30 results on '"Robert Challen"'
Search Results
2. Serotype Distribution and Disease Severity in Adults Hospitalized with Streptococcus pneumoniae Infection, Bristol and Bath, UK, 2006‒2022
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Catherine Hyams, Robert Challen, David Hettle, Zahin Amin-Chowdhury, Charli Grimes, Gabriella Ruffino, Rauri Conway, Robyn Heath, Paul North, Adam Malin, Nick A. Maskell, Philip Williams, O. Martin Williams, Shamez N. Ladhani, Leon Danon, and Adam Finn
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pneumonia ,Streptococcus pneumoniae ,bacteria ,pneumococcus ,serotypes ,serotype distribution ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Ongoing surveillance after pneumococcal conjugate vaccination (PCV) deployment is essential to inform policy decisions and monitor serotype replacement. We report serotype and disease severity trends in 3,719 adults hospitalized for pneumococcal disease in Bristol and Bath, United Kingdom, during 2006–2022. Of those cases, 1,686 were invasive pneumococcal disease (IPD); 1,501 (89.0%) had a known serotype. IPD decreased during the early COVID-19 pandemic but during 2022 gradually returned to prepandemic levels. Disease severity changed throughout this period: CURB65 severity scores and inpatient deaths decreased and ICU admissions increased. PCV7 and PCV13 serotype IPD decreased from 2006–2009 to 2021–2022. However, residual PCV13 serotype IPD remained, representing 21.7% of 2021–2022 cases, indicating that major adult PCV serotype disease still occurs despite 17 years of pediatric PCV use. Percentages of serotype 3 and 8 IPD increased, and 19F and 19A reemerged. In 2020–2022, a total of 68.2% IPD cases were potentially covered by PCV20.
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- 2023
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3. Combined multiplex panel test results are a poor estimate of disease prevalence without adjustment for test error.
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Robert Challen, Anastasia Chatzilena, George Qian, Glenda Oben, Rachel Kwiatkowska, Catherine Hyams, Adam Finn, Krasimira Tsaneva-Atanasova, and Leon Danon
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Biology (General) ,QH301-705.5 - Abstract
Multiplex panel tests identify many individual pathogens at once, using a set of component tests. In some panels the number of components can be large. If the panel is detecting causative pathogens for a single syndrome or disease then we might estimate the burden of that disease by combining the results of the panel, for example determining the prevalence of pneumococcal pneumonia as caused by many individual pneumococcal serotypes. When we are dealing with multiplex test panels with many components, test error in the individual components of a panel, even when present at very low levels, can cause significant overall error. Uncertainty in the sensitivity and specificity of the individual tests, and statistical fluctuations in the numbers of false positives and false negatives, will cause large uncertainty in the combined estimates of disease prevalence. In many cases this can be a source of significant bias. In this paper we develop a mathematical framework to characterise this issue, we determine expressions for the sensitivity and specificity of panel tests. In this we identify a counter-intuitive relationship between panel test sensitivity and disease prevalence that means panel tests become more sensitive as prevalence increases. We present novel statistical methods that adjust for bias and quantify uncertainty in prevalence estimates from panel tests, and use simulations to test these methods. As multiplex testing becomes more commonly used for screening in routine clinical practice, accumulation of test error due to the combination of large numbers of test results needs to be identified and corrected for.
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- 2024
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4. Parapneumonic effusions related to Streptococcus pneumoniae: serotype and disease severity trends from 2006 to 2018 in Bristol, UK
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Nick Maskell, Shamez Ladhani, Norman K Fry, Robert Challen, Adam Finn, Paul North, Catherine Hyams, David T Arnold, Zahin Amin-Chowdhury, Leon Danon, O Martin Williams, Philip Williams, Robyn Heath, David Hettle, Gabriella Ruffino, and Charli Grimes
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Medicine ,Diseases of the respiratory system ,RC705-779 - Abstract
Rationale Streptococcus pneumoniae epidemiology is changing in response to vaccination and some data suggest that empyema incidence is increasing. However, differences exist between the UK and US studies. We describe trends in the clinical phenotype of adult pneumococcal pleural infection, including simple parapneumonic effusions (SPE) in the pneumococcal conjugate vaccination (PCV) era.Objectives To determine whether there were differences in pneumococcal disease presentation and severity associated with pleural infection.Methods A retrospective cohort study, all adults ≥16 years admitted to three large UK hospitals, 2006–2018 with pneumococcal disease. 2477 invasive pneumococcal cases were identified: 459 SPE and 100 pleural infection cases. Medical records were reviewed for each clinical episode. Serotype data were obtained from the UK Health Security Agency national reference laboratory.Results Incidence increased over time, including non-PCV-serotype disease. PCV7-serotype disease declined following paediatric PCV7 introduction, but the effect of PCV13 was less apparent as disease caused by the additional six serotypes plateaued with serotypes 1 and 3 causing such parapneumonic effusions from 2011 onwards.Patients with pleural infection had a median survival 468 days (95% CI 340 to 590) vs 286 days (95% CI 274 to 335) in those with SPE. Pleural infection associated with frank pus had lower 90-day mortality than pleural infection without pus (0% vs 29%, p
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- 2023
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5. Severity of Omicron (B.1.1.529) and Delta (B.1.617.2) SARS-CoV-2 infection among hospitalised adults: A prospective cohort study in Bristol, United KingdomResearch in context
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Catherine Hyams, Robert Challen, Robin Marlow, Jennifer Nguyen, Elizabeth Begier, Jo Southern, Jade King, Anna Morley, Jane Kinney, Madeleine Clout, Jennifer Oliver, Sharon Gray, Gillian Ellsbury, Nick Maskell, Luis Jodar, Bradford Gessner, John McLaughlin, Leon Danon, Adam Finn, Amelia Langdon, Anabella Turner, Anya Mattocks, Bethany Osborne, Charli Grimes, Claire Mitchell, David Adegbite, Emma Bridgeman, Emma Scott, Fiona Perkins, Francesca Bayley, Gabriella Ruffino, Gabriella Valentine, Grace Tilzey, James Campling, Johanna Kellett Wright, Julia Brzezinska, Julie Cloake, Katarina Milutinovic, Kate Helliker, Katie Maughan, Kazminder Fox, Konstantina Minou, Lana Ward, Leah Fleming, Leigh Morrison, Lily Smart, Louise Wright, Lucy Grimwood, Maddalena Bellavia, Marianne Vasquez, Maria Garcia Gonzalez, Milo Jeenes-Flanagan, Natalie Chang, Niall Grace, Nicola Manning, Oliver Griffiths, Pip Croxford, Peter Sequenza, Rajeka Lazarus, Rhian Walters, Robyn Heath, Rupert Antico, Sandi Nammuni Arachchge, Seevakumar Suppiah, Taslima Mona, Tawassal Riaz, Vicki Mackay, Zandile Maseko, Zoe Taylor, Zsolt Friedrich, and Zsuzsa Szasz-Benczur
