COVID-19 Monitoring and Response Among U.S. Air Force Basic Military Trainees - Texas, March-April 2020.

The coronavirus disease 2019 (COVID-19) pandemic has resulted in substantial morbidity and mortality since it was first described in December 2019 (1). Based on epidemiologic data showing spread in congregate settings (2-4), national, state, and local governments instituted significant restrictions on large gatherings to prevent transmission of disease in early March 2020. This and other nonpharmaceutical interventions (NPIs) have shown initial success in slowing the pandemic across the country (5). This report examines the first 7 weeks (March 1-April 18) of implementation of NPIs in Basic Military Training (BMT) at a U.S. Air Force base. In a population of 10,579 trainees, COVID-19 incidence was limited to five cases (47 per 100,000 persons), three of which were in persons who were contacts of the first patient. Transmission of symptomatic COVID-19 was successfully limited using strategies of quarantine, social distancing, early screening of trainees, rapid isolation of persons with suspected cases, and monitored reentry into training for trainees with positive test results after resolution of symptoms.

Deaths Among U.S. Air Force Basic Military Trainees, 2008-2020.

INTRODUCTION: The U.S. Air Force (USAF) Basic Military Training (BMT), a rigorous training program for all enlisted members of the USAF, trains roughly 36,000 recruits annually. Transforming civilians into ready warrior airmen has inherent risks to trainee health, which has infrequently included death. While the average death rate at USAF BMT has decreased between 1956 and 2007 due to process improvement and preventive medicine efforts, further review is warranted to examine the deaths that have occurred since the last published period (1997-2007) and to determine the impact policy changes and updates have had on death rates since that time. Therefore, the purpose of this paper is to identify death rates and types from 2008 to 2020, explore policy implementation, and identify areas needing further improvement or modifications to the overall safety, fitness, and health of USAF BMT trainees. MATERIALS AND METHODS: All deaths were examined and reviewed from 2008 through 2020 for trainees attending the USAF BMT using medical records and autopsy reports. Death rates were calculated using the total population of trainees in a given year as well as over the entire 13-year study period. RESULTS: From 2008 to 2020, five deaths occurred among USAF BMT trainees (one cardiac, two exertional sickling due to sickle cell trait, one infection, and one suicide). This resulted in an overall average death rate of 1.08 per 100,000 trainees, as compared to 1.46 per 100,000 from 1997 to 2007. The last death in the study period occurred in 2016. CONCLUSION: A modest downward trend of average death rate has continued since 2007, and no deaths from 2016 through 2020 represents the longest time frame without any deaths at USAF BMT over all times reported (dating back to 1956) which suggest that emergency best practice policies are/have improved. However, cardiac death rate and suicide rate have not changed since the last report. Policies and practices should be continuously reviewed and refined to reduce the risk of death at USAF BMT.

Effect of Arrival Quarantine on Subsequent COVID-19 Testing in a Cohort of Military Basic Trainees.

INTRODUCTION: Basic Military Training at Joint Base San Antonio-Lackland implemented several sequential non-pharmaceutical interventions in response to coronavirus disease-2019 (COVID-19). One measure, arrival quarantine, has not been studied as a modern military disease prevention strategy. This study aimed to determine the effect of a 14-day arrival quarantine on symptomatic COVID-19 testing. MATERIAL AND METHODS: A retrospective cohort study compared symptomatic COVID-19 testing among all trainees who entered Basic Military Training between March 17, 2020, and April 17, 2020, before the implementation of universal arrival COVID-19 testing, during their first 2 weeks in arrival quarantine compared to the rest of their training. Furthermore, symptomatic COVID-19 testing in the last 5 weeks of training in those who completed arrival quarantine was compared to testing in the last 5 weeks for trainees who arrived between February 16, 2020, and March 16, 2020, and did not undergo arrival quarantine. Nominal variables were compared by chi-square test, and continuous variables were compared by Mann-Whitney U test. This study was approved as a public health surveillance project by the 59th Medical Wing Institutional Review Board. RESULTS: Five thousand five hundred and seventy-six trainees started training between February 16, 2020, and April 17, 2020, with 2,573 trainees undergoing an arrival quarantine compared to 3,003 trainees who did not. Trainees who underwent arrival quarantine had higher rates of COVID-19 testing while in arrival quarantine (10.5 tests per 1,000 trainee-weeks vs. 2.3, P ≤ .001) and higher rates of concomitant influenza testing (74% vs. 38%, P = .001) compared to after they completed quarantine. Trainees that completed quarantine had less symptomatic COVID-19 testing after day 14 of training (2.3 tests per 1,000 trainee-weeks vs. 14.3, P ≤ .001) and influenza testing (38% vs. 74%, P = .001) compared to trainees that did not undergo arrival quarantine. CONCLUSION: Arrival quarantine appears to be an effective non-pharmaceutical intervention associated with fewer symptomatic COVID-19 tests, especially after completion of quarantine.

