odds ratio, 1.37; 95% confidence interval [CI], 1.24 to 1.52). The distribution of ETEC enterotoxins varied between the symptomatic children (44.2% heat-labile toxin [LT], 38.5% heat-stable toxin [ST], and 17.3% LT/ST) and asymptomatic children (55.5% LT, 34.6% ST, and 9.9% LT/ST) (P < 0.001). The CFAs CFA/I (n = 61), CS3 (n = 8), CS1 plus CS3 (n = 24), CS2 plus CS3 (n = 18), CS6 (n = 45), CS5 plus CS6 (n = 11), CS7 (n = 25), and CS14 (n = 32) were frequently detected in symptomatic children, while CS6 (n = 66), CS12 (n = 51), CFA/I (n = 43), and CS14 (n = 20) were detected at higher frequencies among asymptomatic children. While all toxin phenotypes were associated with diarrheal disease after the initial exposure, only ST and LT/ST-expressing ETEC isolates (P < 0.0001) were associated with disease in repeat infections. The role of enterotoxins and pathogenicity during repeat ETEC infections appears to be variable and dependent on the coexpression of specific CFAs.

Willingness to receive a hypothetical avian influenza vaccine among US military personnel in mid-deployment.

Though no avian influenza vaccine currently exists, development efforts have increased. Given recent reports of suboptimal vaccination rates among US military personnel, we sought to assess factors associated with a willingness to receive a hypothetical avian influenza vaccine. A self-administered questionnaire was completed by US military personnel during mid-deployment to Iraq, Afghanistan, and surrounding regions. Respondents were predominately male (86.2%), Army (72.1%), and enlisted (86.3%) with a mean age of 29.6 y. The majority (77.1%) agreed to receive an avian influenza vaccine if available. Exploratory factor analysis (EFA) identified two factors, vaccine importance and disease risk, that best described the individual perceptions and both were associated with an increased willingness to receive the hypothetical vaccine (OR: 8.2 and 1.6, respectively). Importantly, after controlling for these factors differences in the willingness to receive this hypothetical vaccine were observed across gender and branch of service. These results indicated that targeted education on vaccine safety and efficacy as well as disease risk may modify vaccination patterns in this population.

Genotypic characterization of Egypt enterotoxigenic Escherichia coli isolates expressing coli surface antigen 6.

INTRODUCTION: One approach to control enterotoxigenic Escherichia coli (ETEC) infections has been to develop vaccines focused on inducing protective immunity against surface expressed antigenic factors. One such factor is coli surface antigen 6 (CS6); ETEC isolates expressing CS6 may also simultaneously co-express surface antigens CS4 or CS5. However, there is little information regarding the inter-relationships of isolates expressing the CS6 antigen alone or in combination with CS4 or CS5. METHODOLOGY: A total of 62 CS6-associated ETEC isolates were evaluated for their antimicrobial susceptibility, mechanisms of resistance, toxin genes, colonization factor expression, and XbaI-pulsed-field gel electrophoretic profiles. RESULTS: We observed 46 XbaI profiles; 31 were exclusive to ETEC expressing CS6 alone and 15 among the ETEC co-expressing CS4 or CS5. Nearly half (47%) of these isolates were resistant to ampicillin, a third (37%) of the isolates were resistant to trimethoprim-sulfamethoxazole, and 24% of the isolates were tetracycline-resistant. A blaTEM gene was detected in 24 (83%) ampicillin-resistant isolates. Trimethoprim-sulfamethoxazole-resistant isolates (n = 23) carried either sulI (n = 1, 4%), sulII (n = 8, 35%) or both genes (n = 10, 43%); 4 had no detectable sul gene. CONCLUSIONS: Our results show a lack of clonality among Egypt CS6 E. coli isolates and supports the use and the further research on vaccines targeting this cell surface antigen.

A pilot online survey assessing risk factors for HIV acquisition in the Navy and Marine Corps, 2005-2010.