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COVID-19 ,SARS-CoV-2 ,Respiratory infection ,Vaccination ,Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: There is an urgent public health need to evaluate disease severity in adults hospitalised with Delta and Omicron SARS-CoV-2 variant infections. However, limited data exist assessing severity of disease in adults hospitalised with Omicron SARS-CoV-2 infections, and to what extent patient-factors, including vaccination, age, frailty and pre-existing disease, affect variant-dependent disease severity. Methods: A prospective cohort study of adults (≥18 years of age) hospitalised with acute lower respiratory tract disease at acute care hospitals in Bristol, UK conducted over 10-months. Delta or Omicron SARS-CoV-2 infection was defined by positive SARS-CoV-2 PCR and variant identification or inferred by dominant circulating variant. We constructed adjusted regression analyses to assess disease severity using three different measures: FiO2 >28% (fraction inspired oxygen), World Health Organization (WHO) outcome score >5 (assessing need for ventilatory support), and hospital length of stay (LOS) >3 days following admission for Omicron or Delta infection. Findings: Independent of other variables, including vaccination, Omicron variant infection in hospitalised adults was associated with lower severity than Delta. Risk reductions were 58%, 67%, and 16% for supplementary oxygen with >28% FiO2 [Relative Risk (RR) = 0.42 (95%CI: 0.34–0.52), P 5 [RR = 0.33 (95%CI: 0.21–0.50), P 3 days [RR = 0.84 (95%CI: 0.76–0.92), P
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- 2023
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6. Incidence of community acquired lower respiratory tract disease in Bristol, UK during the COVID-19 pandemic: A prospective cohort study
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Catherine Hyams, Robert Challen, Elizabeth Begier, Jo Southern, Jade King, Anna Morley, Zsuzsa Szasz-Benczur, Maria Garcia Gonzalez, Jane Kinney, James Campling, Sharon Gray, Jennifer Oliver, Robin Hubler, Srinivas Valluri, Andrew Vyse, John M. McLaughlin, Gillian Ellsbury, Nick A. Maskell, Bradford D. Gessner, Leon Danon, Adam Finn, Amelia Langdon, Anabella Turner, Anya Mattocks, Bethany Osborne, Charli Grimes, Claire Mitchell, David Adegbite, Emma Bridgeman, Emma Scott, Fiona Perkins, Francesca Bayley, Gabriella Ruffino, Gabriella Valentine, Grace Tilzey, Johanna Kellett Wright, Julia Brzezinska, Julie Cloake, Katarina Milutinovic, Kate Helliker, Katie Maughan, Kazminder Fox, Konstantina Minou, Lana Ward, Leah Fleming, Leigh Morrison, Lily Smart, Louise Wright, Lucy Grimwood, Maddalena Bellavia, Madeleine Clout, Marianne Vasquez, Milo Jeenes-Flanagan, Natalie Chang, Niall Grace, Nicola Manning, Oliver Griffiths, Pip Croxford, Peter Sequenza, Rajeka Lazarus, Rhian Walters, Robin Marlow, Robyn Heath, Rupert Antico, Sandi Nammuni Arachchge, Seevakumar Suppiah, Taslima Mona, Tawassal Riaz, Vicki Mackay, Zandile Maseko, Zoe Taylor, and Zsolt Friedrich
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Pneumonia ,Lower respiratory tract infection ,Cardiac failure ,COVID-19 ,SARS-CoV-2 ,Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: The emergence of COVID-19 and public health measures implemented to reduce SARS-CoV-2 infections have both affected acute lower respiratory tract disease (aLRTD) epidemiology and incidence trends. The severity of COVID-19 and non-SARS-CoV-2 aLRTD during this period have not been compared in detail. Methods: We conducted a prospective cohort study of adults age ≥18 years admitted to either of two acute care hospitals in Bristol, UK, from August 2020 to November 2021. Patients were included if they presented with signs or symptoms of aLRTD (e.g., cough, pleurisy), or a clinical or radiological aLRTD diagnosis. Findings: 12,557 adult aLRTD hospitalisations occurred: 10,087 were associated with infection (pneumonia or non-pneumonic lower respiratory tract infection [NP-LRTI]), 2161 with no infective cause, with 306 providing a minimal surveillance dataset. Confirmed SARS-CoV-2 infection accounted for 32% (3178/10,087) of respiratory infections. Annual incidences of overall, COVID-19, and non- SARS-CoV-2 pneumonia were 714.1, 264.2, and 449.9, and NP-LRTI were 346.2, 43.8, and 302.4 per 100,000 adults, respectively. Weekly incidence trends in COVID-19 aLRTD showed large surges (median 6.5 [IQR 0.7–10.2] admissions per 100,000 adults per week), while other infective aLRTD events were more stable (median 14.3 [IQR 12.8–16.4] admissions per 100,000 adults per week) as were non-infective aLRTD events (median 4.4 [IQR 3.5–5.5] admissions per 100,000 adults per week). Interpretation: While COVID-19 disease was a large component of total aLRTD during this pandemic period, non- SARS-CoV-2 infection still caused the majority of respiratory infection hospitalisations. COVID-19 disease showed significant temporal fluctuations in frequency, which were less apparent in non-SARS-CoV-2 infection. Despite public health interventions to reduce respiratory infection, disease incidence remains high. Funding: AvonCAP is an investigator-led project funded under a collaborative agreement by Pfizer.
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- 2022
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7. Correction: A flexible method for optimising sharing of healthcare resources and demand in the context of the COVID-19 pandemic.
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Lucas Lacasa, Robert Challen, Ellen Brooks-Pollock, and Leon Danon
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Medicine ,Science - Abstract
[This corrects the article DOI: 10.1371/journal.pone.0241027.].
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- 2021
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8. A flexible method for optimising sharing of healthcare resources and demand in the context of the COVID-19 pandemic.
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Lucas Lacasa, Robert Challen, Ellen Brooks-Pollock, and Leon Danon
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Medicine ,Science - Abstract
As the number of cases of COVID-19 continues to grow, local health services are at risk of being overwhelmed with patients requiring intensive care. We develop and implement an algorithm to provide optimal re-routing strategies to either transfer patients requiring Intensive Care Units (ICU) or ventilators, constrained by feasibility of transfer. We validate our approach with realistic data from the United Kingdom and Spain. In the UK, we consider the National Health Service at the level of trusts and define a 4-regular geometric graph which indicates the four nearest neighbours of any given trust. In Spain we coarse-grain the healthcare system at the level of autonomous communities, and extract similar contact networks. Through random search optimisation we identify the best load sharing strategy, where the cost function to minimise is based on the total number of ICU units above capacity. Our framework is general and flexible allowing for additional criteria, alternative cost functions, and can be extended to other resources beyond ICU units or ventilators. Assuming a uniform ICU demand, we show that it is possible to enable access to ICU for up to 1000 additional cases in the UK in a single step of the algorithm. Under a more realistic and heterogeneous demand, our method is able to balance about 600 beds per step in the Spanish system only using local sharing, and over 1300 using countrywide sharing, potentially saving a large percentage of these lives that would otherwise not have access to ICU.
