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.

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.

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

Background

The COVID-19 pandemic has been associated with significant spread in congregate settings and various forms of non-pharmaceutical interventions (NPI) have been implemented to prevent spread. Basic Military Training at Joint Base-San Antonio is the entrance to the US Air Force and has been associated with respiratory outbreaks in the past. A two-week arrival quarantine was implemented in March 2020. Effects on subsequent testing for COVID-19 after an arrival quarantine is unknown.

Methods

The first four weekly cohorts of trainees who underwent an arrival quarantine between March 16-April 13 were monitored during their 7 week training for COVID-19 symptoms. Symptoms, medical testing, and days removed from training were collected on every patient with possible COVID-19 symptoms including cough, shortness of breath, or fever. Testing during the two-week arrival quarantine were compared to the subsequent five weeks of training. Nominal variables were compared by chi squared or Fisher’s exact test as appropriate. Continuous variables were compared by Mann-Whitney U Test.

Results

A total of 2,573 started training during study period, 89 (3.4%) had symptoms concerning for COVID-19 and were tested. 5 (6%) patients tested positive, all of whom in the arrival quarantine. Compared to patients who completed quarantine (n=29), patients in the arrival quarantine who tested negative for COVID-19 (n=54) were tested more often (26 trainees a week vs. 5.8 later in training, p=< 0.0001), and received more rapid flu tests (74% vs. 38%, p=0.001) and multiplex respiratory PCR (15% vs. 0%, p=0.05). Trainees in quarantine were isolated longer for symptoms than patients who completed quarantine (median 3 vs. 2, p=0.01). There was no difference in presenting symptoms for trainees in quarantine or after quarantine.

Conclusion

Arrival quarantine appears to be an effective NPI, which in conjunction with other interventions prevented any COVID-19 transmission after quarantine completion. For those who went through arrival quarantine, there was more intense initial testing and initial longer symptomatic patient isolation, this was balanced by fewer symptomatic patients, less testing, and shorter isolations later in training.

Disclosures

All Authors: No reported disclosures

Age at dieting onset, body mass index, and dieting practices. A twin study

OBJECTIVE

Using a twin study design, we sought to determine whether an early age at dieting onset is a risk factor for higher adult body mass index (BMI) or use of risky dieting practices, independent of genetic and familial factors.

METHOD

Female twins ages 18-60 years (N=950) from the University of Washington Twin Registry completed 2 surveys an average of 3 years apart. Analyses of individual twins and within-twin pairs tested associations of self-reported age at dieting onset with (1) adult BMI at baseline, (2) change in BMI between the two surveys and (3) risky dieting behaviors at baseline.

RESULTS

In analyses mimicking studies of unrelated individuals, an earlier age at dieting onset was associated with greater adult BMI (p=0.003), higher Restraint Scale scores (p<0.001), greater use of risky dieting behaviors (p=0.04) and more weight cycling episodes (p<0.001). In within-pair models that control for genetic and familial factors, the only significant association was between an earlier age at dieting onset and more weight cycling episodes (p=0.006).

DISCUSSION

Underlying genetic and familial factors may influence associations of early dieting with higher adult BMIs and risky dieting practices in women.

Quality of life improvement in Latin American patients suffering from chronic venous disorder using a combination of Ruscus aculeatus and hesperidin methyl-chalcone and ascorbic acid (quality study)

AIM

The present study assessed the effect of Ruscus aculeatus, hesperidin methyl-chalcone and ascorbic acid (HMC-AA), in the treatment of chronic venous disorders (CVD) in Latin American patients.

METHODS

This study is an observational, single arm, multicentric and prospective trial. Patients suffering from CVD and belonging to C0s-C3 Clinical Etiological Anatomical and Physiopathological (CEAP) classes were included. Patient profiles, risk factors, clinical symptomatology and quality of life (QoL) assessed by SF-12 and CIVIQ questionnaires were evaluated at inclusion and after 12-week treatment.

RESULTS

The main factors influencing the previous management of patients were age, gender, body mass index (BMI), familial history, physical activity, exposure to heat, heavy loads lifting, profession and clinical characteristics. All clinical symptoms significantly improved with treatment and, as BMI and CEAP classes increased. Ankle circumferences decreased over time, correlating with BMI and CEAP classes. The physical and psychological dimensions of the SF-12 score significantly increased over time and improved within each CEAP class. The CIVIQ score significantly improved over time, correlating with age and CEAP classes.

CONCLUSION

A 12-week treatment with Ruscus aculeatus HMC-AA showed a significant decrease in the clinical symptoms and a significant improvement in the QoL of patients with CVD.

