scholarly journals COVID 19: An SEIR model predicting disease progression and healthcare outcomes for Pakistan

2020 ◽  
Author(s):  
Ejaz Ahmad Khan ◽  
Maida Umar ◽  
Maryam Khalid
Keyword(s):  
Transmission Rate ◽  
Asymptomatic Infection ◽  
Control Measures ◽  
System Response ◽  
Inadequate Response ◽  
Healthcare Outcomes ◽  
Susceptible Population ◽  
Seir Model ◽  
Healthcare Facilities ◽  
The Impact

AbstractBackgroundRecent pandemic of the Noval Coronal Virus (COVID 19) has claimed more than 200,000 lives and about 3.8 million infected worldwide. Countries are being gradually exposed to its devastating threat without being properly prepared and with inadequate response. COVID 19’s first two cases were reported in Pakistan on February 26, 2020. We present a model depicting progression of epidemiology curve for Pakistan with and without interventions in view of its health system’ response capacity in near future.MethodologyWe used a modified compartmental epidemiological SEIR model to describe the outbreak of COVID-19 in Pakistan including the possibility of asymptomatic infection and presymptomatic transmission. The behavior of the dynamic model is determined by a set of clinical parameters and transmission rate.ResultsWe estimated that in the absence of a set of proven interventions, the total susceptible population would be 43.24 million, exposed individuals would be almost 32 million, asymptomatic cases would be 13.13 million, mildly infected 30.64 million, severely infected slightly more than 6 million and critical cases would be around 967,000 in number. By that time, almost 760,000 fatalities of infected critical would have taken place. Comparing with the healthcare capacity of Pakistan, if we could “flatten the curve” to a level below the dashed grey line, the healthcare system will be capable of managing the cases with ideal healthcare facilities, where the grey line representing the healthcare capacity of Pakistan. With the intervention in place, the number of symptomatic infected individuals is expected to be almost 20 million.ConclusionWe consider the impact of intervention and control measures on the spread of COVID-19 with 30% reduction in transmission from mild cases in case a set of interventions are judiciously in place to mitigate its impact.

scholarly journals Impact of public health interventions to curb SARS-CoV-2 spread assessed by an evidence-educated Delphi panel and tailored SEIR model

2021 ◽  
Author(s):  
Bernd Brüggenjürgen ◽  
Hans-Peter Stricker ◽  
Lilian Krist ◽  
Miriam Ortiz ◽  
Thomas Reinhold ◽  
...  
Keyword(s):  
Public Health ◽  
Transmission Rate ◽  
Latency Period ◽  
Policy Decision ◽  
Sensitivity Analyses ◽  
Delphi Panel ◽  
Time Step ◽  
Seir Model ◽  
Health Policy Decision ◽  
The Impact

Abstract Aim To use a Delphi-panel-based assessment of the effectiveness of different non-pharmaceutical interventions (NPI) in order to retrospectively approximate and to prospectively predict the SARS-CoV-2 pandemic progression via a SEIR model (susceptible, exposed, infectious, removed). Methods We applied an evidence-educated Delphi-panel approach to elicit the impact of NPIs on the SARS-CoV-2 transmission rate R0 in Germany. Effectiveness was defined as the product of efficacy and compliance. A discrete, deterministic SEIR model with time step of 1 day, a latency period of 1.8 days, duration of infectiousness of 5 days, and a share of the total population of 15% assumed to be protected by immunity was developed in order to estimate the impact of selected NPI measures on the course of the pandemic. The model was populated with the Delphi-panel results and varied in sensitivity analyses. Results Efficacy and compliance estimates for the three most effective NPIs were as follows: test and isolate 49% (efficacy)/78% (compliance), keeping distance 42%/74%, personal protection masks (cloth masks or other face masks) 33%/79%. Applying all NPI effectiveness estimates to the SEIR model resulted in a valid replication of reported occurrence of the German SARS-CoV-2 pandemic. A combination of four NPIs at consented compliance rates might curb the CoViD-19 pandemic. Conclusion Employing an evidence-educated Delphi-panel approach can support SARS-CoV-2 modelling. Future curbing scenarios require a combination of NPIs. A Delphi-panel-based NPI assessment and modelling might support public health policy decision making by informing sequence and number of needed public health measures.