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- 2020
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9. Artificial Intelligence for Collective Intelligence: A National-Scale Research Strategy.
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Seth Bullock, Nirav Ajmeri, Mike Batty, Michaela Black, John Cartlidge, Robert Challen, Cangxiong Chen, Jing Chen, Joan Condell, Leon Danon, Adam Dennett, Alison J. Heppenstall, Paul Marshall, Phil Morgan, Aisling Ann O'Kane, Laura G. E. Smith, Theresa Smith, and Hywel T. P. Williams
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- 2024
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10. dtrackr: An R package for tracking the provenance of data.
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Robert Challen
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- 2022
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11. Trends in serotype distribution and disease severity in adults hospitalised withStreptococcus pneumoniaeinfection in Bristol and Bath: a retrospective cohort study, 2006-2022
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Catherine Hyams, Robert Challen, David Hettle, Zahin Amin-Chowdhury, Charli Grimes, Gabriella Ruffino, Rauri Conway, Robyn Heath, Paul North, Adam Malin, Nick A Maskell, Philip Williams, O. Martin Williams, Shamez N Ladhani, Leon Danon, and Adam Finn
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BackgroundPaediatric pneumococcal conjugate vaccination (PCV) has reduced adult PCV-serotype disease: PCV7 has greater indirect effects than PCV13. Ongoing surveillance is required to evaluate current vaccine usage and inform future vaccine deployment, particularly with respiratory infection epidemiology changing following SARS-CoV-2 emergence.Methods and FindingsA retrospective cohort study, all adults ≥16 years admitted to three UK hospitals, 2006-2022, with pneumococcal disease. Medical records were reviewed for each clinical episode and serotype data were obtained from the UK Health Security Agency national reference laboratory.We identified 1,501 (40.3%) cases of invasive pneumococcal disease (IPD) with known serotype, 134 (3.6%) IPD cases without serotype data, and 2,084 (56.0%) non-IPD cases, which are typically missed in national surveillance. Disease incidence increased progressively from 2006-2020, followed by a sudden decline after COVID-19 emergence and then a gradual increase to pre-pandemic levels.Paediatric PCV7 introduction reduced adult PCV7 serotype IPD from 29.4% [24.1–35.4] of IPD in 2006-09 to 7.0% [3.7–12.7] in 2021-22. PCV13 introduction also decreased adult vaccine serotype IPD, but considerable residual adult disease remains, causing 34.3% [28.6–40.4] of IPD in 2006-09 and 21.7% [15.5–29.6] 9 in 2021-22, respectively. Serotype replacement diminished the benefits of PCV introduction: PCV20-13 and non-PCV serotypes represented 27.0% [21.9–32.9] and 9.3% [6.3–13.5] of disease in 2006-2009, and 39.5% [31.5–48.2] and 31.8% [24.4–40.2] in 2021-2022, respectively.Serotype shifts have resulted in increasing disease caused by serotype 3 and 8, and the re-emergence of serotype 19F and 19A. These serotype shifts occurred as clinical disease severity changed, and whilst the COVID-19 pandemic disrupted disease severity trends, these have now largely reverted to previous trajectories. Patient age trended upwards and although CURB65 severity decreased there were increased ICU admission rates. Overall, inpatient mortality decreased and hospitalisation duration remained stable.ConclusionsAfter 17 years of PCV use, residual pneumococcal disease due to the vaccine serotypes among hospitalised adults remains. The sharp decline in pneumococcal disease during the COVID-19 pandemic has now reversed, with increasing cases due to vaccine serotypes, especially serotype 3. Around 68.2% of cases in 2022 were potentially covered by the recently licensed 20-valent PCV.
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- 2023
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12. Relative vaccine effectiveness (rVE) of mRNA COVID-19 boosters in the UK vaccination programme, during the Spring-Summer (monovalent vaccine) and Autumn-Winter 2022 (bivalent vaccine) booster campaigns: a prospective test negative case-control study
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Catherine Hyams, Robert Challen, Anastasia Chatzilena, Nick Maskell, and Robin Marlow
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BackgroundUnderstanding the relative vaccine effectiveness (rVE) of new COVID-19 vaccine formulations against SARS-CoV-2 infection is an urgent public health priority. A precise comparison of the rVE of monovalent and bivalent boosters given during the 2022 Spring-Summer and Autumn-Winter campaigns, respectively, in a defined population has not been reported. We therefore assessed rVE against hospitalisation for the Spring-Summer (fourth vs third monovalent mRNA vaccine doses) and Autumn-Winter (fifth BA.1/ancestral bivalent vs fourth monovalent mRNA vaccine dose) boosters.MethodsA prospective single-centre test-negative design case-control study of ≥75 year-olds hospitalised with COVID-19 or other acute respiratory disease. We conducted regression analyses controlling for age, gender, socioeconomic status, patient comorbidities, community SARS-CoV-2 prevalence, vaccine brand and time between baseline dose and hospitalisation.Results682 controls and 182 cases were included in the Spring-Summer booster analysis; 572 controls and 152 cases for the Autumn-Winter booster analysis. A monovalent mRNA COVID-19 vaccine as fourth dose showed rVE 46·9% (95% confidence interval [CI] 14·4-67·3) versus those not boosted. A bivalent mRNA COVID-19 vaccine as fifth dose had rVE 46·4% (95%CI 17·5-65), compared to a fourth monovalent mRNA COVID-19 vaccine dose.InterpretationBoth fourth monovalent and fifth BA.1/ancestral mRNA bivalent COVID-19 vaccine doses demonstrated benefit as a booster in older adults. Bivalent mRNA boosters offer equivalent protection against hospitalisation with Omicron infection to monovalent mRNA boosters given earlier in the year. These findings support the current UK immunisation programme that advises the use of bivalent booster doses.
