CT screening for COVID-19 in asymptomatic patients before hospital admission

IntroductionIn the novel coronavirus disease (COVID-19) pandemic era, it is essential to rule out COVID-19 effectively to prevent transmission in both communities and medical facilities. According to previous reports in high prevalence areas, CT screening may be useful in the diagnosis of COVID-19. However, the value of CT screening in low prevalence areas has scarcely been reported.MethodsThis report examines the diagnostic efficacy of CT screening before admission to a hospital in Tokyo. We conducted a retrospective analysis at Keio University Hospital from April 6, 2020, through May 29, 2020. We set up an outpatient screening clinic on April 6 for COVID-19, administering both PCR with nasopharyngeal swabs and chest CT for all patients scheduled for surgery under general anesthesia.ResultsA total of 292 asymptomatic patients were included in this study. There were three PCR-positive patients, and they all had negative CT findings, which revealed that both the sensitivity and positive predictive value of CT (PPV) were 0%. There were nine CT-positive patients; the specificity and the negative predictive value (NPV) were 96.9% and 98.9%, respectively.ConclusionCT screening was not useful in low prevalence areas at this time in Tokyo, even with the inclusion of the most prevalent phase. Given that the utility of CT screening depends on disease prevalence, the criteria for performing CT screening based on the prevalence of COVID-19 should be established.     

COVID-19 in Health Care Personnel: Significance of Health Care Role,Contact History,and Symptoms in Those Who Test Positive for SARS-CoV-2 Infection

ObjectiveTo identify significant factors that help predict whether health care personnel (HCP) will test positive for severe acute respiratory coronavirus 2 (SARS-CoV-2).Patients and MethodsWe conducted a prospective cohort study among 7015 symptomatic HCP from March 25, 2020, through November 11, 2020. We analyzed the associations between health care role, contact history, symptoms, and a positive nasopharyngeal swab SARS-CoV-2 polymerase chain reaction test results, using univariate and multivariable modelling.ResultsOf the symptomatic HCP, 624 (8.9%) were positive over the study period. On multivariable analysis, having a health care role other than physician or advanced practice provider, contact with family or community member with known or suspected coronavirus disease 2019 (COVID-19), and seven individual symptoms (cough, anosmia, ageusia, fever, myalgia, chills, and headache) were significantly associated with higher adjusted odds ratios for testing positive for SARS-CoV-2. For each increase in symptom number, the odds of testing positive nearly doubled (odds ratio, 1.93; 95% CI, 1.82 to 2.07, P<.001).ConclusionSymptomatic HCP have higher adjusted odds of testing positive for SARS-CoV-2 based on three distinct factors: (1) nonphysician/advanced practice provider role, (2) contact with a family or community member with suspected or known COVID-19, and (3) specific symptoms and symptom number. Differences among health care roles, which persisted after controlling for contacts, may reflect the influence of social determinants. Contacts with COVID-19–positive patients and/or HCP were not associated with higher odds of testing positive, supporting current infection control efforts. Targeted symptom and contact questionnaires may streamline symptomatic HCP testing for COVID-19.     

Immunochromatography and chemiluminescent enzyme immunoassay for COVID-19 diagnosis

IntroductionThe rapid and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required to prevent the spread of COVID-19. This study evaluated the utility of two SARS-CoV-2 antigen detection methods.MethodsWe evaluated two types of antigen detection methods using immunochromatography (Espline) and quantitative chemiluminescent enzyme immunoassay (Lumipulse). RT-PCR was performed as a standard procedure for COVID-19 diagnosis. Lumipulse and RT-PCR were performed for all 486 nasopharyngeal swabs and 136 saliva samples, and the Espline test was performed for 271 nasopharyngeal swabs and 93 saliva samples.ResultsThe sensitivity and specificity of the Espline test were 10/11 and 260/260 (100%), respectively for the nasopharyngeal swabs and 3/9 and 84/84 (100%), respectively for the saliva samples. High sensitivities for both saliva (8/9) and nasopharyngeal swabs (22/24) were observed in the Lumipulse test. The specificities of the Lumipulse test for nasopharyngeal swabs and saliva samples were 460/462 (99.6%) and 123/127 (96.9%), respectively.ConclusionThe Espline test is not effective for saliva samples but is useful for simple and rapid COVID-19 tests using nasopharyngeal swabs because it does not require special devices. The Lumipulse test is a powerful high-throughput tool for COVID-19 diagnosis because it has high detection performance for nasopharyngeal swabs and saliva samples.     