scholarly journals A modified SEIR model to predict the behavior of the early stage in coronavirus and coronavirus-like outbreaks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wilfredo Angulo ◽  
José M. Ramírez ◽  
Dany De Cecchis ◽  
Juan Primera ◽  
Henry Pacheco ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Risk Perceptions ◽  
Transmission Rate ◽  
Early Stage ◽  
Individual Risk ◽  
Seir Model ◽  
Proposed Model ◽  
Probable Site ◽  
Adjusted Model ◽  
The Impact

AbstractCOVID-19 is a highly infectious disease that emerged in China at the end of 2019. The COVID-19 pandemic is the first known pandemic caused by a coronavirus, namely, the new and emerging SARS-CoV-2 coronavirus. In the present work, we present simulations of the initial outbreak of this new coronavirus using a modified transmission rate SEIR model that takes into account the impact of government actions and the perception of risk by individuals in reaction to the proportion of fatal cases. The parameters related to these effects were fitted to the number of infected cases in the 33 provinces of China. The data for Hubei Province, the probable site of origin of the current pandemic, were considered as a particular case for the simulation and showed that the theoretical model reproduces the behavior of the data, thus indicating the importance of combining government actions and individual risk perceptions when the proportion of fatal cases is greater than $$4\%$$ 4 % . The results show that the adjusted model reproduces the behavior of the data quite well for some provinces, suggesting that the spread of the disease differs when different actions are evaluated. The proposed model could help to predict outbreaks of viruses with a biological and molecular structure similar to that of SARS-CoV-2.

scholarly journals The impact of temperature and absolute humidity on the coronavirus disease 2019 (COVID-19) outbreak - evidence from China

2020 ◽  
Author(s):  
Peng Shi ◽  
Yinqiao Dong ◽  
Huanchang Yan ◽  
Xiaoyang Li ◽  
Chenkai Zhao ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Infectious Diseases ◽  
Transmission Rate ◽  
Mainland China ◽  
Weather Condition ◽  
Absolute Humidity ◽  
List Type ◽  
Seir Model ◽  
Provincial Level ◽  
The Impact

ABSTRACTOBJECTIVETo investigate the impact of temperature and absolute humidity on the coronavirus disease 2019 (COVID-19) outbreak.DESIGNEcological study.SETTING31 provincial-level regions in mainland China.MAIN OUTCOME MEASURESData on COVID-19 incidence and climate between Jan 20 and Feb 29, 2020.RESULTSThe number of new confirm COVID-19 cases in mainland China peaked on Feb 1, 2020. COVID-19 daily incidence were lowest at -10 °C and highest at 10 °C, while the maximum incidence was observed at the absolute humidity of approximately 7 g/m3. COVID-19 incidence changed with temperature as daily incidence decreased when the temperature rose. No significant association between COVID-19 incidence and absolute humidity was observed in distributed lag nonlinear models. Additionally, A modified susceptible-exposed-infectious-recovered (M-SEIR) model confirmed that transmission rate decreased with the increase of temperature, leading to further decrease of infection rate and outbreak scale.CONCLUSIONTemperature is an environmental driver of the COVID-19 outbreak in China. Lower and higher temperatures might be positive to decrease the COVID-19 incidence. M-SEIR models help to better evaluate environmental and social impacts on COVID-19.What is already known on this topicMany infectious diseases present an environmental pattern in their incidence.Environmental factors, such as climate and weather condition, could drive the space and time correlations of infectious diseases, including influenza.Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be transmitted through aerosols, large droplets, or direct contact with secretions (or fomites) as influenza virus can.Little is known about environmental pattern in COVID-19 incidence.What this study addsThe significant association between COVID-19 daily incidence and temperature was confirmed, using 3 methods, based on the data on COVID-19 and weather from 31 provincial-level regions in mainland China.Environmental factors were considered on the basis of SEIR model, and a modified susceptible-exposed-infectious-recovered (M-SEIR) model was developed.Simulations of the COVID-19 outbreak in Wuhan presented similar effects of temperature on incidence as the incidence decrease with the increase of temperature.

scholarly journals Impact of Telemedicine on Hospitalisation and Mortality Rates in Community-Based Haemodialysis Centres in Singapore During the COVID-19 Pandemic