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- 2023
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13. Meta-analysis of the severe acute respiratory syndrome coronavirus 2 serial intervals and the impact of parameter uncertainty on the coronavirus disease 2019 reproduction number
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Robert Challen, Ellen Brooks-Pollock, Krasimira Tsaneva-Atanasova, and Leon Danon
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Statistics and Probability ,Health Information Management ,SARS-CoV-2 ,Epidemiology ,Reproduction ,Uncertainty ,COVID-19 ,Humans ,Disease Outbreaks - Abstract
The serial interval of an infectious disease, commonly interpreted as the time between the onset of symptoms in sequentially infected individuals within a chain of transmission, is a key epidemiological quantity involved in estimating the reproduction number. The serial interval is closely related to other key quantities, including the incubation period, the generation interval (the time between sequential infections), and time delays between infection and the observations associated with monitoring an outbreak such as confirmed cases, hospital admissions, and deaths. Estimates of these quantities are often based on small data sets from early contact tracing and are subject to considerable uncertainty, which is especially true for early coronavirus disease 2019 data. In this paper, we estimate these key quantities in the context of coronavirus disease 2019 for the UK, including a meta-analysis of early estimates of the serial interval. We estimate distributions for the serial interval with a mean of 5.9 (95% CI 5.2; 6.7) and SD 4.1 (95% CI 3.8; 4.7) days (empirical distribution), the generation interval with a mean of 4.9 (95% CI 4.2; 5.5) and SD 2.0 (95% CI 0.5; 3.2) days (fitted gamma distribution), and the incubation period with a mean 5.2 (95% CI 4.9; 5.5) and SD 5.5 (95% CI 5.1; 5.9) days (fitted log-normal distribution). We quantify the impact of the uncertainty surrounding the serial interval, generation interval, incubation period, and time delays, on the subsequent estimation of the reproduction number, when pragmatic and more formal approaches are taken. These estimates place empirical bounds on the estimates of most relevant model parameters and are expected to contribute to modeling coronavirus disease 2019 transmission.
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- 2021
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14. Severity of Omicron (B.1.1.529) and Delta (B.1.1.617.2) SARS-CoV-2 infection among hospitalised adults: a prospective cohort study
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Catherine Hyams, Robert Challen, Robin Marlow, Jennifer Nguyen, Elizabeth Begier, Jo Southern, Jade King, Anna Morley, Jane Kinney, Madeleine Clout, Jennifer Oliver, Gillian Ellsbury, Nick Maskell, Luis Jodar, Bradford Gessner, John McLaughlin, Leon Danon, and Adam Finn
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Limited data exist assessing severity of disease in adults hospitalised with Omicron SARS-CoV-2 variant infections, and to what extent patient-factors, including vaccination and pre-existing disease, affect variant-dependent disease severity. This prospective cohort study of all adults (≥18 years of age) hospitalised at acute care hospitals in Bristol, UK assessed disease severity using 3 different measures: FiO2 >28%, World Health Organization (WHO) outcome score >5, and hospital length of stay (LOS) >3 days following admission for Omicron or Delta variant infection. Independent of other variables, including vaccination, Omicron variant infection was associated with a statistically lower severity compared to Delta; risk reductions were 58%, 67%, and 16% for FiO2, WHO score, and LOS, respectively. Younger age and vaccination with two or three doses were also independently associated with lower COVID-19 severity. Despite lower severity relative to Delta, Omicron infection still resulted in substantial patient and public health burden following admission.
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- 2022
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15. Severity of Omicron (B.1.1.529) and Delta (B.1.617.2) SARS-CoV-2 infection among hospitalised adults: a prospective cohort study in Bristol, United Kingdom
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Catherine Hyams, Robert Challen, Robin Marlow, Jennifer Nguyen, Elizabeth Begier, Jo Southern, Jade King, Anna Morley, Jane Kinney, Madeleine Clout, Jennifer Oliver, Sharon Gray, Gillian Ellsbury, Nick Maskell, Luis Jodar, Bradford Gessner, John McLaughlin, Leon Danon, and Adam Finn
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BackgroundThere is an urgent public health need to evaluate disease severity in adults hospitalised with Delta and Omicron SARS-CoV-2 variant infections. However, limited data exist assessing severity of disease in adults hospitalised with Omicron SARS-CoV-2 infections, and to what extent patient-factors, including vaccination, age, frailty and pre-existing disease, affect variant-dependent disease severity.MethodsA prospective cohort study of adults (≥18 years of age) hospitalised with acute lower respiratory tract disease at acute care hospitals in Bristol, UK conducted over 10-months. Delta or Omicron SARS-CoV-2 infection was defined by positive SARS-CoV-2 PCR and variant identification or inferred by dominant circulating variant. We constructed adjusted regression analyses to assess disease severity using three different measures: FiO2>28% (fraction inspired oxygen), World Health Organization (WHO) outcome score >5 (assessing need for ventilatory support), and hospital length of stay (LOS) >3 days following admission for Omicron or Delta infection.FindingsIndependent of other variables, including vaccination, Omicron variant infection in hospitalised adults was associated with lower severity than Delta. Risk reductions were 58%, 67%, and 16% for supplementary oxygen with >28% FiO2[Relative Risk (RR)=0·42 (95%CI: 0·34-0·52),P5 [RR=0·33 (95%CI: 0·21-0·50),P3 days [RR=0·84 (95%CI: 0·76-0·92),PInterpretationWe provide reassuring evidence that Omicron infection results in less serious adverse outcomes than Delta in hospitalised patients. Despite lower severity relative to Delta, Omicron infection still resulted in substantial patient and public health burden and an increased admission rate of older patients with Omicron which counteracts some of the benefit arising from less severe disease.FundingAvonCAP is an investigator-led project funded under a collaborative agreement by Pfizer.RESEARCH IN CONTEXTEvidence before this studyThe burden of COVID-19 on hospital services is determined by the prevalence and severity of SARS-CoV-2 variants, and modified by individual factors such as age, frailty and vaccination status. Real world data suggest that vaccine effectiveness is lower and may wane faster over time against symptomatic disease with Omicron (B.1.1.529) than with Delta (B.1.617.2) SARS-CoV-2 variant. However, numbers of hospitalisations as a case proportion during the Omicron wave have been considerably lower than previous waves. Several reports have compared the risk of hospitalisation or severe disease based on SARS-CoV-2 variant, some suggesting that Omicron is probably less severe than Delta in vaccinated and unvaccinated individuals.Added value of this studyThis study provides robust data assessing the relative severity of Delta and Omicron SARS-CoV-2 variants in patients admitted to hospital, including the first analysis assessing risk for any positive pressure ventilatory support, as well as risk of supplementary oxygen requirement and extended hospital admission, that may guide resource planning in hospitals. We found evidence that infection with Omicron was associated with a milder clinical course following hospital admission than that caused by Delta and that vaccination was independently associated with lower in-hospital disease severity using these three separate severity measures. Specifically, compared to Delta, Omicron-related hospitalizations were 58%, 67%, and 16% less likely to require high flow oxygen >28% FiO2, positive pressure ventilatory support or more critical care, and to have a hospital stay lasting more than three days, respectively.This study reports the considerable morbidity resulting from Omicron infection, with 18% of Omicron admissions requiring oxygen supplementation FiO2>28%, 6% requiring positive pressure ventilation, 62% needing hospitalization ≥four days, and 4% in-hospital mortality. In determining the reduced requirement of increased oxygen requirement and total positive pressure requirement, including non-invasive ventilation, this analysis should contribute to future hospital care and service planning assessments.Implications of all the available evidenceThe risk of severe outcomes following SARS-CoV-2 infection is substantially lower for Omicron than for Delta, with greater reductions for more severe disease outcomes. Significant variation in risk occurs with age and vaccination status, with older and unvaccinated individuals remaining at particular risk of adverse outcome. These results highlight the importance of maintaining high levels of vaccine coverage in patient groups at risk of severe disease.The impact of lower severity Omicron-related hospitalization must be balanced against increased transmissibility and overall higher numbers of infections with this variant and there remains a substantial patient and public health burden. The increased admission rate of older patients with Omicron counteracts some of the benefit arising from less severe disease. Despite the risk reduction in high level oxygen supplementation requirement and high dependency care with Omicron compared to earlier variants at the individual level, healthcare systems could still be overwhelmed.