Outcomes of Embedded Athletic Training Services Within United States Air Force Basic Military Training.

CONTEXT: Musculoskeletal injury is the leading cause of attrition from military training. OBJECTIVE: To assess the effect of an embedded athletic training musculoskeletal care model within a basic military training unit. DESIGN: Cluster randomized trial. SETTING: United States Air Force Basic Military Training, Joint Base San Antonio-Lackland. PATIENTS OR OTHER PARTICIPANTS: Military recruits randomly assigned to 1 of 3 training squadrons, 2 control and 1 experimental, between January 2016 and December 2018. INTERVENTION(S): A sports medicine care model was established in 1 squadron by embedding 2 certified athletic trainers overseen by a sports medicine fellowship-trained physician. The athletic trainers diagnosed and coordinated rehabilitation as the primary point of contact for recruits and developed interventions with medical and military leadership based on injury trends. MAIN OUTCOME MEASURE(S): Recruit attrition from basic training due to a musculoskeletal injury. Secondary outcomes were all-cause attrition, on-time graduation, rates of lower extremity injury and stress fracture, rates of specialty care appointments, and fiscal costs. RESULTS: Recruits in the athletic training musculoskeletal care arm experienced 25% lower musculoskeletal-related attrition (risk ratio = 0.75 [95% CI = 0.64, 0.89]) and 15% lower all-cause attrition (risk ratio = 0.85 [95% CI = 0.80, 0.91]), translating to a net saving of more than $10 million. The intervention reduced the incidence of lower extremity stress fracture by 16% (rate ratio = 0.84 [95% CI = 0.73, 0.97]). CONCLUSIONS: An embedded athletic training musculoskeletal care model outperformed usual care across operational, medical, and fiscal outcomes.

Risk Factors Associated With COVID-19 Transmission Among US Air Force Trainees in a Congregant Setting.

