scholarly journals Analysis and Evaluation of Non-Pharmaceutical Interventions on Prevention and Control of COVID-19: A Case Study of Wuhan City

2021 ◽  
Vol 10 (7) ◽  
pp. 480
Author(s):  
Wen Cao ◽  
Haoran Dai ◽  
Jingwen Zhu ◽  
Yuzhen Tian ◽  
Feilin Peng
Keyword(s):  
Prevention And Control ◽  
Transmission Model ◽  
Model Parameters ◽  
Protection Measures ◽  
Dynamic Transmission Model ◽  
Sufficient Intensity ◽  
And Control ◽  
Self Protection ◽  
The Impact ◽  
Pharmaceutical Interventions

As the threat of COVID-19 increases, many countries have carried out various non-pharmaceutical interventions. Although many studies have evaluated the impact of these interventions, there is a lack of mapping between model parameters and actual geographic areas. In this study, a non-pharmaceutical intervention model of COVID-19 based on a discrete grid is proposed from the perspective of geography. This model can provide more direct and effective information for the formulation of prevention and control policies. First, a multi-level grid was introduced to divide the geographical space, and the properties of the grid boundary were used to describe the quarantine status and intensity in these different spaces; this was also combined with the model of hospital isolation and self-protection. Then, a process for the spatiotemporal evolution of the early COVID-19 spread is proposed that integrated the characteristics of residents’ daily activities. Finally, the effect of the interventions was quantitatively analyzed by the dynamic transmission model of COVID-19. The results showed that quarantining is the most effective intervention, especially for infectious diseases with a high infectivity. The introduction of a quarantine could effectively reduce the number of infected humans, advance the peak of the maximum infected number of people, and shorten the duration of the pandemic. However, quarantines only function properly when employed at sufficient intensity; hospital isolation and self-protection measures can effectively slow the spread of COVID-19, thus providing more time for the relevant departments to prepare, but an outbreak will occur again when the hospital reaches full capacity. Moreover, medical resources should be concentrated in places where there is the most urgent need under a strict quarantine measure.

scholarly journals Determinants of RSV epidemiology following suppression through pandemic contact restrictions

2021 ◽  
Author(s):  
Mihaly Koltai ◽  
Fabienne Krauer ◽  
David Hodgson ◽  
Edwin van Leeuwen ◽  
Marina Treskova-Schwarzbach ◽  
...  
Keyword(s):  
Mitigation Measures ◽  
Transmission Model ◽  
Temporary Increase ◽  
Previous Exposure ◽  
Dynamic Transmission Model ◽  
Contact Frequency ◽  
Age Structured ◽  
Immune Maturation ◽  
The Impact ◽  
Pharmaceutical Interventions

Introduction COVID-19 related non-pharmaceutical interventions (NPIs) led to a suppression of RSV circulation in winter 2020/21 throughout Europe and an off-season resurgence in Summer 2021 in several European countries. We explore how such temporary interruption may shape future RSV epidemiology and what factors drive the associated uncertainty. Methods We developed an age-structured dynamic transmission model to simulate pre-pandemic RSV infections and hospitalisations. We sampled parameters governing RSV seasonality, immunity acquisition and duration of post-infection immunity and retained those simulations that qualitatively fit the UK's pre-pandemic epidemiology. From Spring 2020 to Summer 2021 we assumed a 50% reduced contact frequency, returning to pre-pandemic levels from mid-May 2021. We simulated transmission forwards until 2023 and evaluated the impact of the sampled parameters on the projected trajectories of RSV hospitalisations. Results Following a lifting of contact restrictions in summer 2021 the model replicated an out-of-season resurgence of RSV. If unmitigated, paediatric RSV hospitalisation incidence in the 2021/22 season was projected to increase by 32% to 67% compared to pre-pandemic levels. The size of the increase depended most on whether infection risk was primarily determined by immunity acquired from previous exposure or general immune maturation. While infants were less affected, the increase in seasonal hospitalisation incidence exceeded 100% in 1-2 year old children and 275% in 2-5 year old children, respectively, in some simulations where immunity from previous exposure dominated. Consequently, the average age of a case increased by 1 to 5 months, most markedly if there was strong immunity acquisition from previous exposure. If immunity to infection was largely determined by age rather than previous exposure, the 2021/22 season started earlier and lasted longer but with a peak incidence lower or similar to pre-pandemic levels. For subsequent seasons, simulations suggested a quick return to pre-pandemic epidemiology, with some slight oscillating behaviour possible depending on the strength of post-exposure immunity. Conclusion COVID-19 mitigation measures stopped RSV circulation in the 2020/21 season and generated immunity debt that will likely lead to a temporary increase in RSV burden in the season following the lifting of restrictions, particularly in 1 to 5 year old children. A more accurate understanding of immunity drivers for RSV is needed to better predict the size of such an increase and plan a potential expansion of pharmaceutical and non-pharmaceutical mitigation measures.

