Sociodemographic and Occupational Characteristics Associated with Early and Continued COVID-19 Vaccine Uptake Among Healthcare Personnel: Monroe County, NY

OBJECTIVE

Identify characteristics of healthcare personnel (HCP) who did not have timely initiation of the COVID-19 primary series, as well as HCP who did not receive a booster vaccine.

METHODS

Characteristics of HCP enrolled in a COVID-19 vaccine effectiveness study between 12/28/2020-12/01/2022 were compared by timing of receipt of 1st mRNA dose, and by receipt of a booster dose. Data for this retrospective cohort analysis came from HCP working at a large healthcare system in Monroe County, New York, and included standardized questionnaires and verified vaccination status. HCP were categorized by whether they received their 1stmRNA COVID-19 vaccine between 12/14/2020-03/30/2021 (earlier) or 04/01/2021-09/28/2021 (later) based on timing of local vaccine eligibility and mandates, and by whether they received a 3rdmRNA booster dose by 12/01/22. Logistic regression models were run to identify characteristics of HCP who had later 1stdose receipt or did not receive a booster.

RESULTS

3,375 HCP were enrolled. Of these, 86.8 % had early initiation of their 1stCOVID-19 vaccine, and 85.0 % received a booster dose. Low education, low household income, younger age (<50), non-White race and public health insurance were all significant predictors of later receipt of 1stdose and lack of uptake of a booster. However, advanced professional role was only found to be a significant predictor of early 1stdose receipt.

CONCLUSIONS

Continual monitoring of COVID-19 vaccine uptake among HCP to identify those less likely to receive new booster doses will be crucial to support targeted vaccine campaigns in this important population.

Effectiveness of a bivalent mRNA vaccine dose against symptomatic SARS-CoV-2 infection among U.S. Healthcare personnel, September 2022-May 2023

BACKGROUND

Bivalent mRNA vaccines were recommended since September 2022. However, coverage with a recent vaccine dose has been limited, and there are few robust estimates of bivalent VE against symptomatic SARS-CoV-2 infection (COVID-19). We estimated VE of a bivalent mRNA vaccine dose against COVID-19 among eligible U.S. healthcare personnel who had previously received monovalent mRNA vaccine doses.

METHODS

We conducted a case-control study in 22 U.S. states, and enrolled healthcare personnel with COVID-19 (case-participants) or without COVID-19 (control-participants) during September 2022-May 2023. Participants were considered eligible for a bivalent mRNA dose if they had received 2-4 monovalent (ancestral-strain) mRNA vaccine doses, and were ≥67 days after the most recent vaccine dose. We estimated VE of a bivalent mRNA dose using conditional logistic regression, accounting for matching by region and four-week calendar period. We adjusted estimates for age group, sex, race and ethnicity, educational level, underlying health conditions, community COVID-19 exposure, prior SARS-CoV-2 infection, and days since the last monovalent mRNA dose.

RESULTS

Among 3,647 healthcare personnel, 1,528 were included as case-participants and 2,119 as control-participants. Participants received their last monovalent mRNA dose a median of 404 days previously; 1,234 (33.8%) also received a bivalent mRNA dose a median of 93 days previously. Overall, VE of a bivalent dose was 34.1% (95% CI, 22.6%-43.9%) against COVID-19 and was similar by product, days since last monovalent dose, number of prior doses, age group, and presence of underlying health conditions. However, VE declined from 54.8% (95% CI, 40.7%-65.6%) after 7-59 days to 21.6% (95% CI 5.6%-34.9%) after ≥60 days.

CONCLUSIONS

Bivalent mRNA COVID-19 vaccines initially conferred approximately 55% protection against COVID-19 among U.S. healthcare personnel. However, protection waned after two months. These findings indicate moderate initial protection against symptomatic SARS-CoV-2 infection by remaining up-to-date with COVID-19 vaccines.

Residential social vulnerability among healthcare personnel with and without severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection in Five US states, May-December 2020

OBJECTIVE

To characterize residential social vulnerability among healthcare personnel (HCP) and evaluate its association with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection.

DESIGN

Case-control study.

SETTING

This study analyzed data collected in May-December 2020 through sentinel and population-based surveillance in healthcare facilities in Colorado, Minnesota, New Mexico, New York, and Oregon.

PARTICIPANTS

Data from 2,168 HCP (1,571 cases and 597 controls from the same facilities) were analyzed.

METHODS

HCP residential addresses were linked to the social vulnerability index (SVI) at the census tract level, which represents a ranking of community vulnerability to emergencies based on 15 US Census variables. The primary outcome was SARS-CoV-2 infection, confirmed by positive antigen or real-time reverse-transcriptase- polymerase chain reaction (RT-PCR) test on nasopharyngeal swab. Significant differences by SVI in participant characteristics were assessed using the Fisher exact test. Adjusted odds ratios (aOR) with 95% confidence intervals (CIs) for associations between case status and SVI, controlling for HCP role and patient care activities, were estimated using logistic regression.

