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1.
Ann Epidemiol ; 82: 66-76.e6, 2023 06.
Article in English | MEDLINE | ID: covidwho-2252905

ABSTRACT

PURPOSE: Most index cases with novel coronavirus infections transmit disease to just one or two other individuals, but some individuals "super-spread"-they infect many secondary cases. Understanding common factors that super-spreaders may share could inform outbreak models, and be used to guide contact tracing during outbreaks. METHODS: We searched in MEDLINE, Scopus, and preprints to identify studies about people documented as transmitting pathogens that cause SARS, MERS, or COVID-19 to at least nine other people. We extracted data to describe them by age, sex, location, occupation, activities, symptom severity, any underlying conditions, disease outcome and undertook quality assessment for outbreaks published by June 2021. RESULTS: The most typical super-spreader was a male age 40+. Most SARS or MERS super-spreaders were very symptomatic, the super-spreading occurred in hospital settings and frequently the individual died. In contrast, COVID-19 super-spreaders often had very mild disease and most COVID-19 super-spreading happened in community settings. CONCLUSIONS: SARS and MERS super-spreaders were often symptomatic, middle- or older-age adults who had a high mortality rate. In contrast, COVID-19 super-spreaders tended to have mild disease and were any adult age. More outbreak reports should be published with anonymized but useful demographic information to improve understanding of super-spreading, super-spreaders, and the settings in which super-spreading happens.


Subject(s)
COVID-19 , Adult , Male , Humans , COVID-19/epidemiology , SARS-CoV-2 , Disease Outbreaks
2.
Risk Anal ; 42(7): 1571-1584, 2022 07.
Article in English | MEDLINE | ID: covidwho-2097864

ABSTRACT

Understanding is still developing about spatial risk factors for COVID-19 infection or mortality. This is a secondary analysis of patient records in a confined area of eastern England, covering persons who tested positive for SARS-CoV-2 through end May 2020, including dates of death and residence area. We obtained residence area data on air quality, deprivation levels, care home bed capacity, age distribution, rurality, access to employment centers, and population density. We considered these covariates as risk factors for excess cases and excess deaths in the 28 days after confirmation of positive Covid status relative to the overall case load and death recorded for the study area as a whole. We used the conditional autoregressive Besag-York-Mollie model to investigate the spatial dependency of cases and deaths allowing for a Poisson error structure. Structural equation models were applied to clarify relationships between predictors and outcomes. Excess case counts or excess deaths were both predicted by the percentage of population age 65 years, care home bed capacity and less rurality: older population and more urban areas saw excess cases. Greater deprivation did not correlate with excess case counts but was significantly linked to higher mortality rates after infection. Neither excess cases nor excess deaths were predicted by population density, travel time to local employment centers, or air quality indicators. Only 66% of mortality was explained by locally high case counts. Higher deprivation clearly linked to higher COVID-19 mortality separate from wider community prevalence and other spatial risk factors.


Subject(s)
Air Pollution , COVID-19 , Aged , Air Pollution/adverse effects , England/epidemiology , Humans , Mortality , Risk Factors , SARS-CoV-2
3.
Am J Infect Control ; 2022 Nov 02.
Article in English | MEDLINE | ID: covidwho-2094996

ABSTRACT

BACKGROUND: Staff actions to prevent infection introduction and transmission in long-term care facilities (LTCFs) were key to reducing morbidity and mortality from COVID-19. Implementing infection control measures (ICMs) requires training, adherence and complex decision making while trying to deliver high quality care. We surveyed LTCF staff in England about their preparedness and morale at 3 timepoints during the COVID-19 epidemic. METHODS: Online structured survey targeted at LTCF workers (any role) administered at 3 timepoints (November 2020-January 2021; August-November 2021; March-May 2022). Narrative summary of answers, narrative and statistical summary (proportionality with Pearson's chi-square or Fisher's Exact Test) of possible differences in answers between waves. RESULTS: Across all 3 survey waves, 387 responses were received. Morale, attitudes towards working environment and perception about colleague collaboration were mostly positive at all survey points. Infection control training was perceived as adequate. Staff felt mostly positive emotions at work. The working environment remained challenging. Masks were the single form of PPE most consistently used; eye protection the least used. Mask-wearing was linked to poorer communication and resident discomfort as well as mild negative health impacts on many staff, such as dehydration and adverse skin reactions. Hand sanitizer caused skin irritation. CONCUSIONS: Staff morale and working practices were generally good even though the working environment provided many new challenges that did not exist pre-pandemic.

