Host Bloodmeal Identification in Cave-Dwelling Ornithodoros turicata Dugès (Ixodida: Argasidae), Texas, USA.

Tick-host bloodmeal associations are important factors when characterizing risks of associated pathogen transmission and applying appropriate management strategies. Despite their biological importance, comparatively little is known about soft tick (Argasidae) host associations in the United States compared to hard ticks (Ixodidae). In this study, we evaluated a PCR and direct Sanger sequencing method for identifying the bloodmeal hosts of soft ticks. We collected 381 cave-associated Ornithodoros turicata near San Antonio, Texas, USA, and also utilized eight colony-reared specimens fed artificially on known host blood sources over 1.5 years ago. We correctly identified the vertebrate host bloodmeals of two colony-reared ticks (chicken and pig) up to 1,105 days post-feeding, and identified bloodmeal hosts from 19 out of 168 field-collected soft ticks, including raccoon (78.9%), black vulture (10.5%), Texas black rattlesnake (5.3%), and human (5.3%). Our results confirm the retention of vertebrate blood DNA in soft ticks and advance the knowledge of argasid host associations in cave-dwelling O. turicata.

Diagnostic evaluation of military blood donors screening positive for Trypanosoma cruzi infection.

Routine blood donor screening for Trypanosoma cruzi, the causative parasitic agent of Chagas disease, began in the U.S. in 2007. Results of follow-up testing and evaluation after a positive screen have not been studied in the armed forces. Among first-time donors at the Joint Base San Antonio- Lackland Blood Donor Center between January 2014 and December 2016 (N=43,402), a total of 23 (0.05%) screened positive for T. cruzi. This descriptive study highlights demographic and follow-up information for all 22 active duty service members who screened positive; a non-active duty member was excluded due to unavailability of clinical records. Members who screened positive received 13 different combinations of confirmatory testing (mean: 2.7 tests per person). In select cases, clinical evaluation included electrocardiogram (n=15) and 30-second rhythm strip (n=5). Two patients met criteria for Chagas disease; 11 patients were considered negative; and nine patients were indeterminate. Among a small cohort of active duty service members who screened positive for T. cruzi infection on blood donation, diagnostic evaluation varied considerably. Opportunities exist to decrease heterogeneity of clinical workup and improve evaluation of persons who screen positive.

Prevalence and Seroprevalence of Trypanosoma cruzi Infection in a Military Population in Texas.

Recent biosurveillance findings at Joint Base San Antonio (JBSA), a large military installation located in south-central Texas, indicate the potential for vector-borne human Chagas disease. A cross-sectional study was conducted to determine the prevalence and seroprevalence of Trypanosoma cruzi infection in highest risk subpopulations on the installation, including students and instructors who work and sleep in triatomine-endemic field settings. Real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and indirect immunofluorescent antibody assay were performed on enrolled subjects (N = 1,033), none of whom tested positive for T. cruzi or anti-T. cruzi antibodies. Current countermeasures used during field training on JBSA appear to be sufficient for preventing autochthonous human Chagas disease.

Association Between Single Gene Polymorphisms and Bone Biomarkers and Response to Calcium and Vitamin D Supplementation in Young Adults Undergoing Military Training.