scholarly journals The impact of non-pharmaceutical interventions on the prevention and control of COVID-19 in New York City

2021 ◽  
Vol 31 (2) ◽  
pp. 021101
Author(s):  
Jiannan Yang ◽  
Qingpeng Zhang ◽  
Zhidong Cao ◽  
Jianxi Gao ◽  
Dirk Pfeiffer ◽  
...  
Keyword(s):  
New York ◽  
New York City ◽  
York City ◽  
Prevention And Control ◽  
And Control ◽  
The Impact ◽  
Pharmaceutical Interventions

scholarly journals The impact of testing and infection prevention and control strategies on within-hospital transmission dynamics of COVID-19 in English hospitals

2021 ◽  
Vol 376 (1829) ◽  
pp. 20200268
Author(s):  
Stephanie Evans ◽  
Emily Agnew ◽  
Emilia Vynnycky ◽  
James Stimson ◽  
Alex Bhattacharya ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Infection Prevention ◽  
Control Strategies ◽  
Nosocomial Transmission ◽  
Transmission Model ◽  
Infection Prevention And Control ◽  
The Uk ◽  
Hospital Acquired ◽  
And Control ◽  
The Impact

Nosocomial transmission of SARS-CoV-2 is a key concern, and evaluating the effect of testing and infection prevention and control strategies is essential for guiding policy in this area. Using a within-hospital SEIR transition model of SARS-CoV-2 in a typical English hospital, we estimate that between 9 March 2020 and 17 July 2020 approximately 20% of infections in inpatients, and 73% of infections in healthcare workers (HCWs) were due to nosocomial transmission. Model results suggest that placing suspected COVID-19 patients in single rooms or bays has the potential to reduce hospital-acquired infections in patients by up to 35%. Periodic testing of HCWs has a smaller effect on the number of hospital-acquired COVID-19 cases in patients, but reduces infection in HCWs by as much as 37% and results in only a small proportion of staff absences (approx. 0.3% per day). This is considerably less than the 20–25% of staff that have been reported to be absent from work owing to suspected COVID-19 and self-isolation. Model-based evaluations of interventions, informed by data collected so far, can help to inform policy as the pandemic progresses and help prevent transmission in the vulnerable hospital population. This article is part of the theme issue ‘Modelling that shaped the early COVID-19 pandemic response in the UK’.

scholarly journals A COVID-19 Spread Model of the Discrete Grid to Assess the Potential of Non-pharmaceutical Interventions

2021 ◽  
Author(s):  
Wen Cao ◽  
Haoran Dai ◽  
Xiaochong Tong ◽  
Jingwen Zhu ◽  
Yuzhen Tian ◽  
...  
Keyword(s):  
Early Stage ◽  
Transmission Model ◽  
Model Parameters ◽  
Protection Measure ◽  
Protection Measures ◽  
Buffer Time ◽  
Spread Model ◽  
Self Protection ◽  
Discrete Grid ◽  
Quarantine Measure

Abstract Background: The outbreak of COVID-19 posed a serious threat to human health, economic development, and social stability worldwide, and many countries had taken different interventions to control the deterioration of the epidemic. Although many studies have evaluated the effectiveness of these interventions, there were few reasonable explanations for the practical geographic significance of the model parameters. Our aim was to evaluate the potential of different interventions to mitigate the spread of the epidemic, including discussion about the different time and intensity of implementation, and map parameters of model to the practical application meanings of the special interventions.Methods: In this study, a COVID-19 spread model based on the discrete grid was proposed from perspective of geography. A multi-level grid was introduced to describe the quarantine status and intensity in different spaces, which also combined with the model of medical reception-cured and self-protection, and the spatiotemporal evolution process of early COVID-19 spread was simulated based on the spatial correlation, finally, the effect of interventions was quantitatively analyzed by the dynamic transmission model of COVID-19.Results: Quarantine measure were the most effective interventions, which could effectively reduce the peak value of infection, advance the arrival time of the peak, and shorten the duration of the epidemic, but it only played a role under sufficient intensity; the medical reception-cured and self-protection measure could effectively fatten the infection curve and slowed the spread of the epidemic in the early stage, which could provide more buffer time for the relevant government departments, but the practical effect was not obvious because of the limitation of actually invested resources. The role of the medical reception-cured measure was more reflected in the reduction of the number of deaths, and the effect of the self-protection measure could be reduced in strict quarantine measure.Conclusions: Results of the study indicated that the quarantine, medical reception-cured and self-protection measures were effective, and mitigating the spread of COVID-19 by achieving strong interventions was necessary. Strict quarantine should be implementing as soon as possible in countries with serious development of COVID-19.