2020 ◽  
Vol 49 (10) ◽  
pp. 756-763
Author(s):  
Tripti Singh ◽  
Clara LY Ngoh ◽  
Weng Kin Wong ◽  
Behram Ali Khan
Keyword(s):  
Healthcare System ◽  
Healthcare Delivery ◽  
Movement Control ◽  
Mortality Rates ◽  
Control Measures ◽  
Healthcare Outcomes ◽  
National Kidney Foundation ◽  
Movement Restriction ◽  
Community Based ◽  
Healthcare Facilities

Introduction: With the unprecedented challenges imposed on the modern healthcare system due to the COVID-19 pandemic, innovative solutions needed to be swiftly implemented to maintain clinical oversight on patient care. Telemedicine was introduced in Singapore in community-based haemodialysis (HD) centres to comply with the Ministry of Health’s directives on movement restriction of healthcare workers and related measures to minimise the spread of SARS-CoV-2 in healthcare facilities. Methods: We describe here our experience of 26 community haemodialysis centres in Singapore, analysing clinical audit data, as well as comparing hospitalisation and mortality rates as outcomes in the time frames of pre- and post-introduction of telemedicine. Results: We found that the hospitalisation rate was 13.9% (95% CI: 5.6%–21.5%, P<0.001) lower in the period after telemedicine rounds were introduced. The mortality rates per 100 person-years (95% CI) were 11.04 versus 7.99 in the compared groups, respectively, with no significant increase in mortality during the months when telemedicine was performed. Conclusion: Patients received appropriate care in a timely manner, with telemedicine implementation, and such measures did not lead to suboptimal healthcare outcomes. Telemedicine was a successful tool for physician oversight under movement control measures implemented during the COVID-19 pandemic and may continue to prove useful in the ‘new normal’ era of healthcare delivery for HD patients in community-based dialysis centres, operated by the National Kidney Foundation in Singapore. Keywords: Healthcare outcomes healthcare system, National Kidney Foundation, SARS-CoV2, telemedicine rounds

scholarly journals Modelling the potential role of super spreaders on COVID-19 transmission dynamics

2021 ◽  
Author(s):  
Josiah Mushanyu ◽  
Williams Chukwu ◽  
Farai Nyabadza ◽  
Gift Muchatibaya
Keyword(s):  
Potential Role ◽  
Transmission Rate ◽  
Control Measures ◽  
Contact Radius ◽  
Public Health Burden ◽  
Effective Contact ◽  
Rate Functions ◽  
Parameter Values ◽  
The Impact

Superspreading phenomenon has been observed in many infectious diseases and contributes significantly to public health burden in many countries. Superspreading events have recently been reported in the transmission of the COVID-19 pandemic. The present study uses a set of nine ordinary differential equations to investigate the impact of superspreading on COVID-19 dynamics. The model developed in this study addresses the heterogeineity in infectiousness by taking into account two forms of transmission rate functions for superspreaders based on clinical (infectivity level) and social or environmental (contact level). The basic reproduction number has been derived and the contribution of each infectious compartment towards the generation of new COVID-19 cases is ascertained. Data fitting was performed and parameter values were estimated within plausible ranges. Numerical simulations performed suggest that control measures that decrease the effective contact radius and increase the transmission rate exponent will be greatly beneficial in the control of COVID-19 in the presence of superspreading phenomen

scholarly journals The effect of control measures on COVID-19 transmission in South Korea

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249262
Author(s):  
Taeyong Lee ◽  
Hee-Dae Kwon ◽  
Jeehyun Lee
Keyword(s):  
Transmission Rate ◽  
School Closure ◽  
Control Measures ◽  
After School ◽  
Epidemic Threshold ◽  
Social Distancing ◽  
Control And Prevention ◽  
Age Structured ◽  
Net Reproduction ◽  
The Impact

