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1.
Future Microbiol ; 17: 411-416, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1742148

ABSTRACT

Aim: To evaluate the role and perceptions of trainees during the COVID-19 pandemic. Method: An online survey was designed to provide an insight into the significance of the COVID-19 pandemic on working conditions of infectious diseases and clinical microbiology trainees. Results: The main roles of trainees included management of patients hospitalized for COVID-19 (55%), research (53%) and diagnostic procedures (43%). The majority (82%) of trainees felt useful in managing the crisis. However, more than two-thirds felt more stressed and more tired compared with other rotations. Only 39% of the participants had access to psychological support. Conclusion: Due to the significant impact of the pandemic on infectious diseases and clinical microbiology trainees, further research should focus on their health and welfare in the post-pandemic period.


Subject(s)
COVID-19 , Communicable Diseases , COVID-19/epidemiology , Communicable Diseases/diagnosis , Communicable Diseases/epidemiology , Humans , Pandemics , Perception , SARS-CoV-2 , Surveys and Questionnaires
2.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327074

ABSTRACT

ABSTRACT BACKGROUND Debate about the level of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues. The amount of evidence is increasing and study designs have changed over time. We conducted a living systematic review to address three questions: (1) Amongst people who become infected with SARS-CoV-2, what proportion does not experience symptoms at all during their infection? (2) What is the infectiousness of asymptomatic and presymptomatic, compared with symptomatic, SARS-CoV-2 infection? (3) What proportion of SARS-CoV-2 transmission in a population is accounted for by people who are asymptomatic or presymptomatic? METHODS AND FINDINGS The protocol was first published on 1 April 2020 and last updated on 18 June 2020. We searched PubMed, Embase, bioRxiv and medRxiv, aggregated in a database of SARS-CoV-2 literature, most recently on 2 February 2021. Studies of people with PCR-diagnosed SARS-CoV-2, which documented symptom status at the beginning and end of follow-up, or mathematical modelling studies were included. Studies restricted to people already diagnosed, of single individuals or families, or without sufficient follow-up were excluded. One reviewer extracted data and a second verified the extraction, with disagreement resolved by discussion or a third reviewer. Risk of bias in empirical studies was assessed with a bespoke checklist and modelling studies with a published checklist. All data syntheses were done using random effects models. Review question (1): We included 94 studies. Heterogeneity was high and we could not reliably estimate values for the proportion of asymptomatic infections overall (interquartile range 13-45%, prediction interval 2-89%), or in studies based on screening of defined populations (interquartile range 18-59%, prediction interval 3-95%). In screening studies at low risk of information bias, the prediction interval was 4-69% (summary proportion 23%, 95% CI 14-35%). In 40 studies based on contact or outbreak investigations, the summary proportion asymptomatic was 18% (95% CI 14-24%, prediction interval 3-64%) and, in studies at low risk of selection bias, 25% (95% CI 18-33%, prediction interval 5-66%). (2) The secondary attack rate in contacts of people with asymptomatic infection compared with symptomatic infection was 0.43 (95% CI 0.05-3.44, 5 studies). (3) In 11 modelling studies fit to data, the proportion of all SARS-CoV-2 transmission from presymptomatic individuals was higher than from asymptomatic individuals. Limitations of the evidence include high heterogeneity in studies that were not designed to measure persistently asymptomatic infection, high risks of selection and information bias, and the absence of studies about variants of concern or in people who have been vaccinated. CONCLUSIONS This review does not provide a summary estimate of the proportion of asymptomatic SARS-CoV-2 across all study designs. In studies based on contact and outbreak investigation, most SARS-CoV-2 infections were not persistently asymptomatic. Summary estimates from meta-analysis may be misleading when variability between studies is extreme. Without prospective longitudinal studies with methods that minimise selection and measurement biases, further updates with the study types included in this living systematic review are unlikely to be able to provide a reliable summary estimate of the proportion of asymptomatic infections caused by wild-type SARS-CoV-2. REVIEW PROTOCOL Open Science Framework ( https://osf.io/9ewys/ )

