SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant

Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes

Background The first epidemic wave of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over one-third of care homes reported an outbreak, while there was limited testing of hospital patients discharged to care homes. Aim To investigate patients discharged from hospitals as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave. Methods A clinical review was performed for all patients discharges from hospitals to care homes from 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease 2019 (COVID-19) test history, clinical assessment at discharge, whole-genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis using Cluster Investigation and Virus Epidemiological Tool software. Patient timelines were obtained using electronic hospital records. Findings In total, 787 patients discharged from hospitals to care homes were identified. Of these, 776 (99%) were ruled out for subsequent introduction of SARS-CoV-2 into care homes. However, for 10 episodes, the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data were available. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission, leading to 10 positive cases in their care home. Conclusion The majority of patients discharged from hospitals were ruled out for introduction of SARS-CoV-2 into care homes, highlighting the importance of screening all new admissions when faced with a novel emerging virus and no available vaccine

Value of Mandatory Screening Studies in Emergency Department Patients Cleared for Psychiatric Admission

Introduction: Laboratory and radiographic studies are often required by psychiatric services priorto admitting emergency patients who are otherwise deemed medically stable. Such testing mayrepresent an unnecessary expense that prolongs emergency department stays without significantlyimproving care. This study determines the prevalence of such testing and how often it leads tochanges in care.Methods: We prospectively tracked laboratory testing among psychiatric patients presenting tothe emergency departments of two academic tertiary care facilities. For each visit we determinedwhether laboratory or radiographic studies were ordered, and whether the examination wasconducted at the request of the emergency physician as part of a medical screening examinationor requested by the psychiatry service. We then determined if this testing changed patientdisposition.Results: Our study enrolled 598 patients. Of these, emergency physicians ordered testing as a partof medical screening on 155 patients (25.9%). We found the psychiatry service ordered laboratoryor radiographic studies for 191 of 434 patients (44.0%) who emergency physicians determineddid not require ancillary testing for medical clearance. Of these 191 patients, only one (0.5%; 95%Confidence Interval: 0.01% - 2.9%) had an abnormal result that led to a change in disposition. TotalMedicare reimbursement rates for the additional ancillary testing in this study was $37,682.Conclusion: Ancillary testing beyond what is required for medical clearance of psychiatricemergency patients rarely alters care. Policies that require panels of testing prior to psychiatricadmission are costly and appear to be unnecessary

Value of Mandatory Screening Studies in Emergency Department Patients Cleared for Physchiatric Admission

Introduction: Laboratory and radiographic studies are often required by psychiatric services prior to admitting emergency patients who are otherwise deemed medically stable. Such testing may represent an unnecessary expense that prolongs emergency department stays without significantly improving care. This study determines the prevalence of such testing and how often it leads to changes in care.Methods: We prospectively tracked laboratory testing among psychiatric patients presenting to the emergency departments of two academic tertiary care facilities. For each visit we determined whether laboratory or radiographic studies were ordered, and whether the examination was conducted at the request of the emergency physician as part of a medical screening examination or requested by the psychiatry service. We then determined if this testing changed patient disposition.Results: Our study enrolled 598 patients. Of these, emergency physicians ordered testing as a part of medical screening on 155 patients (25.9%). We found the psychiatry service ordered laboratory or radiographic studies for 191 of 434 patients (44.0%) who emergency physicians determined did not require ancillary testing for medical clearance. Of these 191 patients, only one (0.5%; 95% Confidence Interval: 0.01% - 2.9%) had an abnormal result that led to a change in disposition. Total Medicare reimbursement rates for the additional ancillary testing in this study was $37,682.Conclusion: Ancillary testing beyond what is required for medical clearance of psychiatric emergency patients rarely alters care. Policies that require panels of testing prior to psychiatric admission are costly and appear to be unnecessary. [West J Emerg Med 2012;13(5):388-393.

Value of Mandatory Screening Studies in Emergency Department Patients Cleared for Physchiatric Admission