Rapid Exclusion of COVID Infection With the Artificial Intelligence Electrocardiogram

ObjectiveTo rapidly exclude severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using artificial intelligence applied to the electrocardiogram (ECG).MethodsA global, volunteer consortium from 4 continents identified patients with ECGs obtained around the time of polymerase chain reaction–confirmed COVID-19 diagnosis and age- and sex-matched controls from the same sites. Clinical characteristics, polymerase chain reaction results, and raw electrocardiographic data were collected. A convolutional neural network was trained using 26,153 ECGs (33.2% COVID positive), validated with 3826 ECGs (33.3% positive), and tested on 7870 ECGs not included in other sets (32.7% positive). Performance under different prevalence values was tested by adding control ECGs from a single high-volume site.ResultsThe area under the curve for detection of acute COVID-19 infection in the test group was 0.767 (95% CI, 0.756 to 0.778; sensitivity, 98%; specificity, 10%; positive predictive value, 37%; negative predictive value, 91%). To more accurately reflect a real-world population, 50,905 normal controls were added to adjust the COVID prevalence to approximately 5% (2657/58,555), resulting in an area under the curve of 0.780 (95% CI, 0.771 to 0.790) with a specificity of 12.1% and a negative predictive value of 99.2%.ConclusionInfection with SARS-CoV-2 results in electrocardiographic changes that permit the artificial intelligence–enhanced ECG to be used as a rapid screening test with a high negative predictive value (99.2%). This may permit the development of electrocardiography-based tools to rapidly screen individuals for pandemic control.     

Epidemiological study using IgM and IgG antibody titers against SARS-CoV-2 in The University of Tokyo,Japan (UT-CATS)

IntroductionThe worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to date. Given that some of the patients with coronavirus disease 2019 (COVID-19) are asymptomatic, antibody tests are useful to determine whether there is a previous infection with SARS-CoV-2. In this study, we measured IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects in The University of Tokyo, Japan.MethodsFrom June 2020, we recruited participants, who were students, staff, and faculty members of The University of Tokyo in the project named The University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS). Following blood sample collection, participants were required to answer an online questionnaire about their social and health information. We measured IgG and IgM titers against SARS-CoV-2 using iFlash-SARS-CoV-2 IgM and IgG detection kit which applies a chemiluminescent immunoassay (CLIA) for the qualitative detection.ResultsThere were 6609 volunteers in this study. After setting the cutoff value at 10 AU/mL, 32 (0.48%) were positive for IgG and 16 (0.24%) for IgM. Of six participants with a history of COVID-19, five were positive for IgG, whereas all were negative for IgM. The median titer of IgG was 0.40 AU/mL and 0.39 AU/mL for IgM. Both IgG and IgM titers were affected by gender, age, smoking status, and comorbidities.ConclusionsPositive rates of IgG and IgM titers were relatively low in our university. Serum levels of these antibodies were affected by several factors, which might affect the clinical course of COVID-19.     

Pernio (Chilblains), SARS-CoV-2, and COVID Toes Unified Through Cutaneous and Systemic Mechanisms

Pernio or chilblains is characterized by erythema and swelling at acral sites (eg, toes and fingers), typically triggered by cold exposure. Clinical and histopathologic features of pernio are well described, but the pathogenesis is not entirely understood; vasospasm and a type I interferon (IFN-I) immune response are likely involved. During the coronavirus disease 2019 (COVID-19) pandemic, dermatologists have observed an increase in pernio-like acral eruptions. Direct causality of pernio due to COVID-19 has not been established in many cases because of inconsistent testing methods (often negative results) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, a form of COVID-19?associated pernio (also called COVID toes) is probable because of increased occurrence, frequently in young patients with no cold exposure or a history of pernio, and reports of skin biopsies with positive SARS-CoV-2 immunohistochemistry. PubMed was searched between January 1, 2020, and December 31, 2020 for publications using the following keywords: pernio, chilblain, and acral COVID-19. On the basis of our review of the published literature, we speculate that several unifying cutaneous and systemic mechanisms may explain COVID-19?associated pernio: (1) SARS-CoV-2 cell infection occurs through the cellular receptor angiotensin-converting enzyme 2 mediated by transmembrane protease serine 2, subsequently affecting the renin-angiotensin-aldosterone system with an increase in the vasoconstricting, pro-inflammatory, and prothrombotic angiotensin II pathway. (2) Severe acute respiratory syndrome coronavirus 2 cell infection triggers an immune response with robust IFN-I release in patients predisposed to COVID-19?associated pernio. (3) Age and sex discrepancies correlated with COVID-19 severity and manifestations, including pernio as a sign of mild disease, are likely explained by age-related immune and vascular differences influenced by sex hormones and genetics, which affect susceptibility to viral cellular infection, the renin-angiotensin-aldosterone system balance, and the IFN-I response.     