Initial military training (IMT) is associated with increased stress fracture risk. In prior studies, supplemental calcium (Ca) and vitamin D provided daily throughout IMT reduced stress fracture incidence, suppressed parathyroid hormone (PTH), and improved measures of bone health compared with placebo. Data were analyzed from a randomized, double-blind, placebo-controlled trial to determine whether single-nucleotide polymorphisms (SNPs) in Ca and vitamin D-related genes were associated with circulating biomarkers of bone metabolism in young adults entering IMT, and whether responses to Ca and vitamin D supplementation were modulated by genotype. Associations between SNPs, including vitamin D receptor (VDR), vitamin D binding protein (DBP), and 1-alpha-hydroxylase (CYP27B1), and circulating biomarkers were measured in fasting blood samples from volunteers (n = 748) starting IMT. Volunteers were block randomized by race and sex to receive Ca (2000 mg) and vitamin D (1000 IU) or placebo daily throughout Army or Air Force IMT (7 to 9 weeks). Total Ca and vitamin D intakes were calculated as the sum of supplemental intake based on intervention compliance and dietary intake. Relationships between SNPs, Ca, and vitamin D intake tertile and change in biomarkers were evaluated in trial completers (n = 391). At baseline, the minor allele of a DBP SNP (rs7041) was positively associated with both 25OHD (B = 4.46, p = 1.97E-10) and 1,25(OH)2 D3 (B = 9.63, p < 0.001). Combined genetic risk score (GRS) for this SNP and a second SNP in the VDR gene (rs1544410) was inversely associated with baseline 25OHD (r = -0.28, p < 0.001) and response to Ca and vitamin D intake differed by GRS (p < 0.05). In addition, presence of the minor allele of a second VDR SNP (rs2228570) was associated with lower P1NP (B = -4.83, p = 0.04) and osteocalcin (B = -0.59, p = 0.03). These data suggest that VDR and DBP SNPs are associated with 25OHD status and bone turnover and those with the highest GRS require the greatest vitamin D intake to improve 25OHD during IMT. © 2016 American Society for Bone and Mineral Research.

Adherence to the Dietary Guidelines for Americans Is Associated with Psychological Resilience in Young Adults: A Cross-Sectional Study.

BACKGROUND: The 2010 Healthy Eating Index (HEI-2010), a measure of diet quality, is used to quantify adherence to the Dietary Guidelines for Americans. Better HEI scores have been associated with positive health outcomes; however, the relationship between diet quality and psychological resilience, a mental health attribute for coping with adversity, has not been assessed. OBJECTIVE: The objective of the present study was to assess the relationship between diet quality and psychological resilience, and the relationship between resilience and demographics, anthropometrics, socioeconomic status, and health behavior. DESIGN: In this cross-sectional study, HEI-2010 scores and resilience were assessed using the Block food frequency questionnaire and the Connor-Davidson Resilience Scale. Other factors that can affect the relationship between HEI-2010 scores and resilience were assessed using surveys, and height and weight were measured to calculate body mass index. PARTICIPANTS/SETTING: Male and female Army and Air Force recruits (n=834) enrolled in a randomized controlled trial and 656 (mean±standard deviation [SD] age=21±3.3 years) were included in this analysis. Data were collected before the initiation of military training at Fort Sill, OK (2012-2013) and Lackland Air Force Base, TX (2013-2014). STATISTICAL ANALYSIS PERFORMED: Participants were split into low- and high-resilience groups based on Connor-Davidson Resilience Scale scores. Student's t test and χ2 tests were used to determine differences between groups for continuous and categorical variables, respectively. Logistic regression was utilized to identify predictors of resilience. RESULTS: Better diet quality was associated with resilience; higher HEI predicted an increased likelihood (odds ratio=1.02; 95% CI 1.01 to 1.04) of a participant being in the high-resilience group after including race, ethnicity, education, smoking, age, body mass index, sex, and military branch in the full model. The data indicate that with every 10-point increase in HEI score, there was a 22% increased likelihood of being in the high-resilience group. CONCLUSIONS: Registered dietitian nutritionists should continue to encourage attainable changes to improve diet; study data suggest that small improvements in diet quality can be associated with better psychological resilience.

Changes in Clinical Presentation and Epidemiology of Respiratory Pathogens Associated With Acute Respiratory Illness in Military Trainees After Reintroduction of Adenovirus Vaccine.