Countries around the world have taken control measures to mitigate the spread of COVID-19, including Korea. Social distancing is considered an essential strategy to reduce transmission in the absence of vaccination or treatment. While interventions have been successful in controlling COVID-19 in Korea, maintaining the current restrictions incurs great social costs. Thus, it is important to analyze the impact of different polices on the spread of the epidemic. To model the COVID-19 outbreak, we use an extended age-structured SEIR model with quarantine and isolation compartments. The model is calibrated to age-specific cumulative confirmed cases provided by the Korea Disease Control and Prevention Agency (KDCA). Four control measures—school closure, social distancing, quarantine, and isolation—are investigated. Because the infectiousness of the exposed has been controversial, we study two major scenarios, considering contributions to infection of the exposed, the quarantined, and the isolated. Assuming the transmission rate would increase more than 1.7 times after the end of social distancing, a second outbreak is expected in the first scenario. The epidemic threshold for increase of contacts between teenagers after school reopening is 3.3 times, which brings the net reproduction number to 1. The threshold values are higher in the second scenario. If the average time taken until isolation and quarantine reduces from three days to two, cumulative cases are reduced by 60% and 47% in the first scenario, respectively. Meanwhile, the reduction is 33% and 41%, respectively, for rapid isolation and quarantine in the second scenario. Without social distancing, a second wave is possible, irrespective of whether we assume risk of infection by the exposed. In the non-infectivity of the exposed scenario, early detection and isolation are significantly more effective than quarantine. Furthermore, quarantining the exposed is as important as isolating the infectious when we assume that the exposed also contribute to infection.

scholarly journals Knowing More of the Iceberg: How Detecting a Greater Proportion of Carbapenem-Resistant Enterobacteriaceae Carriers Influences Transmission

2019 ◽  
Vol 221 (11) ◽  
pp. 1782-1794 ◽  
Author(s):  
Sarah M Bartsch ◽  
Kim F Wong ◽  
Owen J Stokes-Cawley ◽  
James A McKinnell ◽  
Chenghua Cao ◽  
...  
Keyword(s):  
Control Measures ◽  
Infection Prevention And Control ◽  
Healthcare Facilities ◽  
Contact Precautions ◽  
Carbapenem Resistant ◽  
Adult Inpatient ◽  
Prevention And Control Measures ◽  
And Control ◽  
The Impact ◽  
Carbapenem Resistant Enterobacteriaceae

Abstract Background Clinical testing detects a fraction of carbapenem-resistant Enterobacteriaceae (CRE) carriers. Detecting a greater proportion could lead to increased use of infection prevention and control measures but requires resources. Therefore, it is important to understand the impact of detecting increasing proportions of CRE carriers. Methods We used our Regional Healthcare Ecosystem Analyst–generated agent-based model of adult inpatient healthcare facilities in Orange County, California, to explore the impact that detecting greater proportions of carriers has on the spread of CRE. Results Detecting and placing 1 in 9 carriers on contact precautions increased the prevalence of CRE from 0% to 8.0% countywide over 10 years. Increasing the proportion of detected carriers from 1 in 9 up to 1 in 5 yielded linear reductions in transmission; at proportions &gt;1 in 5, reductions were greater than linear. Transmission reductions did not occur for 1, 4, or 5 years, varying by facility type. With a contact precautions effectiveness of ≤70%, the detection level yielding nonlinear reductions remained unchanged; with an effectiveness of &gt;80%, detecting only 1 in 5 carriers garnered large reductions in the number of new CRE carriers. Trends held when CRE was already present in the region. Conclusion Although detection of all carriers provided the most benefits for preventing new CRE carriers, if this is not feasible, it may be worthwhile to aim for detecting &gt;1 in 5 carriers.

scholarly journals Effects of mobility and multi-seeding on the propagation of the COVID-19 in Spain

2020 ◽  
Author(s):  
Mattia Mazzoli ◽  
David Mateo ◽  
Alberto Hernando ◽  
Sandro Meloni ◽  
Jose Javier Ramasco
Keyword(s):  
Early Stage ◽  
High Mobility ◽  
Mobility Control ◽  
Control Measures ◽  
Order Effects ◽  
Crucial Importance ◽  
Epidemic Spreading ◽  
Susceptible Population ◽  
The Impact ◽  
Higher Order Effects