Prevalence of SARS-CoV-2 Antibodies in a Multistate Academic Medical Center

ObjectiveTo estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in health care personnel.MethodsThe Mayo Clinic Serology Screening Program was created to provide a voluntary, two-stage testing program for SARS-CoV-2 antibodies to health care personnel. The first stage used a dried blood spot screening test initiated on June 15, 2020. Those participants identified as reactive were advised to have confirmatory testing via a venipuncture. Venipuncture results through August 8, 2020, were considered. Consent and authorization for testing was required to participate in the screening program. This report, which was conducted under an institutional review board–approved protocol, only includes employees who have further authorized their records for use in research.ResultsA total of 81,113 health care personnel were eligible for the program, and of these 29,606 participated in the screening program. A total of 4284 (14.5%) of the dried blood spot test results were “reactive” and warranted confirmatory testing. Confirmatory testing was completed on 4094 (95.6%) of the screen reactive with an overall seroprevalence rate of 0.60% (95% CI, 0.52% to 0.69%). Significant variation in seroprevalence was observed by region of the country and age group.ConclusionThe seroprevalence for SARS-CoV-2 antibodies through August 8, 2020, was found to be lower than previously reported in other health care organizations. There was an observation that seroprevalence may be associated with community disease burden.     

No SARS-CoV-2 RNA detected in the convalescent plasma of COVID-19 patients with different disease severity

IntroductionConvalescent plasma transfusion (CPT), a potential therapy for coronavirus disease 2019 (COVID-19), requires strict quality control of the donor blood. Whether to confirm the disappearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA (RNAemia) in convalescent donor blood or not is unclear. Reports recommending the proof of viral disappearance from the blood are controversial. Foreseeing CPT in treating COVID-19 patients in Japan, we investigated RNAemia in 100 convalescent donors with mild, moderate, and severe COVID-19.MethodsBetween April 30 and July 30, 2020, we measured RNAemia in the plasma samples of donors with resolved COVID-19. Data on patients’ demographics, comorbidities, pneumonia, treatment, and real-time polymerase chain reaction results for SARS-CoV-2 were collected. Date of onset of initial symptoms or date of positive testing (for asymptomatic patients) were self-reported by the patients. Disease severity was defined as: no, mild, moderate oxygen demand, or severe (requiring mechanical ventilation).ResultsOf 100 donors (58 males [58.0%]; median age, 47 [range 22–69] years) screened as of July 30, 2020, 77 (77.0%); 19 (19.0%); and 4 (4.0%) had mild, moderate, and severe disease, respectively. Median time between onset and testing was 68.5 (range, 21–167) days. SARS-CoV-2 RNA was not detected in any of the plasma samples.ConclusionRNAemia was not found in recovered COVID-19 patients at least 21, 27, and 57 days after the onset of mild, moderate, and severe symptoms. Our study may contribute to determining a suitable time for collecting convalescent plasma from COVID-19 patients and to future CPT use.     

Nerve Compression Injuries After Prolonged Prone Position Ventilation in Patients With SARS-CoV-2: A Case Series

BackgroundProne positioning improves oxygenation in adult respiratory distress syndrome. This procedure has been widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. However, this procedure can also be responsible for nerve damage and plexopathy.MethodsWe retrospectively reviewed a series of 7 infectious patients with coronavirus disease 2019 who underwent prone positioning ventilation at the San Raffaele Hospital of Milan, Italy, during the SARS-CoV-2 pandemic.ResultsClinical and neurophysiological data of 7 patients with nerve compression injuries have been reported.ConclusionsHealth care workers should take into consideration the risk factors for prone positioning–related plexopathy and nerve damage, especially in patients with coronavirus disease 2019, to prevent this type of complication.     