Introduction: Laboratory and radiographic studies are often required by psychiatric services prior to admitting emergency patients who are otherwise deemed medically stable. Such testing may represent an unnecessary expense that prolongs emergency department stays without significantly improving care. This study determines the prevalence of such testing and how often it leads to changes in care.Methods: We prospectively tracked laboratory testing among psychiatric patients presenting to the emergency departments of two academic tertiary care facilities. For each visit we determined whether laboratory or radiographic studies were ordered, and whether the examination was conducted at the request of the emergency physician as part of a medical screening examination or requested by the psychiatry service. We then determined if this testing changed patient disposition.Results: Our study enrolled 598 patients. Of these, emergency physicians ordered testing as a part of medical screening on 155 patients (25.9%). We found the psychiatry service ordered laboratory or radiographic studies for 191 of 434 patients (44.0%) who emergency physicians determined did not require ancillary testing for medical clearance. Of these 191 patients, only one (0.5%; 95% Confidence Interval: 0.01% - 2.9%) had an abnormal result that led to a change in disposition. Total Medicare reimbursement rates for the additional ancillary testing in this study was $37,682.Conclusion: Ancillary testing beyond what is required for medical clearance of psychiatric emergency patients rarely alters care. Policies that require panels of testing prior to psychiatric admission are costly and appear to be unnecessary. [West J Emerg Med 2012;13(5):388-393.

Prevalence and Clinical Import of Thoracic Injury Identified by Chest Computed Tomography but Not Chest Radiography in Blunt Trauma: Multicenter Prospective Cohort Study.

Study objectiveChest computed tomography (CT) diagnoses more injuries than chest radiography, so-called occult injuries. Wide availability of chest CT has driven substantial increase in emergency department use, although the incidence and clinical significance of chest CT findings have not been fully described. We determine the frequency, severity, and clinical import of occult injury, as determined by changes in management. These data will better inform clinical decisions, need for chest CT, and odds of intervention.MethodsOur sample included prospective data (2009 to 2013) on 5,912 patients at 10 Level I trauma center EDs with both chest radiography and chest CT at physician discretion. These patients were 40.6% of 14,553 enrolled in the parent study who had either chest radiography or chest CT. Occult injuries were pneumothorax, hemothorax, sternal or greater than 2 rib fractures, pulmonary contusion, thoracic spine or scapula fracture, and diaphragm or great vessel injury found on chest CT but not on preceding chest radiography. A priori, we categorized thoracic injuries as major (having invasive procedures), minor (observation or inpatient pain control >24 hours), or of no clinical significance. Primary outcome was prevalence and proportion of occult injury with major interventions of chest tube, mechanical ventilation, or surgery. Secondary outcome was minor interventions of admission rate or observation hours because of occult injury.ResultsTwo thousand forty-eight patients (34.6%) had chest injury on chest radiography or chest CT, whereas 1,454 of these patients (71.0%, 24.6% of all patients) had occult injury. Of these, in 954 patients (46.6% of injured, 16.1% of total), chest CT found injuries not observed on immediately preceding chest radiography. In 500 more patients (24.4% of injured patients, 8.5% of all patients), chest radiography found some injury, but chest CT found occult injury. Chest radiography found all injuries in only 29.0% of injured patients. Two hundred and two patients with occult injury (of 1,454, 13.9%) had major interventions, 343 of 1,454 (23.6%) had minor interventions, and 909 (62.5%) had no intervention. Patients with occult injury included 514 with pulmonary contusions (of 682 total, 75.4% occult), 405 with pneumothorax (of 597 total, 67.8% occult), 184 with hemothorax (of 230 total, 80.0% occult), those with greater than 2 rib fractures (n=672/1,120, 60.0% occult) or sternal fracture (n=269/281, 95.7% occult), 12 with great vessel injury (of 18 total, 66.7% occult), 5 with diaphragm injury (of 6, 83.3% occult), and 537 with multiple occult injuries. Interventions for patients with occult injury included mechanical ventilation for 31 of 514 patients with pulmonary contusion (6.0%), chest tube for 118 of 405 patients with pneumothorax (29.1%), and 75 of 184 patients with hemothorax (40.8%). Inpatient pain control or observation greater than 24 hours was conducted for 183 of 672 patients with rib fractures (27.2%) and 79 of 269 with sternal fractures (29.4%). Three of 12 (25%) patients with occult great vessel injuries had surgery. Repeated imaging was conducted for 50.6% of patients with occult injury (88.1% chest radiography, 11.9% chest CT, 7.5% both). For patients with occult injury, 90.9% (1,321/1,454) were admitted, with 9.1% observed in the ED for median 6.9 hours. Forty-four percent of observed patients were then admitted (4.0% of patients with occult injury).ConclusionIn a more seriously injured subset of patients with blunt trauma who had both chest radiography and chest CT, occult injuries were found by chest CT in 71% of those with thoracic injuries and one fourth of all those with blunt chest trauma. More than one third of occult injury had intervention (37.5%). Chest tubes composed 76.2% of occult injury major interventions, with observation or inpatient pain control greater than 24 hours in 32.4% of occult fractures. Only 1 in 20 patients with occult injury was discharged home from the ED. For these patients with blunt trauma, chest CT is useful to identify otherwise occult injuries