scholarly journals Accounting for underreporting in mathematical modelling of transmission and control of COVID-19 in Iran

2020 ◽  
Author(s):  
Meead Saberi ◽  
Homayoun Hamedmoghadam ◽  
Kaveh Madani ◽  
Helen M. Dolk ◽  
Andrei S. Morgan ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Estimation Method ◽  
Case Fatality ◽  
Transmission Model ◽  
School Closures ◽  
The Public ◽  
Case Fatality Ratio ◽  
And Control ◽  
The Impact ◽  
Pharmaceutical Interventions

SUMMARYBackgroundIran has been the hardest hit country by the outbreak of SARS-CoV-2 in the Middle East with 74,877 confirmed cases and 4,683 deaths as of 15 April 2020. With a relatively high case fatality ratio and limited testing capacity, the number of confirmed cases reported is suspected to suffer from significant under-reporting. Therefore, understanding the transmission dynamics of COVID-19 and assessing the effectiveness of the interventions that have taken place in Iran while accounting for the uncertain level of underreporting is of critical importance. We use a mathematical epidemic model utilizing official confirmed data and estimates of underreporting to understand how transmission in Iran has been changing between February and April 2020.MethodsWe developed a compartmental transmission model to estimate the effective reproduction number and its fluctuations since the beginning of the outbreak in Iran. We associate the variations in the effective reproduction number with a timeline of interventions and national events. The estimation method also accounts for the underreporting due to low case ascertainment by estimating the percentage of symptomatic cases using delay-adjusted case fatality ratio based on the distribution of the delay from hospitalization-to-death.FindingsOur estimates of the effective reproduction number ranged from 0.66 to 1.73 between February and April 2020, with a median of 1.16. We estimate a reduction in the effective reproduction number during this period, from 1.73 (95% CI 1.60 – 1.87) on 1 March 2020 to 0.69 (95% CI 0.68-0.70) on 15 April 2020, due to various non-pharmaceutical interventions including school closures, a ban on public gatherings including sports and religious events, and full or partial closure of non-essential businesses. Based on these estimates and given that a near complete containment is no longer feasible, it is likely that the outbreak may continue until the end of the 2020 if the current level of physical distancing and interventions continue and no effective vaccination or therapeutic are developed and made widely available.InterpretationThe series of non-pharmaceutical interventions and the public compliance that took place in Iran are found to be effective in slowing down the speed of the spread of COVID-19 within the studied time period. However, we argue that if the impact of underreporting is overlooked, the estimated transmission and control dynamics could mislead the public health decisions, policy makers, and general public especially in the earlier stages of the outbreak.FundingNil.

Hazards for Construction Workers

2017 ◽  
Author(s):  
Gavin H. West ◽  
Laura S. Welch
Keyword(s):  
Heavy Metals ◽  
Prevention And Control ◽  
Respiratory Diseases ◽  
Noise Exposure ◽  
Engineered Nanomaterials ◽  
Construction Workers ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
And Control ◽  
The Impact

This chapter describes the hazards for construction workers, with a particular focus on injuries as well as exposures to hazardous chemicals and dusts. A section describes hazardous exposures to lead and other heavy metals. Another section describes noise exposure. The impact of musculoskeletal disorders among construction workers is then discussed. A section on respiratory diseases focuses on asbestosis, silicosis, chronic obstructive pulmonary disease, and asthma. Exposures known to cause dermatitis and cancer are reviewed. There is a discussion of engineered nanomaterials as a potential emerging hazard. Various approaches to prevention and control, including regulations and health services, are described.

scholarly journals Evolution of disease transmission during the COVID-19 pandemic: patterns and determinants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Zhu ◽  
Blanca Gallego
Keyword(s):  
Public Health ◽  
Disease Transmission ◽  
Clustering Algorithm ◽  
Health Interventions ◽  
Transmission Model ◽  
Model Parameters ◽  
Public Health Interventions ◽  
Forecasting Accuracy ◽  
Time Lagged ◽  
The Impact

