In this study, we investigate the dynamics of the COVID-19 epidemic in Northern Ireland from 1<sup>st</sup> March 2020 up to 25<sup>th</sup> December 2020, using sever</span><span>&...In this study, we investigate the dynamics of the COVID-19 epidemic in Northern Ireland from 1<sup>st</sup> March 2020 up to 25<sup>th</sup> December 2020, using sever</span><span><span style="font-family:Verdana;">al copies of a Susceptible-Exposed-Infectious-Recovered (<i></span><i><span style="font-family:Verdana;">SEIR</span></i><span style="font-family:Verdana;"></i>) compart</span></span><span style="font-family:Verdana;">mental model, and compare it to </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">detailed publicly available dataset. We split the data into 10 time intervals and fit the models on the consecutive intervals to the cumulative number of confirmed positive cases on each interval. Using the fitted parameter estimates, we also provide estimates of the reproduction number.</span><span style="font-family:Verdana;"> We also discuss the limitations and possible extensions of the employed model.展开更多
The identification and understanding of COVID-19 potential routes of transmission are fundamental to informing policies and strategies to successfully control the outbreak. Various studies highlighted asymptomatic inf...The identification and understanding of COVID-19 potential routes of transmission are fundamental to informing policies and strategies to successfully control the outbreak. Various studies highlighted asymptomatic infections as one of the silent drivers of the epidemic. An accurate estimation of the asymptomatic cases and the understanding of their contribution to the spread of the disease could enhance the effectiveness of current control strategies, mainly based on the symptom onset, to curb transmission. We investigate the dynamics of the COVID-19 epidemic in Northern Ireland during the period 1st March 25th to December 2020 to estimate the proportion of the asymptomatic infections in the country. We extended our previous model to include the stage of the asymptomatic infection, and we implement the corresponding deterministic model using a publicly available dataset. We partition the data into 11 sets over the period of study and fit the model parameters on the consecutive intervals using the cumulative number of confirmed positive cases for each interval. Moreover, we assess numerically the impacts of uncertainty in testing and we provide estimates of the reproduction numbers using the fitted parameters. We found that the proportion of asymptomatically infectious subpopulations, in Northern Ireland during the period of study, ranged between 5% and 25% of exposed individuals. Also, the estimate of the basic reproduction number, R<sub>0</sub>, is 3.3089. The lower and upper estimates for herd immunity are (0.6181, 0.7243) suggesting that around 70% of the population of Northern Ireland should acquire immunity via infection or vaccination, which is in line with estimates reported in other studies.展开更多
Background Sub-Saharan Africa experiences a disproportionate amount of pediatric surgical disease,with 80%of children lacking access to timely,affordable,and safe surgical care.This study aims to characterize the burd...Background Sub-Saharan Africa experiences a disproportionate amount of pediatric surgical disease,with 80%of children lacking access to timely,affordable,and safe surgical care.This study aims to characterize the burden of disease and outcomes of pediatric surgical conditions at Connaught Hospital,the main pediatric referral hospital in Sierra Leone.Methods This retrospective and hospital-based study included children up to 15 years old who were operated on between 2015 and June 2016 at Connaught Hospital in Freetown,Sierra Leone.Descriptive and inferential statistics were used to characterize the distribution of disease and compare all variables against age category and mortality.Findings A total of 215 patients were included in this study of which 72.5%(n=132)were male and 27.5%(n=50)were female.Most of the patients were diagnosed with congenital anomalies(60.9%;n=131).However,infection was the leading diagnosis(60.5%;n=23)among patients aged 5–10 years(n=38).Inguinal hernia was the leading condition(65.0%;n=85)among patients presenting with a congenital anomaly.The condition with the highest mortality was infections(17.0%;n=8),followed by other conditions(9.1%;n=2)and congenital anomalies(3.1%;n=4).Based on the results of this study,over 7000 children with inguinal hernias remain untreated annually in Freetown,Sierra Leone.Conclusion This study quantifies the burden of surgical disease among children,a foundational step toward the prioritization of pediatric surgical care in national health agendas,the development of evidence-based interventions,and the strategic allocation of resources in Sierra Leone.展开更多
文摘In this study, we investigate the dynamics of the COVID-19 epidemic in Northern Ireland from 1<sup>st</sup> March 2020 up to 25<sup>th</sup> December 2020, using sever</span><span><span style="font-family:Verdana;">al copies of a Susceptible-Exposed-Infectious-Recovered (<i></span><i><span style="font-family:Verdana;">SEIR</span></i><span style="font-family:Verdana;"></i>) compart</span></span><span style="font-family:Verdana;">mental model, and compare it to </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">detailed publicly available dataset. We split the data into 10 time intervals and fit the models on the consecutive intervals to the cumulative number of confirmed positive cases on each interval. Using the fitted parameter estimates, we also provide estimates of the reproduction number.</span><span style="font-family:Verdana;"> We also discuss the limitations and possible extensions of the employed model.