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- 2022
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16. Factors influencing digital review of pathology test results in an inpatient setting: a cross-sectional study
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Luke Gompels, Krasimira Tsaneva-Atanasova, Mark Dayer, Thomas L Edwards, Leon Danon, Martin Pitt, and Robert Challen
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Quality management ,AcademicSubjects/SCI01060 ,Cross-sectional study ,test result follow-up ,Health Informatics ,Research and Applications ,Delayed diagnosis ,quality improvement ,laboratory informatics ,03 medical and health sciences ,0302 clinical medicine ,data quality ,Medicine ,030212 general & internal medicine ,business.industry ,030503 health policy & services ,Inpatient setting ,Phlebotomy ,medicine.disease ,Test (assessment) ,clinical workflow ,Workflow ,Data quality ,Medical emergency ,AcademicSubjects/SCI01530 ,AcademicSubjects/MED00010 ,0305 other medical science ,business - Abstract
Background Delay or failure to view test results in a hospital setting can lead to delayed diagnosis, risk of patient harm, and represents inefficiency. Factors influencing this were investigated to identify how timeliness and completeness of test review could be improved through an evidence-based redesign of the use of clinical test review software. Methods A cross-section of all abnormal hematology and biochemistry results which were published on a digital test review platform over a 3-year period were investigated. The time it took for clinicians to view these results, and the results that were not viewed within 30 days, were analyzed relative to time of the week, the detailed type of test, and an indicator of patient record data quality. Results The majority of results were viewed within 90 min, and 93.9% of these results viewed on the digital platform within 30 days. There was significant variation in results review throughout the week, shown to be due to an interplay between technical and clinical workflow factors. Routine results were less likely to be reviewed, as were those with patient record data quality issues. Conclusion The evidence suggests that test result review would be improved by stream-lining access to the result platform, differentiating between urgent and routine results, improving handover of responsibility for result review, and improving search for temporary patient records. Altering the timing of phlebotomy rounds and a review of the appropriateness of routine test requests at the weekend may also improve result review rates.
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- 2020
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17. Parapneumonic effusions related toStreptococcus pneumoniae: serotype and disease severity trends from 2006 to 2018 in Bristol, UK
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Catherine Hyams, David T Arnold, Robyn Heath, Zahin Amin-Chowdhury, David Hettle, Gabriella Ruffino, Paul North, Charli Grimes, Norman K Fry, Philip Williams, Robert Challen, Leon Danon, O Martin Williams, Shamez Ladhani, Adam Finn, and Nick A Maskell
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Pulmonary and Respiratory Medicine - Abstract
RationaleStreptococcus pneumoniaeepidemiology is changing in response to vaccination and some data suggest empyema incidence is increasing. However, differences exist between UK and USA studies. We describe trends in the clinical phenotype of adult pneumococcal pleural infection, including simple parapneumonic effusions (SPE) in the pneumococcal conjugate vaccination (PCV) era.ObjectivesTo determine whether there were differences in pneumococcal disease presentation and severity associated with pleural infection.MethodsA retrospective cohort study, all adults ≥16 years admitted to three large UK hospitals, 2006-2018 with pneumococcal disease. 2477 invasive pneumococcal cases were identified: 459 SPE and 100 pleural infection cases. Medical records were reviewed for each clinical episode. Serotype data were obtained from the UK Health Security Agency national reference laboratory.ResultsIncidence increased over time, including non-PCV-serotype disease. PCV7-serotype disease declined following paediatric PCV7 introduction, but the effect of PCV13 was less apparent as disease caused by the additional six serotypes plateaued with serotypes 1 and 3 causing such parapneumonic effusions from 2011 onwards.Patients with pleural infection had a median survival 468 days (95% CI 340-590), versus 286 days (95% CI 274-335) in those with SPE. Pleural infection associated with frank pus had lower 90-day mortality than pleural infection without pus (0% versus 29%,PP=0.049).ConclusionsPneumococcal infection continues to cause severe disease despite the introduction of PCVs. The predominance of serotype 1 and 3 in this adult UK cohort is in keeping with previous studies in paediatric and non-UK studies. Rising non-PCV serotype disease and limited impact of PCV13 on cases caused by serotypes 1 and 3 offset the reductions in adult pneumococcal parapneumonic effusion disease burden observed following introduction of the childhood PCV7 programme.KEY MESSAGESWhat is already known on this topicThe epidemiology of pneumococcal infection is changing in both adults and children following pneumococcal conjugate vaccine (PCV) introduction, as a result of direct and indirect vaccine effects. Other studies have reported that serotypes 1 and 3 disproportionately cause pneumococcal pleural disease; however, the clinical phenotype of parapneumonic effusions associated with pneumococcal infection in adults following PCV introduction is not well described.What this study addsIn this study which presents the largest cohort of patients with a single-organism pleural infection, we demonstrate an increasing incidence of parapneumonic effusions related toStreptococcus pneumoniaein adults, attributable to serotype 1 and 3 disease, despite the introduction of PCV13 in the UK childhood vaccination programme. Interestingly, our data suggest that pneumococcal pleural infection is associated with improved survival up to one-year compared to patients with pneumococcal simple parapneumonic effusions.How this study might affect research, practice or policyCareful assessment of the need for specialist respiratory and thoracic surgical intervention in the context of increasing incidence of adult parapneumonic effusions related toStreptococcus pneumoniaewill be required, in addition to ongoing monitoring of the effect on serotype distribution and clinical phenotype of current and future vaccines against pneumococcus.