AbstractEpidemic models are being used by governments to inform public health strategies to reduce the spread of SARS-CoV-2. They simulate potential scenarios by manipulating model parameters that control processes of disease transmission and recovery. However, the validity of these parameters is challenged by the uncertainty of the impact of public health interventions on disease transmission, and the forecasting accuracy of these models is rarely investigated during an outbreak. We fitted a stochastic transmission model on reported cases, recoveries and deaths associated with SARS-CoV-2 infection across 101 countries. The dynamics of disease transmission was represented in terms of the daily effective reproduction number ($$R_t$$ R t ). The relationship between public health interventions and $$R_t$$ R t was explored, firstly using a hierarchical clustering algorithm on initial $$R_t$$ R t patterns, and secondly computing the time-lagged cross correlation among the daily number of policies implemented, $$R_t$$ R t , and daily incidence counts in subsequent months. The impact of updating $$R_t$$ R t every time a prediction is made on the forecasting accuracy of the model was investigated. We identified 5 groups of countries with distinct transmission patterns during the first 6 months of the pandemic. Early adoption of social distancing measures and a shorter gap between interventions were associated with a reduction on the duration of outbreaks. The lagged correlation analysis revealed that increased policy volume was associated with lower future $$R_t$$ R t (75 days lag), while a lower $$R_t$$ R t was associated with lower future policy volume (102 days lag). Lastly, the outbreak prediction accuracy of the model using dynamically updated $$R_t$$ R t produced an average AUROC of 0.72 (0.708, 0.723) compared to 0.56 (0.555, 0.568) when $$R_t$$ R t was kept constant. Monitoring the evolution of $$R_t$$ R t during an epidemic is an important complementary piece of information to reported daily counts, recoveries and deaths, since it provides an early signal of the efficacy of containment measures. Using updated $$R_t$$ R t values produces significantly better predictions of future outbreaks. Our results found variation in the effect of early public health interventions on the evolution of $$R_t$$ R t over time and across countries, which could not be explained solely by the timing and number of the adopted interventions.

scholarly journals The effects of non-pharmaceutical interventions on SARS-CoV-2 transmission in different socioeconomic populations in Kuwait: a modeling study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fatima Khadadah ◽  
Abdullah A. Al-Shammari ◽  
Ahmad Alhashemi ◽  
Dari Alhuwail ◽  
Bader Al-Saif ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Reproduction Number ◽  
Transmission Model ◽  
Socioeconomic Groups ◽  
Before And After ◽  
Cross Transmission ◽  
Community Transmission ◽  
The Impact ◽  
Pharmaceutical Interventions ◽  
The Basic Reproduction Number

Abstract Background Aggressive non-pharmaceutical interventions (NPIs) may reduce transmission of SARS-CoV-2. The extent to which these interventions are successful in stopping the spread have not been characterized in countries with distinct socioeconomic groups. We compared the effects of a partial lockdown on disease transmission among Kuwaitis (P1) and non-Kuwaitis (P2) living in Kuwait. Methods We fit a modified metapopulation SEIR transmission model to reported cases stratified by two groups to estimate the impact of a partial lockdown on the effective reproduction number ($$ {\mathcal{R}}_e $$ R e ). We estimated the basic reproduction number ($$ {\mathcal{R}}_0 $$ R 0 ) for the transmission in each group and simulated the potential trajectories of an outbreak from the first recorded case of community transmission until 12 days after the partial lockdown. We estimated $$ {\mathcal{R}}_e $$ R e values of both groups before and after the partial curfew, simulated the effect of these values on the epidemic curves and explored a range of cross-transmission scenarios. Results We estimate $$ {\mathcal{R}}_e $$ R e at 1·08 (95% CI: 1·00–1·26) for P1 and 2·36 (2·03–2·71) for P2. On March 22nd, $$ {\mathcal{R}}_e $$ R e for P1 and P2 are estimated at 1·19 (1·04–1·34) and 1·75 (1·26–2·11) respectively. After the partial curfew had taken effect, $$ {\mathcal{R}}_e $$ R e for P1 dropped modestly to 1·05 (0·82–1·26) but almost doubled for P2 to 2·89 (2·30–3·70). Our simulated epidemic trajectories show that the partial curfew measure greatly reduced and delayed the height of the peak in P1, yet significantly elevated and hastened the peak in P2. Modest cross-transmission between P1 and P2 greatly elevated the height of the peak in P1 and brought it forward in time closer to the peak of P2. Conclusion Our results indicate and quantify how the same lockdown intervention can accentuate disease transmission in some subpopulations while potentially controlling it in others. Any such control may further become compromised in the presence of cross-transmission between subpopulations. Future interventions and policies need to be sensitive to socioeconomic and health disparities.