Three SARS-CoV-2 PCR-negative cases of COVID-19 diagnosed using isothermal amplification methods

Coronavirus disease (COVID-19) is a viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 can be detected by polymerase chain reaction (PCR) and isothermal nucleic acid amplification tests, including loop-mediated isothermal amplification (LAMP) and nicking endonuclease amplification reaction (NEAR) tests. Although PCR is the most sensitive and specific method and is generally considered to be the gold standard, it is time-consuming and costly. Isothermal nucleic acid amplification tests have lower sensitivity and specificity than PCR, but are less time-consuming and costly. We encountered three cases of SARS-CoV-2 infection in which the isothermal amplification test was positive but the PCR test was negative on the day of admission; however, the PCR test was positive the next day. These cases showed that some COVID-19 patients can test negative by PCR but positive using isothermal nucleic acid amplification methods. As PCR tests have the possibility of false-negative results, tests that use isothermal amplification methods which can be performed in a shorter time and at a lower cost than PCR tests, may be able to diagnose patients who have false negative PCR results.     

Place and Underlying Cause of Death During the COVID-19 Pandemic: Retrospective Cohort Study of 3.5 Million Deaths in England and Wales, 2014 to 2020

ObjectiveTo describe the place and cause of death during the coronavirus disease 2019 (COVID-19) pandemic to assess its impact on excess mortality.MethodsThis national death registry included all adult (aged ≥18 years) deaths in England and Wales between January 1, 2014, and June 30, 2020. Daily deaths during the COVID-19 pandemic were compared against the expected daily deaths, estimated with use of the Farrington surveillance algorithm for daily historical data between 2014 and 2020 by place and cause of death.ResultsBetween March 2 and June 30, 2020, there was an excess mortality of 57,860 (a proportional increase of 35%) compared with the expected deaths, of which 50,603 (87%) were COVID-19 related. At home, only 14% (2267) of the 16,190 excess deaths were related to COVID-19, with 5963 deaths due to cancer and 2485 deaths due to cardiac disease, few of which involved COVID-19. In care homes or hospices, 61% (15,623) of the 25,611 excess deaths were related to COVID-19, 5539 of which were due to respiratory disease, and most of these (4315 deaths) involved COVID-19. In the hospital, there were 16,174 fewer deaths than expected that did not involve COVID-19, with 4088 fewer deaths due to cancer and 1398 fewer deaths due to cardiac disease than expected.ConclusionThe COVID-19 pandemic has resulted in a large excess of deaths in care homes that were poorly characterized and likely to be the result of undiagnosed COVID-19. There was a smaller but important and ongoing excess in deaths at home, particularly from cancer and cardiac disease, suggesting public avoidance of hospital care for non–COVID-19 conditions.     

Curbing the Delta Surge: Clinical Outcomes After Treatment With Bamlanivimab-Etesevimab,Casirivimab-Imdevimab,or Sotrovimab for Mild to Moderate Coronavirus Disease 2019

ObjectiveTo describe and compare the clinical outcomes of bamlanivimab-etesevimab, casirivimab-imdevimab, and sotrovimab treatment of mild to moderate coronavirus disease 2019 (COVID-19) during the severe acute respiratory coronavirus 2 (SARS-CoV-2) B.1.617.2 Delta surge.MethodsThis is a retrospective study of high-risk patients who received bamlanivimab-etesevimab, casirivimab-imdevimab, and sotrovimab for mild to moderate COVID-19 between August 1, 2021, and December 1, 2021. Rates of severe disease, hospitalization, intensive care unit admission, and death were assessed.ResultsAmong 10,775 high-risk patients who received bamlanivimab-etesevimab, casirivimab-imdevimab, or sotrovimab for mild to moderate COVID-19 during the Delta surge, 287 patients (2.7%) developed severe disease that led to hospitalization, oxygen supplementation, or death within 30 days after treatment. The rates of severe disease were low among patients treated with bamlanivimab-etesevimab (1.2%), casirivimab-imdevimab (2.9%), and sotrovimab (1.6%; P<.01). The higher rate of severe outcomes among patients treated with casirivimab-imdevimab may be related to a significantly lower COVID-19 vaccination rate in that cohort. Intensive care unit admission was comparable among patients treated bamlanivimab-etesevimab, casirivimab-imdevimab, or sotrovimab (1.0%, 1.0%, and 0.4%, respectively).ConclusionThis real-world study of a large cohort of high-risk patients shows low rates of severe disease, hospitalization, intensive care unit admission, and mortality after treatment with bamlanivimab-etesevimab, casirivimab-imdevimab, and sotrovimab for mild to moderate COVID-19 during the SARS-CoV-2 Delta surge.     