文摘The identification and understanding of COVID-19 potential routes of transmission are fundamental to informing policies and strategies to successfully control the outbreak. Various studies highlighted asymptomatic infections as one of the silent drivers of the epidemic. An accurate estimation of the asymptomatic cases and the understanding of their contribution to the spread of the disease could enhance the effectiveness of current control strategies, mainly based on the symptom onset, to curb transmission. We investigate the dynamics of the COVID-19 epidemic in Northern Ireland during the period 1st March 25th to December 2020 to estimate the proportion of the asymptomatic infections in the country. We extended our previous model to include the stage of the asymptomatic infection, and we implement the corresponding deterministic model using a publicly available dataset. We partition the data into 11 sets over the period of study and fit the model parameters on the consecutive intervals using the cumulative number of confirmed positive cases for each interval. Moreover, we assess numerically the impacts of uncertainty in testing and we provide estimates of the reproduction numbers using the fitted parameters. We found that the proportion of asymptomatically infectious subpopulations, in Northern Ireland during the period of study, ranged between 5% and 25% of exposed individuals. Also, the estimate of the basic reproduction number, R<sub>0</sub>, is 3.3089. The lower and upper estimates for herd immunity are (0.6181, 0.7243) suggesting that around 70% of the population of Northern Ireland should acquire immunity via infection or vaccination, which is in line with estimates reported in other studies.
文摘Background Sub-Saharan Africa experiences a disproportionate amount of pediatric surgical disease,with 80%of children lacking access to timely,affordable,and safe surgical care.This study aims to characterize the burden of disease and outcomes of pediatric surgical conditions at Connaught Hospital,the main pediatric referral hospital in Sierra Leone.Methods This retrospective and hospital-based study included children up to 15 years old who were operated on between 2015 and June 2016 at Connaught Hospital in Freetown,Sierra Leone.Descriptive and inferential statistics were used to characterize the distribution of disease and compare all variables against age category and mortality.Findings A total of 215 patients were included in this study of which 72.5%(n=132)were male and 27.5%(n=50)were female.Most of the patients were diagnosed with congenital anomalies(60.9%;n=131).However,infection was the leading diagnosis(60.5%;n=23)among patients aged 5–10 years(n=38).Inguinal hernia was the leading condition(65.0%;n=85)among patients presenting with a congenital anomaly.The condition with the highest mortality was infections(17.0%;n=8),followed by other conditions(9.1%;n=2)and congenital anomalies(3.1%;n=4).Based on the results of this study,over 7000 children with inguinal hernias remain untreated annually in Freetown,Sierra Leone.Conclusion This study quantifies the burden of surgical disease among children,a foundational step toward the prioritization of pediatric surgical care in national health agendas,the development of evidence-based interventions,and the strategic allocation of resources in Sierra Leone.