3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-316983

ABSTRACT

People with persistently asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection experience no symptoms throughout the course of infection, while pre-symptomatic individuals report symptoms attributable to the virus. Transmission of SARS-CoV-2 from individuals without symptoms contributes to pandemic spread, but the extent of transmission from persistently asymptomatic individuals remains unknown. We describe three methodological issues that hinder attempts to estimate this proportion. First, incomplete symptom assessment likely overestimates the asymptomatic fraction. Second, studies with inadequate follow-up misclassify pre-symptomatic individuals. Third, serological studies may identify people with previously unrecognized infection, but reliance on poorly defined antibody responses and retrospective symptom assessment may result in misclassification. We provide recommendations regarding definitions, detection, documentation and follow-up to improve the identification and evaluation of people with persistently asymptomatic SARS-CoV-2 infection and their contacts. Accurate characterisation of the persistently asymptomatic fraction may shed light on COVID-19 pathogenesis, transmission dynamics, and inform public health responses.

5.
BMJ ; 375: n3105, 2021 12 20.
Article in English | MEDLINE | ID: covidwho-1597444
6.
Ann Intern Med ; 174(2): 283-284, 2021 02.
Article in English | MEDLINE | ID: covidwho-1553980
7.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-292969

ABSTRACT

The number of occupants in a space influences the risk of far-field airborne transmission of the SARS-CoV-2 virus because the likelihood of having infectious and susceptible people both scale with the number of occupants. Mass-balance and dose-response models determine far-field transmission risks for an individual person and a population of people after sub-dividing a large reference space into 10 identical comparator spaces. For a single infected person when the per capita ventilation rate is preserved, the dose received by an individual person in the comparator space is 10-times higher because the equivalent ventilation rate per infected person is lower. However, accounting for population dispersion, such as the community infection rate, the probability of an infected person being present and uncertainty in their viral load, shows the probability of transmission increases with occupancy. Also, far-field transmission is likely to be a rare event that requires a set of Goldilocks conditions that are just right, when mitigation measures have limited effect. Therefore, resilient buildings should deliver the equivalent ventilation rate required by standards and increase the space volume per person, but also require reductions in the viral loads and the infection rate of the wider population.

8.
Future Microbiol ; 16: 687-695, 2021 07.
Article in English | MEDLINE | ID: covidwho-1511960

ABSTRACT

Trainees represent the medical practice of tomorrow. Interactions and collaborations at the early stage in career will strengthen the future of our specialties, clinical microbiology and infectious diseases. Trainee networks at the national level help access the best education and career opportunities. The aim of this collaborative white paper between the Trainee Association of European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and four national trainee networks is to discuss the motivation for building such networks and offer guidance for their creation and sustainability even during a health crisis.


Subject(s)
Education, Medical/organization & administration , Infectious Disease Medicine/education , Microbiology/education , Humans
9.
Cell ; 184(20): 5077-5081, 2021 09 30.
Article in English | MEDLINE | ID: covidwho-1474390

ABSTRACT

As the SARS-CoV-2 pandemic evolves, new variants continue to emerge. Some highly transmissible variants, such as Delta, also raised concerns about the effectiveness provided by current vaccines. Understanding immunological correlates of protection and how laboratory findings correspond to clinical effectiveness is imperative to shape future vaccination strategies.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/epidemiology , COVID-19/prevention & control , Pandemics/prevention & control , SARS-CoV-2/immunology , Vaccination/methods , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/classification , Humans , Immunity, Cellular , Immunogenicity, Vaccine , Mutation , SARS-CoV-2/genetics
10.
Clin Infect Dis ; 73(7): e2095-e2106, 2021 10 05.
Article in English | MEDLINE | ID: covidwho-1455268

