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Viral RNA in fine (< 5 µm) aerosols from 13 patients infected by the SARS-CoV-2 virus were obtained using the Gesundheit-II (G-II) equipment which collects respiratory emissions. The collection was performed in isolation wards of the National Centre for Infectious Diseases of Singapore under an approved protocol. The patients breathed normally for 30 minutes, talk, and sing for 15 minutes each (with 30 minutes rest in between activity) into a specially designed aerosol collector in two size fractions. The coarse fraction (> 5 µm) and the fine aerosols (< 5 µm) are subsequently collected and subjected to PCR analysis for their viral load quantification. Viral RNA detected from 59% of the patients showed that patients earlier in illness were more likely to emit detectable RNA, and loads differed significantly between breathing, talking, and singing. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
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The National Centre for Infectious Diseases (NCID) is the result of many years in the planning, and it finally officially opened its doors in September 2019, just months before the entire world was tested by the COVID-19 pandemic. This book is the work of many people who represent an even larger pool of people from NCID, Singapore and the rest of the world in trying to understand and contain the SARS- CoV-2 virus. There are chapters on science, the public health response both locally and globally, as well as personal reflections from NCID and Tan Tock Seng Hospital staff and staff from other public healthcare institutions who were deployed to NCID which bring home the human impact of the pandemic. We are very grateful to all the authors for taking the time to put together their thoughtful chapters as well as the senior academics and public health leaders who have provided us with generous comments on the manuscript. We hope that the readers of the book will gain a better insight into the response to the virus from so many different perspectives. Although the pandemic has evolved far beyond the pages of this book globally, the lessons learned from the early days are still relevant. We hope that the chapters will be helpful as we review our experience of this pandemic and face the next emerging infectious disease in the years to come. This book provides a comprehensive look at many different aspects of response in Singapore to the pandemic in the crucial first several months, including clinical, laboratory, epidemiology, research, community engagement and the unprecedented challenge of outbreak involving migrant workers in dormitory settings. On a personal note, it has first-hand accounts of staff at the NCID who were at the forefront of battling COVID-19 in Singapore. It also gives a global perspective of the pandemic, together with insights into the unique Singapore experience of managing the pandemic. The Singapore response to the pandemic has been something which the global community has been very interested in and this book is the first to comprehensively describe that response from a number of different angles which will be useful to scientists, clinicians, public health professionals and policy makers. © 2022 by World Scientific Publishing Co. Pte. Ltd.
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Background. In the early months of the COVID-19 pandemic, the vast majority of infected persons were migrant workers living in dormitories who were young and with few medical co-morbidities. In 2021, this shifted to the more vulnerable and elderly population within the local community. We examined trends amongst the hospitalised cases, in order to demonstrate changes in disease severity in association with the evolving demographics. Demographic shifts in hospitalised patients with COVID-19. Proportion of hospitalised patients with COVID-19 requiring intensive care over time in Singapore Methods. All patients with PCR-positive SARS-CoV-2 admitted from February 2020 to October 2021 were included, and subsequently stratified by their year of admission (2020 or 2021). Demographics were also classified by sex, ethnicity, as well as mode of transmission, namely i) imported cases, ii) locally-transmitted cases outside of migrant worker dormitories, and iii) migrant worker dormitory cases. We compared the baseline clinical characteristics, clinical presentation and outcomes. Results. A majority of cases were seen in 2020 (n=1359), compared with 2021 (n=422), due to the large outbreaks in migrant worker dormitories. Nevertheless, the greater proportion of locally-transmitted cases outside of dormitories in 2021 (78.7% vs 12.3%) compared with 2020 meant a significantly older population with more medical co-morbidities were exposed to COVID-19. This led to an observably higher proportion of patients with severe disease, presenting with raised inflammatory markers, need for therapeutics, supplemental oxygenation and higher mortality. Baseline characteristics of hospitalised patients with COVID-19 in Singapore over time. Conclusion. Changing demographics and the characteristics of the exposed populations are associated with distinct differences in clinical presentation and outcomes. Understanding demographic shifts may be crucial in appropriate allocation of healthcare resources in managing hospitalised patients with COVID-19.