Background. Adenovirus (Ad) has long been the predominant cause of acute respiratory illness (ARI) in military trainees. In 2011, live oral Ad vaccines for serotypes 4 and 7 were reintroduced into US basic military training populations. This study evaluated the impact on clinical presentations and other respiratory pathogens. Methods. The Center for Advanced Molecular Detection at Joint Base San Antonio-Lackland prospectively collects demographic, clinical, and polymerase chain reaction data from respiratory specimens (throat swab and nasal wash) among Air Force trainees presenting for care of ARI. Results. From June 2008 to August 2013, 2660 trainees enrolled and were tested for selected respiratory pathogens. Post-vaccine introduction (VI), reported systemic symptoms were less frequent, including fever (38% vs 94%) and myalgia (37% vs 67%; P < .01). Median temperature and heart rate decreased (98.4 vs 101.3°F, 81 vs 96 beats per minute; P < .01). Ad detection decreased for all Ad (3% vs 68%), Ad4 (1% vs 70%), 7 (0% vs 8%), 14 (0% vs 5%), and 3 (0.1% vs 2%); P < .01). Rhinovirus and cases with no pathogen identified increased in frequency (35% vs 18%, 51% vs 14%; P < .01). Conclusions. Acute respiratory illness in military trainees post-VI is associated with decreased severity of systemic symptoms and reduced fever and heart rate. Marked reductions in frequency of Ad serotypes are seen, including those in the vaccine, with no serotype shift. However, detection of several other respiratory pathogens, most notably rhinovirus, is observed in increasing proportions, and a majority are now undiagnosed clinical syndromes.

The effects of prenatal vitamin supplementation on operationally significant health outcomes in female air force trainees.

OBJECTIVES: A prenatal vitamin supplementation program for female basic military trainees at Joint Base San Antonio-Lackland was initiated in June 2012 with the goals of decreasing attrition and improving performance. This project examined whether supplementation influences attrition rates, incidence of stress fractures and iron deficiency anemia, and physical performance. METHODS: This was a cohort-based pilot study with an historical control group. Primary outcome measures included all-cause attrition, medical attrition, stress fractures, and iron deficiency anemia. RESULTS: Incidence rates of all-cause attrition, medical attrition, stress fractures, and anemia were similar in both groups, although the lower medical attrition in the supplementation group approached statistical significance (risk ratio, 0.74; 95% confidence interval, 0.54-1.01). CONCLUSION: Although this study found no statistical benefit, the operationally significant reduction in medical attrition of 26% suggests that providing prenatal vitamin supplementation to female basic trainees in the Air Force may be worthwhile.

Concurrent bilateral femoral neck stress fractures in a military recruit: a case report.

BACKGROUND: Stress fractures are overuse injuries that historically afflict a large number of military recruits, likely because of the sudden increase of high-intensity activity, such as running and marching. CASE: A 23-year-old male U.S. Air Force recruit presented with hip pain during his second week of basic training and was diagnosed with bilateral femoral neck stress fractures, grade 4 on the right and grade 3 on the left. This is the first known case of concurrent bilateral femoral neck stress fractures in a U.S. military recruit reported in the medical literature. CONCLUSION: This report describes a severe case of stress fracture in an individual with no readily identifiable risk factors.

Prevalence and Impact of Anemia on Basic Trainees in the US Air Force.