Assessing the impact of mobility on epidemic spreading is of crucial importance for understanding the effect of policies like mass quarantines and selective re-openings. High mobility between areas contribute to the importation of cases, affecting the spread of the disease. While many factors influence local incidence and making it more or less homogeneous with respect to other areas, the importance of multi-seeding has often been overlooked. Multi-seeding occurs when several independent (non-clustered) infected individuals arrive at a susceptible population. This can give rise to autonomous outbreaks that impact separate areas of the contact (social) network. Such mechanism has the potential to boost local incidence and size, making control and tracing measures less effective. In Spain, the high heterogeneity in incidence between similar areas despite the uniform mobility control measures taken suggests that multi-seeding could have played an important role in shaping the spreading of the disease. In this work, we focus on the spreading of SARS-CoV-2 among the $52$ Spanish provinces, showing that local incidence strongly correlates with mobility occurred in the early-stage weeks from and to Madrid, the main mobility hub and where the initial local outbreak unfolded. These results clarify the higher order effects that mobility can have on the evolution of an epidemic and highlight the relevance of its control.

scholarly journals (P1-83) Infectious Diseases Following Natural Disasters: Prevention and Control Measures

2011 ◽  
Vol 26 (S1) ◽  
pp. s125-s126
Author(s):  
I.K. Kouadio ◽  
T. Kamigai ◽  
O. Hitoshi
Keyword(s):  
Public Health ◽  
Infectious Diseases ◽  
Natural Disasters ◽  
Prevention And Control ◽  
Health Planning ◽  
Control Measures ◽  
Susceptible Population ◽  
Prevention And Control Measures ◽  
And Control ◽  
The Impact

Communicable diseases represent a public health problem in developing countries, especially in those affected by disasters, and necessitate an appropriate and coordinated response from national and international partners. The importance of rapid epidemiological assessment for public health planning and resources allocation is critical. This review assesses infectious disease outbreaks during and after disasters caused by natural hazards and describes comprehensive prevention and control measures. The natural hazard event that causes a disaster does not transmit infectious diseases in the immediate aftermath of the disaster, nor do dead bodies. During the impact phase, most of the deaths are associated to blunt trauma, crush-related injuries, burns, and drowning rather than from infectious diseases. Most pathogens cannot not continue to survive in a corpse. The remaining survivors are the ones from which infectious diseases can be transmitted under appropriate conditions created by the natural disasters. Among several diseases, diarrheal diseases, leptospirosis, viral hepatitis, typhoid fever, acute respiratory infections, measles, meningitides, tuberculosis, malaria, dengue fever, and West Nile Virus commonly were described days, weeks, or months after the disaster event in areas where they are endemic. Therefore, diseases can also be imported by healthy carriers among a susceptible population. The objective of the public health intervention is to prevent and control epidemics among the disaster-affected populations. The rapid implementation of control measures should be a public health priority especially in the absence of pre-disaster surveillance data, through the re-establishment and improvement of the delivery of primary health care and restoration of affected health services. Adequate shelter and sanitation, water and food safety, appropriate surveillance, immunization and management approaches, as well health education will be strongly required for the reduction of morbidity and mortality.

scholarly journals A study on COVID-19 transmission dynamics: stability analysis of SEIR model with Hopf bifurcation for effect of time delay

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
M. Radha ◽  
S. Balamuralitharan
Keyword(s):  
Hopf Bifurcation ◽  
Time Delay ◽  
Transmission Rate ◽  
Real Life ◽  
Least Square Method ◽  
Least Square ◽  
Transmission Dynamics ◽  
Seir Model ◽  
Sensitivity Indices ◽  
The Impact

Abstract This paper deals with a general SEIR model for the coronavirus disease 2019 (COVID-19) with the effect of time delay proposed. We get the stability theorems for the disease-free equilibrium and provide adequate situations of the COVID-19 transmission dynamics equilibrium of present and absent cases. A Hopf bifurcation parameter τ concerns the effects of time delay and we demonstrate that the locally asymptotic stability holds for the present equilibrium. The reproduction number is brief in less than or greater than one, and it effectively is controlling the COVID-19 infection outbreak and subsequently reveals insight into understanding the patterns of the flare-up. We have included eight parameters and the least square method allows us to estimate the initial values for the Indian COVID-19 pandemic from real-life data. It is one of India’s current pandemic models that have been studied for the time being. This Covid19 SEIR model can apply with or without delay to all country’s current pandemic region, after estimating parameter values from their data. The sensitivity of seven parameters has also been explored. The paper also examines the impact of immune response time delay and the importance of determining essential parameters such as the transmission rate using sensitivity indices analysis. The numerical experiment is calculated to illustrate the theoretical results.

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