RESULTS

Significantly higher proportions of certified nursing assistants (48.0%) and medical assistants (44.1%) resided in high SVI census tracts, compared to registered nurses (15.9%) and physicians (11.6%). HCP cases were more likely than controls to live in high SVI census tracts (aOR, 1.76; 95% CI, 1.37-2.26).

CONCLUSIONS

These findings suggest that residing in more socially vulnerable census tracts may be associated with SARS-CoV-2 infection risk among HCP and that residential vulnerability differs by HCP role. Efforts to safeguard the US healthcare workforce and advance health equity should address the social determinants that drive racial, ethnic, and socioeconomic health disparities.

Determinates of Clostridioides difficile infection (CDI) testing practices among inpatients with diarrhea at selected acute-care hospitals in Rochester, New York, and Atlanta, Georgia, 2020-2021

OBJECTIVE

We evaluated the impact of test-order frequency per diarrheal episodes on Clostridioides difficile infection (CDI) incidence estimates in a sample of hospitals at 2 CDC Emerging Infections Program (EIP) sites.

DESIGN

Observational survey.

SETTING

Inpatients at 5 acute-care hospitals in Rochester, New York, and Atlanta, Georgia, during two 10-workday periods in 2020 and 2021.

OUTCOMES

We calculated diarrhea incidence, testing frequency, and CDI positivity (defined as any positive NAAT test) across strata. Predictors of CDI testing and positivity were assessed using modified Poisson regression. Population estimates of incidence using modified Emerging Infections Program methodology were compared between sites using the Mantel-Hanzel summary rate ratio.

RESULTS

Surveillance of 38,365 patient days identified 860 diarrhea cases from 107 patient-care units mapped to 26 unique NHSN defined location types. Incidence of diarrhea was 22.4 of 1,000 patient days (medians, 25.8 for Rochester and 16.2 for Atlanta; P < .01). Similar proportions of diarrhea cases were hospital onset (66%) at both sites. Overall, 35% of patients with diarrhea were tested for CDI, but this differed by site: 21% in Rochester and 49% in Atlanta (P < .01). Regression models identified location type (ie, oncology or critical care) and laxative use predictive of CDI test ordering. Adjusting for these factors, CDI testing was 49% less likely in Rochester than Atlanta (adjusted rate ratio, 0.51; 95% confidence interval [CI], 0.40-0.63). Population estimates in Rochester had a 38% lower incidence of CDI than Atlanta (summary rate ratio, 0.62; 95% CI, 0.54-0.71).

CONCLUSION

Accounting for patient-specific factors that influence CDI test ordering, differences in testing practices between sites remain and likely contribute to regional differences in surveillance estimates.

Defining a Relationship Between Postoperative Antibiotic Use and Wound Complications in the Setting of an Uncomplicated Laparoscopic Appendectomy

INTRODUCTION

Appendicitis is a very common diagnosis that surgeons manage daily. Some surgeons are still giving antibiotics to patients suffering from uncomplicated appendicitis in the postoperative setting, despite an abundance of evidence to support a single preoperative dose of antibiotics. In this paper, we will describe the management of post-operative antibiotics at our institutions following uncomplicated appendicitis with regard to the use of antibiotics in the post-operative setting.

METHODS

A retrospective chart review was performed analyzing post-operative antibiotic use and postoperative complications in 179 patients undergoing laparoscopic appendectomy for uncomplicated appendicitis. We retrospectively examined the patients to change our future practices as we perform appendectomies routinely, and there is practice variation at our centers. Current Procedural Terminology (CPT) codes for 'laparoscopic appendectomy' were used to identify the patients within our inclusion criteria. Twenty-four patients were excluded from the analysis as they had complicated appendicitis or met other exclusion criteria. We only studied the patient with uncomplicated appendicitis, as those with complicated appendicitis have a different clinical course that involves post-operative antibiotic administration or prolonged antibiotic administration with or without drain placement. Both arms of the study were homogeneous regarding patient characteristics. An independent test of the development of wound infection for those patients receiving post-operative antibiotics versus those not receiving post-operative antibiotics was conducted using the SPC XL 2010 Microsoft Excel (Redmond, USA) add-in. A p-value of <0.05 was considered statistically significant. This included the odds ratio for the development of complications.  Results: There was no difference in the risk of infection rate in patients given post-operative antibiotics; however, given the odds ratio of 6.53, there is an association between an increased wound infection rate and patients who received post-operative antibiotics.  Discussion: An appendectomy is a standard surgical procedure for acute appendicitis. The guidelines for using pre-operative antibiotics in uncomplicated appendicitis are well established; however, there is no specific recommendation on whether to continue antibiotics post-operatively. However, there is significant provider variability on this topic. Antibiotic use post-operatively in clean-contaminated cases, such as uncomplicated acute appendicitis, has been associated with higher risks of surgical site infections.  Conclusion: The use of antibiotics post-operatively may not be indicated for uncomplicated laparoscopic appendectomy and may increase wound infections. A large-scale study including a larger population and extending it to other hospitals may increase statistical significance and help guide physician management.