ABSTRACT

BACKGROUND: Evidence is conflicting about how human immunodeficiency virus (HIV) modulates coronavirus disease 2019 (COVID-19). We compared the presentation characteristics and outcomes of adults with and without HIV who were hospitalized with COVID-19 at 207 centers across the United Kingdom and whose data were prospectively captured by the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) World Health Organization (WHO) Clinical Characterization Protocol (CCP) study. METHODS: We used Kaplan-Meier methods and Cox regression to describe the association between HIV status and day-28 mortality, after separate adjustment for sex, ethnicity, age, hospital acquisition of COVID-19 (definite hospital acquisition excluded), presentation date, 10 individual comorbidities, and disease severity at presentation (as defined by hypoxia or oxygen therapy). RESULTS: Among 47 592 patients, 122 (0.26%) had confirmed HIV infection, and 112/122 (91.8%) had a record of antiretroviral therapy. At presentation, HIV-positive people were younger (median 56 vs 74 years; P < .001) and had fewer comorbidities, more systemic symptoms and higher lymphocyte counts and C-reactive protein levels. The cumulative day-28 mortality was similar in the HIV-positive versus HIV-negative groups (26.7% vs. 32.1%; P = .16), but in those under 60 years of age HIV-positive status was associated with increased mortality (21.3% vs. 9.6%; P < .001 [log-rank test]). Mortality was higher among people with HIV after adjusting for age (adjusted hazard ratio [aHR] 1.47, 95% confidence interval [CI] 1.01-2.14; P = .05), and the association persisted after adjusting for the other variables (aHR 1.69; 95% CI 1.15-2.48; P = .008) and when restricting the analysis to people aged <60 years (aHR 2.87; 95% CI 1.70-4.84; P < .001). CONCLUSIONS: HIV-positive status was associated with an increased risk of day-28 mortality among patients hospitalized for COVID-19.


Subject(s)
COVID-19 , HIV Infections , Adult , HIV , HIV Infections/complications , HIV Infections/epidemiology , Hospitalization , Humans , Middle Aged , Observational Studies as Topic , SARS-CoV-2 , United Kingdom , World Health Organization
12.
Lancet Reg Health Eur ; 8: 100186, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1397545

ABSTRACT

BACKGROUND: This study sought to establish the long-term effects of Covid-19 following hospitalisation. METHODS: 327 hospitalised participants, with SARS-CoV-2 infection were recruited into a prospective multicentre cohort study at least 3 months post-discharge. The primary outcome was self-reported recovery at least ninety days after initial Covid-19 symptom onset. Secondary outcomes included new symptoms, disability (Washington group short scale), breathlessness (MRC Dyspnoea scale) and quality of life (EQ5D-5L). FINDINGS: 55% of participants reported not feeling fully recovered. 93% reported persistent symptoms, with fatigue the most common (83%), followed by breathlessness (54%). 47% reported an increase in MRC dyspnoea scale of at least one grade. New or worse disability was reported by 24% of participants. The EQ5D-5L summary index was significantly worse following acute illness (median difference 0.1 points on a scale of 0 to 1, IQR: -0.2 to 0.0). Females under the age of 50 years were five times less likely to report feeling recovered (adjusted OR 5.09, 95% CI 1.64 to 15.74), were more likely to have greater disability (adjusted OR 4.22, 95% CI 1.12 to 15.94), twice as likely to report worse fatigue (adjusted OR 2.06, 95% CI 0.81 to 3.31) and seven times more likely to become more breathless (adjusted OR 7.15, 95% CI 2.24 to 22.83) than men of the same age. INTERPRETATION: Survivors of Covid-19 experienced long-term symptoms, new disability, increased breathlessness, and reduced quality of life. These findings were present in young, previously healthy working age adults, and were most common in younger females. FUNDING: National Institute for Health Research, UK Medical Research Council, Wellcome Trust, Department for International Development and the Bill and Melinda Gates Foundation.

13.
Clin Infect Dis ; 73(Suppl 2): S170-S176, 2021 07 30.
Article in English | MEDLINE | ID: covidwho-1387773

ABSTRACT

It is generally agreed that striking a balance between resuming economic and social activities and keeping the effective reproductive number (R0) below 1 using nonpharmaceutical interventions is an important goal until and even after effective vaccines become available. Therefore, the need remains to understand how the virus is transmitted in order to identify high-risk environments and activities that disproportionately contribute to its spread so that effective preventative measures could be put in place. Contact tracing and household studies, in particular, provide robust evidence about the parameters of transmission. In this Viewpoint, we discuss the available evidence from large-scale, well-conducted contact-tracing studies from across the world and argue that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission dynamics should inform policy decisions about mitigation strategies for targeted interventions according to the needs of the society by directing attention to the settings, activities, and socioeconomic factors associated with the highest risks of transmission.