The Department of Defense policy Don't Ask, Don't Tell (DADT) ended in September, 2011. The Navy Bloodborne Infection Management Center conducted a post-DADT pilot survey of HIV seroconverters identified when the DADT policy was in effect. Sailors and Marines newly diagnosed as HIV positive from 2005 to 2010 were invited to participate in an online survey. A structured questionnaire elicited risk information about the 3-year period before HIV diagnosis. Respondents reported engaging commonly in same sex sexual activity, having concurrent partners, and poor condom use for anal sex. In this first post-DADT repeal report of self-reported behaviors, male-to-male sexual contact was a much more common mode of infection than previously reported. Several opportunities for primary prevention messaging now possible after DADT repeal are evident.

Specific IgA antibodies in the diagnosis of acute brucellosis.

An Egyptian female with night sweats, headache, and back pain was diagnosed with acute brucellosis one week after returning from a North African country. Humoral immune responses to specific immunogenic proteins were investigated before and after treatment. ELISA was performed to detect levels of specific antibody (Ab) titers. Immunoblot analysis of Ab recognizing specific Brucella antigenic bands was also performed. IgA was detected on the day of disease onset. Specific agglutination titer was 1:160; it doubled three days later and treatment was implemented. Blood culture yielded Gram-negative coccobacilli after one month, confirmed as B. melitensis by AMOS-PCR. Immunoblotting revealed IgM Abs against two protein bands of 112 and 130-kDa observed only during the acute stage. On the other hand, the intensity of IgG Abs against 21 and 21.5-kDa protein bands positively correlated with the time of convalescence. Based on our observations we conclude that specific IgA levels may be used as an early diagnostic marker for Brucella and high molecular weight protein bands may be useful in the differentiation between acute and chronic brucellosis.

Knowledge, attitudes, and practice of travelers' diarrhea management among frontline providers.

BACKGROUND: Many studies have found acute gastrointestinal infections to be among the most likely reason for clinic visits among forward deployed soldiers and are considered a significant contributor to morbidity in this population. This occurs despite the controlled food and water distribution systems under which military populations operate. Furthermore, recent studies have indicated that providers often fail to appropriately identify and treat the typical causes of these infections. To adequately address this issue, an assessment of gaps in knowledge, practice, and management of acute diarrhea in deployed troops was conducted. METHODS: A multiple-choice survey was developed by clinical researchers with expertise in travelers' diarrhea (TD) and provided to a convenience sample of clinical providers with a broad range of training and operational experience. The survey evaluated provider's knowledge of TD along with their ability to identify etiologies of various syndromic categories of acute gastrointestinal infections. Providers were also queried on selection of treatment approaches to a variety of clinical-based scenarios. RESULTS: A total of 117 respondents completed the survey. Most were aware of the standard definition of TD (77%); however, their knowledge about the epidemiology was lower, with less than 24% correctly answering questions on etiology of diarrhea, and 31% believing that a viral pathogen was the primary cause of watery diarrhea during deployment. Evaluation of scenario-based responses showed that 64% of providers chose not to use antibiotics to treat moderate TD. Furthermore, 19% of providers felt that severe inflammatory diarrhea was best treated with hydration only while 25% felt hydration was the therapy of choice for dysentery. Across all provider types, three practitioner characteristics appeared to be related to better scores on responses to the nine management scenarios: having a Doctor of Medicine or Doctor of Osteopathy degree, greater knowledge of TD epidemiology, and favorable attitudes toward antimotility or antibiotic therapy. CONCLUSION: Results from this survey support the need for improving knowledge and management of TD among deploying providers. The information from this study should be considered to support the establishment and dissemination of military diarrhea-management guidelines to assist in improving the health of military personnel.

Pre-deployment vaccinations and perception of risk among US military personnel.