Sliding Inguinal Bladder Hernia: An Open and Minimally Invasive Robotic-Assisted Repair

Inguinal hernia repair, although a common procedure, can present in complicated ways such as a sliding inguinal bladder hernia (IBH). This rare type of hernia can alter a patient's quality of life by obstructing urination, requiring manual scrotal compression to fully empty the bladder, and lead to devastating complications such as hydronephrosis and kidney failure. Treatment is typically by open inguinal hernia repair with manual bladder reduction, but this method poses risks of iatrogenic injury to the bladder. Within this case series, IBH repairs via open and robotic-assisted laparoscopic procedures are compared, and the morbidity and mortality of each method are analyzed. Although risk of recurrence is similar for both procedures, robotic surgeries are linked to decreased postoperative pain and length of hospital stay. The ease of dissection of pelvic anatomy and detailed view of the associated structures that robotic surgery can provide during a complex hernia repair encourages its use for IBH.

Seroepidemiologic Investigation of a COVID-19 Outbreak Aboard a U.S. Navy Ship

The crew of USS Kidd experienced a COVID-19 outbreak identified in April 2020. This is the earliest documented COVID-19 study with RT-PCR, serology, and pre-exposure test data on the entirety of the exposed population (n=333). Case definitions included 121 confirmed (36.3% of crewmembers) and 18 probable (5.4% of crewmembers) based on laboratory diagnostic test results. At the time of testing positive, 62 (44.6%) cases reported no symptoms. Hispanic ethnicity (AOR: 2.71, CI: 1.40-5.25) and non-smoker status (AOR: 2.28, CI: 1.26-4.12) were identified as statistically significant risk factors. This study highlights the value of rapid, onboard diagnostic testing to quickly identify an outbreak and enumerate cases, as well as the serological testing to flag potential cases missed with standard viral case identification methodologies.

Development, testing and validation of a SARS-CoV-2 multiplex panel for detection of the five major variants of concern on a portable PCR platform

Many SARS-CoV-2 variants have emerged during the course of the COVID-19 pandemic. These variants have acquired mutations conferring phenotypes such as increased transmissibility or virulence, or causing diagnostic, therapeutic, or immune escape. Detection of Alpha and the majority of Omicron sublineages by PCR relied on the so-called S gene target failure due to the deletion of six nucleotides coding for amino acids 69-70 in the spike (S) protein. Detection of hallmark mutations in other variants present in samples relied on whole genome sequencing. However, whole genome sequencing as a diagnostic tool is still in its infancy due to geographic inequities in sequencing capabilities, higher cost compared to other molecular assays, longer turnaround time from sample to result, and technical challenges associated with producing complete genome sequences from samples that have low viral load and/or high background. Hence, there is a need for rapid genotyping assays. In order to rapidly generate information on the presence of a variant in a given sample, we have created a panel of four triplex RT-qPCR assays targeting 12 mutations to detect and differentiate all five variants of concern: Alpha, Beta, Gamma, Delta, and Omicron. We also developed an expanded pentaplex assay that can reliably distinguish among the major sublineages (BA.1-BA.5) of Omicron. In silico, analytical and clinical testing of the variant panel indicate that the assays exhibit high sensitivity and specificity. This panel can help fulfill the need for rapid identification of variants in samples, leading to quick decision making with respect to public health measures, as well as treatment options for individuals. Compared to sequencing, these genotyping PCR assays allow much faster turn-around time from sample to results-just a couple hours instead of days or weeks.

Establishment of SARS-CoV-2 genomic surveillance within the Military Health System during 1 March-31 December 2020

This report describes SARS-CoV-2 genomic surveillance conducted by the Department of Defense (DoD) Global Emerging Infections Surveillance Branch and the Next-Generation Sequencing and Bioinformatics Consortium (NGSBC) in response to the COVID-19 pandemic. Samples and sequence data were from SARS-CoV-2 infections occurring among Military Health System (MHS) beneficiaries from 1 March to 31 December 2020. There were 1,366 MHS samples sequenced from 10 countries, 36 U.S states or territories, and 5 Geographic Combatant Commands, representing approximately 2% of DoD cases in 2020. Genomes from these samples were compared with other public sequences; observed trends were similar to those of Centers for Disease Control and Prevention national surveillance in the U.S. with B.1, B.1.2, and other sub-lineages comprising the dominant variants of SARS-CoV-2. Sequence data were used to monitor transmission dynamics on U.S. Navy ships and at military training centers and installations. As new variants emerge, DoD medical and public health practitioners should maximize the use of genomic surveillance resources within DoD to inform force health protection measures.