Subject(s)
COVID-19 , SARS-CoV-2 , Basic Reproduction Number , Contact Tracing , Humans , Policy
14.
Lancet Infect Dis ; 21(11): 1472-1474, 2021 11.
Article in English | MEDLINE | ID: covidwho-1386926
17.
Cell ; 184(5): 1127-1132, 2021 03 04.
Article in English | MEDLINE | ID: covidwho-1188379

ABSTRACT

Recent reports suggest that some SARS-CoV-2 genetic variants, such as B.1.1.7, might be more transmissible and are quickly spreading around the world. As the emergence of more transmissible variants could exacerbate the pandemic, we provide public health guidance for increased surveillance and measures to reduce community transmission.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Communicable Disease Control , SARS-CoV-2/genetics , Age Factors , COVID-19/epidemiology , COVID-19/virology , Epidemiological Monitoring , Global Health , Humans , Mandatory Programs , Pandemics , SARS-CoV-2/physiology , Travel/legislation & jurisprudence , United Kingdom/epidemiology , Vulnerable Populations
18.
Clin Microbiol Infect ; 27(4): 511-519, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1174178

ABSTRACT

BACKGROUND: Reports suggest that asymptomatic individuals (those with no symptoms at all throughout infection) with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are infectious, but the extent of transmission based on symptom status requires further study. PURPOSE: This living review aims to critically appraise available data about secondary attack rates from people with asymptomatic, pre-symptomatic and symptomatic SARS-CoV-2 infection. DATA SOURCES: Medline, EMBASE, China Academic Journals full-text database (CNKI), and pre-print servers were searched from 30 December 2019 to 3 July 2020 using relevant MESH terms. STUDY SELECTION: Studies that report on contact tracing of index cases with SARS-CoV-2 infection in either English or Chinese were included. DATA EXTRACTION: Two authors independently extracted data and assessed study quality and risk of bias. We calculated the secondary attack rate as the number of contacts with SARS-CoV-2, divided by the number of contacts tested. DATA SYNTHESIS: Of 927 studies identified, 80 were included. Summary secondary attack rate estimates were 1% (95% CI 0%-2%) with a prediction interval of 0%-10% for asymptomatic index cases in ten studies, 7% (95% CI 3%-11%) with a prediction interval of 1%-40% for pre-symptomatic cases in 11 studies and 6% (95% CI 5%-8%) with a prediction interval of 5%-38% for symptomatic index cases in 40 studies. The highest secondary attack rates were found in contacts who lived in the same household as the index case. Other activities associated with transmission were group activities such as sharing meals or playing board games with the index case, regardless of the disease status of the index case. LIMITATIONS: We excluded some studies because the index case or number of contacts were unclear. CONCLUSION: Asymptomatic patients can transmit SARS-CoV-2 to others, but our findings indicate that such individuals are responsible for fewer secondary infections than people with symptoms. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020188168.


Subject(s)
Asymptomatic Infections/epidemiology , COVID-19/transmission , COVID-19/epidemiology , Contact Tracing , Family Characteristics , Humans , Incidence
19.
Lancet Microbe ; 2(1): e13-e22, 2021 01.
Article in English | MEDLINE | ID: covidwho-1152742