Diferencias entre nonagenarios según su lugar de residencia. Estudio NonaSantfeliu

OBJECTIVE

By means of a cross-sectional study, describe the differential characteristics between a group of inhabitants of a same municipality over 89 years of age who are permanently institutionalized and those of the same age who continue to live in the community, trying to identify a profile of nonagenarians with high risk of living in a nursing home.

MATERIAL AND METHODS

One hundred and eighty six nonagenarians were studied: 137 (74%) were living in their home and 49 (26%) in a nursing home. Sociodemographic data, ability to perform basic daily activities with Barthel Index (BI) or instrumental activities with Lawton and Brody Index (LI), cognition with the Spanish version of the Mini-Mental State Examination (MEC) and comorbidity (Charlson Index) were evaluated. Cardiovascular risk factors and other prevalent diseases were also studied.

RESULTS

A total of 143 women (76.5%) and 43 men with a mean age of 93.06 years were studied. A predominance of women, single persons, worse IL, and greater consumption of drugs was observed in the bivariate analysis in the nonagenarians living in residences and widowers than in those living in the community. The multivariate analysis showed that the features of being single and having a lower IL were independent factors of living in a nursing home.

CONCLUSIONS

The main difference between nonagenargian patients who live in the community and those in residences is that the latter are mainly single and have a low score on a scale that quantities instrumental activities of the daily life.

Pilot study of expedited HIV-1 testing of women in labor at an inner-city hospital in New York City

To evaluate the feasibility of offering voluntary counseling and expedited human immunodeficiency virus (HIV) testing to women in labor, and to assess the characteristics of two rapid HIV assays compared with results from an expedited standard enzyme immunoassay (EIA), with Western blot confirmation, as indicated, we undertook a pilot study immediately prior to enactment of New York State regulations (August 1999) requiring expedited testing of laboring women (or newborns) with undocumented HIV status. From June 9, 1999 through July 2, 1999, we offered HIV counseling and testing (C&T) to all medically stable women in active labor, 106 of 125 (85%) of whom accepted. One woman was confirmed HIV-1 seropositive. Rapid assay sensitivity and specificity were: SUDS 100 and 98%, and Multispot 100 and 100%, respectively in comparison with 100 and 99% for the standard EIA. The positive predictive values (PPV) were SUDS 33%; Multispot 100%; and EIA 50%. While our sample size was small, it appears that the accuracy of rapid and expedited HIV assays may be improved by requiring two different reactive assays before informing women of HIV-seropositive results or initiating antiretroviral treatment.

Pseudo-Meigs' Syndrome

Meigs' syndrome is defined as a hydrothorax with ascites and a pelvic tumor, both of which resolve on removal of the tumor. Pseudo-Meigs' is a variant not possessing the original tumor cell types described by Meigs. Both these syndromes should be considered in otherwise healthy women who present with either new or recurrent hydrothorax and ascites. This case concerns a 21-year-old woman who presented to the emergency department (ED) with a recurrent hydrothorax. After performing a pelvic examination that was suspicious for a pelvic mass, further evaluation by ultrasonography showed ascites and a pelvic tumor. Surgeons from the Obstetrics and Gynecology Department performed an exploratory laparotomy with removal of the tumor. Subsequently, there was no recurrence of the ascites and hydrothorax. The tumor was diagnosed histologically as a benign mature teratoma. The literature of Meigs' and Pseudo-Meigs' is reviewed, focusing on the history, pathology, and clinical characteristics. The clinical significance for the emergency physician is discussed.

Simultaneous radial, femoral, and aortic arterial pressures during human cardiopulmonary resuscitation

OBJECTIVE

To examine the validity of interchanging arterial sites and their responses to graded doses of epinephrine during human cardiopulmonary resuscitation (CPR).

DESIGN

Consecutive case series.

SETTING

Large, urban Emergency Department.

PATIENTS

Adult, normothermic, nonhemorrhagic cardiac arrest patients.

INTERVENTIONS

While receiving advanced cardiac life support, patients received right atrial (n = 40), aortic (n = 40), radial (n = 40), and femoral (n = 17) artery catheters. Pressures were measured simultaneously at baseline, after 0.01 mg/kg and 0.2 mg/kg of epinephrine.