Cervical Myelopathy: Diagnosis, Contemporary Treatment, and Outcomes

Cervical myelopathy is a clinical syndrome caused by compression of the spinal cord between the levels of the C1 and T1 vertebrae. Its clinical presentation can mimic other degenerative and neurological pathologies, making diagnosis challenging. Diagnosis is confirmed with appropriate imaging studies carefully correlated with history and physical examination. Treatment options are focused on decompression of the spinal canal from an anterior, posterior, or combined anterior and posterior surgical approach depending on the location of compression and patient factors. Outcomes are favorable if treatment is performed prior to severe symptom onset.

Risk Factors for SARS-CoV-2 Infection Among US Healthcare Personnel, May-December 2020

To determine risk factors for coronavirus disease (COVID-19) among US healthcare personnel (HCP), we conducted a case-control analysis. We collected data about activities outside the workplace and COVID-19 patient care activities from HCP with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test results (cases) and from HCP with negative test results (controls) in healthcare facilities in 5 US states. We used conditional logistic regression to calculate adjusted matched odds ratios and 95% CIs for exposures. Among 345 cases and 622 controls, factors associated with risk were having close contact with persons with COVID-19 outside the workplace, having close contact with COVID-19 patients in the workplace, and assisting COVID-19 patients with activities of daily living. Protecting HCP from COVID-19 may require interventions that reduce their exposures outside the workplace and improve their ability to more safely assist COVID-19 patients with activities of daily living.

Six weeks of intensive rehearsals for the Swan Lake ballet shows ultrasound tissue characterization changes of the Achilles tendons in dancers

The objective was to investigate, first, whether six weeks of intensive ballet dance exposure is associated with structural and clinical changes in the Achilles tendon; second, the importance of demographics, self-reported Achilles pain, and generalized joint hypermobility (GJH). Data were collected at baseline and at six weeks' follow-up, using Achilles tendon ultrasound tissue characteristics (UTC) as primary outcome (percentage distribution of echo-type I-IV: type I = intact and aligned bundles, type II = discontinuous/wavy bundles, type III = fibrillar, and type IV = amorphous cells/fluid). Secondary outcomes included clinical signs of Achilles tendinopathy, Achilles tendon pain during single-leg heel raise, self-reported symptoms (VISA-A questionnaire), and GJH. Sixty-three ballet dancers (aged 18-41) participated. From baseline to follow-up, UTC echo-type I decreased significantly (β = -3.6, p = 0.001; 95% CI: -5.8;-1.4), whereas echo-type II increased significantly (β = 3.2, p < 0.0001, 95% CI: 1.6;4.8). Furthermore, a significant effect of limb (left limb showed decreased echo-type I and increased echo-type III + IV) and sex (women showed decreased echo-type I and increased in type II) was found. No significant changes in the remaining secondary outcomes were found. Ballet dancers showed structural changes in UTC, corresponding to a decreased echo-type I distribution after six weeks of rehearsing for Swan Lake ballet. No changes in self-reported symptoms, clinical signs of Achilles tendinopathy, and single-leg heel raise test were seen from pre- to post-rehearsal. Thus, UTC changes in the Achilles tendon seem to appear earlier than clinical signs of tendinopathy.

The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

Sudden Cardiac Death in the Adolescent Athlete: History, Diagnosis, and Prevention

Sudden cardiac death in young athletes is a devastating condition that occurs without warning. While most middle and high school athletes require preparticipation screening, many predisposing conditions go undiagnosed until they occur. The frequency of sudden cardiac death is often under-reported because there is no mandatory system for reporting sports-related death in high school sports. Additionally, there is debate about the cost-effectiveness of more advanced screening tests, such as electrocardiogram, due to high false-positive rates. It is, however, accepted that participants with a family history of sudden cardiac death should undergo more in-depth screening. If sudden cardiac arrest occurs, it is important for the patient to undergo immediate defibrillation. Community outreach to ensure that automated external defibrillators are present at athletic events, as well as cardiopulmonary resuscitation training for coaches, could potentially save lives. Ultimately, prevention of sudden cardiac death depends on physician awareness of how to properly screen and identify those at risk, and how to best be prepared if sudden cardiac arrest occurs.

2756. Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD (PAIVED), Influenza-Like-Illnesses (ILIs) Sub-Study at the Marine Corps Recruit Depot-San Diego, CA (MCRD-SD) During the 2018–2019 Influenza Season

Background

Military recruits suffer high rates of influenza and influenza-like illness (ILI) during training. ILIs may lead to morbidity, lost training time, and hospitalization. We evaluated the incidence and clinical outcomes of ILI among recruits at Marine Corps Recruit Depot San Diego (MCRD-SD) in a prospective trial of influenza vaccine efficacy.