ABSTRACT

BACKGROUND: Viral load kinetics and duration of viral shedding are important determinants for disease transmission. We aimed to characterise viral load dynamics, duration of viral RNA shedding, and viable virus shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in various body fluids, and to compare SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) viral dynamics. METHODS: In this systematic review and meta-analysis, we searched databases, including MEDLINE, Embase, Europe PubMed Central, medRxiv, and bioRxiv, and the grey literature, for research articles published between Jan 1, 2003, and June 6, 2020. We included case series (with five or more participants), cohort studies, and randomised controlled trials that reported SARS-CoV-2, SARS-CoV, or MERS-CoV infection, and reported viral load kinetics, duration of viral shedding, or viable virus. Two authors independently extracted data from published studies, or contacted authors to request data, and assessed study quality and risk of bias using the Joanna Briggs Institute Critical Appraisal Checklist tools. We calculated the mean duration of viral shedding and 95% CIs for every study included and applied the random-effects model to estimate a pooled effect size. We used a weighted meta-regression with an unrestricted maximum likelihood model to assess the effect of potential moderators on the pooled effect size. This study is registered with PROSPERO, CRD42020181914. FINDINGS: 79 studies (5340 individuals) on SARS-CoV-2, eight studies (1858 individuals) on SARS-CoV, and 11 studies (799 individuals) on MERS-CoV were included. Mean duration of SARS-CoV-2 RNA shedding was 17·0 days (95% CI 15·5-18·6; 43 studies, 3229 individuals) in upper respiratory tract, 14·6 days (9·3-20·0; seven studies, 260 individuals) in lower respiratory tract, 17·2 days (14·4-20·1; 13 studies, 586 individuals) in stool, and 16·6 days (3·6-29·7; two studies, 108 individuals) in serum samples. Maximum shedding duration was 83 days in the upper respiratory tract, 59 days in the lower respiratory tract, 126 days in stools, and 60 days in serum. Pooled mean SARS-CoV-2 shedding duration was positively associated with age (slope 0·304 [95% CI 0·115-0·493]; p=0·0016). No study detected live virus beyond day 9 of illness, despite persistently high viral loads, which were inferred from cycle threshold values. SARS-CoV-2 viral load in the upper respiratory tract appeared to peak in the first week of illness, whereas that of SARS-CoV peaked at days 10-14 and that of MERS-CoV peaked at days 7-10. INTERPRETATION: Although SARS-CoV-2 RNA shedding in respiratory and stool samples can be prolonged, duration of viable virus is relatively short-lived. SARS-CoV-2 titres in the upper respiratory tract peak in the first week of illness. Early case finding and isolation, and public education on the spectrum of illness and period of infectiousness are key to the effective containment of SARS-CoV-2. FUNDING: None.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Humans , RNA, Viral , SARS-CoV-2 , Viral Load , Virus Shedding
20.
Clin Microbiol Infect ; 27(7): 1007-1010, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1141681

ABSTRACT

OBJECTIVES: To compare the gender distribution of clinical trial leadership in coronavirus disease 2019 (COVID-19) clinical trials. METHODS: We searched https://clinicaltrials.gov/ and retrieved all clinical trials on COVID-19 from 1 January 2020 to 26 June 2020. As a comparator group, we have chosen two fields that are not related to emerging infections and infectious diseases: and considered not directly affected by the pandemic: breast cancer and type 2 diabetes mellitus (T2DM) and included studies within the aforementioned study period as well as those registered in the preceding year (pre-study period: 1 January 2019 to 31 December 2019). Gender of the investigator was predicted using the genderize.io application programming interface. The repository of the data sets used to collect and analyse the data are available at https://osf.io/k2r57/. RESULTS: Only 27.8% (430/1548) of principal investigators among COVID-19-related studies were women, which is significantly different compared with 54.9% (156/284) and 42.1% (56/133) for breast cancer (p < 0.005) and T2DM (p < 0.005) trials over the same period, respectively. During the pre-study period, the proportion of principal investigators who were predicted to be women were 49.7% (245/493) and 44.4% (148/333) for breast cancer and T2DM trials, respectively, and the difference was not statistically significant when compared with results from the study period (p > 0.05). CONCLUSION: We demonstrate that less than one-third of COVID-19-related clinical trials are led by women, half the proportion observed in non-COVID-19 trials over the same period, which remained similar to the pre-study period. These gender disparities during the pandemic may not only indicate a lack of female leadership in international clinical trials and involvement in new projects but also reveal imbalances in women's access to research activities and funding during health emergencies.


Subject(s)
COVID-19 , Leadership , Women , Breast Neoplasms , Clinical Trials as Topic/statistics & numerical data , Diabetes Mellitus, Type 2 , Female , Humans , Male , Research Personnel/statistics & numerical data , Sex Ratio , Sexism
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