MEASUREMENTS AND MAIN RESULTS

The mean aortic compression-phase pressure was 9.3 +/- 10 (SD), 8.1 +/- 11, and 4.4 +/- 9.5 mm Hg higher than radial artery pressure at baseline, after 0.01 mg/kg, and 0.2 mg/kg of epinephrine, respectively (all statistically significant). When compared with the femoral artery at the same time points, the mean aortic compression-phase pressure was also 3.0 +/- 6.8, 1.9 +/- 8, and 0.6 +/- 7.7 mm Hg higher, respectively (none statistically significant). The aortic relaxation-phase pressure was 1.3 +/- 3.6, 1.1 +/- 3.8, and 1.6 +/- 2.5 mm Hg lower than the radial artery at baseline, after 0.01 mg/kg and 0.2 mg/kg of epinephrine, respectively (all statistically significant). When compared with the femoral artery at the same time points, the aortic relaxation-phase pressure was 0.6 +/- 2.0, 0.3 +/- 3.3, and 0.3 +/- 2.4 mm Hg lower, respectively (none statistically significant).

CONCLUSIONS

Radial artery relaxation-phase pressure, although statistically higher, correlated with aortic relaxation-phase pressure. Femoral artery relaxation-phase pressure was not statistically different from aortic relaxation-phase pressure. Aortic pressure was statistically higher and had a lower correlation with radial artery pressures during compression phase. The aortic to radial artery and aortic to femoral artery compression-phase gradients abated with increasing doses of epinephrine therapy. Caution must be used when substituting compression-phase pressure obtained at radial or femoral artery sites for aortic pressure during human CPR. Coronary artery perfusion pressures obtained with radial and femoral arteries correlate with aortic pressure when measuring the response to vasopressor therapy during CPR when an interpretable waveform exists.

CPR-dependent consciousness: evidence for cardiac compression causing forward flow

We present the case of a patient with cardiac arrest and resuscitation in whom, consistent with direct cardiac compression, large aortic-to-right atrial systolic pressure gradients occurred. Forward blood flow during CPR was sufficient for the patient to maintain consciousness. Although aortic-to-right atrial diastolic gradients adequate to maintain coronary perfusion in experimental models were generated, in our patient, cardiac function could not be restored and the resuscitation was ultimately unsuccessful.

Simultaneous loss of bacteriophage receptor and coaggregation mediator activities in Actinomyces viscosus MG-1

Actinomyces bacteriophages were used as tools to study coaggregation between actinomyces and streptococci. Four bacteriophage isolates, phages AV-1, AV-2, AV-3, and 1281, bound to coaggregation group A Actinomyces viscosus and to group E A. naeslundii. No binding to groups B, C, D, or F was observed. Only A. viscosus MG-1 was capable of supporting a productive infection by these phages. Spontaneously occurring bacteriophage-resistant mutants of A. viscosus MG-1 were isolated and were shown to fall into two classes. Class I mutants were resistant to all four phages, whereas class II mutants were resistant only to phage AV-3. In each case, strains resistant to a particular phage were unable to bind that phage, suggesting that a loss or alteration of the cell surface phage receptor had occurred. Both classes of mutants were unable to coaggregate with streptococci representing coaggregation group 1 and had also lost the ability to mediate one type of coaggregation with group 4 streptococci. Class II mutants also were unable to coaggregate with group 2 streptococci. Lactose-inhibitable interactions with other streptococci (groups 3 and 4) were unchanged in the mutants. The simultaneous loss of sensitivity to phage AV-3 and the ability to coaggregate with coaggregation group 1 streptococci suggests the possibility of a relationship between these two cell surface structures.

Resuscitative thoracotomy for patients with traumatic injury

The clinical course and final outcome were determined for 63 trauma victims who underwent resuscitative thoracotomy (RT) for hypovolemic cardiac arrest in the Department of Emergency Medicine during a 24-month period. The objectives of the study were to determine the efficacy of and indications for RT and to define the prognostic signs for survival. Of 63 patients, six were successfully resuscitated (9.5%), and five of these were discharged from the hospital (7.9%). The presence of pupillary reactions was an extremely reliable indicator of successful outcome (P = 0.0009), as was the presence of some respiratory effort (P = 0.025). None of the victims of blunt trauma (n = 6) or severe head injury (n = 13) survived. Three of 17 patients (17.6%) with stab wounds and two of 36 (5.6%) with gunshot wounds survived the procedure. RT was beneficial in 13.6% of patients who had isolated organ system injuries, but no patient with injuries to more than two organ systems survived. Victims of isolated penetrating thoracic trauma had an 11.8% survival rate, as opposed to a 0% survival rate for those with abdominal trauma. The best prognosis was in victims with penetrating cardiac injuries, who had a 22.7% survival rate. The cost of RT averaged $1660 per patient, exclusive of physician charges. In our experience, RT is most beneficial for victims of penetrating thoracic trauma, especially those with cardiac injuries. However, routine use of this high cost/low benefit procedure cannot be recommended for patients who have cardiac arrest secondary to blunt trauma or severe head injuries. Also, it is not recommended for patients whose pupillary reflexes and respiratory movements are absent.