A comparison on the percentage of polymerase chain reaction positivity for SARS-CoV-2 between Public Health Center referrals and direct walk-in patients: A single center retrospective analysis in Tokyo

IntroductionThe Public Health Center (PHC)—known as hokenjo in Japan—assume a crucial role in disease control. Coronavirus disease 2019 (COVID-19) is one of many designated infectious diseases monitored by the agency. During the present pandemic, patients who suspected COVID-19 were instructed to call the Coronavirus Consultation Center in the PHC prior to visiting the hospital. The aim of this study was to elucidate the differences in polymerase chain reaction (PCR) positivity between PHC referrals and direct walk-in patients.MethodsThe present was a single-center, retrospective cohort study conducted at the Tokyo Metropolitan Hospital from March to September, 2020. Patients who received a PCR test for SARS-CoV-2 were included and categorized into the PHC referral or direct walk-in groups. The outcomes included the total number of patients undergoing PCR tests and the percentage of PCR positivity in each group.ResultsWe identified 1680 patients (781 PHC referred and 899 direct walk-in groups). The percentage of PCR positivity did not significantly differ between the PHC referral and direct walk-in groups during the first wave (30.5% vs. 29.2%; p = 0.78). PCR positivity was significantly higher in the PHC referral group than the direct walk-in group during the second wave (30.1% vs. 23.1%; p = 0.051) and entire study period (30.2% vs. 24.7%; p = 0.011).ConclusionsDespite health authority recommendations, the number of direct walk-in patients were higher than PHC referral patients. The percentage of PCR positivity was significantly higher in the PHC referral group than in the direct walk-in group.     

Accuracy of rapid antigen detection test for nasopharyngeal swab specimens and saliva samples in comparison with RT-PCR and viral culture for SARS-CoV-2 detection

IntroductionRapid antigen detection (RAD) tests are convenient tools for detecting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in clinics, and testing using saliva samples could decrease the risk of infection during sample collection. This study aimed to assess the accuracy of the SARS-CoV-2 RAD for testing of nasopharyngeal swab specimens and saliva samples in comparison with the RT-PCR tests and viral culture for detecting viable virus.MethodsOne hundred seventeen nasopharyngeal swab specimens and 73 saliva samples with positive results on RT-PCR were used. Residual samples were assayed using a commercially available RAD test immediately, and its positivity was determined at various time points during the clinical course. The concordance between 54 nasopharyngeal swab samples and saliva samples that were collected simultaneously was determined. Viral culture was performed on 117 samples and compared with the results of the RAD test.ResultsThe positive rate of RAD test using saliva samples was low throughout the clinical course. Poor concordance was observed between nasopharyngeal swab specimens and saliva samples (75.9%, kappa coefficient 0.310). However, a substantially high concordance between the RAD test and viral culture was observed in both nasopharyngeal swab specimens (86.8%, kappa coefficient 0.680) and saliva samples (95.1%, kappa coefficient 0.643).ConclusionsThe sensitivity of the SARS-CoV-2 RAD test was insufficient, particularly for saliva samples. However, a substantially high concordance with viral culture suggests its potential utility as an auxiliary test for estimating SARS-CoV-2 viability.     

Comparison of clinical characteristics of COVID-19 in pregnant women between the Delta and Omicron variants of concern predominant periods

BackgroundInformation regarding effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant strains on clinical manifestations and outcomes of coronavirus disease 2019 (COVID-19) in pregnant women is limited.MethodsA retrospective observational study was conducted using the data from the nationwide COVID-19 registry in Japan. We identified pregnant patients with symptomatic COVID-19 hospitalized during the study period. The Delta and Omicron variants of concern (VOC) predominant periods were defined as August 1 to December 31, 2021 and January 1 to May 31, 2022, respectively. Clinical characteristics were compared between the patients in the Delta and Omicron VOC periods. In addition, logistic regression analysis was performed to identify risk factors for developing moderate-to-severe COVID-19.ResultsDuring the study period, 310 symptomatic COVID-19 cases of pregnant women were identified; 111 and 199 patients were hospitalized during the Delta and Omicron VOC periods, respectively. Runny nose and sore throat were more common, and fatigue, dysgeusia, and olfactory dysfunction were less common manifestations observed in the Omicron VOC period. In the multivariable logistic regression analysis, onset during the later stage of pregnancy (OR: 2.08 [1.24–3.71]) and onset during the Delta VOC period (OR: 2.25 [1.08–4.90]) were independently associated with moderate-to-severe COVID-19, whereas two doses of SARS-CoV-2 vaccine were protective against developing moderate-to-severe COVID-19 (OR: 0.34 [0.13–0.84]).ConclusionsClinical manifestations of COVID-19 in pregnant women differed between the Delta and Omicron VOC periods. SARS-CoV-2 vaccination was still effective in preventing severe COVID-19 throughout the Delta and Omicron VOC periods.