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- 2022
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18. Effectiveness of BNT162b2 COVID-19 Vaccination in Prevention of Hospitalisations and Severe Disease in Adults with Delta (B.1.617.2) and Omicron (B.1.1.529) Variant SARS-CoV-2 Infection: A Prospective Test Negative Case-Control Study
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Anastasia Chatzilena, Catherine Hyams, Robert Challen, Robin Marlow, Jade King, David Adegbite, Jane Kinney, Madeleine Clout Clout, Nick A. Maskell, Jennifer Oliver, Leon Danon, and Adam Finn
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- 2022
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19. Incidence of Community Acquired Lower Respiratory Tract Disease in Bristol, UK During the COVID-19 Pandemic
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Catherine Hyams, Robert Challen, Elizabeth Begier, Jo Southern, Jade King, Anna Morley, Zsuzsa Szasz-Benczur, Maria Garcia Gonzalez, Jane Kinney, James Campling, Sharon Gray, Jennifer Oliver, Robin Hubler, Srinivas R. Valluri, Andrew Vyse, John M. McLaughlin, Gillian Ellsbury, Nick Maskell, Bradford Gessner, Leon Danon, and Adam Finn
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
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20. Impact of SARS-CoV-2 Infective Exacerbation of Chronic Obstructive Pulmonary Disease (COPD) on Clinical Outcomes in a Prospective Cohort Study of Hospitalised Adults
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Catherine Hyams, George Qian, George Nava, Robert Challen, Elizabeth Begier, Jo Southern, Maria Laheurta, Jennifer L. Nguyen, Jade King, Anna Morley, Madeleine Clout Clout, Nick A. Maskell, Luis Jodar, Jennifer Oliver, Gillian Ellsbury, John M. McLaughlin, Bradford Gessner, Adam Finn, Leon Danon, James Dodd, and The Avon CAP Research Group
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
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21. Commentary on the use of the reproduction number
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Carolin, Vegvari, Sam, Abbott, Frank, Ball, Ellen, Brooks-Pollock, Robert, Challen, Benjamin S, Collyer, Ciara, Dangerfield, Julia R, Gog, Katelyn M, Gostic, Jane M, Heffernan, T Déirdre, Hollingsworth, Valerie, Isham, Eben, Kenah, Denis, Mollison, Jasmina, Panovska-Griffiths, Lorenzo, Pellis, Michael G, Roberts, Gianpaolo, Scalia Tomba, Robin N, Thompson, and Pieter, Trapman
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Reproduction ,Basic Reproduction Number ,COVID-19 ,Humans ,Pandemics ,Forecasting - Abstract
Since the beginning of the COVID-19 pandemic, the reproduction number [Formula: see text] has become a popular epidemiological metric used to communicate the state of the epidemic. At its most basic, [Formula: see text] is defined as the average number of secondary infections caused by one primary infected individual. [Formula: see text] seems convenient, because the epidemic is expanding if [Formula: see text] and contracting if [Formula: see text]. The magnitude of [Formula: see text] indicates by how much transmission needs to be reduced to control the epidemic. Using [Formula: see text] in a naïve way can cause new problems. The reasons for this are threefold: (1) There is not just one definition of [Formula: see text] but many, and the precise definition of [Formula: see text] affects both its estimated value and how it should be interpreted. (2) Even with a particular clearly defined [Formula: see text], there may be different statistical methods used to estimate its value, and the choice of method will affect the estimate. (3) The availability and type of data used to estimate [Formula: see text] vary, and it is not always clear what data should be included in the estimation. In this review, we discuss when [Formula: see text] is useful, when it may be of use but needs to be interpreted with care, and when it may be an inappropriate indicator of the progress of the epidemic. We also argue that careful definition of [Formula: see text], and the data and methods used to estimate it, can make [Formula: see text] a more useful metric for future management of the epidemic.
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- 2021
22. Commentary on the use of the reproduction number R during the COVID-19 pandemic
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T. Déirdre Hollingsworth, Michael G. Roberts, Carolin Vegvari, Ellen Brooks-Pollock, Jasmina Panovska-Griffiths, Julia R. Gog, Eben Kenah, Robin N Thompson, Frank Ball, Ciara Dangerfield, Gianpaolo Scalia Tomba, Jane M. Heffernan, Robert Challen, Sam Abbott, Valerie Isham, Pieter Trapman, Lorenzo Pellis, Benjamin S Collyer, Katelyn M. Gostic, Denis Mollison, Vegvari, Carolin [0000-0003-2018-011X], Challen, Robert [0000-0002-5504-7768], Thompson, Robin N [0000-0001-8545-5212], and Apollo - University of Cambridge Repository
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Statistics and Probability ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,Epidemiology ,Reproduction number ,Reproduction (economics) ,Secondary infection ,Basic Reproduction Number ,COVID-19 pandemic ,03 medical and health sciences ,0302 clinical medicine ,Health Information Management ,Pandemic ,Statistics ,Humans ,030212 general & internal medicine ,Pandemics ,030304 developmental biology ,Mathematics ,Estimation ,0303 health sciences ,Reproduction ,COVID-19 ,3. Good health ,Settore MAT/06 ,Metric (mathematics) ,FOS: Medical biotechnology ,Value (mathematics) ,Forecasting - Abstract
Funder: NHS Global Digital Exemplar programme, Funder: James S. McDonnell Foundation; FundRef: https://doi.org/10.13039/100000913, Funder: NIHR Health Protection Research Unit in Behavioural Science and Evaluation at the University of Bristol, Funder: Wellcome Trust; FundRef: https://doi.org/10.13039/100004440, Funder: Canadian Institutes for Health Research, Funder: Natural Science and Engineering Research Council of Canada, Since the beginning of the COVID-19 pandemic, the reproduction number [Formula: see text] has become a popular epidemiological metric used to communicate the state of the epidemic. At its most basic, [Formula: see text] is defined as the average number of secondary infections caused by one primary infected individual. [Formula: see text] seems convenient, because the epidemic is expanding if [Formula: see text] and contracting if [Formula: see text]. The magnitude of [Formula: see text] indicates by how much transmission needs to be reduced to control the epidemic. Using [Formula: see text] in a naïve way can cause new problems. The reasons for this are threefold: (1) There is not just one definition of [Formula: see text] but many, and the precise definition of [Formula: see text] affects both its estimated value and how it should be interpreted. (2) Even with a particular clearly defined [Formula: see text], there may be different statistical methods used to estimate its value, and the choice of method will affect the estimate. (3) The availability and type of data used to estimate [Formula: see text] vary, and it is not always clear what data should be included in the estimation. In this review, we discuss when [Formula: see text] is useful, when it may be of use but needs to be interpreted with care, and when it may be an inappropriate indicator of the progress of the epidemic. We also argue that careful definition of [Formula: see text], and the data and methods used to estimate it, can make [Formula: see text] a more useful metric for future management of the epidemic.