BACKGROUND: Vaccination programs have significantly reduced the incidence of numerous infectious diseases; however, public attitudes toward immunization oftentimes remain contentious. Concerns over vaccine safety and effectiveness, compounded with reduced perceived risk of disease, influence decision making and frequently override public health recommendations. Although vaccinations are compulsory for US military personnel, their concerns mirror the general population, resulting in sub-optimal coverage. RESULTS: Demographics of the 1,757 respondents: 83.3% male, 71.1% Army, 87.5% enlisted, mean age of 29.2 years (standard deviation: 8.3). The majority (89.3%) reported receiving all pre-deployment vaccines; 17.1% stated they would decline if given the opportunity. Factors associated with an increased likelihood of declining vaccines included a perception that the vaccines were not safe (odds ratio [OR]: 3.7; p < 0.001) and rarely/never believing information from the military command (OR: 2.2; p < 0.001). Those with a perceived risk for the diseases targeted by the vaccines were less likely to decline (OR: 0.6; p < 0.001). DISCUSSION: In US military personnel, negative perceptions of pre-deployment vaccines exist. These attitudes appear to be associated with negative perceptions of vaccine safety and low perceived disease risk. Targeted interventions, focusing on the drivers of negative perceptions toward vaccines, and accounting for the source of the educational material, may influence attitudes and improve vaccination perceptions. METHODS: A self-administered questionnaire was completed by a convenience sample of US military personnel deployed to Iraq, Afghanistan and surrounding regions. Questions solicited demographic information and assessed agreement with statements in an attempt to identify factors associated with declining pre-deployment vaccines.

Discovery and phylogenetic analysis of novel members of class b enterotoxigenic Escherichia coli adhesive fimbriae.

Enterotoxigenic Escherichia coli (ETEC) is recognized to be a common cause of acute watery diarrhea in children from developing countries. Colonization factors (CFAs) have been identified predominantly in ETEC isolates secreting heat-stable enterotoxin (ST) or cosecreting ST with a heat-labile toxin (LT). We hypothesized that LT-only-secreting ETEC produces unique colonization factors not previously described in ST and LTST-secreting ETEC. A set of degenerate primers based on nucleotide sequence similarities between the major structural genes of CS20 (csnA), CS18 (fotA), CS12 (cswA), and porcine antigen 987 (fasA) was developed and used to screen a collection of 266 LT-secreting ETEC isolates in which no known CFA was detected. PCR-amplified products of different molecular masses were obtained from 49 (18.4%) isolates. Nucleotide sequence analysis of the PCR amplicons followed by GenBank nucleotide BLASTn analysis revealed five novel DNA sequences; translated amino acid BLASTx analysis confirmed sequence similarity to class 1b major structural proteins encoded by csnA, fotA, and fasA. Strains expressing the novel CFAs were phylotyped and analyzed using multilocus sequence typing (MLST; Achtman scheme), and the types detected were compared to those of a collection of archived global E. coli strains. In conclusion, application of the degenerate primer sets to ETEC isolates from surveillance studies increased the total number of ETEC isolates with detectable CFAs by almost 20%. Additionally, MLST analysis suggests that for many CFAs, there may be a requirement for certain genetic backgrounds to acquire and maintain plasmids carrying genes encoding CFAs.

A randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of rifaximin for the prevention of travelers' diarrhea in US military personnel deployed to Incirlik Air Base, Incirlik, Turkey.