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Background. The Coronavirus disease 2019 (COVID-19) pandemic continues to threaten many countries globally. Large-scale vaccination exercises have helped to reduce transmission and severity of disease. We sought to modify an existing clinical score (the ISARIC-4C mortality score) to include serological status to better prognosticate hospitalized patients with COVID-19. Methods. We examined the first 1781 consecutive hospitalized patients with polymerase chain reaction (PCR) confirmed COVID-19 in a tertiary academic centre. We divided the study population into those requiring intensive care and those who did not require throughout their inpatient stay. Baseline characteristics examined include medical comorbidities, vaccination status, SARS-CoV-2 serology spike protein, duration of fever and haemodynamics were compared. Adverse outcomes were defined as patients who required intensive care or mortality. Performance of the risk scores were measured by the area under receiver operating characteristic curves (AUC) in predicting adverse outcomes. Results. The 55 patients requiring intensive care during their inpatient stay tended to have persistent fever beyond 72 hours and had lower titres of spike protein antibodies. (58.9 (+/-105.3) U/mL vs 144.2 (+/-116.2) U/mL, p = 0.007). A high spike protein antibody titre >75 U/mL was independently protective for adverse outcomes (adjusted OR 0.15, 95% CI 0.04-0.53), even after adjusting for the ISARIC-4C score and the presence of persistent fever. Adding the serological status and presence of persistent fever to the ISARIC-4C score improved its performance in predicting adverse outcomes (AUC 0.84, 95% CI 0.78-0.89). Conclusion. Addition of the SARS-CoV-2 serology spike protein titre and prolonged fever to the ISARIC-4C mortality score helps to better prognosticate adverse clinical outcomes in hospitalized patients with COVID-19.
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Background. Early in the coronavirus disease 2019 (COVID-19) pandemic, a low incidence of cardiovascular complications was reported amongst hospitalised patients with COVID-19 in Singapore. Little was known about the trend of cardiovascular complications as the pandemic progressed. As such, we sought to examine the evolving trends in electrocardiographic and cardiovascular manifestations in patients hospitalised for COVID-19 infection. Methods. We examined the first 1781 consecutive hospitalised patients with polymerase chain reaction (PCR) confirmed COVID-19 in a tertiary academic centre. We divided the population based on those who had an abnormal electrocardiogram (ECG) and those who had a normal ECG, comparing the baseline characteristics and outcomes between the 2 groups. Cardiovascular complications such as acute myocardial infarction, stroke, pulmonary embolism, myocarditis and mortality were also examined over time. Results. Of the 261 (14.7%) patients presenting with abnormal ECG, they were more likely to be symptomatic with complaints of breathlessness, palpitations and chest pain. Sinus tachycardia was the most common arrhythmia. Troponin I levels (41.6+/-264.3 vs 97.0+/-482.9, p=0.047) and C-reactive protein levels (20.1+/-50.7 vs 13.9+/-24.1 mumol/L, p=0.003) were significantly higher amongst those with abnormal ECGs at presentation, with a higher prevalence of myocarditis (1.9% vs 0.5%, p=0.021), pulmonary embolism (1.9% vs 0.3%, p=0.009) and acute myocardial infarction (1.1% vs 0.1%, p=0.025). Over time, there was a trend towards a higher proportion of hospitalised patients with cardiovascular complications. Baseline characteristics of hospitalised patients with COVID-19, with or without abnormal ECG at presentation Changes in percentage of hospitalised patients with COVID-19, experiencing cardiovascular events (acute myocardial infarction, stroke, myocarditis, pulmonary embolism and death) over time Conclusion. A baseline ECG at presentation is a simple test that provides valuable information on potential cardiovascular complications in the context of COVID-19. Although the prevalence of abnormal ECGs is relatively low, it appears to be increasing over time amongst hospitalised patients with COVID-19.