Methods

Recruits at MCRD-SD were enrolled to compare the effectiveness of 3 types of FDA approved influenza vaccine: Afluria®, an egg-based vaccine; Flucelvax®, a cell-culture-derived vaccine; and Flublok®, a recombinant vaccine. Four companies of recruits were enrolled sequentially from 28 November 2018 to 19 December 2018, then randomized in a 1:1:1 ratio. Participants were followed for 18 weeks at MCRD-SD and Camp Pendleton. All participants who presented with ILI symptoms at medical care sites underwent viral diagnostic testing in addition to immunologic studies. Recruits were excluded from participation if <18 years of age, if previously vaccinated in the 2018–2019 season, or if reporting allergy to the vaccines.

Results

Of 1338 recruits approached, 771 (57.6%) participants consented for enrollment. All recruits were men between 18 and 28 years. There were 182 ILIs amongst 177 recruits (23% of 771 recruits). Nasal swabs were obtained in 180/182 cases (99%). Mean duration of ILI symptoms was 7 days. Mean days of fever was 4. Subjects reported a total 168 days of reduced training (range 0–14 days; mean 0.9 days). There were 47 total days of missed training for all subjects (range of 0–4 days; mean 0.3 days/subject). There were no hospitalizations related to ILIs. Approximately 82% (148/182) of ILIs presented within the first 3 weeks of training; 44% (80/182) of ILIs occurred during the second week of training. PCR- nasal swabs results; race/ethnicity data, and frequency of ILI mapped to week of training are illustrated below.

Conclusion

ILIs can negatively impact training effectiveness. Days lost to training from ILIs and hospitalizations can prevent successful completion of training with impact on military readiness. PAIVED may inform the DoD on future strategies to minimize influenza and other respiratory threats in recruit military populations. Influenza vaccine effectiveness will be reported separately.

Disclosures

All authors: No reported disclosures.

Naval Health Research Center Surveillance for Meningococcal Disease

Historically, meningococcal disease has had a devastating impact on U.S. military personnel, but since the introduction of a vaccine in the 1970s, rates have dropped over 90%.1 Department of Defense instructions mandate a meningococcal vaccine for all service personnel. In the last 5 years, rates of meningococcal disease in the military are similar to the U.S. general population. The active duty incidence was 0.21 cases per 100,000 person-years from 2013-2017. Six cases occurred in the 6 months between September 2016 and February 2017; of these, only one was determined to be a vaccine-covered strain. Ongoing surveillance shows vaccination has resulted in a dramatic reduction in meningococcal cases in the military; however, it also demonstrates cases continue to occur sporadically. The recent emergence of new cases reminds us that surveillance and accompanying research are important for evaluating changes in the disease and informing new vaccine development and policy.

The epididymal amyloid matrix: structure and putative functions

BACKGROUND

We previously demonstrated the normal mouse epididymal lumen contains a non-pathological amyloid matrix that surrounds spermatozoa and plays important roles in sperm maturation and protection.

OBJECTIVE

The objective herein was to present a review of this work, including studies showing the amyloid structures of four members of the CRES (cystatin-related epididymal spermatogenic) subgroup are integral and essential components of the amyloid matrix.

METHODS

We used conformation-dependent reagents that recognize the cross-β-sheet structure characteristic of amyloid, including thioflavin S (ThS), thioflavin T (ThT), anti-amyloid antibodies, and X-ray diffraction, as well as negative-stain transmission electron microscopy (TEM) to visualize amyloid structures in the epididymal lumen. Antibodies that specifically detect each CRES subgroup family member were also used in indirect immunofluorescence analysis.

RESULTS AND DISCUSSION

The epididymal lumen contains an amyloid matrix that surrounds maturing spermatozoa and represents a functional amyloid. Alterations in the structure of the amyloid matrix by the loss of the CRES subgroup members or the overexpression of cystatin C result in epididymal pathologies, including infertility. Preliminary data suggest the epididymal amyloid matrix is structurally and functionally similar to bacterial biofilms.

CONCLUSION

Together, these results suggest the amyloid matrix serves important roles in epididymal function including sperm maturation and protection.

Visualizing Individual RuBisCO and Its Assembly into Carboxysomes in Marine Cyanobacteria by Cryo-Electron Tomography

Cyanobacteria are photosynthetic organisms responsible for ~25% of the organic carbon fixation on earth. A key step in carbon fixation is catalyzed by ribulose bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme in the biosphere. Applying Zernike phase-contrast electron cryo-tomography and automated annotation, we identified individual RuBisCO molecules and their assembly intermediates leading to the formation of carboxysomes inside Syn5 cyanophage infected cyanobacteria Synechococcus sp. WH8109 cells. Surprisingly, more RuBisCO molecules were found to be present as cytosolic free-standing complexes or clusters than as packaged assemblies inside carboxysomes. Cytosolic RuBisCO clusters and partially assembled carboxysomes identified in the cell tomograms support a concurrent assembly model involving both the protein shell and the enclosed RuBisCO. In mature carboxysomes, RuBisCO is neither randomly nor strictly icosahedrally packed within protein shells of variable sizes. A time-averaged molecular dynamics simulation showed a semi-liquid probability distribution of the RuBisCO in carboxysomes and correlated well with carboxysome subtomogram averages. Our structural observations reveal the various stages of RuBisCO assemblies, which could be important for understanding cellular function.