BACKGROUND: Infectious diarrhea is an important problem among travelers and deployed US military overseas causing substantial morbidity due to acute illness and may result in burdensome postinfectious sequelae. METHODS: The nonsystemic antibiotic rifaximin was evaluated for prevention of travelers' diarrhea (TD) in a US military and civilian adult beneficiary population in a randomized, double-blind, placebo-controlled clinical trial. In all, 100 volunteers deployed to Incirlik Air Base, Turkey, received rifaximin 1,100 mg once daily or placebo for 2 weeks, and participants were followed daily for 2 weeks. RESULTS: In an intention to treat analysis (n = 95), TD (based on subjects meeting case definition or early treatment) developed in 6.3% (3 of 48) of the rifaximin group compared with 19.2% (9 of 47) in the placebo group (Fisher's exact test p = 0.07). Rifaximin provided 67% (95% confidence interval, -13% to 91%, p = 0.07) protection against TD. Rifaximin 1,100 mg once daily was well tolerated with no observed differences in adverse events, whether solicited or unsolicited among the two treatment groups. CONCLUSIONS: Rifaximin may represent an option among military personnel on deployment for prevention of TD with supportive future studies that consider deployment length, settings, and operational situations where widespread use of chemoprophylaxis may increase force health protection without undue risk during critical deployments.

Design and validation of a multiplex polymerase chain reaction for the identification of enterotoxigenic Escherichia coli and associated colonization factor antigens.

Development of a genetic tool for the detection of genes encoding enterotoxins and colonization factors would greatly enhance enterotoxigenic Escherichia coli (ETEC) surveillance. Oligonucleotide primers were designed to amplify genes encoding human ST, porcine ST, LT and the structural genes of colonization factor antigen (CFA)/I, CS1 to CS8, CS12 to CS15, CS17 to CS22, and PCFO71. Screening 89 ETEC isolates phenotypically expressing a known CFA showed that, without exception, the multiplex polymerase chain reaction (mPCR) detected the structural gene of the expressed CFA, in addition to CS21 in 22.5% of isolates. Silent genes such as cssB (CS6) were also detected in 9.0%. Additionally, we screened 71 CFA phenotypically negative isolates and detected a CFA in more than 50% of tested isolates. In conclusion, we have designed a simple 4-step mPCR for the rapid detection of ETEC virulence factors. The assay is rapid, reproducible, relatively inexpensive, and has the potential to be field applicable.

Outcomes of diarrhea management in operations Iraqi Freedom and Enduring Freedom.

INTRODUCTION: Among deployed U.S. military personnel, a sub-population of international travelers, acute infectious diarrhea continues to be a leading cause of morbidity and a potential threat to military effectiveness. METHODS: To assess outcomes and satisfaction of diarrhea management in the field, a systematic survey was given to military personnel during mid- or post-deployment from Iraq or Afghanistan, from January through August 2004. RESULTS: Sixty-three percent of those surveyed reported at least one episode of diarrhea, while less than half sought care for their symptoms. Overall, trends of decreased post-treatment duration were noted as traveler's diarrhea therapy modalities grew more complex, controlling for severity of illness at presentation. Among those reporting diarrhea, the greatest level of satisfaction was seen in treatment with IV fluids (59%) followed by antibiotics (46%) and loperamide (40%). The greatest amount of dissatisfaction was seen in treatments with oral fluids only. CONCLUSION: While current standard of care is self-treatment of diarrhea in civilian travelers, the U.S. military lacks standards outlining self-treatment of personnel at the individual level. Further research is needed to develop treatment guidelines on diarrhea management during military deployment.

Nonbattle injury among deployed troops: an epidemiologic study.

(n = 150) Nonbattle injury (NBI) continues to be a leading cause of morbidity among troops currently deployed to Iraq and Afghanistan. To assess NBI incidence, impact, and risk factors, a survey was given to soldiers during mid- or postdeployment from Iraq, Afghanistan, and surrounding region, from January 2005 through May 2006. Among 3,367 troops completing a survey, 19.5% reported at least one NBI, and 85% sought care at least once for their symptoms. Service component, rank, and unit type were among factors associated with differential NBI risk. Twenty percent stated that NBI resulted in back-up personnel being called or shift change to cover impacted duties, and among those reported having been grounded from flight status, a third were the result of NBI. NBI continues to be a problem in recent deployments, and given the findings on individual and potential operational impact indicators, NBI should be viewed as a primary force health protection problem.