Importance: Owing to concerns of coronavirus disease 2019 (COVID-19) outbreaks, many congregant settings are forced to close when cases are detected because there are few data on the risk of different markers of transmission within groups. Objective: To determine whether symptoms and laboratory results on the first day of COVID-19 diagnosis are associated with development of a case cluster in a congregant setting. Design, Setting, and Participants: This cohort study of trainees with COVID-19 from May 11 through August 24, 2020, was conducted at Joint Base San Antonio-Lackland, the primary site of entry for enlistment in the US Air Force. Symptoms and duration, known contacts, and cycle threshold for trainees diagnosed by reverse transcription-polymerase chain reaction were collected. A cycle threshold value represents the number of nucleic acid amplification cycles that occur before a specimen containing the target material generates a signal greater than the predetermined threshold that defines positivity. Cohorts with 5 or more individuals with COVID-19 infection were defined as clusters. Participants included 10 613 trainees divided into 263 parallel cohorts of 30 to 50 people arriving weekly for 7 weeks of training. Exposures: All trainees were quarantined for 14 days on arrival. Testing was performed on arrival, on day 14, and anytime during training when indicated. Protective measures included universal masking, physical distancing, and rapid isolation of trainees with COVID-19. Main Outcomes and Measures: Association between days of symptoms, specific symptoms, number of symptoms, or cycle threshold values of individuals diagnosed with COVID-19 via reverse transcription-polymerase chain reaction and subsequent transmission within cohorts. Results: In this cohort study of 10 613 US Air Force basic trainees in 263 cohorts, 403 trainees (3%) received a diagnosis of COVID-19 in 129 cohorts (49%). Among trainees with COVID-19 infection, 318 (79%) were men, and the median (interquartile range [IQR]) age was 20 (19-23) years; 204 (51%) were symptomatic, and 199 (49%) were asymptomatic. Median (IQR) cycle threshold values were lower in symptomatic trainees compared with asymptomatic trainees (21.2 [18.4-27.60] vs 34.8 [29.3-37.4]; P < .001). Cohorts with clusters of individuals with COVID-19 infection were predominantly men (204 cohorts [89%] vs 114 cohorts [64%]; P < .001), had more symptomatic trainees (146 cohorts [64%] vs 53 cohorts [30%]; P < .001), and had more median (IQR) symptoms per patient (3 [2-5] vs 1 [1-2]; P < .001) compared with cohorts without clusters. Within cohorts, subsequent development of clusters of 5 or more individuals with COVID-19 infection compared with those that did not develop clusters was associated with cohorts that had more symptomatic trainees (31 of 58 trainees [53%] vs 43 of 151 trainees [28%]; P = .001) and lower median (IQR) cycle threshold values (22.3 [18.4-27.3] vs 35.3 [26.5-37.8]; P < .001). Conclusions and Relevance: In this cohort study of US Air Force trainees living in a congregant setting during the COVID-19 pandemic, higher numbers of symptoms and lower cycle threshold values were associated with subsequent development of clusters of individuals with COVID-19 infection. These values may be useful if validated in future studies.

Outbreak of cyclosporiasis in a U.S. Air Force training population, Joint Base San Antonio-Lackland, TX, 2018.

Diarrheal illnesses have an enormous impact on military operations in the deployed and training environments. While bacteria and viruses are the usual causes of gastrointestinal disease outbreaks, 2 Joint Base San Antonio-Lackland, TX, training populations experienced an outbreak of diarrheal illness caused by the parasite Cyclospora cayetanensis in June and July 2018. Cases were identified from outpatient medical records and responses to patient questionnaires. A confirmed case was defined by diarrhea and laboratory confirmation, and patients without a positive lab were classified as suspected cases. In cluster 1, 46 suspected and 7 confirmed cases occurred among technical training students who reported symptom onset from 12 June to 21 June. In cluster 2, 18 suspected and 14 confirmed cases in basic military training trainees reported symptom onset from 29 June to 8 July. Numerous lessons from cluster 1 were applied to cluster 2. Crucial lessons learned during this cyclosporiasis outbreak included the importance of maintaining clinical suspicion for cyclosporiasis in persistent gastrointestinal illness and obtaining confirmatory laboratory testing for expedited diagnosis and treatment.

Physical and Mental Health of US Air Force Military Training Instructors.