Visualizing Individual RuBisCO and Its Assembly into Carboxysomes in Marine Cyanobacteria by Cryo-Electron Tomography

Cyanobacteria are photosynthetic organisms responsible for ~25% of the organic carbon fixation on earth. A key step in carbon fixation is catalyzed by ribulose bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme in the biosphere. Applying Zernike phase-contrast electron cryo-tomography and automated annotation, we identified individual RuBisCO molecules and their assembly intermediates leading to the formation of carboxysomes inside Syn5 cyanophage infected cyanobacteria Synechococcus sp. WH8109 cells. Surprisingly, more RuBisCO molecules were found to be present as cytosolic free-standing complexes or clusters than as packaged assemblies inside carboxysomes. Cytosolic RuBisCO clusters and partially assembled carboxysomes identified in the cell tomograms support a concurrent assembly model involving both the protein shell and the enclosed RuBisCO. In mature carboxysomes, RuBisCO is neither randomly nor strictly icosahedrally packed within protein shells of variable sizes. A time-averaged molecular dynamics simulation showed a semi-liquid probability distribution of the RuBisCO in carboxysomes and correlated well with carboxysome subtomogram averages. Our structural observations reveal the various stages of RuBisCO assemblies, which could be important for understanding cellular function.

Adenovirus 4/7 Vaccine's Effect on Disease Rates Is Associated With Disappearance of Adenovirus on Building Surfaces at a Military Recruit Base

BACKGROUND

Febrile respiratory illness resulting from adenovirus types 4 and 7 (Ad4/7) was endemic at military training camps, but controlled by an Ad4/7 vaccine from the 1970s to 1999, the year it was discontinued. Thereafter, rates returned to prevaccine levels. Rates dropped after reintroduction of an Ad4/7 vaccine in 2011.

METHODS

Surfaces of the barracks and medical clinic of a training camp were swabbed in 3 studies in 2004 and 1 study in 2007, and tested with culture and polymerase chain reaction (PCR). Similar swabbing was done in 2013 and 2015 and tested with PCR.

FINDINGS

In the studies before 2011 (prevaccine), 12% of samples were Ad4/7 positive by culture and 27% positive by PCR. In the 2 studies after 2011 (postvaccine), no samples were Ad4/7 positive.

DISCUSSION/IMPACT/RECOMMENDATIONS

The Ad 4/7 vaccine has resulted in the near elimination of Ad4/7-related disease and the disappearance of Ad4/7 from surfaces in a military basic training camp. Renewed transmission of Ad4/7 in this setting would likely require new importation from military recruits and an immunologically naive cohort, which the current vaccination program prevents.

Teaming With a Synthetic Teammate: Insights into Human-Autonomy Teaming

Objective Three different team configurations are compared with the goal of better understanding human-autonomy teaming (HAT). Background Although an extensive literature on human-automation interaction exists, much less is known about HAT in which humans and autonomous agents interact as coordinated units. Further research must be conducted to better understand how all-human teams compare to HAT. Methods In an unmanned aerial system (UAS) context, a comparison was made among three types of three-member teams: (1) synthetic teams in which the pilot role is assigned to a synthetic teammate, (2) control teams in which the pilot was an inexperienced human, and (3) experimenter teams in which an experimenter served as an experienced pilot. Ten of each type of team participated. Measures of team performance, target processing efficiency, team situation awareness, and team verbal behaviors were analyzed. Results Synthetic teams performed as well at the mission level as control (all human) teams but processed targets less efficiently. Experimenter teams performed better across all other measures compared to control and synthetic teams. Conclusion Though there is potential for a synthetic agent to function as a full-fledged teammate, further advances in autonomy are needed to improve team-level dynamics in HAT teams. Application This research contributes to our understanding of how to make autonomy a good team player.

Initial performance evaluation of a spotted array Mobile Analysis Platform (MAP) for the detection of influenza A/B, RSV, and MERS coronavirus

Clinical samples were evaluated with the Mobile Analysis Platform (MAP) to determine platform performance for detecting respiratory viruses in samples previously characterized using clinical reverse transcriptase polymerase chain reaction assays. The percent agreement between MAP and clinical results was 97% for influenza A (73/75), 100% (21/21) for influenza B, 100% (6/6) for respiratory syncytial virus (RSV), and 80% (4/5) for negative specimens. The approximate limit of detection of the MAP was 30 copies/assay for RSV and 1500 copies/assay for Middle East respiratory syndrome coronavirus.