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- 2021
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23. Early epidemiological signatures of novel SARS-CoV-2 variants: establishment of B.1.617.2 in England
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Julia R. Gog, Matthew James Keeling, David J Pascall, Helena B. Stage, Francesca Scarabel, Michael J. Tildesley, Leon Danon, Jonathan M Read, Ben Youngman, Stefan Siegert, Ellen Brooks-Pollock, Laura Guzman-Rincon, Louise Dyson, Xiaoyu Xiong, Daniel Williamson, Paula Blomquist, Edward M. Hill, Robert Challen, Christopher E. Overton, and Lorenzo Pellis
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medicine.medical_specialty ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,Routine testing ,Transmission (medicine) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Epidemiology ,Pandemic ,medicine ,Biology ,Virology - Abstract
The rapid emergence of SARS-CoV-2 mutants with new phenotypic properties is a critical challenge to the control of the ongoing pandemic. B.1.1.7 was monitored in the UK through routine testing and S-gene target failures (SGTF), comprising over 90% of cases by March 2021. Now, the reverse is occurring: SGTF cases are being replaced by an S-gene positive variant, which we associate with B.1.617.2. Evidence from the characteristics of S-gene positive cases demonstrates that, following importation, B.1.617.2 is transmitted locally, growing at a rate higher than B.1.1.7 and a doubling time between 5-14 days. S-gene positive cases should be prioritised for sequencing and aggressive control in any countries in which this variant is newly detected.One-Sentence SummaryThe B.1.617.2 variant of SARS-CoV-2 is replacing B.1.1.7 and emerging as the dominant variant in England, evidenced by sustained local transmission.
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- 2021
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24. Increased hazard of mortality in cases compatible with SARS-CoV-2 variant of concern 202012/1 - a matched cohort study
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Robert Challen, Ellen Brooks-Pollock, Krasimira Tsaneva-Atanasova, Leon Danon, Louise Dyson, and Jonathan M. Read
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Matched cohort ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Risk of mortality ,Ethnic group ,Medicine ,Spike Protein ,New variant ,business ,Hazard ,Demography - Abstract
ObjectivesTo establish whether there is any change in mortality associated with infection of a new variant of SARS-CoV-2, designated a Variant of Concern in December 2020 (VOC-202012/1) compared to that associated with infection with circulating SARS-CoV-2 variants.DesignMatched cohort study. Cases are matched by age, gender, ethnicity, index of multiple deprivation, lower tier local authority region, and sample date of positive specimen, and differing only by detectability of the spike protein gene using the TaqPath assay - a proxy measure of VOC-202012/1 infection.SettingUnited Kingdom, community - based (Pillar 2) COVID-19 testing centres using the TaqPath assay.Participants54,906 pairs of participants testing positive for SARS-CoV-2 in Pillar 2 between 1st October 2020 and 29th January 2021, followed up until the 12th February 2021.Main outcome measuresDeath within 28 days of first positive SARS-CoV-2 test.ResultsThere is a high probability that the risk of mortality is increased by infection with VOC-202012/01 (p ConclusionsIf this finding is generalisable to other populations, VOC-202012/1 infections have the potential to cause substantial additional mortality compared to previously circulating variants. Healthcare capacity planning, national and international control policies are all impacted by this finding, with increased mortality lending weight to the argument that further coordinated and stringent measures are justified to reduce deaths from SARS-CoV-2.
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- 2021
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25. A flexible method for optimising sharing of healthcare resources and demand in the context of the COVID-19 pandemic
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Ellen Brooks-Pollock, Robert Challen, Leon Danon, and Lucas Lacasa
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Patient Transfer ,2019-20 coronavirus outbreak ,Knowledge management ,Coronavirus disease 2019 (COVID-19) ,Critical Care ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Science ,Pneumonia, Viral ,Context (language use) ,Betacoronavirus ,Pandemic ,Health care ,Humans ,Pandemics ,Multidisciplinary ,Ventilators, Mechanical ,business.industry ,SARS-CoV-2 ,Correction ,COVID-19 ,Models, Theoretical ,United Kingdom ,Intensive Care Units ,Hospital Bed Capacity ,Spain ,Health Resources ,Medicine ,business ,Coronavirus Infections ,Algorithms - Abstract
As the number of cases of COVID-19 continues to grow, local health services are at risk of being overwhelmed with patients requiring intensive care. We develop and implement an algorithm to provide optimal re-routing strategies to either transfer patients requiring Intensive Care Units (ICU) or ventilators, constrained by feasibility of transfer. We validate our approach with realistic data from the United Kingdom and Spain. In the UK, we consider the National Health Service at the level of trusts and define a 4-regular geometric graph which indicates the four nearest neighbours of any given trust. In Spain we coarse-grain the healthcare system at the level of autonomous communities, and extract similar contact networks. Through random search optimisation we identify the best load sharing strategy, where the cost function to minimise is based on the total number of ICU units above capacity. Our framework is general and flexible allowing for additional criteria, alternative cost functions, and can be extended to other resources beyond ICU units or ventilators. Assuming a uniform ICU demand, we show that it is possible to enable access to ICU for up to 1000 additional cases in the UK in a single step of the algorithm. Under a more realistic and heterogeneous demand, our method is able to balance about 600 beds per step in the Spanish system only using local sharing, and over 1300 using countrywide sharing, potentially saving a large percentage of these lives that would otherwise not have access to ICU.
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- 2021
26. Estimates of regional infectivity of COVID-19 in the United Kingdom following imposition of social distancing measures
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Luke Gompels, Tom Edwards, Krasimira Tsaneva-Atanasova, Ellen Brooks-Pollock, Lucas Lacasa, Martin Pitt, Robert Challen, Leon Danon, Engineering and Physical Sciences Research Council (UK), National Institutes of Health (US), Alan Turing Institute, Medical Research Council (UK), National Institute for Health Research (UK), and University of Bristol
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0301 basic medicine ,Reproduction (economics) ,Physical Distancing ,Psychological intervention ,Basic Reproduction Number ,Distribution (economics) ,General Biochemistry, Genetics and Molecular Biology ,Disease Outbreaks ,03 medical and health sciences ,0302 clinical medicine ,Pandemic ,Humans ,030212 general & internal medicine ,Pandemics ,Research Articles ,business.industry ,SARS-CoV-2 ,Social distance ,COVID-19 ,reproduction number ,regional variation ,Articles ,Models, Theoretical ,United Kingdom ,030104 developmental biology ,Geography ,Regional variation ,Contact Tracing ,General Agricultural and Biological Sciences ,business ,Basic reproduction number ,Demography ,Serial interval - Abstract
This article is part of the theme issue ‘Modelling that shaped the early COVID-19 pandemic response in the UK'., The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reproduction number has become an essential parameter for monitoring disease transmission across settings and guiding interventions. The UK published weekly estimates of the reproduction number in the UK starting in May 2020 which are formed from multiple independent estimates. In this paper, we describe methods used to estimate the time-varying SARS-CoV-2 reproduction number for the UK. We used multiple data sources and estimated a serial interval distribution from published studies. We describe regional variability and how estimates evolved during the early phases of the outbreak, until the relaxing of social distancing measures began to be introduced in early July. Our analysis is able to guide localized control and provides a longitudinal example of applying these methods over long timescales., Support for R.C. and K.T.A.'s research is provided by the EPSRC via grant no. EP/N014391/1; R.C. is also funded by TSFT as part of the NHS Global Digital Exemplar programme (GDE); there were no financial relationships with any organizations that might have an interest in the submitted work in the previous 3 years, no other relationships or activities that could appear to have influenced the submitted work. L.D. and K.T.A. gratefully acknowledge the financial support of The Alan Turing Institute under the EPSRC grant no. EP/N510129/1. L.L. acknowledges the financial support of the EPSRC via Early Career Fellowship EP/P01660X/1. L.D. and E.B.P. are supported by Medical Research Council (MRC) (MC/PC/19067). E.B.P. was partly supported by the NIHR Health Protection Research Unit in Behavioural Science and Evaluation at University of Bristol, in partnership with PHE.