4.
Am J Infect Control ; 50(8): 878-884, 2022 08.
Article in English | MEDLINE | ID: covidwho-2000218

ABSTRACT

BACKGROUND: Face shields were widely used in 2020-2021 as facial personal protective equipment (PPE). Laboratory evidence about how protective face shields might be and whether real world user priorities and usage habits conflicted with best practice for maximum possible protection was lacking - especially in limited resource settings. METHODS: Relative protective potential of 13 face shield designs were tested in a controlled laboratory setting. Community and health care workers were surveyed in middle income country cities (Brazil and Nigeria) about their preferences and perspectives on face shields as facial PPE. Priorities about facial PPE held by survey participants were compared with the implications of the laboratory-generated test results. RESULTS: No face shield tested totally eliminated exposure. Head orientation and design features influenced the level of protection. Over 600 individuals were interviewed in Brazil and Nigeria (including 240 health care workers) in March-April 2021. Respondents commented on what influenced their preferred forms of facial PPE, how they tended to clean face shields, and their priorities in choosing a face cover product. Surveyed health care workers commonly bought personal protection equipment for use at work. CONCLUSIONS: All face shields provided some protection but none gave high levels of protection against external droplet contamination. Respondents wanted facial PPE that considered good communication, secure fixture, good visibility, comfort, fashion, and has validated protectiveness.


Subject(s)
COVID-19 , Personal Protective Equipment , COVID-19/prevention & control , Developing Countries , Health Personnel , Humans , Protective Devices
5.
Infection ; 50(5): 1171-1178, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1729430

ABSTRACT

BACKGROUND: It is useful to document whether each newly dominant SARS-CoV-2 variant of concern was more or less dangerous than preceding dominant variant(s). We assessed if the emergence of the Alpha (B.1.1.7) variant in autumn 2020 could be linked to higher case fatality rates, compared to original wild-type COVID-19, subgrouping by age band, sex, deprivation or month of diagnosis as potential risk factors. METHODS: Observational study and secondary analysis were conducted of SARS-CoV-2 cases diagnosed due to medical need or occupational exposure in an administrative area of Eastern England, UK (base population 1 million), who first tested positive in the period 1 March 2020 to 28 February 2021. Multivariate logistic regression was performed to examine relationships of age group, sex, deprivation group and month of diagnosis with case fatality rates within 28 days of diagnosis. Marginal probabilities for risk of dying were calculated separately for the first two main 'wave' periods of the English pandemic. RESULTS: Older age and male sex consistently raised the risk of mortality in both wave periods. Higher deprivation was linked to mortality risk in the first wave period, but not in the second wave. Mortality decreased over time during the first wave period, but slightly increased over time during the second wave. Cases were younger in the second wave, and median age of the deceased varied little between waves. INTERPRETATION: The Alpha variant of SARS-CoV-2 did not lead to higher mortality rates for any age, deprivation or sex group, compared to case fatality rates in the early part of the pandemic period.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , England/epidemiology , Humans , Infant, Newborn , Male , Pandemics
6.
Clin Nutr ESPEN ; 47: 96-105, 2022 02.
Article in English | MEDLINE | ID: covidwho-1520793