BACKGROUND: Anemia has been implicated in adverse health outcomes of athletes and military trainees, ranging from overuse injuries to degraded physical and cognitive performance. The purpose of this study was to investigate prevalence of anemia among US Air Force (USAF) basic trainees, to compare physical performance and discharge rates between anemic and non-anemic trainees, and to determine the risks and relative risks of being discharged for anemic versus non-anemic women and men. METHODS: All USAF basic trainees were screened for anemia between July 2013 and January 2014, during an 8-week basic training course at Joint Base San Antonio-Lackland, TX. Age, sex, screening hemoglobin, anthropometric measurements, initial/final physical fitness assessment scores, and discharge data were collected from trainees. Those identified as anemic (hemoglobin <13.5 g/dL for males and <12.0 g/dL for females) received additional labwork, nutritional counseling, and oral iron-replacement, if indicated. Mean percent improvement was calculated for all performance parameters from beginning to end of training. Anemic trainees were compared to non-anemic trainees by t test with Welch modification. Results were stratified by sex and anemia severity with post-hoc Bonferroni correction. RESULTS: Prevalence of anemia was 12.6 % (N = 18,827). Respective prevalence of borderline, moderate, and severe anemia was 12.6, 10.9, and 1.9 % for females and 4.8, 3.8, and 0.3 % for males. Mean 1.5-mile run-time, push-up and sit-up counts improved from beginning to end of training for both anemic and non-anemic trainees (p < 0.001 both). Non-anemic trainees had slightly greater run-time improvements than borderline and moderate anemics (female: 17.7 vs. 15.2, and 15.1 % improvement, p < 0.05 both; male: 14.9 vs. 13.2, and 13.5 % improvement, p < 0.05 both). One-way ANOVA demonstrated statistically significant differences between initial and final fitness data for all measures and both genders (p < 0.001) with the exception of final sit-up counts for male trainees (p = 0.082). Discharge rate for anemic trainees was 9.0 % (20 % for severely anemic trainees) as compared to 5.7 % for non-anemics. CONCLUSIONS: Anemia was prevalent among USAF basic trainees. Identification and treatment of anemia may optimize physical performance and decrease the rate of medical discharge.

Assessment of rabies exposure risk in a group of U.S. Air Force basic trainees - Texas, January 2014.

In January 2014, members of the Joint Base San Antonio (JBSA)-Lackland, Texas, preventive medicine and public health teams evaluated a U.S. Air Force basic training squadron for potential exposure in sleeping bays to rabies virus carried by Mexican free-tailed bats (Tadarida brasiliensis). Exposure to bats while asleep or otherwise unaware is an important risk factor for rabies in the United States. Over the past several decades, most indigenous human rabies infections in the United States have resulted from the bite of an infected bat, and the bite was not reported in more than half of the cases. Mexican free-tailed bats in Texas often carry rabies virus. Among 8,904 bats tested during 2001-2010, a total of 1,558 (18%) tested positive for rabies. To assess the risk to the Air Force trainees and identify those for whom rabies postexposure prophylaxis (PEP) might be indicated, Lackland preventive medicine and public health teams interviewed 922 persons (866 trainees and 56 instructors) and determined that PEP, consisting of human rabies immune globulin and the 4-dose vaccination series given over 14 days, was indicated for 200 persons (22%). This report describes the public health response to a mass indoor exposure to bats, including group-based rabies risk stratification, adverse reactions to PEP, and infestation remediation. These interventions can be considered for future mass exposures to bats.

Pandemic influenza virus 2009 H1N1 and adenovirus in a high risk population of young adults: epidemiology, comparison of clinical presentations, and coinfection.

BACKGROUND: In 2009, pandemic H1N1 influenza virus (2009 H1N1) emerged worldwide, causing morbidity and mortality that disproportionately affected young adults. Upper respiratory infection (URI), largely due to adenovirus, is an endemic cause of morbidity in military training. Whether clinical presentations differ or excess morbidity results from coinfection is unclear. METHODS: The Center for Advanced Molecular Detection evaluates epidemiology and rapid diagnostics of respiratory pathogens in trainees with URI. From May 1, 2009, to November 30, 2009, demographic, clinical, and PCR data from throat and nasal specimens for adenovirus and 2009 H1N1 were prospectively collected. RESULTS: 375 trainees with URI enrolled and were tested for both adenovirus and 2009 H1N1 by PCR (median age 20; 89% male). Adenovirus PCR was positive in 72% (96% serotype E-4) and 2009 H1N1 in 20%. Males were more likely to have adenovirus and females more likely to have 2009 H1N1 (p  =  0.047). Subjects with 2009 H1N1 presented an average of 1 week earlier in training, had shorter illness duration before enrollment, less sore throat, diarrhea, and fewer abnormal findings on throat exam. Coryza and cough were more common with 2009 H1N1 compared to adenovirus. Subjects with 2009 H1N1 were less likely to have adenovirus than those without, despite persistently high frequencies of adenovirus detections during peak 2009 H1N1 weeks (15% vs. 83%, p < 0.01). Coinfection with adenovirus and 2009 H1N1 was rare (4%). Rates of hospitalization and pneumonia did not differ between the adenovirus, 2009 H1N1, or coinfected groups. CONCLUSION: Military trainees with 2009 H1N1 vs. adenovirus have differing clinical presentations, and males are more likely to have adenovirus. Despite high frequencies of adenovirus infection, coinfection with adenovirus and 2009 H1N1 is rare and apparently does not result in increased morbidity.