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Background: Acute ischemic stroke (AIS) is a life-threatening complication of coronavirus disease 2019 (COVID-19) infection. Increasing reports suggest an association between COVID-19 and AIS, although the underlying mechanism remains uncertain. Objectives: We performed a systematic review to characterize the clinical characteristics, neuroimaging findings, and outcomes of AIS in COVID-19 patients. Methods: A literature search was performed in PubMed and Embase using a suitable keyword search strategy from 1st December 2019 to 29th May 2020. All studies reporting AIS occurrence in COVID-19 patients were included. Results: A total of 39 studies comprising 135 patients were studied. The pooled incidence of AIS in COVID-19 patients from observational studies was 1.2% (54/4466) with a mean age of 63.4 ± 13.1 years. The mean duration of AIS from COVID-19 symptoms onset was 10 ± 8 days, and the mean NIHSS score was 19 ± 8. Laboratory investigations revealed an elevated mean D-dimer (9.2 ± 14.8 mg/L) and fibrinogen (5.8 ± 2.0 g/L). Antiphospholipid antibodies were detected in a significant number of cases. The majority of AIS neuroimaging patterns observed was large vessel thrombosis, embolism or stenosis (62.1%, 64/103), followed by multiple vascular territory (26.2%, 27/103). A high mortality rate was reported (38.0%, 49/129). Conclusion: We report the pooled incidence of AIS in COVID-19 patients to be 1.2%, with a high mortality rate. Elevated D-dimer, fibrinogen and the presence of antiphospholipid antibodies appear to be prominent in COVID-19 patients with concomitant AIS, but further mechanistic studies are required to elucidate their role in pathogenesis.
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BACKGROUND/INTRODUCTION: There are little data on outcomes of COVID-19 patients with the presence of fever compared to the presence of symptoms. AIM: We examined the associations between symptomology, presence of fever and outcomes of a COVID-19 cohort. DESIGN AND METHODS: Between 23 January and 30 April 2020, 554 COVID-19 patients were admitted to a tertiary hospital in Singapore. They were allocated into four groups based on symptomology and fever-Group 1: asymptomatic and afebrile, Group 2: symptomatic but afebrile, Group 3: febrile but asymptomatic and Group 4: symptomatic and febrile. The primary outcomes were intensive care unit (ICU) admissions and mortality. The composite end-point included ICU admissions, mortality or any COVID-19 related end-organ involvement. RESULTS: There were differences in ferritin (P=0.003), C-reactive protein (CRP) levels (P<0.001) and lymphopenia (P=0.033) across all groups, with the most favourable biochemical profile in Group 1, and the least in Group 4. Symptomatic groups (Groups 2 and 4) had higher ICU admissions (1.9% and 6.0%, respectively, P=0.003) than asymptomatic groups (Groups 1 and 3). Composite end-point was highest in Group 4 (24.0%), followed by Group 3 (8.6%), Group 2 (4.8%) and Group 1 (2.4%) (P<0.001). The presence of fever (OR 4.096, 95% CI 1.737-9.656, P=0.001) was associated with the composite end-point after adjusting for age, pulse rate, comorbidities, lymphocyte, ferritin and CRP. Presence of symptoms was not associated with the composite end-point. DISCUSSION/CONCLUSION: In this COVID-19 cohort, presence of fever was a predictor of adverse outcomes. This has implications on the management of febrile but asymptomatic COVID-19 patients.
Subject(s)
COVID-19 , Humans , SARS-CoV-2ABSTRACT
OBJECTIVE: This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients. METHODS: Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing. RESULTS: Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%). CONCLUSION: The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.
Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoglobulin G/blood , Antibody Formation , Humans , Sensitivity and Specificity , Singapore , Time FactorsABSTRACT
Super-spreading events in an outbreak can change the nature of an epidemic. Therefore, it is useful for public health teams to determine whether an ongoing outbreak has any contribution from such events, which may be amenable to interventions. We estimated the basic reproductive number (R0) and the dispersion factor (k) from empirical data on clusters of epidemiologically linked coronavirus disease 2019 (COVID-19) cases in Hong Kong, Japan and Singapore. This allowed us to infer the presence or absence of super-spreading events during the early phase of these outbreaks. The relatively large values of k implied that large cluster sizes, compatible with super-spreading, were unlikely.