ABSTRACT

BACKGROUND AND AIMS: Advice to drink plenty of fluid is common in respiratory infections. We assessed whether low fluid intake (dehydration) altered outcomes in adults with pneumonia. METHODS: We systematically reviewed trials increasing fluid intake and well-adjusted, well-powered observational studies assessing associations between markers of low-intake dehydration (fluid intake, serum osmolality, urea or blood urea nitrogen, urinary output, signs of dehydration) and mortality in adult pneumonia patients (with any type of pneumonia, including community acquired, health-care acquired, aspiration, COVID-19 and mixed types). Medline, Embase, CENTRAL, references of reviews and included studies were searched to 30/10/2020. Studies were assessed for inclusion, risk of bias and data extracted independently in duplicate. We employed random-effects meta-analysis, sensitivity analyses, subgrouping and GRADE assessment. Prospero registration: CRD42020182599. RESULTS: We identified one trial, 20 well-adjusted cohort studies and one case-control study. None suggested that more fluid (hydration) was associated with harm. Ten of 13 well-powered observational studies found statistically significant positive associations in adjusted analyses between dehydration and medium-term mortality. The other three studies found no significant effect. Meta-analysis suggested doubled odds of medium-term mortality in dehydrated (compared to hydrated) pneumonia patients (GRADE moderate-quality evidence, OR 2.3, 95% CI 1.8 to 2.8, 8619 deaths in 128,319 participants). Heterogeneity was explained by a dose effect (greater dehydration increased risk of mortality further), and the effect was consistent across types of pneumonia (including community-acquired, hospital-acquired, aspiration, nursing and health-care associated, and mixed pneumonia), age and setting (community or hospital). The single trial found that educating pneumonia patients to drink ≥1.5 L fluid/d alongside lifestyle advice increased fluid intake and reduced subsequent healthcare use. No studies in COVID-19 pneumonia met the inclusion criteria, but 70% of those hospitalised with COVID-19 have pneumonia. Smaller COVID-19 studies suggested that hydration is as important in COVID-19 pneumonia mortality as in other pneumonias. CONCLUSIONS: We found consistent moderate-quality evidence mainly from observational studies that improving hydration reduces the risk of medium-term mortality in all types of pneumonia. It is remarkable that while many studies included dehydration as a potential confounder, and major pneumonia risk scores include measures of hydration, optimal fluid volume and the effect of supporting hydration have not been assessed in randomised controlled trials of people with pneumonia. Such trials, are needed as potential benefits may be large, rapid and implemented at low cost. Supporting hydration and reversing dehydration has the potential to have rapid positive impacts on pneumonia outcomes, and perhaps also COVID-19 pneumonia outcomes, in older adults.


Subject(s)
COVID-19 , Pneumonia , Aged , Case-Control Studies , Drinking , Humans , SARS-CoV-2
7.
Euro Surveill ; 26(28)2021 07.
Article in English | MEDLINE | ID: covidwho-1315937

ABSTRACT

IntroductionThe current pandemic of coronavirus disease (COVID-19) is unparalleled in recent history as are the social distancing interventions that have led to a considerable halt on the economic and social life of so many countries.AimWe aimed to generate empirical evidence about which social distancing measures had the most impact in reducing case counts and mortality.MethodsWe report a quasi-experimental (observational) study of the impact of various interventions for control of the outbreak through 24 April 2020. Chronological data on case numbers and deaths were taken from the daily published figures by the European Centre for Disease Prevention and Control and dates of initiation of various control strategies from the Institute of Health Metrics and Evaluation website and published sources. Our complementary analyses were modelled in R using Bayesian generalised additive mixed models and in STATA using multilevel mixed-effects regression models.ResultsFrom both sets of modelling, we found that closure of education facilities, prohibiting mass gatherings and closure of some non-essential businesses were associated with reduced incidence whereas stay-at-home orders and closure of additional non-essential businesses was not associated with any independent additional impact.ConclusionsOur findings are that schools and some non-essential businesses operating 'as normal' as well as allowing mass gatherings were incompatible with suppressing disease spread. Closure of all businesses and stay at home orders are less likely to be required to keep disease incidence low. Our results help identify what were the most effective non-pharmaceutical interventions in this period.


Subject(s)
COVID-19 , Bayes Theorem , Europe , Humans , Pandemics , SARS-CoV-2
8.
Risk Anal ; 41(12): 2286-2292, 2021 12.
Article in English | MEDLINE | ID: covidwho-1255471

ABSTRACT

The COVID-19 pandemic has disrupted economies and societies throughout the world since early 2020. Education is especially affected, with schools and universities widely closed for long periods. People under 25 years have the lowest risk of severe disease but their activities can be key to persistent ongoing community transmission. A challenge arose for how to provide education, including university level, without the activities of students increasing wider community SARS-CoV-2 infections. We used a Hazard Analysis of Critical Control Points (HACCP) framework to assess the risks associated with university student activity and recommend how to mitigate these risks. This tool appealed because it relies on multiagency collaboration and interdisciplinary expertise and yet is low cost, allowing rapid generation of evidence-based recommendations. We identified key critical control points associated with university student' activities, lifestyle, and interaction patterns both on-and-off campus. Unacceptable contact thresholds and the most up-to-date guidance were used to identify levels of risk for potential SARS-CoV-2 transmission, as well as recommendations based on existing research and emerging evidence for strategies that can reduce the risks of transmission. Employing the preventative measures we suggest can reduce the risks of SARS-CoV-2 transmission among and from university students. Reduction of infectious disease transmission in this demographic will reduce overall community transmission, lower demands on health services and reduce risk of harm to clinically vulnerable individuals while allowing vital education activity to continue. HACCP assessment proved a flexible tool for risk analysis in a specific setting in response to an emerging infectious disease threat. Systematic approaches to assessing hazards and risk critical control points (#HACCP) enable robust strategies for protecting students and staff in HE settings during #COVID19 pandemic.