Syncope among U.S. Air Force basic military trainees, August 2012-July 2013.

Syncope is a common event with many possible etiologies, ranging from benign to severe. Syncopal episodes of any origin, however, may result in traumatic injury due to postural collapse. Based on the prevalence of internal and external stressors during training, basic military trainees may be at increased risk for syncope. Between 1 August 2012 and 31 July 2013, there were 112 unique individuals who experienced syncopal or pre-syncopal events among basic military trainees at Joint Base San Antonio-Lackland, Texas, the only basic training site in the U.S. Air Force. The overall rate was 19.6 cases per 1,000 person-years (18.4 and 36.1 per 1,000 person-years in males and females, respectively). Based upon the findings of electronic chart review of the 112 cases, a majority of events occurred either during or immediately after exercise (n=38) or during a blood draw, immunization, or laceration repair (n=22). The most common etiologies were judged to be neurocardiogenic (n=54) and orthostatic hypotension (n=40), and two cases were attributed to cardiovascular disease. These findings support current preventive measures, including anemia screening during medical in-processing, an emphasis on hydration throughout training, and a padded floor in the trainee vaccination bay.

Staphylococcus aureus and other skin and soft tissue infections among basic military trainees, Lackland Air Force Base, Texas, 2008-2012.

Military training environments have been identified as high-risk settings for acquisition of skin and soft tissue infections (SSTIs), including those caused by methicillin-resistant Staphylococcus aureus (MRSA). Among the 148,355 basic military trainees at Lackland Air Force Base, Texas, between 1 October 2008 and 30 September 2012, there were 289 SSTIs, including 48 cases of culture-confirmed MRSA and 48 cases of possible MRSA-defined as SSTIs treated with both incision and drainage and MRSA drug coverage (i.e., trimethoprim-sulfamethoxazole, clindamycin, a tetracycline, or linezolid). The period prevalence rates of all SSTIs and MRSA SSTIs increased annually since fiscal year 2010. Of the 87 SSTIs cultured during the surveillance period, 74 were positive: MRSA (n=48); methicillin-sensitive Staphylococcus aureus (n=24); Haemophilus parainfluenzae (n=1); and viridans Streptococcus (n=1). Among MRSA positive cultures, three were resistant to clindamycin, one to tetracycline, and one to both clindamycin and tetracycline; none was resistant to trimethoprim-sulfamethoxazole. An algorithmic clinical approach and heightened public health measures may reduce rates of future SSTIs among basic trainees at Lackland Air Force Base.

U.S. military officer participation in the Centers for Disease Control and Prevention's Epidemic Intelligence Service (1951-2001).

The Epidemic Intelligence Service (EIS) was created in 1951 to provide epidemiologists to investigate natural and intentional disease epidemics. From an initial class of 23 U.S. citizens, the program has evolved into a globally recognized, hands-on learning experience, accepting approximately 65 to 75 new officers each year. The first U.S. military epidemic intelligence service officer (EISO) was accepted into the program in 1994. Since that time, 12 such officers have completed, or have begun, EIS training. They have comprised 2.1% of all EISOs from 1994 to 2001 and 0.47% of all EISOs. This total has included nine Air Force veterinarians, one Army veterinarian, one Army physician, and one Navy physician. Each military EISO had the opportunity to lead investigations of significant public health events (e.g., Ebola, monkeypox, malaria, Nipah virus, West Nile fever, and anthrax outbreaks). All graduates from the military returned to active duty assignments in operational medical units, research institutes, or the intelligence community.