Oseltamivir, amantadine, and ribavirin combination antiviral therapy versus oseltamivir monotherapy for the treatment of influenza: a multicentre, double-blind, randomised phase 2 trial

BACKGROUND

Influenza continues to have a substantial socioeconomic and health impact despite a long established vaccination programme and approved antivirals. Preclinical data suggest that combining antivirals might be more effective than administering oseltamivir alone in the treatment of influenza.

METHODS

We did a randomised, double-blind, multicentre phase 2 trial of a combination of oseltamivir, amantadine, and ribavirin versus oseltamivir monotherapy with matching placebo for the treatment of influenza in 50 sites, consisting of academic medical centre clinics, emergency rooms, and private physician offices in the USA, Thailand, Mexico, Argentina, and Australia. Participants who were aged at least 18 years with influenza and were at increased risk of complications were randomly assigned (1:1) by an online computer-generated randomisation system to receive either oseltamivir (75 mg), amantadine (100 mg), and ribavirin (600 mg) combination therapy or oseltamivir monotherapy twice daily for 5 days, given orally, and participants were followed up for 28 days. Blinded treatment kits were used to achieve masking of patients and staff. The primary endpoint was the percentage of participants with virus detectable by PCR in nasopharyngeal swab at day 3, and was assessed in participants who were randomised, had influenza infection confirmed by the central laboratory on a baseline nasopharyngeal sample, and had received at least one dose of study drug. Safety assessment was done in all patients in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01227967.

FINDINGS

Between March 1, 2011, and April 29, 2016, 633 participants were randomly assigned to receive combination antiviral therapy (n=316) or monotherapy (n=317). Seven participants were excluded from analysis: three were not properly randomised, three withdrew from the study, and one was lost to follow-up. The primary analysis included 394 participants, excluding 47 in the pilot phase, 172 without confirmed influenza, and 13 without an endpoint sample. 80 (40·0%) of 200 participants in the combination group had detectable virus at day 3 compared with 97 (50·0%) of 194 (mean difference 10·0, 95% CI 0·2-19·8, p=0·046) in the monotherapy group. The most common adverse events were gastrointestinal-related disorders, primarily nausea (65 [12%] of 556 reported adverse events in the combination group vs 63 [11%] of 585 reported adverse events in the monotherapy group), diarrhoea (56 [10%] of 556 vs 64 [11%] of 585), and vomiting (39 [7%] of 556 vs 23 [4%] of 585). There was no benefit in multiple clinical secondary endpoints, such as median duration of symptoms (4·5 days in the combination group vs 4·0 days in the monotherapy group; p=0·21). One death occurred in the study in an elderly participant in the monotherapy group who died of cardiovascular failure 13 days after randomisation, judged by the site investigator as not related to study intervention.

INTERPRETATION

Although combination treatment showed a significant decrease in viral shedding at day 3 relative to monotherapy, this difference was not associated with improved clinical benefit. More work is needed to understand why there was no clinical benefit when a difference in virological outcome was identified.

FUNDING

National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA.

Synthetic Teammate Communication and Coordination With Humans

A synthetic teammate based on ACT-R cognitive architecture has been developed to function as an Air Vehicle Operator in the context of a three-agent Unmanned Aerial Vehicle (UAV) ground control team taking part in studies in a Synthetic Task Environment (STE). In order for the synthetic teammate to function as team player with human teammates, it needs to skillfully handle the subtleties of team communication and coordination. Data from early synthetic teammate interactions with two human teammates are presented here to illustrate team communication and coordination challenges for the synthetic teammate. In turn, the synthetic teammate limitations have highlighted the intricacies involved in effective teamwork. Communication, though a terrifically challenging problem in itself, is only a foundation for coordinated teamwork or interacting as a team player.

Helpful or Harmful? Examining the Effects of Interruptions on Task Performance

Most research on interruptions has shown that they can be disruptive by causing a longer time to complete the primary task and by causing more errors on the primary task. However, a limited amount of research has shown that interruptions can actually be beneficial to simple primary tasks, a benefit that has been explained by arousal. We sought to replicate the finding that simple tasks can benefit from interruptions and to examine the specific processes that are actually improving as a result of the interruptions. More specifically, reaction time data and eye movement data were collected to account for motor actions and perceptual processes. Results indicate that participants' immediate action following the interruption was disrupted. However, participants' other actions during the interruption trials were actually performed faster and with fewer errors as compared to the control. This speed-up is not attributed to faster motor responses, but actually to faster perceptual processing.