Subject(s)
COVID-19/epidemiology , Hazard Analysis and Critical Control Points , Students , Universities , COVID-19/prevention & control , COVID-19/virology , Humans , Pandemics , SARS-CoV-2/isolation & purification
9.
J Public Health (Oxf) ; 43(2): 228-235, 2021 06 07.
Article in English | MEDLINE | ID: covidwho-998463

ABSTRACT

BACKGROUND: Residential care homes for the elderly are important settings for transmission of the SARS-CoV-2 virus that causes COVID-19 disease. METHODS: We undertook secondary analysis of 248 care homes in Norfolk, UK. The dataset counted nurses, care workers and non-care workers, their status (available, absent due to leave or sickness and extra staff needed to address the coronavirus pandemic) and residents (if any) with suspected COVID-19 in the period 6 April to 6 May 2020. Concurrent descriptions of access by the home to personal protection equipment (PPE: gloves, masks, eye protection, aprons and sanitizer) were in the data. PPE access was categorized as (most to least) green, amber or red. We undertook two-stage modelling, first for suspected COVID-19 cases amongst residents and second relating any increases in case counts after introduction to staffing or PPE levels. RESULTS: Counts of non-care workers had strongest relationships (P < 0.05) to introduction of suspected SARS-CoV-2 to the homes. Higher staff levels and more severe PPE shortages were linked to higher case counts (P < 0.05) during the monitoring period. CONCLUSION: Managing aspects of staff interaction with residents and some working practices might reduce ingression to and spread of COVID-19-like illness within care homes.


Subject(s)
COVID-19 , Aged , Health Personnel , Humans , Pandemics , Personal Protective Equipment , SARS-CoV-2 , United Kingdom/epidemiology
10.
Euro Surveill ; 25(49)2020 12.
Article in English | MEDLINE | ID: covidwho-972565

ABSTRACT

BackgroundEvidence for face-mask wearing in the community to protect against respiratory disease is unclear.AimTo assess effectiveness of wearing face masks in the community to prevent respiratory disease, and recommend improvements to this evidence base.MethodsWe systematically searched Scopus, Embase and MEDLINE for studies evaluating respiratory disease incidence after face-mask wearing (or not). Narrative synthesis and random-effects meta-analysis of attack rates for primary and secondary prevention were performed, subgrouped by design, setting, face barrier type, and who wore the mask. Preferred outcome was influenza-like illness. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) quality assessment was undertaken and evidence base deficits described.Results33 studies (12 randomised control trials (RCTs)) were included. Mask wearing reduced primary infection by 6% (odds ratio (OR): 0.94; 95% CI: 0.75-1.19 for RCTs) to 61% (OR: 0.85; 95% CI: 0.32-2.27; OR: 0.39; 95% CI: 0.18-0.84 and OR: 0.61; 95% CI: 0.45-0.85 for cohort, case-control and cross-sectional studies respectively). RCTs suggested lowest secondary attack rates when both well and ill household members wore masks (OR: 0.81; 95% CI: 0.48-1.37). While RCTs might underestimate effects due to poor compliance and controls wearing masks, observational studies likely overestimate effects, as mask wearing might be associated with other risk-averse behaviours. GRADE was low or very low quality.ConclusionWearing face masks may reduce primary respiratory infection risk, probably by 6-15%. It is important to balance evidence from RCTs and observational studies when their conclusions widely differ and both are at risk of significant bias. COVID-19-specific studies are required.


Subject(s)
COVID-19/prevention & control , Eye Protective Devices , Influenza, Human/prevention & control , Masks , Picornaviridae Infections/prevention & control , Respiratory Tract Infections/prevention & control , Tuberculosis/prevention & control , COVID-19/transmission , Coronavirus Infections/prevention & control , Coronavirus Infections/transmission , Humans , Influenza, Human/transmission , Picornaviridae Infections/transmission , Respiratory Protective Devices , Respiratory Tract Infections/transmission , SARS-CoV-2 , Tuberculosis/transmission
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