scholarly journals The Impact of COVID-19 on Pedestrian Flow Patterns in Urban POIs—An Example from Beijing

2021 ◽  
Vol 10 (7) ◽  
pp. 479
Author(s):  
Yihang Li ◽  
Liyan Xu
Keyword(s):  
Prevention And Control ◽  
Control Period ◽  
Flow Patterns ◽  
Control Measures ◽  
Pedestrian Flow ◽  
Prevention Measures ◽  
Government Control ◽  
Functional Categories ◽  
And Control ◽  
The Impact

The COVID-19 pandemic is a major challenge for society as a whole, and analyzing the impact of the spread of the epidemic and government control measures on the travel patterns of urban residents can provide powerful help for city managers to designate top-level epidemic prevention policies and specific epidemic prevention measures. This study investigates whether it is more appropriate to use groups of POIs with similar pedestrian flow patterns as the unit of study rather than functional categories of POIs. In this study, we analyzed the hour-by-hour pedestrian flow data of key locations in Beijing before, during, and after the strict epidemic prevention and control period, and we found that the pedestrian flow patterns differed greatly in different periods by using a composite clustering index; we interpreted the clustering results from two perspectives: groups of pedestrian flow patterns and functional categories. The results show that depending on the specific stage of epidemic prevention and control, the number of unique pedestrian flow patterns decreased from four before the epidemic to two during the strict control stage and then increased to six during the initial resumption of work. The restrictions on movement are correlated with most of the visitations, and the release of restrictions led to an increase in the variety of unique pedestrian flow patterns compared to that in the pre-restriction period, even though the overall number of visitations decreased, indicating that social restrictions led to differences in the flow patterns of POIs and increased social distance.

scholarly journals The experience of European hospital-based health care workers on following infection prevention and control procedures for COVID-19

2020 ◽  
Author(s):  
Denise van Hout ◽  
Paul Hutchinson ◽  
Marta Wanat ◽  
Caitlin Pilbeam ◽  
Herman Goossens ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Prevention And Control ◽  
Infection Prevention ◽  
Infection Risk ◽  
Infection Prevention And Control ◽  
Emotional Wellbeing ◽  
Care Workers ◽  
And Control ◽  
The Impact

ABSTRACTBackgroundWorking under pandemic conditions exposes health care workers (HCWs) to infection risk and psychological strain. Protecting the physical and psychological health of HCWs is a key priority. This study assessed the perceptions of European hospital HCWs of local infection prevention and control (IPC) procedures during the COVID-19 pandemic and the impact on their emotional wellbeing.MethodsWe performed two rounds of an international cross-sectional survey, between 31 March and 17 April 2020 via existing research networks (round 1), and between 14 May and 31 August 2020 via online convenience sampling (round 2). Main outcome measures were (1) behavioural determinants of HCW adherence with IPC procedures, (2) WHO-5 Well-Being Index, a validated scale of 0-100 reflecting emotional wellbeing. The WHO-5 was interpreted as a score below or above 50 points, a cut-off score used in previous literature to screen for depression.Results2,289 HCWs (round 1: n=190, round 2: n=2,099) from 40 countries in Europe participated. Mean age of respondents was 42 (±11) years, 66% were female, 47% and 39% were medical doctors and nurses, respectively. 74% (n=1699) of HCWs were directly treating patients with COVID-19, of which 32% (n=527) reported they were fearful of caring for these patients. HCWs reported high levels of concern about COVID-19 infection risk to themselves (71%) and their family (82%) as a result of their job. 40% of HCWs considered that getting infected with COVID-19 was not within their control. This was more common among junior than senior HCWs (46% versus 38%, P value <.01). Sufficient COVID-19-specific IPC training, confidence in PPE use and institutional trust were positively associated with the feeling that becoming infected with COVID-19 was within their control. Female HCWs were more likely than males to report a WHO-5 score below 50 points (aOR 1.5 (95% confidence interval (CI) 1.2-1.8).ConclusionsIn Europe, the COVID-19 pandemic has had a differential impact on those providing direct COVID-19 patient care, junior staff and women. Health facilities must be aware of these differential impacts, build trust and provide tailored support for this vital workforce during the current COVID-19 pandemic.

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