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- 2021
27. Meta-analysis of the SARS-CoV-2 serial interval and the impact of parameter uncertainty on the COVID-19 reproduction number
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Robert Challen, Leon Danon, Krasimira Tsaneva-Atanasova, and Ellen Brooks-Pollock
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Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Meta-analysis ,Statistics ,Log-normal distribution ,Gamma distribution ,Empirical distribution function ,Serial interval ,Mathematics ,Incubation period - Abstract
The serial interval of an infectious disease, commonly interpreted as the time between onset of symptoms in sequentially infected individuals within a chain of transmission, is a key epidemiological quantity involved in estimating the reproduction number. The serial interval is closely related to other key quantities, including the incubation period, the generation interval (the time between sequential infections) and time delays between infection and the observations associated with monitoring an outbreak such as confirmed cases, hospital admissions and deaths. Estimates of these quantities are often based on small data sets from early contact tracing and are subject to considerable uncertainty, which is especially true for early COVID-19 data. In this paper we estimate these key quantities in the context of COVID-19 for the UK, including a meta-analysis of early estimates of the serial interval. We estimate distributions for the serial interval with a mean 5.6 (95% CrI 5.1–6.2) and SD 4.2 (95% CrI 3.9–4.6) days (empirical distribution), the generation interval with a mean 4.8 (95% CrI 4.3–5.41) and SD 1.7 (95% CrI 1.0–2.6) days (fitted gamma distribution), and the incubation period with a mean 5.5 (95% CrI 5.1–5.8) and SD 4.9 (95% CrI 4.5–5.3) days (fitted log normal distribution). We quantify the impact of the uncertainty surrounding the serial interval, generation interval, incubation period and time delays, on the subsequent estimation of the reproduction number, when pragmatic and more formal approaches are taken. These estimates place empirical bounds on the estimates of most relevant model parameters and are expected to contribute to modelling COVID-19 transmission.
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- 2020
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28. Estimates of regional infectivity of COVID-19 in the United Kingdom following imposition of social distancing measures
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Luke Gompels, Ellen Brooks-Pollock, Gareth J Griffith, Thomas L Edwards, Robert Challen, Martin Pitt, Lucas Lacasa, Chris Martin, Leon Danon, and Krasimira Tsaneva-Atanasova
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Infectivity ,0303 health sciences ,Coronavirus disease 2019 (COVID-19) ,Social distance ,Variable time ,Outbreak ,3. Good health ,03 medical and health sciences ,0302 clinical medicine ,Geography ,Regional variation ,Spatial ecology ,030212 general & internal medicine ,Viral spread ,030304 developmental biology ,Demography - Abstract
We describe regional variation in the reproduction number of SARS-CoV-2 infections observed using publicly reported data in the UK, with a view to understanding both if there are clear hot spots in viral spread in the country, or if there are any clear spatial patterns. We estimate that the viral replication number remains slightly above 1 overall but that its trend is to decrease, based on case data up to the 8 April. This suggests the peak of the first wave of COVID-19 patients is imminent. We find that there is significant regional variation in different regions of the UK and that this is changing over time. Within England currently the reproductive ratio is lowest in the Midlands (1.11 95% CI 1.07; 1.14), and highest in the North East of England (1.38 95% CI 1.33-1.42). It remains unclear whether the overall reduction in the reproductive number is a result of social distancing measures, due to the long and variable time delays between infection and positive detection of cases. As we move forwards, if we are to prevent further outbreaks, it is critical that we can both reduce the time taken for detection and improve our ability to predict the regional spread of outbreaks
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- 2020
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29. Risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1: matched cohort study
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Louise Dyson, Jonathan M. Read, Ellen Brooks-Pollock, Leon Danon, Robert Challen, and Krasimira Tsaneva-Atanasova
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Adult ,Male ,medicine.medical_specialty ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Cohort Studies ,COVID-19 Testing ,Matched cohort ,Risk Factors ,Internal medicine ,Risk of mortality ,Humans ,Medicine ,Statistics & numerical data ,Aged ,Proportional Hazards Models ,Aged, 80 and over ,SARS-CoV-2 ,Proportional hazards model ,business.industry ,Research ,Vaccination ,Hazard ratio ,COVID-19 ,Covid19 ,General Medicine ,Middle Aged ,United Kingdom ,Confidence interval ,Female ,business ,RA ,Cohort study - Abstract
Objective To establish whether there is any change in mortality from infection with a new variant of SARS-CoV-2, designated a variant of concern (VOC-202012/1) in December 2020, compared with circulating SARS-CoV-2 variants. Design Matched cohort study. Setting Community based (pillar 2) covid-19 testing centres in the UK using the TaqPath assay (a proxy measure of VOC-202012/1 infection). Participants 54 906 matched pairs of participants who tested positive for SARS-CoV-2 in pillar 2 between 1 October 2020 and 29 January 2021, followed-up until 12 February 2021. Participants were matched on age, sex, ethnicity, index of multiple deprivation, lower tier local authority region, and sample date of positive specimens, and differed only by detectability of the spike protein gene using the TaqPath assay. Main outcome measure Death within 28 days of the first positive SARS-CoV-2 test result. Results The mortality hazard ratio associated with infection with VOC-202012/1 compared with infection with previously circulating variants was 1.64 (95% confidence interval 1.32 to 2.04) in patients who tested positive for covid-19 in the community. In this comparatively low risk group, this represents an increase in deaths from 2.5 to 4.1 per 1000 detected cases. Conclusions The probability that the risk of mortality is increased by infection with VOC-202012/01 is high. If this finding is generalisable to other populations, infection with VOC-202012/1 has the potential to cause substantial additional mortality compared with previously circulating variants. Healthcare capacity planning and national and international control policies are all impacted by this finding, with increased mortality lending weight to the argument that further coordinated and stringent measures are justified to reduce deaths from SARS-CoV-2.
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- 2021
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30. Artificial intelligence, bias and clinical safety
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Robert, Challen, Joshua, Denny, Martin, Pitt, Luke, Gompels, Tom, Edwards, and Krasimira, Tsaneva-Atanasova
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Bias ,Artificial Intelligence ,Humans ,Patient Safety ,Algorithms ,Quality of Health Care - Published
- 2018
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