Factors associated with the use of protective measures against vector-borne diseases among troops deployed to Iraq and Afghanistan.

BACKGROUND AND METHODS: Vector-borne diseases are known threats to deployed troops. We performed a cross-sectional study of troops deployed to Southwest Asia between January 2005 and February 2007 to evaluate practices of personal protective measures and their relationship to self-report of Old World cutaneous leishmaniasis (CL), a marker of vector-borne disease threat. RESULTS: Regular or always N, N-diethyl-m-toluamide (DEET) use was low (2-5%). Associations for DEET use were command emphasis, branch of service, uniform treatment with permethrin, and duty station. Uniform treatment with permethrin was associated with branch of service, command emphasis, and use of DEET. We identified 22 cases of CL (incidence density of 1.8-3.7 per 100 person-years) with increased risk among Reserve/National Guard components, Air Force and Marine personnel. CONCLUSIONS: Commanders can influence the use of the military insect repellent system. Unit-based treatment of uniforms improves prevalence. CL incidence may be higher than previously reported.

Past trends and current status of self-reported incidence and impact of disease and nonbattle injury in military operations in Southwest Asia and the Middle East.

OBJECTIVES: To evaluate the evolutional changes in disease and nonbattle injury in a long-term deployment setting, we investigated trends of selected disease and nonbattle injury (NBI) incidence among US military personnel deployed in ongoing military operations in Southwest Asia and the Middle East. METHODS: Participants completed an anonymous questionnaire concerning diarrhea, acute respiratory illness (ARI), and NBIs. We compared incidence, morbidity, and risk associations of disease and NBI incidence with historical data. We analyzed a clinic screening form to describe trends in diarrhea incidence over a 3-year period. RESULTS: Between April 2006 and March 2007, 3374 troops completed deployment questionnaires. Incidence of diarrhea was higher than that of ARI and NBI (12.1, 7.1, and 2.5 episodes per 100 person-months, respectively), but ARI and NBI resulted in more-frequent health system utilization (both P < .001) and decreased work performance (P < .001 and P = .05, respectively) than did diarrhea. Compared with historical disease and NBI incidence rates, diarrhea and NBI incidence declined over a 4-year period, whereas ARI remained relatively constant. CONCLUSIONS: Diarrhea, ARI, and NBI are important health concerns among deployed military personnel. Public health and preventive measures are needed to mitigate this burden.

Attitudes toward predeployment and experimental vaccinations among troops deployed to Operation Iraqi Freedom and Operation Enduring Freedom.

BACKGROUND: The Department of Defense is actively engaged in the research and development of vaccine(s) to mitigate the burden of disease associated with diarrhea among deployed troops. Soldiers' attitudes and beliefs toward predeployment vaccines and participation in experimental research with vaccines are unknown. METHODS: To assess these attitudes, a survey was distributed among soldiers who had been and were currently deployed to Operations Iraqi and Enduring Freedom. RESULTS: Sixty-one percent of soldiers believe that predeployment vaccines are important, and 21% are hesitant to receive these vaccinations. Fifteen percent of soldiers stated that they would be willing to enroll in a study evaluating experimental vaccines, and 14% stated that they would participate in military research for vaccine development. Both male and female soldiers agreed that predeployment vaccines were important (86 and 92%, respectively); however, compared to their male counterparts, females were more hesitant to receive routine vaccinations (45% vs 37%) and less likely to volunteer for an experimental vaccine study (12% vs 20%). Officers and Air Force personnel were less hesitant to receive routine vaccinations compared to enlisted and other service personnel, respectively. Furthermore, if a soldier experienced three or more episodes of diarrhea, he or she was more likely to try an experimental vaccine to prevent diarrhea (23% vs 13%, p < 0.0001). CONCLUSIONS: A disconnect exists between the belief that immunizations are important and the hesitancy to receive them. Future studies should be directed to understand this gap and emphasize the critical importance of vaccines for health of US personnel in garrison and on deployment.