INTRODUCTION: Many epidemiologic studies have been performed in military recruit populations, but little is known about the health of those who conduct the training. This study aims to characterize the physical and mental health of a military trainer cohort. MATERIALS AND METHODS: All US Air Force military training instructors (MTIs) who served between 1 October 2011 and 30 September 2016 were included in this retrospective descriptive study. All International Classification of Diseases, Ninth or Tenth Revision codes received by MTIs as inpatients or outpatients in the TRICARE system were obtained and mapped to Clinical Classifications Software levels. After excluding routine and administrative codes, the relative burden of disease by diagnostic category and subcategory was calculated, with further classification of musculoskeletal conditions by anatomic site. For all conditions accounting for at least 1.0% of the burden of care, incidence density rates and incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were calculated to compare males and females. RESULTS: A total of 1,269 MTIs received 32,601 non-administrative, non-routine diagnoses while accumulating 50,376 person-months of exposure during the surveillance period. Musculoskeletal conditions were the greatest contributor to overall disease burden, accounting for 39.1% of all diagnoses, followed by mental health (10.4%), respiratory (10.1%), and neurologic and sensory (9.8%). The burden attributed to mental health conditions decreased by 54% over the 5-year period. Twenty-three conditions accounted for at least 1.0% of the healthcare burden. The highest incidence conditions were connective tissue disease (27.18 per 1,000 person-months), non-traumatic joint disorders (25.74), upper respiratory infections (25.14), and back pain (23.70). As compared to males, females had a higher incidence of several conditions, including adjustment disorders (IRR: 2.57; 95% CI: 1.61, 4.11) and anxiety disorders (IRR: 2.24; 95% CI: 1.33, 3.77). CONCLUSIONS: Musculoskeletal conditions are the leading contributor to burden of care among US Air Force MTIs, followed by mental health, respiratory, and neurologic and sensory conditions. The burden of healthcare among US Air Force MTIs more closely resembles active component service members than recruit trainees.

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.

Description and Rate of Musculoskeletal Injuries in Air Force Basic Military Trainees, 2012-2014.

CONTEXT: Musculoskeletal injuries are common in military trainees and have significant medical and operational effects. OBJECTIVE: To provide current musculoskeletal injury epidemiology data for US Air Force basic military trainees. DESIGN: Descriptive epidemiologic study with cross-sectional features. SETTING: US Air Force Basic Military Training, Joint Base San Antonio-Lackland, Texas. PATIENTS OR OTHER PARTICIPANTS: All recruits who entered training between July 1, 2012, and June 30, 2014. MAIN OUTCOME MEASURE(S): Incidence density rate of all musculoskeletal injuries (stratified by body region and type) and factors and costs associated with injuries. RESULTS: Of the 67 525 trainees, 12.5% sustained 1 or more musculoskeletal injuries. The overall incidence density rate was 18.3 injuries per 1000 person-weeks (15.1 for men and 29.4 for women). The most common diagnosis (n = 2984) was Pain in joint, lower leg, as described in the International Classification of Diseases, Ninth Revision, Clinical Modification, code 719.46. Injuries were more common among those with lower levels of baseline aerobic and muscular fitness. Injured trainees were 3.01 times (95% confidence interval = 2.85, 3.18) as likely to be discharged, and injured trainees who did graduate were 2.88 times (95% confidence interval = 2.72, 3.04) as likely to graduate late. During the surveillance period, injuries resulted in more than $43.7 million in medical ($8.7 million) and nonmedical ($35 million) costs. CONCLUSIONS: Musculoskeletal injuries, predominantly of the lower extremities, have significant fiscal and operational effects on Air Force Basic Military Training. Further research into prevention and early rehabilitation of these injuries in military trainees is warranted.

Sexually transmitted infections in U.S. Air Force recruits in basic military training.

This study reports the counts, prevalence, and trends of five common sexually transmitted infections (STIs) among U.S. Air Force recruits during 2012-2014. Chlamydia and genital herpes simplex virus (HSV) were the most commonly identified STIs in females, with a prevalence of 4,841.2 and 432.3 per 100,000, respectively. Genital HSV was the most commonly identified STI in males at 133.4 per 100,000. There were 13 cases of chlamydia and gonorrhea co-infection among females and none among males. STI prevalence was lower than in a similarly aged U.S. civilian population.

Epidemiology, microbiology, and antibiotic susceptibility patterns of skin and soft tissue infections, Joint Base San Antonio-Lackland, Texas, 2012-2014.