The Synthetic Teammate as a Team Player in Command-and-Control Teams

Project overview. The current project is part of a larger effort that focuses on Human-Automation Teaming (HAT) interaction in the context of the development, integration, and validation of a computational cognitive model that acts as a full-fledged synthetic teammate for a three-agent Unmanned Aircraft System (UAS) ground control crew. Our most recent effort looked at team process and team performance within the HAT. In order to be considered a team player, the synthetic teammate must be able to communicate and coordinate with its human teammates and do so in a subtle manner (Demir et al., 2016). In this task, there were three different and interdependent team members: 1) Air Vehicle Operator (AVO) – controls the UAS’s heading, altitude, and airspeed; 2) Data Exploitation, Mission Planning, and Communications (DEMPC) – provides a dynamic flight plan as well as speed and altitude restrictions; and 3) Payload Operator (PLO) – monitors sensor equipment, negotiates with the AVO, and takes photographs of target waypoints. The communication within a three-agent UAS team occurred over a text-based communications system. In this research, there were three conditions which are differentiated by the AVO role: 1) the Synthetic - the synthetic teammate was assigned the AVO role; 2) the Control - the AVO was an inexperienced human participant; 3) the Experimenter - the AVO was one of the experimenters who was experienced with the task. The experimenter AVO asked questions of other team members to ensure timely and adaptive passing of information at target waypoints. In this current study, the coordination among the team members occurs at each target waypoint and requires a specific sequence of information passing for an optimum team performance (Cooke, Gorman, Duran, & Taylor, 2007): the information is provided by the DEMPC about the upcoming target waypoint to the AVO. After that, the PLO and the AVO negotiate regarding an appropriate altitude and airspeed for the target waypoints about required camera settings. Finally, the PLO sends feedback to other team members about the status of the target photo.

Method. Activities during this period included conducting an experiment to: 1) evaluate the synthetic teammate’s performance, and the HAT team performance in comparison to all human teams, 2) understand how team process differs between all human and human-synthetic teams and how this impacts performance, and 3) compare the human-synthetic teams and all human control teams to a team with a pilot that is experienced in pushing and pulling information across the team. For this experiment, participants were randomly assigned for the duration of the experiment. Within each of the five missions, teams were told to obtain as many “good” photos as possible while avoiding alarms and rule violations in less than 40 minutes. The overall focus of this paper is: team process that is comprised of eight verbal behaviors associated with team effectiveness; team performance that is a combination of mission variables, including the rate of successful target photographs, time spent in alarm and warning states (for each individual), and the critical waypoint acquisition rate; and target processing efficiency took into account the time spent inside a target waypoint to get a good photo.

Results and discussion. In general, findings indicate that synthetic AVOs perform more poorly than control AVOs in terms of team performance. Synthetic teams perform as well at the mission level as control teams. However, in terms of target processing efficiency, synthetic teams perform poorer than control teams. In terms of team process, synthetic teams demonstrate interaction patterns corresponding to more pulling of information than pushing with little change over time. In summary, these results indicate that there is a strong potential for using synthetic team member as a teammate in real world tasks and for training.

Identification of Photosynthesis-Associated C4 Candidate Genes through Comparative Leaf Gradient Transcriptome in Multiple Lineages of C3 and C4 Species

Leaves of C4 crops usually have higher radiation, water and nitrogen use efficiencies compared to the C3 species. Engineering C4 traits into C3 crops has been proposed as one of the most promising ways to repeal the biomass yield ceiling. To better understand the function of C4 photosynthesis, and to identify candidate genes that are associated with the C4 pathways, a comparative transcription network analysis was conducted on leaf developmental gradients of three C4 species including maize, green foxtail and sorghum and one C3 species, rice. By combining the methods of gene co-expression and differentially co-expression networks, we identified a total of 128 C4 specific genes. Besides the classic C4 shuttle genes, a new set of genes associated with light reaction, starch and sucrose metabolism, metabolites transportation, as well as transcription regulation, were identified as involved in C4 photosynthesis. These findings will provide important insights into the differential gene regulation between C3 and C4 species, and a good genetic resource for establishing C4 pathways in C3 crops.

Functional connectivity of human chewing: an fcMRI study

Mastication is one of the most important orofacial functions. The neurobiological mechanisms of masticatory control have been investigated in animal models, but less so in humans. This project used functional connectivity magnetic resonance imaging (fcMRI) to assess the positive temporal correlations among activated brain areas during a gum-chewing task. Twenty-nine healthy young-adults underwent an fcMRI scanning protocol while they chewed gum. Seed-based fcMRI analyses were performed with the motor cortex and cerebellum as regions of interest. Both left and right motor cortices were reciprocally functionally connected and functionally connected with the post-central gyrus, cerebellum, cingulate cortex, and precuneus. The cerebellar seeds showed functional connections with the contralateral cerebellar hemispheres, bilateral sensorimotor cortices, left superior temporal gyrus, and left cingulate cortex. These results are the first to identify functional central networks engaged during mastication.