Skin and soft tissue infections (SSTIs), including those caused by methicillin-resistant Staphylococcus aureus (MRSA), are common in military training environments. In 2014, the healthcare providers for trainees at Joint Base San Antonio (JBSA)-Lackland, TX, notified the surveillance unit of increased antibiotic resistance reported on wound cultures of purulent SSTIs. To provide updated clinical guidance to local providers, the surveillance unit conducted a review of all SSTIs diagnosed among trainees at JBSA-Lackland between 1 October 2012 and 31 December 2014. SSTI cumulative incidence during the surveillance period was 0.81%, with similar rates between males (0.80%) and females (0.84%) and between basic (0.82%) and technical (0.79%) trainees. Of 772 total cases, 254 were cultured; 196 resulted in growth of one or more pathogens: MRSA (n=110); methicillin-sensitive S. aureus (n=68); other gram-positive cocci (n=5); and gram-negative rods (n=18). In vitro activity of commonly used antibiotics against S. aureus isolates dropped slightly from the previous surveillance period. In addition to novel antibiotic research and development, these trends warrant enhanced local preventive efforts and close adherence to evidence-based treatment algorithms.

The effect of race/ethnicity on gestational weight gain.

Minority women are gaining more weight than recommended during pregnancy. This study aimed to determine the risk of excessive gestational weight gain (GWG) in Hispanic and Black women compared to non-Hispanic women in Colorado. A retrospective cohort study of all birth records from 2007 to 2010 in Colorado was conducted. The primary outcome was GWG, and the exposure was race/ethnicity. Covariates were marital status, education, intensity of prenatal care, age, parity, tobacco use, alcohol use and years in the US. Chi square and multiple logistic regression was performed. 230,698 records were analyzed. Half of the Hispanic and Black women began their pregnancy overweight or obese. Hispanic women had a 0.84 (95% CI 0.8-0.9) and Black women had a 0.95 (95% CI 0.9-1.0) risk of excessive GWG than NHW women. Pre-pregnancy weight is an independent risk for adverse outcomes. The study findings provide healthcare providers focal points in preconception health care and programming.

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.

Spread of vaccinia virus through shaving during military training, Joint Base San Antonio-Lackland, TX, June 2014.

Although naturally occurring smallpox virus was officially declared eradicated in 1980, concern for biological warfare prompted the U.S. Government in 2002 to recommend smallpox vaccination for select individuals. Vaccinia, the smallpox vaccine virus, is administered into the skin, typically on the upper arm, where the virus remains viable and infectious until the scab falls off and the epidermis is fully intact - typically 2-4 weeks. Adverse events following smallpox vaccination may occur in the vaccinee, in individuals who have contact with the vaccinee (i.e., secondary transmission), or in individuals who have contact with the vaccinee's contact (i.e., tertiary transmission). In June 2014 at Joint Base San Antonio-Lackland, TX, two cases of inadvertent inoculation of vaccinia and one case of a non-viral reaction following vaccination occurred in the security forces training squadron. This includes the first reported case of shaving as the likely source of autoinoculation after contact transmission. This paper describes the diagnosis and treatment of these cases, the outbreak investigation, and steps taken to prevent future transmission.

Legislation restricting access to indoor tanning throughout the world.

OBJECTIVE: To compile current legislation of indoor tanning throughout the world and compare them with existing legislation found in 2003. DESIGN: Cross-sectional study. SETTING: International. PARTICIPANTS: All nations with legislation regarding access to indoor tanning found through web-based Internet search. MAIN OUTCOME MEASURES: Number of nations with legislation and changes to laws regarding access to indoor tanning since 2003. RESULTS: The number of countries with nationwide indoor tanning legislation restricting youth 18 years or younger increased from 2 countries in 2003 to 11 countries in 2011. Six states or territories in Australia restricted indoor tanning in all minors; a province and a region in Canada implemented youth tanning laws; and 8 states, in addition to 3 preexisting state laws, in the United States implemented indoor tanning legislation since 2003. CONCLUSION: Since 2003, access to indoor tanning has become increasingly restricted around the world.